AuNPs Enhanced Microwave Coupled Lipase Synthesis of Starch Oleate Ester

The nano-gold immobilized lipase (CAL@AuNPs) was prepared to synthesize starch oleate ester efficiently by using pre-treated corn starch and oleic acid as raw materials. Optimisation of the preparation conditions of CAL@AuNPs was carried out using oleic acid conversion rate as an indicator. The substitution degree was used as an indicator to investigate the catalytic efficiency of free enzyme, commercial immobilised enzyme and nanogold immobilised lipase under microwave-assisted conditions. The experimental results showed that the immobilized lipase with the strongest catalytic activity could be obtained by using AuNPs of 14 nm as carrier at 40 ℃ for 6 h. The starch oleate ester with the highest substitution degree of 0.0259 could be prepared by using CAL@AuNPs as catalyst under the condition of 400 W, 35 ℃ for 40 min. Compared with free enzyme, and commercial immobilized enzyme , the CAL@AuNPs could shorten reaction time and improve the degree of substitution.