ABSTRACTThe study aims to evaluate the potential of chicken by-products for production of animal feed through the physicochemial and functional properties

ABSTRACTThe study aims to evaluate the potential of chicken by-products for production of animal feed through the physicochemial and functional properties. The poultry industry is an important and diverse component of the food sector and the number of parent stock farms is increasing from day to day. As a result, the rest of the chicken (feather, head, feet, and intestine) is including the amount of waste (12,690 kg per day) that is most widely discarded without being processed into something useful. There are some problems occurring in chicken processing industries such bad smell, flies and dirt place present that can disturb environment impact and residents living nearby. Besides, it is difficult to find more data from local journals because there is still less utilization of wastes to useful resources in Malaysia and not officially written in journals. The purposes of this study are determining the physicochemical such as weight and proximate analysis (crude protein, fat, crude fibre, ash, carbohydrates and calorific value) and functional properties such as water holding capacity and oil absorption of chicken by-products and study the potential of chicken by-products as a source of animal feed. The preparation of samples is starting from collect, a transfer from the slaughterhouse in Selangor, wash, and clean, make them into powder form. Storage temperature of 3-5?C is for the intestine powder, head and feet (protein hydrolysate) powder and the feather is room temperature before further analysis. The results indicate that the head and feet have the highest in protein and ash, which are 87.36% and 4.46%. Next, the highest percentage of moisture content, fat and crude fibre is in intestines respectively 83.69%, 1.45% and 0.2%. Furthermore, the feathers are having the highest value of oil absorption with 8.36 ml/g. In conclusion, physicochemical and functional properties of chicken by-products are determined. They also have potential to be as a source that can produce the animal feed.

ABSTRAKKajian ini bertujuan untuk menilai potensi produk sampingan ayam untuk pengeluaran makanan haiwan berdasarkan fizikokimia dan ciri-ciri fungsian. Industri ayam adalah komponen penting dalam pelbagai sektor makanan dan bilangan ladang induk semakin meningkat dari hari ke hari. Hasilnya, sisa ayam (bulu, kepala, kaki, dan usus) termasuk jumlah sisa (12,690 kg sehari) yang paling banyak dibuang tanpa diproses menjadi sesuatu yang berguna. Terdapat beberapa masalah yang berlaku dalam industri pemprosesan ayam seperti bau busuk, tempat lalat dan kotoran yang dapat mengganggu alam sekitar dan penduduk yang tinggal berdekatan. Selain itu, sukar untuk mencari lebih banyak data dari jurnal tempatan kerana masih kurang penggunaan sisa tersebut untuk sumber berguna di Malaysia dan tidak ditulis dalam jurnal secara rasmi. Tujuan kajian ini adalah menentukan fizikokimia seperti analisis berat badan dan proksimat (protein mentah, lemak, serat mentah, abu, karbohidrat dan nilai kalori) dan ciri-ciri fungsian seperti kapasiti pegangan air dan penyerapan minyak produk sampingan ayam dan kajian potensi produk sampingan ayam sebagai sumber makanan haiwan. Penyediaan sampel bermula dari pengumpulan, pemindahan dari rumah sembelih di Selangor, mencuci, dan membersihkan, menjadikannya serbuk. Suhu penyimpanan 3-5?C adalah serbuk usus, kepala dan kaki (protein hidrolyzate) dan bulu adalah suhu bilik sebelum analisis lanjut. Keputusan menunjukkan bahawa kepala dan kaki mempunyai protein dan abu tertinggi, iaitu 87.36% dan 4.46%. Seterusnya, peratusan tertinggi kandungan lembapan, lemak dan serat mentah di dalam usus masing-masing adalah 83.69%, 1.45% dan 0.2%. Selain itu, bulu mempunyai nilai penyerapan minyak tertinggi dengan 8.36 ml/g. Sebagai kesimpulan, sifat fizikokimia dan fungsian ayam sampingan ditentukan. Mereka juga berpotensi menjadi sumber yang boleh menghasilkan makanan haiwan.

CHAPTER 1INTRODUCTION1.1 BACKGROUNDThe poultry industry is an important and diverse component of the food sector and poultry products including chickens represent an important protein source in the diets of most people. Chickens are omnivores which they frequently scratch on the soil to look for seeds, bus or even animals which includes worms, lizards, small snakes or younger mice. There are many categories of chicken such as broilers, roosters, laying hens and cock of the black-red type (ayam kampung). They will stay for five to ten years, relying on the breed. Chickens reared for meat are known as broilers or broiler chickens. Subsequent, laying hens are the common time period for female and grown chickens that saved commonly for laying eggs. Because of customer demands, the broiler industry has grown to find the money for the chicken meat. The nutrients and traits of breeding are enhancing as to growth the load of the breast muscle. Within the brief period, the economic chickens are bred and developing quicker that allows you to gain weight fast. The slaughtering is the first step before the chickens are sold in the market. According to Berhad, L. (2014), the slaughterhouse of chicken processing has the processing capacity of 6,000 chickens per hour and currently, about 20,000 to 30,000 of chickens per day are slaughtered then results the total slaughtered chickens are 900,000 per month and 10,800,000 per years. Based on Federation of Livestock Farmer’s Associations of Malaysia (INDUSTRY STATISTICS, 2017), the weekly output of broilers in Peninsular Malaysia is shown as in Table 1.1. The weekly output of broilers in Peninsular Malaysia is increased from the year 2004 until 2017 even though there are three years decreased such as 2006, 2008 and 2017 (INDUSTRY STATISTICS, 2017). Therefore, the amount of chicken eggs is also increased and there are three years that have less amount than before such as 2006, 2008 and 2014. The weekly output of broilers in 2017 is less than in 2016 by having different as much as 19,025,724. But the amount of chicken eggs is increased gradually from 2016 until 2017 every week (INDUSTRY STATISTICS, 2017).

Table 1. SEQ Table_1. * ARABIC 1: Weekly Output of Broilers in Peninsular MalaysiaYear Broiler (birds) Chicken Eggs (Unit)
2004 414,350,008 6,871,061,160
2005 437,054,987 7,420,599,487
2006 427,225,469 7,237,692,613
2007 513,799,017 7,772,670,290
2008 491,413,930 7,516,050,893
2009 516,231,809 7,628,783,615
2010 524,035,048 8,564,601,148
2011 614,496,996 8,920,889,949
2012 636,997,602 9,103,145,498
2013 657,095,676 11,123,141,506
2014 724,695,581 10,307,045,418
2015 737,612,422 11,308,020,289
2016 818,649,109 12,699,680,666
2017 799,623,385 (projection) 13,662,580,866
Source: INDUSTRY STATISTICS ( 2017)
For the further study, Selangor is a chosen state of the study of physicochemical and functional properties of by-products and waste materials from chicken processing industries. Based on Table 1.2 (Broiler., 2014), the number of parent stock farms by state is shown from year 2009 until 2012. Parent stock is produced from the eggs, which undergo a special grandparent generation (GP) hatchery and breeders used to produce the broilers which passes the production sector. According to Breeder Management. (2009), the parent stock has to take care more to generate more profits due to high cost in parent stocks. Moreover, the high income can be achieved with hatching eggs and pullet chicks. Therefore, the parent stock management, male breeding stock management and hatchery have to be carried out more carefully. The aim for production of parent stock is to obtain the maximum number good quality, fertile eggs and hatched broiler chicks (Dev, 2011).
In Table 1.2, there is total of 108 parents farms in 2012 compared to 82 in 2009. This shows the increasing of number of parent stock farms. In Selangor, the number of stock farms in 2009 is 4 but it is decreased sharply in 2010. Then, it is increased gradually from year 2011 to 2012 which is from 2 to 5 parent stock farms in Selangor (Broiler., 2014).

Table 1. SEQ Table_1. * ARABIC 2: Number of Parent Stock Farms by State State 2009 2010 2011 2012
Perlis 0 0 0 0
Kedah 4 9 8 9
Penang 6 11 16 9
Perak 13 15 14 13
Selangor 4 0 2 5
Negeri Sembilan 15 17 11 17
Malacca 9 12 12 12
Johor 29 35 35 37
Pahang 1 2 2 2
Kelantan 1 0 1 1
Terengganu 0 1 0 3
Total 82 102 101 108
Source: Broiler. (2014),
Table 1. SEQ Table_1. * ARABIC 3: Number of Chicken Farms by State in Year 2015-2016State Chicken Chicken Breed
Broilers Laying Hens Kampung Broilers Laying Hens Kampung
Perlis 14 0 13 0 0 0
Kedah 238 11 27 10 0 4
Penang 90 81 61 2 0 8
Perak 365 25 23 13 1 3
Selangor 204 26 122 1 1 1
Negeri Sembilan 173 8 2 18 1 0
Malacca 103 23 85 12 8 0
Johor 624 58 11 30 1 5
Pahang 205 8 254 2 0 0
Kelantan 212 0 95 1 0 0
Terengganu 190 2 192 0 0 0
Sabah 63 21 0 9 1 2
Sarawak 195 38 32 8 0 0
TOTAL 2676 301 917 106 13 23
Source: INDUSTRY STATISTICS ( 2017)
Moreover, Table 1.3 ( INDUSTRY STATISTICS, 2017) shows the number of chicken farms in the year 2015 and 2016 in 13 states in Malaysia. There are three categories for chicken and chicken breed such as broilers, laying hens and kampung. The number of chicken farms is high when compared to number of chicken breed farms in Malaysia. In Selangor, the number of laying hen farm is fewer by having 26 when compared to broilers and ayam kampung. Meanwhile, the number of broiler farm is 204 which the highest number of chicken farms in Selangor. The number of farms for all categories of chicken breed is 3.
For the slaughtering, the Department of Islamic Development Malaysia (JAKIM) was developing Malaysian Protocol for the Halal Meat and Poultry Productions to give clear guidance in the production of halal meat and poultry. This protocol used in all industries which producing halal meat, poultry, and their products and it shall be used together with the Malaysian Standard MS 1500:2009 Halal Food – Production, Preparation, Handling and Storage – General Guidelines. Furthermore, a large amount of waste needs to be managed due to the increased production of poultry industry.

1.1.1By-Product from Chickens
The intensive and large scale production of food animals and chicken by-products has resolved the numerous disposition problems for the chicken processing industry. The waste materials from chickens are converted to useful resources such as feathers, heads and feet, and intestines. Based on the large number of broiler population in Selangor, the amount of by-products and waste materials are also increasing. The physicochemical and functional properties should be studied to reduce the amount of waste materials or use them to produce other products.

PROBLEM STATEMENTThe principal sources of wastes in chicken processing are live chicken holding, slaughtering, removal of feathers, cutting and cleanup operations. These wastes include feathers, heads, feet and intestines. This causes the pollution which the most important environmental problems in developed and developing countries. The amount of chicken wastes is increasing day by day. The problems occur in chickens processing industries such as odour, flies and dirt. Commonly, the dirty area is referred to slaughtering area and cleanup operations area. According to Malaymail.com (2014), there are 2,000 poultry slaughterhouses in Malaysia. This large number of slaughterhouses will produce more poultry wastes. The pollutions will be increased if any action or problem solution is not monitored and controlled properly. The dirty area is the main factor to the causes of odour in the air and flies. Mostly the impact of odour is a disturbing environment such as houses nearby that can be smelt within 500 meters from the farm. Then, the flies are coming and interrupted the environment of residents living near chickens processing industries. All these problems can give bad effect to the health of people. Based on the journals past, more about the chicken by-products are from the other country and the method on how to utilize the chicken by-products is less when compared to the suggestions given to make new things from the wastes. It is also difficult to find more data from local journals because there is still less utilization of the wastes to useful resources in our country and not officially written in journals.

OBJECTIVETo determine the physicochemical and functional properties of chicken by-products such as feathers, heads, feet and intestines.

To study the potential of chicken by-products as a source of animal feed.

CHAPTER 2LITERATURE REVIEW2.1Process Flow for Chicken ProcessingChicken processing was started from live stocks and then undergoing processing process. Based on Figure 2.1, the process flow of chickens processing and amount of wastes produced (Jayathilakan et al., 2012) was shown below. During slaughtering, the waste produced was blood and its amount around 3.2-3.7% (Jayathilakan et al., 2012) of live weight. The slaughtered chickens were put into a closed container as they were not flapped far away from slaughtering area. After that, they were put into hot water before feathers removal. The amount of feathers removed between 7 to 8% ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.1007/s13197-011-0290-7”, “ISBN” : “0022-1155\r0975-8402”, “ISSN” : “00221155”, “PMID” : “23729848”, “abstract” : “India is bestowed with vast livestock wealth and it is growing at the rate of 6% per annum. The contribution of livestock industry including poultry and fish is increasing substantially in GDP of country which accounts for >40% of total agricultural sector and >12% of GDP. This contribution would have been much greater had the animal by-products been also efficiently utilized. Efficient utilization of by-products has direct impact on the economy and environmental pollution of the country. Non-utilization or under utilization of by-products not only lead to loss of potential revenues but also lead to the added and increasing cost of disposal of these products. Non-utilization of animal by-products in a proper way may create major aesthetic and catastrophic health problems. Besides pollution and hazard aspects, in many cases meat, poultry and fish processing wastes have a potential for recycling raw materials or for conversion into useful products of higher value. Traditions, culture and religion are often important when a meat by-product is being utilized for food. Regulatory requirements are also important because many countries restrict the use of meat by-products for reasons of food safety and quality. By-products such as blood, liver, lung, kidney, brains, spleen and tripe has good nutritive value. Medicinal and pharmaceutical uses of by-product are also highlighted in this review. Waste products from the poultry processing and egg production industries must be efficiently dealt with as the growth of these industries depends largely on waste management. Treated fish waste has found many applications among with which the most important are animal feed, biodiesel/biogas, dietectic products (chitosan), natural pigments (after extraction) and cosmetics (collagen). Available information pertaining to the utilization of by-products and waste materials from meat, poultry and fish and their processing industries has been reviewed here.”, “author” : { “dropping-particle” : “”, “family” : “Jayathilakan”, “given” : “K.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Sultana”, “given” : “Khudsia”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Radhakrishna”, “given” : “K.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Bawa”, “given” : “A. S.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “Journal of Food Science and Technology”, “id” : “ITEM-1”, “issue” : “3”, “issued” : { “date-parts” : “2012” }, “page” : “278-293”, “title” : “Utilization of byproducts and waste materials from meat, poultry and fish processing industries: A review”, “type” : “article-journal”, “volume” : “49” }, “uris” : “http://www.mendeley.com/documents/?uuid=6da04a98-806e-4abb-a142-48c43ac8b67d” } , “mendeley” : { “formattedCitation” : “(Jayathilakan et al., 2012)”, “plainTextFormattedCitation” : “(Jayathilakan et al., 2012)”, “previouslyFormattedCitation” : “(Jayathilakan et al., 2012)” }, “properties” : { “noteIndex” : 0 }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Jayathilakan et al., 2012) of live weight. The next operation was cleaning up the slaughtered chickens, the wastes and dirt such as intestines, gizzards, proventriculus and others were taken out. Then, the chickens were washed under running tap water to remove blood and other dirt.
3152775-259321Process Flow for Chicken Processing
Process Flow for Chicken Processing

2598420438154679315438156789420438156070601291590Live chickens
Live chickens
44767501291590Put the slaughtered
chickens into closed
container
Type of waste: Blood residue
Put the slaughtered
chickens into closed
container
Type of waste: Blood residue
69437251291590Put into hot
water
Put into hot
water
65455804081145Feathers removal
Type of waste: Feathers
Amount: 7-8% of live
weight
Feathers removal
Type of waste: Feathers
Amount: 7-8% of live
weight
18370554016375Cutting
Types of waste: Heads, feet
Amount: 2.5-3.0% of live
weight (heads),
3.5-4.0% of live weight (feet)
Cutting
Types of waste: Heads, feet
Amount: 2.5-3.0% of live
weight (heads),
3.5-4.0% of live weight (feet)
189166566802040201856673850608203066802074993501814830047269043815
2447068-1022Slaughtering (photo from google.com)
Type of waste: Blood
Amount: 3.2-3.7% of
live weight
0Slaughtering (photo from google.com)
Type of waste: Blood
Amount: 3.2-3.7% of
live weight

678053027680549911031686522707603143254497705275590
592645525463536772852622551919909261979
4091857273050Cleaning up operation
Type of waste: Intestine, glands, gizzard and proventriculus
Amount: 8.5-9.0% (Intestine, glands) , 3.5-4.2% (gizzard, proventriculus) of
live weight
00Cleaning up operation
Type of waste: Intestine, glands, gizzard and proventriculus
Amount: 8.5-9.0% (Intestine, glands) , 3.5-4.2% (gizzard, proventriculus) of
live weight

Figure 2. SEQ Figure_2. * ARABIC 1: Process Flow for Chicken Processing ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.1007/s13197-011-0290-7”, “ISBN” : “0022-1155\r0975-8402”, “ISSN” : “00221155”, “PMID” : “23729848”, “abstract” : “India is bestowed with vast livestock wealth and it is growing at the rate of 6% per annum. The contribution of livestock industry including poultry and fish is increasing substantially in GDP of country which accounts for >40% of total agricultural sector and >12% of GDP. This contribution would have been much greater had the animal by-products been also efficiently utilized. Efficient utilization of by-products has direct impact on the economy and environmental pollution of the country. Non-utilization or under utilization of by-products not only lead to loss of potential revenues but also lead to the added and increasing cost of disposal of these products. Non-utilization of animal by-products in a proper way may create major aesthetic and catastrophic health problems. Besides pollution and hazard aspects, in many cases meat, poultry and fish processing wastes have a potential for recycling raw materials or for conversion into useful products of higher value. Traditions, culture and religion are often important when a meat by-product is being utilized for food. Regulatory requirements are also important because many countries restrict the use of meat by-products for reasons of food safety and quality. By-products such as blood, liver, lung, kidney, brains, spleen and tripe has good nutritive value. Medicinal and pharmaceutical uses of by-product are also highlighted in this review. Waste products from the poultry processing and egg production industries must be efficiently dealt with as the growth of these industries depends largely on waste management. Treated fish waste has found many applications among with which the most important are animal feed, biodiesel/biogas, dietectic products (chitosan), natural pigments (after extraction) and cosmetics (collagen). Available information pertaining to the utilization of by-products and waste materials from meat, poultry and fish and their processing industries has been reviewed here.”, “author” : { “dropping-particle” : “”, “family” : “Jayathilakan”, “given” : “K.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Sultana”, “given” : “Khudsia”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Radhakrishna”, “given” : “K.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Bawa”, “given” : “A. S.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “Journal of Food Science and Technology”, “id” : “ITEM-1”, “issue” : “3”, “issued” : { “date-parts” : “2012” }, “page” : “278-293”, “title” : “Utilization of byproducts and waste materials from meat, poultry and fish processing industries: A review”, “type” : “article-journal”, “volume” : “49” }, “uris” : “http://www.mendeley.com/documents/?uuid=6da04a98-806e-4abb-a142-48c43ac8b67d” } , “mendeley” : { “formattedCitation” : “(Jayathilakan et al., 2012)”, “plainTextFormattedCitation” : “(Jayathilakan et al., 2012)”, “previouslyFormattedCitation” : “(Jayathilakan et al., 2012)” }, “properties” : { “noteIndex” : 0 }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Jayathilakan et al., 2012)
For this operation, the intestines were chosen as sample for further analysis and generally its amount around 8.5-9.0% ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.1007/s13197-011-0290-7”, “ISBN” : “0022-1155\r0975-8402”, “ISSN” : “00221155”, “PMID” : “23729848”, “abstract” : “India is bestowed with vast livestock wealth and it is growing at the rate of 6% per annum. The contribution of livestock industry including poultry and fish is increasing substantially in GDP of country which accounts for >40% of total agricultural sector and >12% of GDP. This contribution would have been much greater had the animal by-products been also efficiently utilized. Efficient utilization of by-products has direct impact on the economy and environmental pollution of the country. Non-utilization or under utilization of by-products not only lead to loss of potential revenues but also lead to the added and increasing cost of disposal of these products. 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S.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “Journal of Food Science and Technology”, “id” : “ITEM-1”, “issue” : “3”, “issued” : { “date-parts” : “2012” }, “page” : “278-293”, “title” : “Utilization of byproducts and waste materials from meat, poultry and fish processing industries: A review”, “type” : “article-journal”, “volume” : “49” }, “uris” : “http://www.mendeley.com/documents/?uuid=6da04a98-806e-4abb-a142-48c43ac8b67d” } , “mendeley” : { “formattedCitation” : “(Jayathilakan et al., 2012)”, “plainTextFormattedCitation” : “(Jayathilakan et al., 2012)”, “previouslyFormattedCitation” : “(Jayathilakan et al., 2012)” }, “properties” : { “noteIndex” : 0 }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Jayathilakan et al., 2012) of live weight meanwhile; the feet’s amount is 3.5-4.0% ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.1007/s13197-011-0290-7”, “ISBN” : “0022-1155\r0975-8402”, “ISSN” : “00221155”, “PMID” : “23729848”, “abstract” : “India is bestowed with vast livestock wealth and it is growing at the rate of 6% per annum. The contribution of livestock industry including poultry and fish is increasing substantially in GDP of country which accounts for >40% of total agricultural sector and >12% of GDP. This contribution would have been much greater had the animal by-products been also efficiently utilized. Efficient utilization of by-products has direct impact on the economy and environmental pollution of the country. Non-utilization or under utilization of by-products not only lead to loss of potential revenues but also lead to the added and increasing cost of disposal of these products. Non-utilization of animal by-products in a proper way may create major aesthetic and catastrophic health problems. Besides pollution and hazard aspects, in many cases meat, poultry and fish processing wastes have a potential for recycling raw materials or for conversion into useful products of higher value. Traditions, culture and religion are often important when a meat by-product is being utilized for food. Regulatory requirements are also important because many countries restrict the use of meat by-products for reasons of food safety and quality. By-products such as blood, liver, lung, kidney, brains, spleen and tripe has good nutritive value. Medicinal and pharmaceutical uses of by-product are also highlighted in this review. Waste products from the poultry processing and egg production industries must be efficiently dealt with as the growth of these industries depends largely on waste management. Treated fish waste has found many applications among with which the most important are animal feed, biodiesel/biogas, dietectic products (chitosan), natural pigments (after extraction) and cosmetics (collagen). Available information pertaining to the utilization of by-products and waste materials from meat, poultry and fish and their processing industries has been reviewed here.”, “author” : { “dropping-particle” : “”, “family” : “Jayathilakan”, “given” : “K.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Sultana”, “given” : “Khudsia”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Radhakrishna”, “given” : “K.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Bawa”, “given” : “A. S.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “Journal of Food Science and Technology”, “id” : “ITEM-1”, “issue” : “3”, “issued” : { “date-parts” : “2012” }, “page” : “278-293”, “title” : “Utilization of byproducts and waste materials from meat, poultry and fish processing industries: A review”, “type” : “article-journal”, “volume” : “49” }, “uris” : “http://www.mendeley.com/documents/?uuid=6da04a98-806e-4abb-a142-48c43ac8b67d” } , “mendeley” : { “formattedCitation” : “(Jayathilakan et al., 2012)”, “plainTextFormattedCitation” : “(Jayathilakan et al., 2012)”, “previouslyFormattedCitation” : “(Jayathilakan et al., 2012)” }, “properties” : { “noteIndex” : 0 }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Jayathilakan et al., 2012) of live weight. These operations during chickens processing cause many wastes that can be some of pollutions such as smell and water pollutions. Thus, the total wastes produced are around 28.2 – 31.9% for each chicken during slaughtering and processing.
2.2By-Products and Waste Materials from Chicken Processing IndustriesPoultry industries are important and various factor of the food sector. Broiler production significantly increased since the 1980s, due to counseled nutritional benefits of chicken meat in comparison with other meals and through an first-rate increase in consumption. This increase has been also authorised to the poultry industries, which deliver processed products which are easier for the client to put together. Poultry industries generate a massive quantity of by-products, mainly in the form of head, feet, feathers, blood and intestines (Brandelli et al., 2015). Waste within the food industry is characterized by using a high ratio of product specific waste no longer simplest does this imply that the era of this waste is unavoidable, however the quantity and sort of waste product which consists often of the natural residue of processed raw materials, can scarcely be altered if the quality of the completed product is to remain steady ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.1007/s13197-011-0290-7”, “ISBN” : “0022-1155\r0975-8402”, “ISSN” : “00221155”, “PMID” : “23729848”, “abstract” : “India is bestowed with vast livestock wealth and it is growing at the rate of 6% per annum. The contribution of livestock industry including poultry and fish is increasing substantially in GDP of country which accounts for >40% of total agricultural sector and >12% of GDP. This contribution would have been much greater had the animal by-products been also efficiently utilized. Efficient utilization of by-products has direct impact on the economy and environmental pollution of the country. Non-utilization or under utilization of by-products not only lead to loss of potential revenues but also lead to the added and increasing cost of disposal of these products. Non-utilization of animal by-products in a proper way may create major aesthetic and catastrophic health problems. Besides pollution and hazard aspects, in many cases meat, poultry and fish processing wastes have a potential for recycling raw materials or for conversion into useful products of higher value. Traditions, culture and religion are often important when a meat by-product is being utilized for food. Regulatory requirements are also important because many countries restrict the use of meat by-products for reasons of food safety and quality. By-products such as blood, liver, lung, kidney, brains, spleen and tripe has good nutritive value. Medicinal and pharmaceutical uses of by-product are also highlighted in this review. Waste products from the poultry processing and egg production industries must be efficiently dealt with as the growth of these industries depends largely on waste management. Treated fish waste has found many applications among with which the most important are animal feed, biodiesel/biogas, dietectic products (chitosan), natural pigments (after extraction) and cosmetics (collagen). Available information pertaining to the utilization of by-products and waste materials from meat, poultry and fish and their processing industries has been reviewed here.”, “author” : { “dropping-particle” : “”, “family” : “Jayathilakan”, “given” : “K.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Sultana”, “given” : “Khudsia”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Radhakrishna”, “given” : “K.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Bawa”, “given” : “A. S.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “Journal of Food Science and Technology”, “id” : “ITEM-1”, “issue” : “3”, “issued” : { “date-parts” : “2012” }, “page” : “278-293”, “title” : “Utilization of byproducts and waste materials from meat, poultry and fish processing industries: A review”, “type” : “article-journal”, “volume” : “49” }, “uris” : “http://www.mendeley.com/documents/?uuid=6da04a98-806e-4abb-a142-48c43ac8b67d” } , “mendeley” : { “formattedCitation” : “(Jayathilakan et al., 2012)”, “plainTextFormattedCitation” : “(Jayathilakan et al., 2012)”, “previouslyFormattedCitation” : “(Jayathilakan et al., 2012)” }, “properties” : { “noteIndex” : 0 }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Jayathilakan et al., 2012). The potential uses can be determined by conducting some experiments on physicochemical and functional properties of waste materials from chickens. Table 2.1 shows the by-products of chickens and their potential uses.

Table 2.1: Chicken By-Products and Their Potential Uses
Type of by-products % of live weight Uses
By-products from production phase
Poultry litter and manure – Recycled feed, surface dressing of agricultural land
Hatchery by-products
Egg shells, infertile eggs, unhatched eggs and dead as well as culled chicks – Hatchery by-product meal up to 3-5% into feed.

Egg shell meal as high calcium diet.

By-products of poultry dressing plant
Feathers 7-8 Bedding material, decorative purpose, sporting equipment, manure or fertilizers, feather meal.

Head 2.5-3.0 Poultry meal
Blood 3.2-3.7 Blood meal
Gizzard and proventriculus 3.5-4.2 Edible, source of chitinolytic enzyme
Feet 3.5-4.0 Soup, technical fat/poultry grease
Intestines and glands 8.5-9.0 Sportgats, meat meal, poultry grease and active principles (hormones and enzymes)
Source: Jayathilakan et al. (2012)
Based on Table 2.1, there are three types of by-products such as by-products from production phase, hatchery and poultry dressing plant. All of the by-products have their own potential uses which are depending to their characteristics. The Table 2.1 is more detail from the Figure 2.1 which is the process flow for chicken processing.
2.3Physicochemical Properties2.3.1Weight
According to Oxford dictionaries, weight is described as a body relative mass or the quantity of depend contained through it, giving upward to a downward force; the heaviness of someone or component. According to Hantanirina et al. (2016), the indigenous race chickens are slaughtered at 1.75 kg with age from 120 to 185 days. Based on Nuralis Agro Sdn. Bhd., where it is one of the local farms, the live weight of chickens slaughtered started from 1.0 kg to 1.5 kg and above. These two differences are because of environment, feed and breed. The live weights for wastes for a chicken are stated in Table 2.1.

2.3.2 Moisture content
Moisture content is defined as the ratio of the mass of water in a pattern of the mass of solids inside the pattern, expressed as a percent (ASTM 2216). Moisture is an vital component in food quality, preservation and resistance to deterioration. Moisture content influences the taste, texture, weight, look and shelf life of foodstuffs. Even a mild deviation from described preferred can adversely effect the physical properties of a food material. For example, substances which are too dry could affect the consistency of the end products (Appoldt & Raihani, 2017). It is also used to outline the weight reduction of mass that takes place as the material is heated. There a few purposes of moisture content analysis inclusive of to make cetain the first-rate manipulate in most production and laboratory facilities and gives impact the physical properties of a material.
Moreover, moisture content to increase the shelf life of processed foods and provisions and reactivity of chemical substances in inventory (SCIENTIST LIVE., 2013).. According to Appoldt & Raihani (2017), there are some advantages and disadvantages of doing moisture content analysis. The advantages of moisture content analysis are the samples can be tested in a large amount at the same time, precise and relatively cheap. Through this analysis, the high accuracy of result can be obtained by using drying oven and fast measurement is obtained by using moisture analyzer. Besides, moisture content analysis requires extended heating intervals and cooling stages, can cause unfavourable and has high capability for mistakes of guide data entry and calculation if use the drying oven.
The Table 2.2 is the results of moisture content for chicken by-products. According to Taheri et al. (2013), the percentage of moisture content for head and feet are 3.78 ±0.04. Next, percentage of moisture content obtained for intestines is 82.61 ±0.90 (Seong, P. N. et al., 2015) and feathers is 12.33 (Tesfaye et al. 2017). The percentage of moisture content of blood is 2.83 ±0.04 (Sorapukdee & Narunatsopanon, 2017). Thus, the intestines have a higher percentage of moisture content among these chicken by-products and blood has the lowest percentage of moisture content.

Table 2.2: Moisture Content of Chicken By-productsMaterial % of composition Reference
Head and feet 3.78 ±0.04Taheri et al. (2013)
Intestines 82.61 ±0.90Seong, P. N. et al. (2015)
Feathers 12.33 Tesfaye et al. (2017)
Blood 2.83 ±0.04Sorapukdee & Narunatsopanon (2017)
2.3.3 Protein
According to Thesaurus.com, protein is defined as huge, complex molecules, considered as a food supply presenting essential amino acids to the body. Proteins are noticeably different elegance of biomolecules. Variations of their chemical properties such as form, length and solubility permit them to carry out many biological functions (Enechi & Emilia, 2013). In addition, they described as polymers of amino acids, the most of which are ?-amino acid having the general formula NH2CHRCOOH, and may hence be outstanding from fat and carbohydrate in being the only macronutrient in foods to comprise nitrogen. Protein is most significance composition in poultry nutrition as a major constituent of the biologically lively compounds within the body. Furthermore, the maximum performance or earnings of broiler, growth performance and development may be received by having the optimum protein concentration in broiler diets (Beski et al., 2015). This is because broilers have high dietary protein requirements. According to (Genetics Home Reference, 2018) , there are some functions of protein such as:
Antibody
Antibodies bind to precise foreign particles including viruses and micro-organism, to help guard the body. For instance, is Immunoglobulin G.

Enzyme
Enzymes perform almost all the thousands of chemical reactions that take region in cells. In addition they help with the formation of recent molecules by analysing the genetic records saved in DNA. For instance, is Phenylalanine hydroxylase.

Messenger
Messenger proteins that are some forms of hormones transmit signals to coordinate biological processes among different cells, tissues and organs, as an instance is growth hormone.

Structural component
Proteins provide structure and help for cells. On a larger scale, they also permit the body to transport. As an instance is, Actin.

Transport or storage
These proteins bind and bring atoms and small molecules within cells and throughout the body. For example, is Ferritin.

Based on the some journals, the results of protein composition for chicken by-products are obtained according to types of materials as shown in Table 2.3 as below. Table 2.3: Protein Content of Chicken By-productsMaterial % of composition Reference
Head and feet 84.66 ±0.09Taheri et al. (2013)
Intestines 11.78 ±0.17Seong, P. N. et al. (2015)
Feathers 82.36 Tesfaye et al. (2017)
Blood 88.27 ±0.04Sorapukdee & Narunatsopanon (2017)
According to Taheri et al. (2013), the percentage of protein for the head and feet are 84.66 ±0.09. Next, the percentage of protein obtained for intestines is 11.78 ±0.17 (Seong et al., 2015) and feathers is 82.36 (Tesfaye et al. 2017). The percentage of protein in blood is 88.27 ±0.04 (Sorapukdee & Narunatsopanon, 2017). Thus, the highest percentage of protein among these chicken by-products is blood and intestines has the lowest percentage of protein.

2.3.4 Fat
Fat is defined as a natural oily substance taking place in animal bodies, in particular while deposited as a layer under the pores and skin or around certain organs. Based on the some journals, the results of fat composition are obtained according to types of chicken by-products as shown in Table 2.4. According to Taheri et al. (2013), the percentage of fat for heads and feet are 0.7 ±0.1. Next, the percentage of fat obtained for intestines is 1.82 ± 0.07 (Seong et al., 2015) and feathers is 0.83 (Tesfaye et al., 2017). The percentage of fat in blood is 0.15 ±0. 06 (Sorapukdee & Narunatsopanon, 2017). Thus, the highest percentage of fat among these chicken by-products is head and feet and blood has the lowest percentage of fat.

Table 2.4: Fat Content of Chicken By-productsMaterial % of composition Reference
Head and feet 0.7 ±0.1Taheri et al. (2013)
Intestines 1.82 ± 0.07 Seong, P. N. et al. (2015)
Feathers 0.83 Tesfaye et al. (2017)
Blood 0.15 ±0.06Sorapukdee & Narunatsopanon (2017)
2.3.5 Ash
Ash is defined as the overall quantity of minerals present inside a food (umass.edu). Based on the Moisture, Ash Testing in Food Processing (2010), ash can assist determine the quantity and sort of minerals in food and also can determine physicochemical properties of foods which it retards the growth of microorganisms. Based on some journals, the results of ash composition for chicken by-products are shown as below in Table 2.5:
Table 2.5: Ash Content of Chicken By-productsMaterial % of composition Reference
Head and feet 4.70 ±0.34Taheri et al. (2013)
Intestines – –
Feathers 1.49 Tesfaye et al. (2017)
Blood 9.93 ±0.34Sorapukdee & Narunatsopanon (2017)
Based on Table 2.5, the percentage of ash for the head and feet are 4.70±0.34 (Taheri et al., 2013). Next, percentage of ash obtained for feathers is 1.49 (Tesfaye et al., 2017) and there is no result of fat percentage for intestines. The percentage of fat in blood is 9.93 ±0.34 (Sorapukdee & Narunatsopanon, 2017). Thus, the highest percentage of ash among these chicken by-products is head and feet and feather has the lowest percentage of ash.

2.3.6 Fiber
Fiber is defined as a kind of carbohydrate that the body can’t digest. It cannot be damaged down into sugar molecules and rather it passes through the body undigested (HARVARD T.H. CHAN, 2016). It is an organic food residue which has been hydrolysed by acid (sulphuric acid and hydrochloric acid) and aqueous alkaline (sodium hydroxide). A determination of crude fiber is used in comparing the performance of milling and setting apart bran from the starchy endosperm. The functions of fiber are to help minimize the caloric density of the diet, reduce the constipation and make a contribution to fecal consistency. Based on the some journals, the results of fiber composition of chicken by-products are not available. This is because the amount of fiber in head, feet, intestines and blood is very small but for the feathers, there they have fiber composition in keratins. Thus, there is no reference percentage of fiber for chicken by-products based on the previous journal referred excluding feathers which has 2.15% of fiber composition (Tesfaye et al., 2017).

2.3.7 Carbohydrate
Carbohydrates are one of the primary forms of nutrients (Chemical Learning, 2009). They carry out as energy sources and as crucial structural components in organisms. They may be called the simple or complicated, depending on their chemical structure. Besides, carbohydrates are found as monosaccharides or diverse mixed forms. The short chains are formed when carbohydrates joined with themselves or with different monosaccharides with the aid of glycosidic bonds and they may be termed oligosaccharides. In the meantime, they are referred as polysaccharides whilst they are joined to form lengthy chains which can comprise as much as thousands of units. Furthermore, the various complex carbohydrates are proper sources of fiber. In addition, the genetic fact is contained in a part of the shape of nucleic acids which includes of carbohydrates. Based on journal referred, there is no data or result about carbohydrate content in chicken by-products.

2.3.8 Calorific Value
Calorific value is defined as the quantity of energy available from an item of food when digested, normally from carbohydrates and fats (Quora, 2017). According to Quora (2017), the heat produced by the whole combustion of a specific amount of it may decide the energy contained in a fuel or food. Generally, the energy or calorific value is expressed in calories per gram. Based on the journal referred, there is only chicken intestines have the calorific value which is 995.00 ±17.89 cal/g (Seong et al., 2015).
Functional Properties2.4.1 Water Holding Capacity (WHC)Water holding capacity (WHC) is the capability of meat to maintain its inherent moisture despite the fact that external pressures (like gravity, heating, centrifugation, pressing) are applied to it. According to Taheri et al. (2013), the WHC result for head and feet of poultry is 2.8 ± 0.2 ml/g hydrolysate. Besides, there are no past results or studies on WHC results for intestines and feathers.
2.4.2 Oil Absorption Capacity (OAC)Oil absorption capacity (OAC) is defined as water-oil absorption index is correlated with emulsifying capacity (EC) for most proteins making it feasible to expect EC in a simple way. According to Taheri et al. (2013), the OAC result for heads and feet of poultry is 2.8 ± 0.1 ml/g hydrolysate. Besides, there are no past results or studies on OAC results for intestines and feathers.
Nutrient Composition of Current Animal FeedsAccording to PoultryHub (2018) , the nutrients that can be provided by having the selected feed ingredients for poultry diets such as the absence of anti-nutritional or toxic factors, their palatability or effect on voluntary feed intake, and their cost. The cereal grains, protein meals, fats and oils, minerals, feed additives, and miscellaneous raw materials are the classifications for feed ingredients. Based on Table 2.6, the nutrient composition of cereal grains is shown by seven types of different ingredient.

Table 2.6: The Nutrient Composition of Cereal Grains
Ingredient Protein (%) ME (kcal/kg) Calcium (%) Available P (%) Lysine (%)
Wheat 13.0 3153 0.05 0.20 0.5
Corn 8.5 3300 0.05 0.20 0.3
Sorghum 9.0 3263 0.02 0.15 0.3
Barley 11.5 2795 0.10 0.20 0.4
Rye 12.5 2734 0.05 0.18 0.5
Triticale 15.4 3110 0.05 0.19 0.4
Oats 12.0 2756 0.10 0.20 0.4
Source: PoultryHub (2018)
According to PoultryHub (2018), the low expected energy content or contamination with mycotoxins or toxin-producing organisms such as fungi and ergot can be caused by the poor growing or storage condition. There are many things will affected by genetic and environmental factors such the content of nutrients in grains and nutrient value which takes into account the digestibility of nutrients contained in an ingredient in the target animal. Thus, the seasonal and storage condition will affected the quality of cereal grains. Moreover, the cereals by-products such as wheat bran, rice bran and DDGS, are used widely in poultry feed. They are high in fiber, or non-starch polysaccharides (NSP) which are poorly utilized in poultry and low in metabolized energy (ME). Besides, there are many oilseeds and legumes contain anti-nutritive factors. Some of them are used in heat-treated meals and can be destroyed by heat. Naturally, the new cultivars of some oilseeds and legumes have been developed are low in anti-nutritive factors (ANF). The nutrient composition of vegetable protein sources are shown in Table 2.7.

Table 2.7: The Nutrient Composition Of Vegetable Protein Sources
Ingredient Protein (%) ME (kcal/kg) Calcium (%) Available P (%) Lysine (%) Main Anti-nutritional factor
Soybean meal 48.0 2557 0.20 0.37 3.2 Trypsin inhibitor
Canola meal 37.5 2000 0.66 0.47 2.2 Glucosinolates
Cottonseed meal 41.0 2350 0.15 0.48 1.7 Gossypol
Sunflower meal 46.8 2205 0.30 0.50 1.6 High fiber
Peas 23.5 2550 0.10 0.20 1.6 Trypsin inhibitor
Lupins 34.5 3000 0.20 0.20 1.7 Toxic alkaloid
Source: PoultryHub (2018)
Furthermore, animal protein meals are the other examples of current feed which providing a good source of essential amino acids uch as lysine and methionine (PoultryHub, 2018). They are also good sources of energy and minerals . The nutrient composition of selected animal protein sources is shown in Table 2.8.
Table 2.8: The Nutrient Composition Of Selected Animal Protein Sources
Ingredient Protein (%) ME (kcal/kg) Calcium (%) Available P (%) Lysine (%)
Meat meal 50.0 2500 8.00 4.00 3.6
Fish meal 60.0 2720 6.50 3.50 5.3
Poultry by-product meal 60.0 2950 3.50 2.10 3.4
Blood meal 80.0 2690 0.28 0.28 6.9
Feather meal 85.0 3016 0.20 0.75 1.7
Source: PoultryHub (2018)
CHAPTER 3METHODOLOGYThis chapter will cover the methodology that has been applied during the study of the chicken by-products that had been conducted. The first stage of study is a visit to the chicken processing industry in Nuralis Agro Sdn. Bhd., Selangor. The study of processing of chicken from the slaughtering until wastes removal is done and the data for average weight of chicken is obtained. In the second stage, the further analysis was made for physicochemical properties which are weight of chicken by-products (g), moisture content (%), fat (%), crude protein (%), ash (%), crude fiber (%), carbohydrate (%), and calorific value (J/kg) and functional properties include water holding capacity (ml/g) and oil absorption capacity (ml/g). The experiments of this study are involving two conditions of waste materials such as original form and dry powder form. These wastes are prepared to be powder sample before further analysis. The summary of the whole process with a flow chart is shown in Figure 3.1.

2076450200025Sample Preparation
00Sample Preparation

2809875635000454977514732000127444515938500126492015875000
779780250190Head ; Feet
00Head ; Feet

128651026479500455041026543000241935015240Intestines
00Intestines
417766513335Feathers
00Feathers

28213059906000
1271270952500
171513577470003939540806450017119607874000
2865120102235Functional Properties
Water holding capacity (WHC)
Oil absorption Capacity (OAC)
00Functional Properties
Water holding capacity (WHC)
Oil absorption Capacity (OAC)
741680100330Physicochemical Properties
-Weight
-Moisture content
-Protein
-Fat
-Ash
-Fiber
-Carbohydrate
– Calorific value
00Physicochemical Properties
-Weight
-Moisture content
-Protein
-Fat
-Ash
-Fiber
-Carbohydrate
– Calorific value

390588515176500
28105102914650016554452895600016548101714500
135064513335Preparation for production of animal feed
00Preparation for production of animal feed

Figure 3. SEQ Figure_3. * ARABIC 1: Overview of Research Activities
3.1Sample preparationBy-products and waste materials from chickens processing industries from Nuralis Agro Sdn. Bhd are used as sample to conduct this study. The wastes are obtained from chicken processing such as head, feet, intestines and feathers. The amount of wastes from slaughterhouse is around 28.2 – 31.9% (Jayathilakan et al., 2011). The wastes were carefully packed and transported to the laboratory. The preparations of samples of these materials are different. Firstly, the collected head and feet from slaughterhouse were washed under running tap water to remove the dirt residue such as blood. The cleaned chicken head and feet is shown in Figure 3.2. After that, some of the head and feet would undergo for physical properties which is weight.
146494512128600
Figure 3. SEQ Figure_3. * ARABIC 2: The cleaned chicken head and feetMeanwhile, the rest of the head and feet are undergoing preparation of protein hydrolysates that used for determining of proximate analysis and functional properties. The protein hydrolysates were prepared before further analysis (Taheri et al., 2013). The head and feet were stored at -20?C before analysis. The frozen head and feet were held until about -4?C for the temperature to increase before doing preparation of protein hydrolysates. After that, they were minced by using chopper knife as shown in APPENDIX A and heated at 85?C in a water bath for 20 minutes and the minced chicken head and feet become steamed as shown in APPENDIX B. The minced chicken head and feet is shown in Figure 3.3.
3341370-40957500
Figure 3. SEQ Figure_3. * ARABIC 3: The minced head and feetAccording to Taheri et al. (2013), the samples were mixed with distilled water 1:2 (w:v). Next, alcalase enzyme (APPENDIX C)was added to the substrate as shown in Figure 3.4. At 52.51?C which is optimum temperature, all reactions were performed in shaking incubator with constant agitation (200 rpm). The reaction was terminated by heating the solution at 95?C for 20 minutes.
230124015938500
Figure 3. SEQ Figure_3. * ARABIC 4: The sample mixed with distilled water and alkalise enzyme after heating process at 90°CAfter that, the hydrolysates were centrifuged at 6700 x g for 20 minutes and the supernatant is yield as shown in Figure 3 (Taheri et al., 2013). Then, the supernatant was freeze-dried for 4 days (Figure 3.6), ground into a fine powder as shown in Figure 3.7 and stored at 4?C in a desiccator for the next analysis.
3105150-31686500247650-30734000
right6350Figure 3.6: Freeze drying of hydrolysates0Figure 3.6: Freeze drying of hydrolysates29337025400Figure 3.5: The hydrolysates after centrifugation process0Figure 3.5: The hydrolysates after centrifugation process
145732532004000
Figure 3. SEQ Figure_3. * ARABIC 7: The protein hydrolysates powderSecondly, the intestines collected from slaughterhouse were washed under running tap water to remove the dirt residue such as blood and faeces. The cleaned intestines are shown in Figure 3.8. After that, some of the intestines would undergo for physical properties to determine weight.
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Figure 3. SEQ Figure_3. * ARABIC 8: The cleaned chicken intestinesMeanwhile, the rest of cleaned intestines were placed in the aluminium tray by covered with aluminium foil as shown in Figure 3.9. They undergo drying at 105?C for 24 hours in the oven (OF-G22W, Jeio Tech, Korea) and grinding process to form powder. Then, the powder of intestines was put chiller at 3-5?C.

1732915825500
Figure 3. SEQ Figure_3. * ARABIC 9: The dried chicken intestinesLastly, the feathers were washed under running tap water after they collected from slaughterhouse to remove the dirt residue such as blood, faeces, skin and dirt. Then, they were washed with the hot water to remove easily removable matters as shown in Figure 3.10.
center8223400
Figure 3. SEQ Figure_3. * ARABIC 10: The chicken feathers were washed with hot waterAfter that, some of the feathers would undergo for physical properties such as weight and moisture content. Meanwhile, the rest of the feather was turned into dried feathers as shown in Figure 3.11 by undergoing drying dried at 105?C for 24 hours in the oven (OF-G22W, Jeio Tech, Korea) and grinding process. Next, they were packed for storage at room temperature.

center762000
Figure 3. SEQ Figure_3. * ARABIC 11: The dried chicken feathers3.2 Physicochemical Properties3.2.1 Determination of weightThe samples that have been collected from slaughtered house such as chicken head, feet, intestines and feathers were weighed.

3.2.2 Determination of moisture content
The crucible was thoroughly washed and dried in an oven (OF-G22W, Jeio Tech, Korea) at 100?C for 30 minutes and allowed to cool inside desiccators. After cooling, they were weighed using a weighing balance and their various weights were recorded as (W1). Then, 3.0 g of the finely-ground samples were put into the crucibles and weighed to determine W2. Thereafter, the sample and crucible were placed inside the oven (OF-G22W, Jeio Tech, Korea) and dried at 100?C for 4 h, then cooled and weighted at the same temperature for 30 min until constant weights were obtained to get W3. Then, the moisture content of the samples was calculated as below (Helrich ; Association of Official Analytical Chemists, 1990):
Initial weight of filled crucible-(Final weight of filled crucible)Initial weight of filled crucible-(Initial weight of empty crucible) ×100 ……………….. (1)
3.2.3 Determination of crude protein
The crude protein content of the samples was determined using the Kjeldahl method of (Helrich ; Association of Official Analytical Chemists, 1990), which involved protein digestion and distillation. For the protein digestion, about 2.0 g of the sample was weighed into a Kjeldahl flask, and two tablets of Kjeldahl Catalyst were added. This was followed by adding 25 mL of concentrated sulphuric acid. The whole mixture was subjected to heat in the fume cupboard. The heating was done gently at first and increased with occasional shaking until the solution acquired a green colour. The temperature of the digester remained above 420 °C for about 30 min. The solution was cooled and the black particles found at the neck of the flask were washed down with distilled water. The solution was re-heated gently at first until the green colour disappeared. Then, it was allowed to cool.

To prepare for protein distillation, the Kjeltec distillation apparatus (KjeltecTM 2300, Foss Analytical; Denmark) was steamed through for 15 min, after which a 100 mL conical flask containing 5 mL of boric acid/indicator was placed under the condenser so that the condenser tip was under the liquid. About 5.0 mL of the digest was pipetted into the body of the apparatus via a small funnel aperture. The digest was washed down with distilled water, followed by the addition of 50 mL of 60 % NaOH solution. The digest in the condenser was steamed through for about 1 to 5 min, after which sufficient ammonium sulphate was collected. The receiving flask was removed and the tip of the condenser was washed down into the flask, after which the condensed water was removed. The solution in the receiving flask was treated with 0.01 M hydrochloric acid. Also, a blank was run through along with the sample (James, 1995). After titration, the percentage of nitrogen was calculated using equation (2).

% N2 = (V1 – V2) X (M) X 0.01410 X (W) X 100%……………………….. (2)
Where;
V1: Volume of the acid used in the titration (ml)
V2: Corresponding amount of acid for the blank titration (ml)
W: Weight of the sample (g) and M: Molarity of acid (M)
On average all biological proteins contain 16 % N. Therefore protein content is estimated by multiplying N % by 6.25 (6.25 is the reciprocal of 0.16). Thus, crude protein does not differentiate between N in feed samples coming from true protein or other non-protein nitrogen (NPN) compounds, nor does it differentiate between available and unavailable protein.

%N × 6.25 = % CP …………………………………… (3)
Where;
N: Nitrogen
CP: Crude Protein
3.2.4 Determination of fat
According to the Soxhlet extraction method, the total fat in the sample was determined by using Soxtec Extraction (SoxtecTM 2050, Foss Analytical, Denmark). A 250 ml clean aluminium cup was dried in an oven at 105 to 110?C for about 30 minutes and cooled in a desiccator. The sample was weighed into labelled thimbles for 1 gram. The aluminium cup was weighed corresponding and filled with 80 ml of petroleum ether which is boiling point from 40 to 60?C. The extraction thimbles were plugged tightly with cotton wool. The Soxtec apparatus was assembled and allowed to reflux for 75 minutes. The thimble was removed with care and petroleum ether was collected from the top container and drained into another container for reuse. After that, the flask was dried at 105 to 110?C for 1 hour when it was almost free of the petroleum ether. After drying, it was cooled in a desiccator and weighed. Then, the fat percentages of the samples were calculated as below (Helrich ; Association of Official Analytical Chemists, 1990):
(Weight of fat) / (weight of sample) x 100% = % fat ………………………. (4)
3.2.5 Determination of ash
Furnace incineration was used to determine the total ash content of the samples based on the vaporization of water and volatiles with burning organic substances in the presence of oxygen in the air to carbon dioxide at a temperature of 550?C. The finely-ground dried sample of 1 gram was placed in a porcelain crucible and incinerated at 525?C for 6 hours in an ashing muffle furnace (KSL-1700X, MTI Corporation, USA) until ash was obtained. The ash was cooled in a desiccator and weighed. The percentage of ash content in the samples was calculated as below (Helrich ; Association of Official Analytical Chemists, 1990):
(Weight of ash) / (weight of the original) x 100% = % ash …………………… (5)
3.2.6 Determination of crude fibre
Crude fiber content was determined using the method described by Horwitz ; Association of Official Analytical Chemists (2000). The 2 g of ground test portion was extract with ether or petroleum ether (initial boiling temperature, 35-38?C; dry-flask end point, 52-60?C; ?95% distilling ;54?C and ?60% distilling ;40?C; specific gravity at 60?F, 0.630-0.660; evaporation residue ?0.002% by weight). The extraction may be omitted if fat is ?1%. The 600 ml reflux beaker was transferred to avoid fiber contamination from paper or brush. The bumping granules was added about 0.25-0.5g, followed by 200 ml near-boiling 1.25% H2SO4, solution in small stream directly on sample to aid in complete wetting of sample. The two blanks were run for every 24 samples. The beakers were placed on digestion apparatus at 5 minutes intervals and 30 minutes for boiling, then the beakers were rotated periodically to keep solids from adhering to sides.
California Buchner was placed at near end of refluxing, previously fitted with No. 9 rubber stopper to provide vacuum seal, into filtration apparatus (Model AS-2000, Analytical Bio-Chemistry Laboratories, Columbia) and vacuum was adjusted to ca 25 mm Hg (735 mm pressure). The near-boiling H2O was flow through funnel to warm it; then the liquid was decanted trough funnel, washing solids into funnel with minimum of near-boiling H2O. After that the filtration was done by using 25 mm vacuum and residue was washed with four 40-50 ml portions near-boiling H2O, then each washing was filtered. Do not add wash to funnel under vacuum; the funnel was lifted from apparatus when adding wash. The residue from funnel into reflux beaker was washed with near-boiling 1.25% NaOH solution. The beakers were placed on reflux apparatus at 5 minutes intervals and reflux 30 minutes. Near end of refluxing, the filtration apparatus was turned on, the crucible was placed and vacuum was adjusted to ca 25 mm. Near-boiling H2O was flow through crucible to warm it. At end of refluxing, the liquid was decanted trough crucible and solids were washed into crucible with minimum of near-boiling H2O. The vacuum was needed to increase to maintain filtration rate.
Next, the residue was washed once with 25-30 ml near-boiling 1.25% H2SO4 solution, and then with two 25-30 ml portions near-boiling H2O, each washing was filtered. The crucible with residue was dried for 2 hours at 130 ±2 ?C or overnight at 110?C, and then it was cooled in desiccator and weighted (W2). After that, it was done for ash at 550 ±10?C for 2 hours. It was then cooled in desiccator before weighted (W3). Do not remove crucibles from furnace until temperature is ?250?C, as fritted disk may be damaged if cooled too rapidly.
Crude fiber (%) = (W2 – W3) – (B2 – B3) / W1 x 100 ………………….……… (6)
Crude fiber on desired moisture basis, % (w/w) =
C x 100-% moisture basis desired100-% moisture in test sample ………………..………………….……… (7)
Or C x % dry matter basis desired% dry matter in test sample .……………………..……………………. (8)
Where B2 and B3 are average weights of all blanks after oven drying and ashing, respectively (Horwitz ; Association of Official Analytical Chemists, 2000).
3.2.7 Determination of carbohydrate
The method used to determine total percentage of carbohydrate content in the samples involves adding the total values of moisture, crude protein, fat, ash and crude fiber constituents of the sample and subtracting it from 100. The determination of carbohydrate was calculated as below (Department of Food Science, 2015):
% Carbohydrate = 100% – (% moisture + % crude protein + % fat +
% ash + % crude fiber) ……………………………….. (8)
3.2.8 Determination of calorific value
According to operating instructional manual of Parr 1341 Oxygen Bomb Calorimeter, the sample was prepared and the oxygen bomb was charged. After that, the dry bucket on a solution or trip balance was tared and the calorimeter bucket was filled; then 2000 (±0.5) grams of water was added. The water temperature should be approximately 1.5?C below room temperature. It is not necessary to use exactly 2000 grams, but the amount selected must be duplicated within ±0.5 gram for each run. Next, the bucket in the calorimeter was set. The cover on the jacket also was set and the 6775 Digital Thermometer was turned on. Then, the stirrer was run for 5 minutes to reach equilibrium before starting a measured run.
The temperatures at one-minute intervals for 5 minutes were read and recorded. The calorimeter was stood back and the bomb was fired by pressing the ignition button and it holds down until the indicator light went out. After firing, the temperature of the bucket would be started to rise within 20 seconds. The time required to reach 60 percent of the total rise was measured by estimating the temperature at the 60% point and the time was observed when the temperature reading reached that point. Next, the temperature at one-minute intervals was recorded after the rapid rise period (about 4 or 5 minutes after ignition) until the difference between successive readings had been constant for five minutes. After the last temperature reading, the motor was stopped, the belt was removed and the cover was lifted from the calorimeter. Then, the knurled knob on the bomb head was opened to release the gas pressure before attempting to remove the cap. All interior surfaces of the bomb were washed with a jet of distilled water and the washings in a beaker were collected.
After that, all unburned pieces of fuse wire were removed from the bomb electrodes; they were straightened and their combined length was measured in centimeters. The bomb washings were titrated with a standard sodium carbonate solution using methyl orange and methyl red indicator. A 0.0709 N sodium carbonate solution was recommended for this titration to simplify the calculation. This was prepared by dissolving 3.76 grams Na2CO3 in water and dilution into one liter NaOH or KOH solutions of the same normality may be used. If it exceeds 0.1 percent, the sulphur content of the sample was determined by analyzing the bomb washings. There are some calculations that compute to determine the energy as below based on operating instructional manual of Parr 1341 Oxygen Bomb Calorimeter:
Assembly of data. The following data should be available at the completion of a test in a 1341 calorimeter:
a = time of firing
b = time (to nearest 0.1 min) when the temperature reaches 60 per cent of the total rise
c = time at beginning of period (after the temperature rise) in which the rate of temperature change has become constant
ta = temperature at time of firing
tc = temperature at time c
r1 = rate (temperature units per minute) at which the temperature was rising during the 5-minutes period before firing
r2 = rate (temperature units per minute) at which the temperature was rising during the 5-minutes period after firing
c1 = millilitres of standard alkali solution used in the acid titration
c2 = percentage of sulphur in the sample
c3 = centimeters of fuse wire consumed in firing
W = energy equivalent of the calorimeter, determined under standardization
m = mass of sample in grams
Temperature rise:t = tc – ta – r1 (b-a) – r2 (c-b) ……………………….. (10)
Thermochemical corrections:
e1 = correction in calories for heat of formation of nitric acid (HNO3)
= c1 if 0.0709 N alkali was used for the titration
e2 = correction in calories for heat of formation of sulphuric acid (H2SO4)
= (13.7) (c2) (m)
e3 = correction in calories for heat of combustion of fuse wire
= (2.3) (c3) when using Parr 45C10 nickel chromium fuse wire, or
= (2.7) (c3) when using No. 34 B. ; S. gage iron fuse wire
Gross heat of combustion: Hg = t.W- e1- e2- e3 m ……………………. (11)
Net heat of combustion:Hn = 1.8Hg – 91.23H …………………………. (12)
Energy equivalent: W = Hm + e1+ e3 t ……………………. (13)
Where;
W = energy equivalent of the calorimeter in calories per ?C (centigrade)
H = heat of combustion of the standard benzoic acid sample in calories per gram
m = mass of the standard benzoic acid sample in grams
t = net corrected temperature rise in ?C
e1 = correction for heat of formation of nitric acid in calories
e3 = correction for heat of combustion of the firing wire in calories
3.3 Functional Properties3.3.1 Determination of water holding capacityThe water holding capacity (WHC) as functional properties was determined for the samples. The method used were described by (Rodríguez-Ambriz et al., 2005) and Taheri et al. (2013). The 100 mg of protein samples were mixed with 1000 µl of distilled water using a stirrer. Then, the protein suspension was centrifuged at 1800 x g for 20 minutes at 22?C. The supernatant was decanted and the tube was drained at a 45? angle for 10 minutes. According to Kanu et al., (2009), the difference between the initial volume of distilled water added to the protein sample and the volume of the supernatant was determined and the results were reported as ml of water absorbed per gram of protein sample.

3.3.2 Determination of oil absorption capacityThe oil absorption capacity (OAC) as functional properties was determined for the samples. Based on Taheri (2013), method LIN ; ZAYAS (1987) was used. The 100 mg of protein sample was vortex with 1000 µl of sunflower oil for 30 seconds. The resulting emulsion was incubated at room temperature for 30 minutes and then centrifuged at 13600 x g for 10 minutes at 25?C. The supernatant was decanted and drained at a 45? angle for 20 minutes. The volume of oil absorbed equals the sample’s fat absorption capacity. According to Kanu et al., (2009), the volume of oil separated from the hydrolysate was measured and OAC was calculated as ml of oil absorbed per gram of protein sample.

CHAPTER 4RESULTS AND DISCUSSIONThis chapter includes the results of the experiments described in the previous chapter. The physicochemical properties of the chicken by-products which are consisting of head, feet, intestines and feathers, their physical properties and chemical properties are presented first. Then, it is followed by the discussion of the functional properties of chicken by-products.

4.1 Physicochemical PropertiesThe samples were obtained from the chicken wastes which are head, feet, intestines and feathers. The physicochemical properties measured were weight of fresh samples, moisture content, crude protein, fat, ash, crude fiber, carbohydrates and calorific value. All the properties were determined by using ground samples and delicate feathers.
4.1.1 WeightIn this study, the cock of the black-red type and also known as ayam kampung is chosen. The weight of chicken and by-products are determined. According to Oxford dictionaries, weight is defined as a body relative mass or the quantity of matter contained by it, giving rise to a downward force; the heaviness of a person or thing. The purposes of study for the weight of chicken are to identify the average weight of chicken in certain areas which differ depends on the environment, feed and other aspects and the total weight or amount of chicken processing per day or a year can be determined. Meanwhile, the purpose study of weight of chicken wastes is to determine the total amount of chicken wastes that produced per day or a year. These two types of weight are important to determine the amount of chicken wastes that can be produced the chicken by-products to reduce the large amount of wastes produced and pollution occurs. Based on the study of chicken processing in Nuralis Agro Sdn. Bhd., Table 4.1 shows the weight for five chickens and the average weight of chickens is 1.8 kg.
Table 4. SEQ Table_4. * ARABIC 1: Weight for Five ChickensChicken Weight (kg)
1 1.8
2 2.3
3 1.5
4 1.6
5 1.8
Average weight 1.8
According to Nuralis Agro Sdn. Bhd., they used the three conditions of weight such as live weight of chickens, weight of frozen and fresh chickens to determine the size of chickens before sell them. The Table 4.2 indicates the size of chickens depends on the three conditions of weight.

Table 4. SEQ Table_4. * ARABIC 2: The Standard of size According to the Weight of ChickenSize98361537084000 Sticker Weight of Chicken (kg)
Live Frozen Fresh
S – 1.2 0.6 – 0.799 0.8 – 0.999
M -590551905000 1.2 – 1.4 0.8 – 0.999 1.0 – 1.1
L -590561460500 1.4 – 1.5 1.0 – 1.1 1.2 – 1.3
XL -495291016000 Above 1.5 Above 1.1 Above 1.3
Thus, the size of an average chicken based on Table 4.1 according to Table 4.2 is XL. The XL size of chicken is used for the analysis to determine the physicochemical and functional properties.

Next, the weight and the percentage of live weight for each chicken by-product such as head, feet, intestine and feathers are determined as shown in Table 4.3. Based on the Table, the highest percentage of live weight is chicken intestines (8.44%) and meanwhile, the chicken head has the lowest percentage of live weight (2.5%).

Table 4. SEQ Table_4. * ARABIC 3: Weight for Each Chicken By-ProductsChicken by-products Weight (g) % of live weight
Head 45 2.5
Feet 65 3.61
Intestine 152 8.44
Feathers 96 5.33
4.1.2 Chemical Properties
The chemical properties of chicken by-products were determined and the results are shown in Table 4.4.
Table 4. SEQ Table_4. * ARABIC 4: Chemical Properties of Chicken By-ProductsHead & Feet Intestines Feathers
Moisture Content (%) 4.78 83.69 13.1
Crude Protein (%) 87.36 12.59 82.43
Fat (%) 0.81 1.45 0.08
Ash (%) 4.46 1.38 0.9
Crude Fiber (%) 0 0.2 0
Carbohydrates (%) 2.59 0.69 3.49
Calorific Value (Cal/g) 5723.32 6826.87 –
4.1.2.1 Moisture Content
Moisture content is the ratio of the mass of water in a sample of the mass of solids in the sample, expressed as a percentage (ASTM 2216). The content of moisture impacts the flavor, texture, weight, look and shelf life of foodstuffs. The results in Table 4.4 show that the percentage of moisture content acquired among the by-products ranging from 4.78 to 83.69, with the highest value was found in the intestines and the lowest value was determined in head and feet. Therefore, the highest value of moisture content is in the intestines, which is 83.69% and then followed by the feathers has 13.1% of moisture content and the lowest value of moisture content is 4.78% in head and feet. In general, there are two types of intestines which include small and large intestine wherein absorb nutrients and water (Organic Chicken Feed, 2011). The Figure 4.1 shows the comparison of the moisture content among the samples based on the experimental and the results in referred journal as theoretical results. The results of moisture content are almost comparable between the experimental results and journal results.

Figure 4. SEQ Figure_4. * ARABIC 1: The Comparison of Moisture Content Results Between Three Samples4.1.2.2 Crude Protein
The crude protein consists of true protein and non-protein nitrogen. The true protein is also called as natural protein. The data in Table 4.4 indicate that the head and feet have the higher percentage of crude protein which is 87.36. It should be stated that the higher protein content is commonly associated with a higher quality protein source (Tesfaye et al., 2017). Moreover, the crude protein is diluted with the fiber content as forages mature. The lower percentage of crude protein content is intestines. The head, and feet and feathers have higher than 80%, which can be benefited as a good source of protein material based on the data of crude protein content. The Figure 4.2 shows the comparison of the percentage of crude protein content among the samples based on the experimental and theoretical results. Thus, the experimental results of crude protein are higher than theoretical results.

Figure 4. SEQ Figure_4. * ARABIC 2: The Comparison of Crude Protein Results Between Three Samples4.1.2.3 Fat
Generally, there are 1 fatty acids and 1 glycerol components consisted in natural fats. The fatty acids are classified as saturated (SFA), unsaturated (USFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids. Moreover, the fatty acid profile of feed affects the fatty acid composition of the tissues of the animals fed with these diets. Furthermore, the productive performance in animal includes poultry can be enhanced by fat supplement. The fat content among the chicken by-products analysed; intestines had the highest content (1.45%), followed by the head and feet (0.805%), while the feathers had the lowest content (0.0804%). According to Ibrahim et al. (2008), fat should be considered as much as important as proteins and carbohydrates for the better feed conversion rate and faster growth. The Figure 4.3 shows the comparison of the percentage of fat content among the samples based on the experimental and theoretical results. Thus, the experimental results of fat are lower than theoretical results.

Figure 4. SEQ Figure_4. * ARABIC 3: The Comparison of Fat Results Between Three Samples4.1.2.4 Ash
The composition of various types of minerals, often from animal sources such as bone and meat is called as ash residue (Quarters, 2013). Some ash is desirable since the minerals are an important part of an animal’s diet. Furthermore, the excess mineral content can cause bone and joint problems in fast growing so, the animal feed with a high ash content should be avoided. Besides, the ash content in head and feet is the highest percentage of 4.46% when compared to intestines and feathers. The intestines have 1.38% of ash content while the feathers have the lowest value of ash content, 0.9%. The results are shown in Table 4.4. There are many effects in presence of ash such as reducing handling and burning capacity, increases handling costs, affects combustion efficiency and boiler efficiency and causes clinkering and slugging (Tesfaye et al., 2017). The Figure 4.4 shows the comparison of the percentage of ash content among the samples based on the experimental and theoretical results. Thus, the experimental results of ash is lower than theoretical results.

Figure 4. SEQ Figure_4. * ARABIC 4: The Comparison of Ash Results Between Three Samples4.1.2.5 Crude Fibre
The crude fiber contains a fraction of the other carbohydrates and cellulose, which are insoluble and they cannot be dissolved with alkali solutions or weak acid. The crude fiber content is important because it is related to the digestibility. The feeds that are high in crude fibre are less digestible than those low in fiber. Furthermore, the data in Table 4.4 indicates that head, and feet and feathers do not contain crude fiber. According to Tesfaye et al. (2017), the chicken feathers have negligible amounts of crude fiber where is they do not contain cellulose, hemicellulose and lignin. Based on Table 4.4, the intestines have the highest percentage of crude fiber content among the others which is 0.2 yet it is also not in large amount of content. The Figure 4.5 shows the comparison of the percentage of crude fiber content among the samples based on the experimental and theoretical results. Thus, the theoretical result of crude fibre for feathers is higher than experimental result, meanwhile the other chicken by-products are also lower than the theoretical result of crude fiber for feathers.

Figure 4. SEQ Figure_4. * ARABIC 5: The Comparison of Crude Fiber Results Between Three Samples4.1.2.6 Carbohydrates
Carbohydrates are organic compounds and the main source of energy for animals. The only elements carbon, hydrogen and oxygen are composted in biochemical compounds. Generally, carbohydrates are polymers made of basic sugar units, such as glucose, fructose, galactose and others. The required energy of animals for energy metabolism is from the carbohydrates in the feeds. Carbohydrates are different when compared to fat and protein. Fat and protein can be burned to provide energy, but carbohydrates can be as a primary source of energy (Chemical Learning., 2009). Based on the Table 4.4, the highest of carbohydrate content in chicken by-products is feathers with 3.49%. Then, it is followed by the head and feet that contain 2.60% of carbohydrates. The intestines have the lowest value of carbohydrate content which is 0.69%. Thus, the feathers have the much energy source than others, according to the high content of carbohydrates. The Figure 4.6 shows the comparison of the percentage of carbohydrate content among the samples. There are no results obtained from the referred journals.

Figure 4. SEQ Figure_4. * ARABIC 6: The Comparison of Carbohydrates Results Between Three Samples4.1.2.7 Calorific Value
Calorific value is defined as the amount of energy available for an item of food when digested, mostly from carbohydrates and fats (Quora, 2017). Subsequent, the calorific value indicates the amount of energy or calorie content in chicken by-products. This value is crucial as a diet statistics for producing the animal feed. Furthermore, the energy content is regularly used to compare feeds and evaluate the quality (Van Saun ; Herdt, 2014). The analysis to determine calorific value is carried out on samples which includes head, and feet and intestines. The calorific values obtained in head, and feet and intestines are 5723.32 Cal/g and 6826.87 Cal/g as shown in Table 4.4. The Figure 4.7 shows the comparison of the calorific values among the samples. There are no results obtained from the referred journals exclude the intestines have the calorific value which is 995.00 ±17.89 Cal/g.

Figure 4. SEQ Figure_4. * ARABIC 7: The Comparison of Calorific Value Results Between Three Samples
4.2 Functional PropertiesIn this study, the functional properties measured were water holding capacity (WHC) and oil absorption capacity (OAC) and determined as shown in Table 4.5.
Table 4. SEQ Table_4. * ARABIC 5: Results of Functional Properties of Chicken By-ProductsHead ; Feet Intestines Feathers
Water Holding Capacity, WHC (ml/g) 2.00 6.03 3.12
Oil Absorption Capacity, OAC (ml/g) 2.03 5.75 8.36
4.2.1 Water Holding CapacityAccording to BLOK et al.(2008), water holding capacity (WHC) or retention is a function of the total pore space (per cent V/V) and a suction force applied (either I cm water pressure or kPa). Besides, enzymatic hydrolysis is causing the increased concentration of polar groups such as COOH and NH2 because it has a substantial effect on the amount of adsorbed water (Taheri et al., 2013). Based on Table 4.5, the intestines had a significantly higher WHC (6.03 ml/g) and then followed by feathers, which is 3.12 ml/g. The lowest value of WHC is head and feet (2.00 ml/g) from the analysis result meanwhile the result from referred journal is 2.8 0.2 ml/g. The results also are shown in Figure 4.8. Based on the journal referred, there are no results for WHC for the intestines and feathers. The results of WHC indicate that the intestines are having more hydrophilic polar side chains, can absorb more water in comparison to the feathers and head, and feet. The hydrolysates could be used as an additive in intermediate-moisture (IM) foods to bind water and improve texture (Taheri et al., 2013).

Figure 4. SEQ Figure_4. * ARABIC 8: The Comparison of WHC Results Between Three Samples4.2.2 Oil Absorption CapacityThe quantity of oil is bound by the protein is shown in OAC results. According to Taheri et al. (2013), OAC is affected by hydroxy proline content and a powder able to absorb more fat when it has the highest amounts of charged amino acids in such as aspartic acid, glutamic acid, lysine and arginine. The results of the OAC are shown in Table 4.5 and Figure 4.9 that the feathers have the highest value (8.36 ml/g) and the intestines are 5.75 ml/g. The lowest OAC value is 2.03 in head and feet and also it lower than the results in referred journal. Based on the journal referred, there are no results for WHC for the intestines and feathers.

Figure 4. SEQ Figure_4. * ARABIC 9: The Comparison of OAC Results Between Three SamplesBased on the experimental results obtained, the chicken by-products have higher potential as animal feed sources when compared to the nutrient composition of current animal feed.
CHAPTER 5CONCLUSIONAs conclusion, the physicochemical and functional properties of chicken by-products (head, and feet, intestines and feathers) are determined by conducting some analysis. Based on the results in Table 4.3, the weight of by-products which includes head, feet, intestines, and feathers are 45g, 65g, 152g, and 96g. Besides, the experimental results of chemical properties are shown in Table 4.4. The moisture content of chicken by-products are 4.78% (head ; feet), 83.69% (intestines), and 13.1% (feathers). Moreover, the crude protein of head ; feet, intestines, and feathers are 87.36%, 12.59%, and 82.43%. Furthermore, the fat content of head ; feet is 0.81%, meanwhile the fat content of intestines and feathers are 1.45% and 0.08%. The percentage of crude fiber content of head ; feet, intestines, and feathers are 0, 0.2, 0. In addition, the carbohydrates of chicken by-products such as head ; feet, intestines, and feathers are 2.59%, 0.69%, and 3.49%. Next, the calorific value of head ; feet is 5723.32 Cal/g meanwhile the intestines have 6826.87 Cal/g of calorific value. Thus, the chicken head and feet are the high potential as a protein source of animal feed among the others because their high crude protein content. Based on subtopics 2.5 of literature review, the experimental results of physicochemical properties of chicken by-products are higher than the nutrient composition of current animal feeds. Moreover, the theoretical results from previous journal and the results obtained are almost same. Consequent, the chicken by-products such as head, and feet, intestines and feathers have potential as a source of animal feed and value added to the current animal feed. Besides, the utilisation of chicken wastes can reduce the pollution occurs and preserve the environment for future. This is also can resolve the problem of increasing the amount of chicken wastes from day to day.This can reduce the cost of imported raw materials from to produce animal feed. But there are some factors that cause the feathers not being as a source of animal feed due to very little information existing regarding the nutrient content of the product and its convenience and still not enough technology in Malaysia to process the feathers.

5.1 Recommendation
For further study, a recommendation can be proposed to improve the research for chicken by-products as animal feed by conducting the analysis in order to determine anti-nutritional or toxic factor.