17E-6 |
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S. SATHIVEL, Fishery Industrial Technology Center, Univ. of Alaska, Fairbanks, School of Fisheries & Ocean Sciences, 118 Trident Way, Kodiak, AK 99615-7401 and P. J. Bechtel, Subarctic Agricultural Research Unit, USDA-ARS-Pacific West Area, Univ. of Alaska, Fairbanks, 245 O'Neill Bldg., Fairbanks, AK 99775-7220. Three times as much pollock (Theragra chalcogramma) is harvested as salmon or cod from Alaska waters. The byproduct yield from pollock processing was estimated to be approximately 66%. Many Pollock byproducts from fish filleting processing can be used directly as foods or further processed to make food ingredients, provided they are handled in the appropriate manner. Proteins can be extracted from byproducts and separated into water soluble and insoluble fractions. The objectives of this study were to isolate the insoluble protein fraction from different Pollock byproducts and evaluate the physicochemical and functional properties of the protein powders. Byproducts used for recovering the insoluble protein fraction included Pollock viscera, heads, frames, trimmings, gonads, and livers. The samples were separately minced, and water was added (water:mince=1:1, V/W). The mixtures were heated at 85oC for 60 minutes and after centrifugation the insoluble protein fractions were recovered and freeze dried. Physicochemical and functional properties of the protein powders were evaluated. The yield of insoluble proteins from Pollock byproducts ranged from 11 –31%. The fat absorption (mL/ g of protein) of insoluble protein powders from viscera, heads, frames, trimmings, gonads, livers, was 11.5, 3.7, 3.4, 2.4, 4.3, and 11.7, respectively. Emulsifying stability (%) of insoluble protein powder from Pollock byproducts ranged from 65-100%. The highest water adsorption capacity (7.1-7.3 mL/ g of protein) was from frame and gonad insoluble protein powders. The amino acid profiles of the insoluble protein powders indicated high quality protein and the mineral content of all samples were determined. Differences (p>0.05) were detected between chemical and functional properties of insoluble protein powders from different Pollock byproducts. The insoluble protein powders had many desirable chemical and functional properties.
Session 17E, Food Chemistry: Proteins
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