89B-35 |
|
S.-M. CHO1, C.-I. Ji2, Y. S. Gu3, J.-W. Woo4, Y.-B. Lee5, and S.-B. Kim5. (1) Dept. of Food Science and Technology /Institute of Seafood Science, Pukyong National Univ., 599-1, Daeyeon-3-Dong, Nam-Gu, Pusan, 608-737, (2) Dept. of Food Science & Biotechnology, Pukyong National Univ., 599-1, Deayeon-3-Dong, Nam-gu, Pusan, 608-737, South Korea, (3) Dept. of Food Science, Univ. of Massachusetts, Amherst, 238 Chenoweth Lab., Amherst, MA 01003, (4) Faculty of Food and Biotechnology /Institute of Seafood Science, Pukyong National Univ., 599-1, Deayeon-3-Dong, Nam-gu, Pusan, 608-737, South Korea, (5) Faculty of Food & Biotechnology /Institute of Seafood Science, Pukyong National Univ., 599-1,Deayeon-3-Dong, Nam-gu, Pusan, 608-737, South Korea Commercial mammalian gelatins have some disadvantages because of bovine spongiform encephalopathy and limited supply. For these reasons, current trends necessitate research into the development of new gelatin sources for replacement of mammalian gelatins. Bone and skin of fish, by-products from fishery processing, have potential for replacing mammalian gelatin. Quality of yellowfin tuna (Thunnus albacares) skin gelatin was compared with mammalian gelatins by measuring proximate composition, pH of gelatin solution, amino acid composition, SDS-PAGE and gelling properties. The preparation of gelatin from yellowfin tuna skin was performed by alkali treatment and hot-water extraction. Moisture, crude protein, lipid, and ash contents were estimated by the AOAC official method with three replicates. SDS-PAGE was performed by using a Mini-Protean 3. Amino acid analysis was done by an amino acid autoanalyzer after acid hydrolysis. Gel strength was determined according to the AOAC official method, using a rheometry. All experiments were analyzed by using SAS software. Ash content of yellowfin tuna skin gelatin was similar to the two mammalian gelatins. Amounts of amino acid chains, components of yellowfin tuna skin gelatin were higher than those of the 2 mammailan gelatins. Yellowfin tuna skin gelatin had the lowest amino acid (proline and hydroxyproline) content, which was consistent with that of other fishes. However, yellowfin tuna skin gelatin was highest in glycine, alanine, and lysine. The gel strengths of all gelatins were proportional to the concentration of gelatin, but yellowfin tuna skin gelatin exhibited the greatest gel strength at each concentration. Yellowfin tuna skin gelatin required a longer maturation time than the two mammalian gelatins to form a firm gel. Higher heating temperature decreased the gel strength of yellowfin tuna skin gelatin more than in the 2 mammalian gelatins. Yellowfin tuna gelatin has higher gel strength than 2 others, and gelling and melting points are also higher than that of other fish gelatins. The high gel strength of yellowfin tuna skin gelatin may expand the range of industrial applications for fish gelatins.
Session 89B, Aquatic Food Products: Surimi, gels and by-products
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |