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.
