Abstract:Enzyme kinetics and spectroscopic analyses were performed to determine the inhibitory effects of ginger juice on α-glucosidase activity and possible inhibitory substances involved were explored. The results showed that the inhibitory effect of Shandong ginger juice on α-glucosidase activity was the best, with an inhibition rate of 73.38%. The results of enzyme kinetics and Lineweaver-Burk double reciprocal analysis showed that the inhibitory effects of ginger juice on α-glucosidase activity were reversible and competitive. The inhibition rate of ginger juice on enzyme activity decreased to 46.5% of the initial inhibition rate after 3 days of storage at 5 ℃. Enzyme activity inhibition rates of stored ginger juice during heat treatment first increased before decreasing. Analysis of components separated by ultrafiltration showed that inhibition rate (67.16%) of the MW≥10 ku component in ginger juice was the highest among components. This indicates that the substances with enzyme inhibiting activity were mainly concentrated in the MW≥10 ku component of ginger juice. In the mixed system of ginger juice and α-glucosidase, the absorbance value of ginger juice components decreased significantly in the ultraviolet absorption spectrum of 240~280 nm, indicating that the components with inhibitory activity in ginger juice were distributed in this band. The results of this study provide a theoretical basis for further research on the hypoglycemic activity of ginger juice as well as the development of further processed products.
