EFFECTS OF EDIBLE COATINGS FROM XANTHUM GUM PRODUCED FROM XANTHOMONAS CAMPESTRIS PAMMEL ON THE SHELF LIFE OF CARICA PAPAYA LINN FRUITS

摘要

Xanthan gum is an extracellular hetero polysaccharide produced by Xanthomonas campestris Pammel, 1895, a bacteria species that causes a variety of plant diseases. Due to its unique rheological behavior, xanthan gum is one of the major microbial polysaccharides employed in many industrial processes. The increase in Carica papaya L. fruit production requires new strategies to extend their storage life. Edible coatings when applied on the surface of fruits act as physical barriers which effectively change their internal atmosphere and delay the ripening process. In this study, effect of edible coatings from xanthan gum was investigated on the quality and storability of papaya fruits. A local isolate of the bacterium X. campestris was obtained from infected cabbage leaves and its identity was confirmed by standard microbiological and biochemical tests. Test fruits were surface sterilized with 100mg/-1 sodium hypochlorite solution, coated with the gum and stored along with the control fruits for seven weeks at an average temperature of 27 ± 2 °C and relative humidity of 55-60 %. The parameters investigated in the fruits were, weight loss, ascorbic acid content, pH, firmness and total soluble solid. The results showed that xanthum gum was effective in extending the shelf-life of papaya fruits when compared to the control.