Microwave- assisted alkylation of pectin and its properties

In order to investigate the feasibility of microwave radiation for assisting alkylation of pectin,the influence of ratio of pectin to bromohexane,microwave power and radiation time on the degree of substitution( DS),as well as the physicochemical properties of alkylated pectin were studied.The results showed that the DS was increased first and reached a plateau value with the increase of the ratio,microwave power,and radiation time.When reaction took place at molar mass ratio of pectin to bromohexane 1 ∶1,and 320 W for 240 s,the DS reached 4.81%,which were superior to that obtained by 24 h traditional method( DS = 3.60%).This results indicated that microwave radiation can improved the DS of alkylated pectin within a shorter processing time. With the increase of DS,microwave- assisted alkylated pectin had higher apparent viscosities,emulsifying capacity( EC) and emulsion stability( ES) compared with original pectin.The maximum EC and ES of microwave- assisted alkylated pectin could reach 57.29% and 93.61%,which was better than that of traditional prepared pectin and the original one.