Effect of Coagulants on the Quality of Soybean Curd Added With Cow's Milk

응고제가 우유 첨가 두부의 품질에 미치는 영향

  • Kim, Tae-Young (Agricultural Science Institute, Rural Development Administration) ;
  • Kim, Joong-Man (Department of Agricultural Chemistry, College of Agriculture, Wonkwang University) ;
  • Cho, Nam-Jun (Agricultural Science Institute, Rural Development Administration)
  • 김태영 (농촌진흥청 농업기술연구) ;
  • 김중만 (원광대학교 농화학과) ;
  • 조남준 (농촌진흥청 농업기술연구)
  • Published : 1994.10.31

Abstract

Soybean curd added with 40% of cow’s milk was prepared with eight coagulants such as calcium acetate, calcium lactate, calcium chloride, calcium sulfate, magnesium chloride, glucono-delta lactone (GDL), acetic acid and lactic acid. The curd products were evaluated by the chemical composition, coprecipitation porperties, mineral content, yield, color and textural characteristics. The lowest concentrations for protein coprepitation were 0.3% (v/v) for calcium salts, 0.4% (v/v) for magnesium chloride, 0.2% (v/v) for organic acids. Turbidity and crude protein of whey were markedly decreased at these concentrations. The optimal concentrations of coagualnts used for soybean curd preperation were 1.2% (v/v) for calcium acetate, calcium sulfate and calcium lactate, 1.0% (v/v) for calcium chloride and GDL, 0.8% (v/v) for magnesium chloride and lactic acid, 0.6% (v/v) for acetic acid. It was observed that of the eight coagulants tested, calcium chloride provided a satisfactory curd in quality. Calcium content of soybean curds by the calcium salt coagulants was higher than that by organic acid coagulants. Through the examination on the textural properties by a texturemeter was found out that acetic acid treated soybean curd among the organic acids, calcium salts and magnesium chloride treated curds had very high hardness value. All the curd products prepared in this experiment had a pale yellow color as affected by the value of L (lightness), a (redness) and b (yellowness). Although the colorimetric readings showed that the soybean curds prepared with the organic acids had higher L value but lower a and b value in comparison to calcium salts and magnesium chloride treated curds.