Influences of Extraction pH on the Functionality of Soybean Protein Isolate

추출 pH가 분리대두단백질의 기능성에 미치는 영향

  • Bae, Song-Hwan (Institute of Natural Resources, Korea University) ;
  • Rhee, Chul (Department of Agricultural Chemistry, Korea University)
  • 배송환 (고려대학교 자연자원연구소) ;
  • 이철 (고려대학교 응용생명환경화학과)
  • Published : 1998.06.01

Abstract

This study was conducted to investigate the functionality of soybean protein isolates extracted in acidic range (pH 2.0 and 3.0), neutral range (pH 7.0) and alkaline range (pH 10.0 and 12.0). The protein content of soybean protein isolates extracted at pH 3.0 was maximum (93.31%), but that of pH 7.0 was minimum (73.93%). The extraction yield of soybean protein isolates extracted at pH 3.0 was minimum (0.36%), but that of pH 12.0 was maximum (47.54%). The functionality (solubility, water absorption, oil absorption, foam capacity, foam stability, emulsion capacity and gelation) of soybean protein isolates was significantly influenced by pH of extraction medium. The soybean protein isolates extracted at pH 2.0 and 3.0 were more soluble at acidic ranges and those of pH 3.0 and 7.0 were more soluble at neutral ranges, but those of pH 2.0, 3.0, 7.0, 10.0 and 12.0 were more soluble at alkaline ranges than other ranges. The soybean protein isolates extracted at pH 2.0 and pH 12.0 gave greater water absorption, oil absorption and foam capacity than those extracted at pH 3.0, pH 7.0 and pH 10.0. And the emulsion capacity of soybean protein isolates was increased by the increase of extraction pH.