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 β 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 β 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 ℃.
| Original language | Chinese (Simplified) |
|---|---|
| Pages (from-to) | 140-144 |
| Number of pages | 5 |
| Journal | 營養學報 (Acta nutrimenta sinica) |
| Volume | 23 |
| Issue number | 2 |
| Publication status | Published - 2001 |
Keywords
- Soymilk
- Thermal treatment
- SDS PAGE
- Trypsin inhibitor
- Sulfhydryl bond