QUALITY CHANGES OF PAPAYA (CARICA PAPAYA L. 'EKSOTIKA') AS AFFECTED BY DIFFERENT CONCENTRATIONS OF CHITOSAN AND GLYCEROL

Edible coatings are well known to be one of the methods used for preserving fresh produce especially fruits. These coatings are used on many products to control moisture transfer, gas exchange and oxidation process. Plasticizers such as glycerol are added into edible formulations to improve coating properties. Chitosan is a polysaccharide that has the ability to form semi-permeable coatings that can modify the internal atmosphere, and thus reduce respiration rates and consequently delay ripening of fruits. Therefore, the aim of this study was to evaluate the effects of different concentrations of chitosan and plasticizer (glycerol) on changes in the quality aspects of ‘Eksotika’ papaya. Coating formulations made of different concentrations of chitosan and glycerol ranging from 0.5-2.5% w/v and 0-2% w/v respectively were used to coat the papaya. The papayas were kept at ambient (26±1°C; 70±10% RH) condition and evaluated for changes in weight loss, firmness, colour and total soluble solids (TSS) after 5 days of storage. Results obtained show that combination of chitosan and glycerol at different concentrations gave significant (p<0.05) effect to all parameters tested. In general, increase in chitosan concentration with combination of lower glycerol concentration gave desirable changes to the responses tested. They were able to reduce changes in weight loss, firmness, peel colour and TSS of ‘Eksotika’ papaya. However, increasing glycerol concentration at fixed amount of chitosan gave negative effects. Thus, the findings of this study suggest that chitosan in combination with lower glycerol concentration can be used to prolong the shelf life and maintaining the quality of fruit during storage.