Preparation of Maillard Reaction Products and Its Application on Microencapsulation of Mixed Oil

Nowadays,high load oil microcapsules still face the problems such as poor physical and chemical properties,low microencapsulation efficiency,poor flowability and storage stability. In order to overcome these disadvantages,in this study,the Maillard reaction products(MRPs)was prepared by wet method with sodium caseinate and isomaltooligosaccharide,and then MRPs were adopted as wall material for microencapsulating mixed oil,which contained mainly medium chain triglycerides. The microcapsules were prepared with high pressure homogenization and spray drying. The optimal parameters were as follows for Maillard reaction:Sodium caseinate concentration was 7%,the mass ratio of sodium caseinate to isomaltooligosaccharide was 1:3 (g/g),the reaction time was 120 min,pH was 8.0,and reaction temperature was 80℃. For emulsification,2% glycerin monostearate and 1% sucrose fatty acid ester were added as emulsifiers followed by two-stage high pressure homogenization(40 and 18 MPa respectively). The surface oil and microencapsulation efficiency of the microcapsules were 3.01% and 95.66%,respectively.Carr's index and Hausner ratio of the microcapsules were 7 and 1.08,respectively. Besides,the scanning electron microscopyimage of the powder showed that the internal and external structure was smooth and compact. After storage at 60℃ for 30 days,the peroxide value of the mixed oil microcapsule was only 9.06 mmol/kg,and the oil retention rate was 90.57%.The results showed that MRPs can effectively protect the core material components and have a strong antioxidant property. Therefore,this study provides certain industrial guidance value.