89B-9 |
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Y.-X. SHEN1, Z. Wang1, Y.-F. Fu1, and Y. Zhao2. (1) College of Food Science, Shanghai Fisheries Univ., 334 Jungong Road, Shanghai, 200090, China, (2) Dept. of Food Science & Technology, Oregon State Univ., 100 Wiegand Hall, Corvallis, OR 97331-6602 Collagens isolated from land-based animal skins have been widely used in pharmaceutical, food, healthcare, and cosmetic industry. However, the incidence of bovine spongiform encephalopathy and foot and mouth disease has raised concerns in their safe applications. Fish skin collagen, a waste product in fish processing, may be a good substitute because of its safety and solubility in neutral salt solution and dilute acids. However, freshwater fish skin has not been utilized rationally in China. The development of fish skin-based collagens would add significant value to the fish processing industry. Our objectives were to study the isolation of collagens from freshwater fish skins and to investigate their physicochemical properties. Collagens were prepared from 3 types of freshwater fishes: silver carp, bighead carp, and grass carp. Soluble non-collagenous proteins were removed by stirring fish skins in 1 to 7.5% NaCl solutions for 12 hr at 5o C twice. Collagen was extracted by swelling and homogenizing in 0.5M acetic acid, 0.1M citric or lactic acid, and purified by vacuum filtering, salting-out, dialyzing and lyophilizing. Collagen contents were determined by measuring hydroxyproline content. The SDS-PAGE, amino acid pattern, intrinsic viscosity and thermal stability of collagen preparations were also evaluated. Results showed that acid extraction resulted in a 79 to 84% collagen recovery rate from fish skins. The collagen preparations showed no non-collagenous protein peak in UV-scanning spectrums. The SDS-PAGE indicated that collagen isolated from three fish skins is type I collagen, with the structure of [945;1(I)2945;2(I)]. The collagen has intrinsic viscosity of 13.5 ±0.4dl/g, shrinkage temperature of 47.8±0.8o C, and denaturation temperature of 28.0±0.6o C. Results suggest that organic acid extraction is an effective method to prepare collagens from freshwater fish skins. The fish collagens may be used as a substitute for land-based animal collagens for enhancing food safety and adding value to the fishery processing industry.
Session 89B, Aquatic Food Products: Surimi, gels and by-products
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |