89B-32 |
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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. The Alaska pollock (Theragra chalcogramma) harvest was 1.4 million metric tons in 2003. It has been estimated that the yield of byproducts from processing is 66% or 924,000 metric tones. At present, pollock fish processing byproducts and byproducts from other coldwater marine species are made into fish meals and oils or discarded. The objective of this study was to extract protein from pollock heads (PH), whole pollock (PW), pollock viscera (PV), and pollock frames (PF) using alkali extraction procedures and characterize the freeze-dried fish protein powders. PW and pollock byproducts were collected from fully automated commercial processing lines and stored at –20oC until thawed for protein extraction. Byproducts were homogenized in 9 volumes of water, proteins solubilized at pH 11, insoluble protein removed after centrifugation, and soluble protein precipitated at pH 5.5. The precipitated soluble protein was collected by centrifugation and freeze dried Yields were determined and samples analyzed for proximate composition, mineral and amino acid contents, solubility, emulsion stability and fat adsorption properties, and SDS-PAGE electrophoresis. PF and PH had higher protein content than the PW and PV. PV powder had a higher lipid content than the other protein powders. Protein powders produced from PH were lighter (L*=49) than protein powders from the PV (L*=39.1), PH (L*=43.1), and PW (L*=43.2). The highest emulsifying stability value was observed for PH powder (79.4%), while PV had highest fat adsorption capacity (12.8 mL of oil/g protein) and density (0.3 g/mL). All protein powders had desirable essential amino acid profiles. Major differences in SDS gel electrophoresis band patterns were observed between samples. The soluble protein powders extracted from pollock byproducts have potential uses as food and feed ingredients.
Session 89B, Aquatic Food Products: Surimi, gels and by-products
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |