Optimization of Cross-Linked Cassava Starch Coating Formulation by Response Surface Methodology and Its Preservation Effects on ‘Shatangju’ Mandarin

Abstract

In this study, cassava starch cross-linked with sodium trimetaphosphate was used as the base material to prepare the preservative coating. Addition levels of β-cyclodextrin, phytic acid, and glycerol were optimized using integrated index oil permeability (OP) and water vapor permeability (WVP) response surface methodology of a starch-based coating. The optimal composition of the cross-linked cassava starch coating was as follows: 3 g/100 g cross-linked cassava starch, 0.7 g/100 g β-cyclodextrin, 0.5 g/100 g phytic acid and 0.5 g/100 g. glycerin. A conservation coating solution prepared according to an optimized formula was used for post-harvest storage of Shatanju variety tangerines. The coating treatment effectively slowed down the decrease in hardness during storage for 20 days at room temperature, reduced the rate of decay (by 111.73%) and the rate of weight loss (by 43.40%), and also inhibited post-harvest respiration (by 42.06%) fruits . The content of soluble solids, titratable acidity and ascorbic acid content of tangerines of the Shatanju variety in the shell were higher by 1.32 times, 1.55 times and 1.52 times, respectively, compared with the corresponding indicators of control fruits. All these results indicate that coating treatment can effectively reduce nutrient loss, delay wilting and rotting, extend post-harvest shelf life, and enhance the commercial value of Shatanju mandarins.