CHANGES OF SDS-PAGE PATTERNS OF SOYMILK PROTEIN AND TRYPSIN INHIBITOR ACTIVITY INDUCED BY HEATING
- VernacularTitle:豆奶蛋白组分和胰蛋白酶抑制剂活性的热变化
- Author:
Huihua HUANG
;
Kinchor KWOK
;
Hanhua LIANG
;
Kongrong GAO
;
- Publication Type:Journal Article
- Keywords:
soymilk;
thermal treatment;
SDS PAGE;
trypsin inhibitor;
sulfhydryl bond
- From:
Acta Nutrimenta Sinica
1956;0(02):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To evaluate the heating effects on SDS PAGE patterns of soymilk protein, trypsin inhibitor activity and sulfhydryl bond content in soymilkMethods: Soymilk samples were heated at 95 ℃,120 ℃ and 140 ℃.SDS PAGE was adopted to detect the pattern changes of soymilk proteins after heating and ? mercaptoethanol pretreatment. Trypsin activities were analyzed to detect the changes of trypsin inhibitor activities. Ellman method was used to detect sulfhydryl bond.Results: The protein bands of 7,8,11,12,13,14,15,16 disappeared and one new band(band 17)with Mr of 104 620 appeared in the SDS PAGE pattern of soymilk proteins after heated at 95 ℃,120 ℃ and 140 ℃. The sulfhydryl bond content decreased after heating and this change contributed to the pattern change of soymilk protein by ? mercaptoethanol pretreatment and by determining the sulfhydryl bond content. The holding time to inactivate 90% of soy bean inhibitor activity at 95 ℃ ,120 ℃ and 140 ℃ were 35 min, 7 min and 60 s respectively.Conclusion: Heating treatment may change the sulfhydryl bond and SDS PAGE pattern of soymilk proteins. The TDT curve indicates that the holding time required to inactivate 90% of soybean trypsin inhibitor could be reduced ten folds by raising 30 ℃ within the temperature range of 95 140 ℃.
