ANTI-SAP CHEMICALS AND HOT WATER QUARANTINE TREATMENT EFFECTS ON STORAGE LIFE AND FRUIT QUALITY OF MANGO CV. SAMAR BAHISHT CHAUNSA

Abstract

This study aimed at testing the combined effects of anti-sap chemicals and hot water quarantine treatment (HWQT: 48°C-60min) on a commercial mango cv. Samar Bahisht (S.B.) Chaunsa, as potential protocol for export to China. The physiologically mature mango fruit were harvested along with 4-5 cm pedicel. After de-stemming, the fruits were treated with potential anti-sap chemicals: calcium hydroxide [Ca(OH)2], potassium aluminium sulphate [KAl(SO4)2.12(H2O)], Tween-80 [C64H124O26]. After chemical application, half of the fruit lot was subjected to HWQT as per protocol, while the remaining half was kept without HWQT. The fruit after treatments were air dried, packed in cardboard boxes and stored (13±1°C, 85% RH) for 21 days. Sapburn injuries were scored after 24, 48, 72 hrs and 21days of storage. After storage the fruit were allowed to ripe at room temperature and assessed for physical disorders and disease incidence. Fruit were also analysed for firmness, peel colour, sugars, titratable acidity, total carotenoids, ascorbic acid contents and organoleptic characteristics (pulp colour, texture, taste, aroma, flavour). Sapburn injury score showed significant differences for chemicals and chemical-HWQT interactions. De-stemming under lime [Ca (OH)2] followed by HWQT showed least sapburn injury with more firm fruit. HW treated fruit showed significantly lower anthracnose disease incidence (1.68 vs 2.42), while higher sugars (18.32 vs 14.56%) with more pulp browning (0.74 vs 0.48) and higher total carotenoids (67.0 vs 56.1µg/g) compared to without HWQT. Organoleptic evaluation revealed smoother pulp texture in fruit without HWQT. It was concluded that mango desapping with 1.0% lime solution, followed by HWQT (48°C-60min), did not significantly impair quality during 21 days of storage, beside controlling sapburn injury and meeting market access requirement. However, in view of the exhibited heat induced effects, more studies are needed on HWQT effects on various maturity levels and improving post-storage colour development in mango cv. S.B. Chaunsa, for its export to China, by sea or road, using refrigerated containers.