45I-18 |
Nutritional properties of protein from Alaska Pollock processing byproducts |
P. J. BECHTEL, Subarctic Agricultural Research Unit, USDA-ARS-Pacific West Area, Univ. of Alaska, Fairbanks, 245 O'Neill Bldg., Fairbanks, AK 99775-7220 The fishery for Alaska Pollock annually generate over 700,000 mt of fish processing byproducts. which include large amounts of viscera, heads, frames, and lesser amounts of skin. These byproducts are easily maintained as separate components during fish processing which could then be used as sources of feed or protein ingredients. The objective of this study was to evaluate some of the nutritional properties of Alaska Pollock byproducts. Three sets of Alaska pollock samples were obtained on separate days from commercial fish processing plants and included; whole fish, heads, viscera, frames, fillets, and skins which were then prepared, and frozen at -80 C. Samples were analyzed for connective tissue content (AOAC meat procedure), pepsin digestibility and calculation of an estimated rat protein efficiency ratio (PRE). Data was analyzed using ANOVA and the Duncan post hoc test and differences reported (p<0.05). The average connective tissue content of the whole fish, heads, viscera, frames, fillets and skins was 6.8%, 9.8%, 1.0%, 7.6%, 1.6% and 45.5%, respectively. Whole fish, heads and frames were similar (p>0.05) and viscera, fillet and skin were each different (p<0.05) from other byproducts. The percent pepsin digestible protein ranged from 92-99% for 0.2% pepsin and 94-99% for 0.002% pepsin, indicating very digestible protein. The calculated rat PER values were 3.0, 2.9, 3.1, 3.0, 2.1 and 3.1 for whole fish, heads, viscera, frames skin and fillet, respectively. Whole fish, heads, and frames were similar (p>0.05) as were viscera and fillet. The connective tissue content of protein from pollock byproducts fell into three general categories which were skin; viscera and fillet; and heads, frames and whole fish. All fish byproduct protein was readily digested by pepsin. These properties are of importance in devising feed ingredients and protein concentrates from pollock processing byproducts.
Session 45I, Nutrition: General
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