RESULTS: This study has shown that lipase-catalyzed esterification of dihydrocaffeic acid with hexanol in ionic liquid (1-butyl-3-methylimidazoliumbis (trifluoromethylsulfonyl) imide) was the best approach for esterification reaction. In order to achieve the maximum yield, the process was optimized by response surface methodology (RSM) based on a five-level and four independent variables such as: dosage of enzyme; hexanol/dihydrocaffeic acid mole ratio; temperature and reaction time. The optimum esterification condition (Y = 84.4%) was predicted to be obtained at temperature of 39.4 °C, time of 77.5 h dosage of enzyme at 41.6% and hexanol/dihydrocaffeic acid mole ratio of 2.1.
CONCLUSION: Finally, this study has produced an efficient enzymatic esterification method for the preparation of hexyl dihydrocaffeate in vitro using a lipase in an ionic liquid system. Concentration of hexanol was the most significant (p
RESULTS: UAE for 15 and 30 min and MAE for 1 and 2 min significantly increased protein yield and extraction efficiency compared to the control. Both UAE and MAE processes, especially MAE for 2 min, greatly improved the emulsifying and foaming properties of extracted proteins. FTAE one and three cycles did not increase the protein yield and extraction efficiency but showed enhanced functional properties, especially foaming. All samples showed changes in protein structure, such as increased exposed sulfhydryl (SH) contents, denaturation temperatures, and enthalpy. Only MAE samples had low-molecular-weight proteins based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. UAE and FTAE samples had significantly higher antioxidant activities, while the MAE process showed the opposite.
CONCLUSION: UAE and MAE processes improved the yield and functionality of extracted silkworm proteins, while MAE negatively impacted protein antioxidant activities. © 2023 Society of Chemical Industry.