Shelf life extension of mangosteen by chitosan coating

Mangosteen is one of the economically important fruits of Thailand, which has a problem of short shelf life. This study investigates this problem through the application of chitosan to the fruit. Chitosan, a natural polysaccharide, is derived from crustacean shells and cephalopod pens. Chitosans applied in this study were obtained from crab shell (Cr, 89% degree of deacetylation, DD), shrimp shell (Sh, 89.2% DD), and squid pen (Sq, 85% DD). All chitosan types were dissolved in 1% acetic acid at the designated concentration (%, w/v) before spraying on the mangosteen. Six treatments were set up using 5 kg each of mangosteen. Those experiments were two controls (no spraying and spraying with 1% acetic acid) and four treatments (1% Sh, 2% Sq, 1% Cr, and 2% Cr). After drying, mangosteens were put into plastic bags and then kept at 10degreesC. The quality indices of mangosteen were hardening of the fruits, fruit color, and taste and juiciness of the flesh. Results showed that the most effective chitosan type and concentration was 2% Cr, which could extend the shelf life of mangosteens to more than 23 days with hardening of only 12%, compared to the control with a shorter shelf life with 22% hardening. This preliminary study has shown that chitosan can be applied as a tool for eradicating the post-harvest loss of mangosteen. Further experiments are needed on other chitosan types, packaging systems, and storage conditions for shelf-life extension.