83A-20 |
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J. JACZYNSKI, Div. of Animal & Veterinary Sciences, West Virginia Univ., G-038 Agricultural Sciences Bldg., PO Box 6108, Morgantown, WV 26506-6108 and S. Beamer, Animal and Veterinary Sciences, West Virginia University, PO Box 6108, Morgantown, WV 26506. Aquaculture has grown four times since 1980, supplying 30% of demand for aquatic foods. Inactive mines in West Virginia (WV) have water discharge ideal for Rainbow trout. Mining companies must reclaim post-mine land. Aquaculture has been approved as post-mine land reclaimation. Therefore, aquaculture in WV is growing rapidly. Mechanical filleting yields 40% fillets from raw trout. Meat left on by-products accounts for 40% of fillets. The isoelectric solubilization/precipitation of muscle proteins offers high recovery yields. Therefore, this technology if applied to trout processing by-products may recover valuable proteins. Our objectives were to determine: (1) solubility of myofibrillar and sarcoplasmic proteins as a function of pH and ionic strength (IS); (2) protein and lipid recovery yields; (3) fatty acid profile (FAP) of recovered lipids; (4) texture and color of gels developed from recovered proteins. Myofibrillar or sarcoplasmic proteins were subjected to 1.5<pH<13.0 and 0.05<IS<3.0. Concentrations of soluble proteins determined using Bradford method were plotted, resulting in protein solubility profiles. The Kjeldahl and Soxhlet methods were used to estimate crude proteins and total lipids, respectively. The recovery yields were calculated as an output of proteins or lipids divided by an input of proteins or lipids. FAP was determined using gas chromatography. Gel texture was determined using Kramer cell and texture profile analysis (TPA). Color was determined using L*a*b* values. While protein solubility was highest at pH 2.0-3.0 and 12.0-13.0, the precipitation was highest at pH=5.5. Protein recovery yields were between 80-90% for 2.0<pH<3.0 and 75-85% for 12.0<pH<13.0. The w-3 and w-6 FA were slightly degraded by 2.0<pH<3.0 and 12.0<pH<13.0. The TPA and Kramer cell showed that gels were very firm; with high gumminess and chewiness values. Our data indicates that the isoelectric solubilization/precipitation can be applied to recover functional trout muscle proteins. This technology also yields good quality fish lipids.
Session 83A, Aquatic Food Products: Byproducts, mince and surimi
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