Improvement on Textural Properties of Soybean Curd by Freeze Denaturation of Soybeans

대두의 동결처리에 의한 두부의 텍스쳐 특성의 증진

  • Baik, Sang-Ho (Department of Food Science and Technology, Chonbuk National University) ;
  • Kim, Myung-Kon (Department of Food Science and Technology, Chonbuk National University) ;
  • Yun, Sei-Eok (Department of Food Science and Technology, Chonbuk National University) ;
  • Joo, Hyun-Kyu (Department of Agricultural Chemistry, Kon-Kuk University)
  • Published : 1996.04.30

Abstract

Effect of freezing of soybeans on instrumental and sensory textures of soybean curd was investigated. The hardness, gumminess and chewiness of soybean curd prepared with frozen soybeans were about three times as high as those prepared with unfrozen soybeans, while cohesiveness and elasticity were affected little by freezing. Sensory evaluation showed that freezing improved the quality of soybean curd. Instrumental and sensory textures of soybean curd prepared with frozen soybeans were excellent and almost same regardless of the boiling time when the soy slurry was boiled for 2.5 min or 5 min. However, the textures of soybean curd prepared with unfrozen soybeans were deteriorated by reducing the boiling time to 2.5 min. It was postulated that freezing facilitate the heat-denaturation of soyprotein to enhance aggregation of soy proteins and formation of cross-linkage between aggregate and $Ca^{++}$. Frozen soybeans resulted in soybean curd which lower fat content, while protein content of soybean curd was almost he same. Frozen soybeans gave a lower yield of soybean curd, which is supposed to be caused by the more fat loss during whey-off.

Keywords

freezing;soybean;soybean curd;textural properties