79-8 |
|
A. JONGJAREONRAK, Department of Food Technology, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand, S. Benjakul, Dept. of Food Technology, Prince of Songkla Univ., Hat Yai, Songkhla, 90112, Thailand, W. Visessanguan, Food Biotechnology Lab., National Center for Genetic Engineering & Biotechnology, 113 Paholayothin Rd., Klong 1, Klong Luang, Pathumthani, 12120, Thailand, and M. Tanaka, Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Kanan4, Minato-KU, Tokyo, 108-8477, Japan. Collagen and gelatin of land animal origin have been widely used in food and pharmaceutical industries. However, the outbreak of mad cow disease has resulted in anxiety among users of cattle gelatin. Additionally, porcine collagen can not be used for some foods due to religious reason. Therefore, alternative sources, especially fish processing wastes including skin, bone or scale, have been paid increasing attention for collagen and gelatin extraction. Our objective was to isolate and characterize collagen from the skin of bigeye snapper (Priacanthus marcracanthus), which is an abundant fish species used for surimi production in Thailand. Acid-solubilized collagen (ASC) was extracted from fish skin using 0.5 M acetic acid. Pepsin solubilized collagen (PSC) was recovered from undissolved residue after acid extraction by limited digestion with pepsin. Protein pattern of collagen was revealed using SDS-PAGE. Peptide mapping were performed using V8 protease and lysyl endopeptidase. Thermal transition was analyzed by DSC. Solubility at various pHs and salt concentrations was determined in 0.5 M acetic acid. ASC and PSC were isolated with the yields of 6.4% and 1.1% on the basis of wet weight, respectively. Both collagens were characterized to be type I without disulfide bond. Peptide map of ASC and PSC showed some differences and were totally different from those of calf skin collagen. The maximum solubility was observed at pH 4 and 5 for ASC and PSC, respectively. The sharp decrease in solubility was found with NaCl concentration above 3% (w/v). Tmax of ASC and PSC were 30.37 and 30.87oC, respectively, which was relatively higher than that of temperate fish collagen. Therefore, bigeye snapper skin is a promising new source for collagen or gelatin, which can be extracted as the value-added products from fish processing wastes. Furthermore, disposal of those wastes can be minimized, leading to the lowered pollution problems.
Session 79, Food Chemistry: Protein and enzyme chemistry
|