89A-1 |
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C. P. VORHOLT, A. C. M. Oliveira, C. Crapo, B. H. Himelbloom, Q. Fong, and R. RaLonde. Fishery Industrial Technology Center, Univ. of Alaska, Fairbanks, School of Fisheries and Ocean Sciences, 118 Trident Way, Kodiak, AK 99615-7401 Oyster farming is a new and growing enterprise for Alaska's coastal economy. Oyster producers need information related to the intrinsic quality of their product to determine optimal harvest strategies to maximize returns. This 12-month study evaluated changes in the intrinsic quality of commercially harvested oysters from three different regions in Alaska. Oysters were sampled monthly from farms located in Prince William Sound (PWS), Kachemak Bay (KB) and Southeast Alaska (SE). For each region, oyster quality and nutritional value was assessed by measuring proximate composition, glycogen content, fatty acids (FA) profile and three methods for condition index. Protein content ranged from 7.5% to 8.9% for all samples investigated. Average protein content between summer and winter oysters were 8.5g/100 g tissue and 8.1g/100 g tissue, respectively. PWS oysters had little protein variation from September to May with an almost 1% increase during summer months. SE oysters had larger variation in protein content that appeared unrelated to season conditions. KB oysters showed a decrease in protein during spring months. Glycogen content was highly dependent on the elapsed time between harvest and shipment arrival dates. Glycogen decreased slightly during winter months. Condition index could not predict oyster quality as effectively as proximate composition and glycogen content. In PWS, KB, and SE oysters, a decrease in polyunsaturated FA was recorded during the summer with a decrease of saturated FA during winter months. Omega-3 FA levels were high throughout the year and ranged from 40.9% to 48.2% of total lipids, regardless of region. Eicosapentaenoic acid and docosahexaenoic acid ranged from 17.7% to 24.9% and 12.9% to 20.9%, respectively. Omega-6 FA content ranged through the year from 3.3% to 7.6%, regardless of farm location throughout the year. Our results suggest that Alaskan maricultured oysters have expected seasonal differences with slight regional variation.
Session 89A, Aquatic Food Products: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |