Comparative study of enzymes inactivation and browning pigmentation of apple (Malus domestica) slices by selected gums during low temperature storage

To compare and understand the ameliorative effect of coating gums and predict accurately the enzymes inactivation and browning pigmentation of apple slice in cold storage condition, this study was conducted. Three gums (Acacia senegal, Xanthan, and Karaya) coating and distilled water (used as control) were applied to apple slices and stored for 21 days. A significant (p < 0.05) reduction in polyphenol oxidase, peroxidase, and ascorbic acid oxidase activities were achieved by these gums. The effectiveness of these gums in resisting the enzymes activities follows the order: Xanthan > Acacia > Karaya. The results show that modified second-order polynomial model and Zero-order kinetic model could satisfactorily describe the kinetic inactivation of enzyme activities with high R-2 (0.9524-0.99337) and browning indexes with highest R-2 values (0.94164-0.99135) and lowest values in chi(2) (0.00183-0.00346) and RMSE (0.01100-0.20536), respectively. Considering the total color change (Delta E), Xanthan coating gums had lower.E value compared to others.