The effect of processing conditions on the properties of gelatin from skate (Raja Kenojei) skins

Department of Food Science and Technology and Institute of Biotechnology, Chonnam National University, 300 Yongbong-dong Buk-gu, Gwangju 500-757, South Korea; Department of Animal Science, Chonnam National University, 300 Yongbong-dong Buk-gu, Gwangju 500-757, South Korea; Virginia Tech. and Virginia Seafood, Agricultural Research and Extension Center, Hampton, VA, 23669, USA
Food Hydrocolloids 01/2006; DOI: 10.1016/j.foodhyd.2005.08.002

ABSTRACT Effects of several conditions (liming concentrations, extraction solution pH, extraction temperature and extraction time) to extract gelatin from skate skin on the yield and quality properties were investigated. The optimum conditions for gelatin extraction are as follows; place skin in a lime solution of 1.5% (w/v) calcium hydroxide, extract with three volumes of water (pH 6.0) for 4 h at 50%, filter gelatin through activated carbon (250–350 mesh, 3%) and freeze-dry the colloidal suspension. The functional properties of skate skin gelatin produced by optimum extraction conditions were: gelling point 16.12 °C; melting point 19.30 °C; isoelectric point 6.45; and turbidity 6.98.

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