Effects of heat treatment on post-harvest quality of mango fruits

Mango fruits (Mangifera indica L.) were harvested at the pre-climacteric stage. Fruits were immersed in 38, 46, and 54 degrees C heated water for 30 min Drier to storage at 5 degrees C for 2, 4, or 6 weeks in carton boxes. After storage, they were kept at 20 degrees C for one week to simulate shelf life. Fruits were evaluated for total soluble solids, titratable acidity beta-carotene content, reducing sugars, starch content, pulp colour, and visible symptoms of chilling injury. Chilling injury index and appearance were influenced significantly by dip temperature and storage period. Total soluble solids was higher in heated fruit at 38 degrees C compared to heated fruits at 46 and 54 degrees C, while titratable acidity was significantly higher in fruit heated at 54 degrees C. Maximum inhibition of carotenoid formation occurred in non-heated and heated fruit at 54 degrees C. Heated water had a significant effect on pulp colour parameters (lightness, hue, and chroma). High correlation coefficients were observed between carotenoid content and colour attributes b*, hue, and chroma. The results of this study indicate that mango tolerance to chilling temperatures may increase after pre-storage heat treatments at temperatures below 54 degrees C.