| The soybean protein isolate(SPI) and chitosan(CS) were used to establish Maillard reaction system. Using DPPH free radical scavenging rate, superoxide anion free radical (O-2·) scavenging rate and antibacterial activity against bacteria, including Escherichia coli, Staphylococcus aureus, and Salmonella as detection indicators, the four factors of reaction temperature, reaction time, relative humidity and mass ratio of SPI to CS of preparing Maillard reaction products(MRPs) with high grafting degree, strong antioxidant activity and antibacterial activity respectively were optimized through single factor experiment and orthogonal experiment. The results showed that when the reaction temperature was 80 ℃, the relative humidity was 51.4%, the reaction time was 5 h and the mass ratio of SPI to CS was 1∶ 1, the grafting degree was the highest, reaching 65.13%. When the reaction temperature was 90 ℃, the relative humidity was 51.4%, the reaction time was 6 h and the mass ratio of SPI to CS was 1∶ 1.5, the DPPH· scavenging rate of MRPs was the best(95.63%). When the reaction temperature was 90 ℃,the relative humidity was 61.0%, the reaction time was 7 h and the mass ratio of SPI to CS was 1∶ 1.5, the O-2· scavenging rate of MRPs was the highest(91.93%). When the reaction temperature was 100 ℃, the relative humidity was 51.4%, the reaction time was 6 h and the mass ratio of SPI to CS was 1∶ 1.5, MRPs had the strongest antibacterial effect on E.coli; when the reaction temperature was 100 ℃, the relative humidity was 73.9%, the reaction time was 7 h and the mass ratio of SPI to CS was 1∶ 2, MRPs had the strongest antibacterial effect on Staphylococcus aureus; when the reaction temperature was 100 ℃, the relative humidity was 26.1%, the reaction time was 3 h and the mass ratio of SPI to CS was 2∶ 1, MRPs had the strongest antibacterial activity against Salmonella. The results showed that by controlling the reaction conditions, the strength of each functional property of MRPs could be adjusted within a certain range to meet different actual needs. |
