الفهرس 
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Abstract
This study was designed to evaluate chemical composition of raw crayfish, crayfish puree, crayfish burger and crayfish nuggets as untraditional product of new and cheap animal protein to cross-gap in protein deficiency by using crayfish, which is considered as waste resource in Egypt. Physical and chemical properties were determined. It was found that yield of raw tail meat of raw crayfish was about 3.98g being 15% of total weight and it had a high amount of protein (81.13%) and pH value of raw crayfish recorded 7.87. On the other hand, crayfish puree recorded 48.85% protein and pH value was 7.29, while crayfish burger and nuggets recorded 60.27and 61.05 % of protein, and pH values were 7.96 and 7.98, respectively. Also, the present study showed that heavy metals concentration in raw crayfish and crayfish products (puree, burger and nuggets) Lead, Zinc and Copper were in the permissible limits. While T.V.N levels were 12.95 mg/100 g protein for raw crayfish and and 2.89, 5.88 and 6.02 mg/100 g protein for crayfish puree, crayfish burger and nuggets, respectively. Amino acids composition of crayfish and crayfish products (puree, burger and nuggets) presence eight essential amino acids and seven non-essential amino acids. Total essential amino acids in raw crayfish were 46.61 % and total Non-essential amino acids were 53.38%. While, total essential amino acids in crayfish puree were45.12% and total Non-essential amino acids were 54.48%, while, total essential amino acids in crayfish burger and nuggets were 44.55and 45.89%, respectively and total non-essential amino acids were 55.44 and 54.11%. WHC and plasticity values for raw crayfish were 4.85 and 3.14, respectively, and 4.42 and 3.96 for crayfish puree. WHC values were 4.17 and 4.23 for crayfish burger and crayfish nuggets%, respectively. While plasticity values were 4.23 and 4.58, respectively. The results of the sensory evaluation showed that over all acceptability of the products puree, burger and nuggets was 88, 85 and 84.30 respectively, compared with some fishery products in the market, fish burger and fish nuggets. Over all acceptability for these products was 83.8 and 82.3, respectively.
Results of texture profile analysis showed that crayfish products was acceptable as a high quality product. Total count of bacteria of raw crayfish (5.3× 10³ cfu/g) is higher than that of crayfish product (puree, burger and nuggets), total count of bacteria of crayfish puree was (2.2×10³ cfu/g). While, total count of bacteria of crayfish burger and nuggets were (3.3×10³ and 3.6×10³cfu/g), respectively. While, E coli and salmonella sp were not detected in raw crayfish and crayfish products (puree, burger and nuggets) samples. A sensory evaluation of crayfish products showed that overall acceptability recorded 88.00, 85.00 and 84.30% for crayfish puree, crayfish burger and crayfish nuggets, respectively. Crayfish products (puree, burger and nuggets) were highly accepted for act as marketing product.