Abstract:Ferulic acid starch ester （FASE）was biosynthesised by lipase as the catalysis under the microwave in non-aqueous system.The pretreatment starch and ethyl ferrate was used as the substrate.Gold nanoparticles（AuNPs）has been added to improve the degree of substitution （DS）of ferulic acid starch ester.It was found that the addition of AuNPs could not significantly change the enzymatic reactivity under conventional heating，but the DS of FASE could be significantly increased in microwave reactor when the synthesis of FASE was catalyzed by lipase.At this point，the amount and the size of AuNPs had a significant impact on the enzymatic.The degree of substitution of the product was determined by ultraviolet spectrophotometer.The effect of reaction reaction conditions on the synthesis of FASE was studied by using DS of ferulic acid starch ester as index.When the microwave power was 80 W，the reaction time was 120 min，the size of AuNPs was 700 nm，and the amount of AuNPs was 0.8%，the DS of FASE was as high as 0.179 8，which is an order of magnitude higher than the existing research.It also greatly reduced the reaction time.The FASE was qualitative analyzed by ultraviolet spectrophotometer and1H NMR.