Effect of Peroxidized Lipid on the Protein Isolate and Protease Activity of Rice Bran

미강의 산화 지질이 단백질과 효소의 활성에 미치는 영향에 관한 연구

  • Song, Yeong-Ok (Dept. of Food Science and Nutrition, Pusan National University) ;
  • Choi, Hong-Sik (Dept. of Food Science and Nutrition, Pusan National University)
  • 송영옥 (부산대학교 식품영양학과) ;
  • 최홍식 (부산대학교 식품영양학과)
  • Published : 1990.10.01


The destructive effect of peroxidized lipid on the amino acid in protein isolate and the proteolytic activity of protease were studied in the model system of rice bran. The content of amino acids in the protein isolate decreased significantly when they reacted with peroxidized lipid (pov. 1200 meq/kg). Most of amino acids were lost by more than 90% in salt soluble protein isolates when analyzed by the method of enzyme hydrolysis. Formaldehyde reduced the activity most severely among peroxidized products. Formic acid, peroxidized lipid and hydroperoxide were also found to reduce the protease activity. The damaging effect of the secondary products on the protease activity was more serious than that of the primary products of lipid peroxidation. The destruction of amino acids in the total protein and Inhibition of protease activity by the peroxidized lipid were apparent.