Changes in Quality and Bioactive Compounds of ‘Nam Dok Mai’ Mango Coated with Chitosan-based Multicoating During Retailing

Rapid physiological changes during retailing of ‘Nam Dok Mai’ mango (Mangifera indica L.) lead to deterioration and nutrition value loss. In postharvest fruit management, chitosan was used widely to be coating materials integrated with other solutions for maintaining the quality of many fruits. This research investigated the suitability of the molecular weight and concentration of chitosan, bound with a layer of 0.5% (w/v) polystyrene sulfonate (PSS) coated on mango fruit a multilayer coating. Chitosan solutions (CTS) were prepared from the high molecular weight (500-700 kDa; H-CTS) and medium molecular weight (310-375 kDa; M-CTS) at 2 concentrations of 0.5% and 1% (w/v). Mature green ‘Nam Dok Mai’ mangoes were coated layer by layer as CTS/PSS/CTS and then incubated at 25°C, 65-70% RH.  The results showed that the concentrations of chitosan affected mango quality more than the molecular weight. Mango coated with 0.5%M-CTS/0.5%PSS/0.5%M-CTS effectively maintained the fruit quality, especially weight loss, and firmness loss. Increasing total soluble solids, peel and pulp color changes, disease incidence, and reducing antioxidant compounds (phenolic content, flavonoids content, and DPPH activity) were significantly high in uncoated fruits.