Changes in cell wall components and its hydrolyzing enzymes of guava fruits due to chitosan and calcium chloride treatments during storage at room and low temperature

Effect of post-harvest treatments of chitosan and CaCl2 alone and in combination on the cell wall components and its hydrolyzing enzymes of guava (Hisar Surkha) fruits were studied. Guava fruits of variety Hisar Surkha treated with chitosan (1.5%), CaCl2 (1.5%) and chitosan (1.5%) + CaCl2 (1.5%), respectively were stored at room temperature (26.3ºC) and in the refrigerator (5±20C).Cell wall components viz. hemicellulose, cellulose and pectin decreased progressively throughout the storage at room temperature and low temperature. The decrease in cell wall components were in co-ordination with enhanced activities of cell wall degrading enzymes viz. PME, PG and cellulase. However, low temperature was effective in slowing down the activities of PG and cellulase as compared to room temperature storage suggesting lower degradation of cell wall components. The treatment of CaCl2 (1.5%)+chitosan (1.5%) was most effective treatment in enhancing keeping quality of guava during storage. Hence fruits given these treatments and stored at low temperature retained their quality for longer duration of time.