|Keywords (Extracted from title, table of contents and abstract of thesis)
surface coating, packaging, keeping quality, mango, mangifera indica l, post harvest life, bee wax, polysaccharide, fungicide, dushehari, sindhri, chaunsa, titratable acidity, ascorbic acid, invert sugars
The objective of the present study was to increase the post harvest life of mango fruit at ambient temperature during storage to boost export of this very tasty and delicious fruit in the international market. Different combinations of Bee wax with polysaccharide based coatings such as CMC, Guar gum, vegetable oil having CaCl2 as firming agent, fungicide like NaOCL and 2,4,5-T as anti ripening agent were employed on hard green, matured, unripened, and uniform sized of Dushehari, Sindhri and Chaunsa White the three very important commercial varieties of mango. Coated fruit was either packed in export quality carton boxes, polyethylene, and wooden alone or in polyethylene-carton and polyethylene-wooden combinations containing KMnO4 sachet to absorb or remove ethylene. The effect of surface coating and packaging on the keeping quality of mango was investigated after an interval of 3 days at ambient temperature (32-35 oC with 53.6 78.8% RH), (35-44oC with 55.9-69.7% RH) and (28-33 oC with 56.7- 69.7% RH) respectively during storage. The data obtained was statistically analyzed for Analysis of Variance (ANOV A) by using 2-Factorial Complete Randomized Design (CRD) and Duncan,s Multiple Range Test (DMRT) was applied to compare the mean values obtained. Results revealed that treatments, storage and their interactions had highly significant effect on keeping quality of mango during storage. It was observed that coating (CMC-WAX + 2,4,5-T+ H3BO3-CaCl2) mixture had shown the best results and maintained 90% green color, firm texture followed by (CMC-W AX + NaOCI), (CMC+ Wax+ KMnO4) and (CMC +Wax + CaCl2 + 2,4,5-T) in which majority of the samples were still green with creamy white pulp even after one month of storage. On the other hand in control sample 70-75% fruit were ripened with full yellow color within a week and blackening of the skin at stem end and rotting in some of the samples was started within 12 days of their storage and due to its unattractive skin, brown pulp color and poor taste fruit was unacceptable after 16 days of storage. Whereas treated fruit without rotting were green even after 21st day of their storage. Therefore, increasing of the storage life of treated Sindhri mango up to 25 days and Chaunsa White more than 30 days is very encouraging as compared to its own original life only 4 to 6 days. It was also investigated that mango packed in polyethylene or coated fruit having with other protective chemicals packed in polyethylene within carton or wooden boxes played a very effective and vital role to control compositional changes by delaying the ripening process and with a minimum quality loss. It was observed that Chaunsa White treated with Wax-CMC coating having ethylene absorbent, fungicide and antiripening agents having NaOCI, KMnO4. 2,4,5-T or 2,4,5-T with CaCl2 and H3BO3 packed in polyethylene or all these combinations along with polyethylene packaged in carton or wooden had lower weight loss, slower increase of TSS, pH, higher retention of acidity, slower increase in AA, RS, TIS, SUC, TS, SAR, or lower score of SKC, FLC, T AS and higher TEX and slower increase of FLA score respectively as compared to fruit packed in carton/wooden box alone or polyethylene packed fruit in carton/wooden without chemical treatments were comparatively less effective.