EFFECT OF COATING WITH ALOE GEL AND CACTUS MUCILAGE ON SHELF LIFE AND POSTHARVEST QUALITY OF MANGO

Abstract

Mango (Mangifera indica L.) is among major fruit crops grown in eastern Ethiopia. However, the postharvest handling problem contributes to huge postharvest loss of fruits. This experiment was conducted to study the effect of coating with Aloe debrana (aloe) gel, Opuntia ficus indica (cactus) mucilage and their combination on the shelf life and postharvest quality of mango fruits. Green mature mango fruits were collected from farmer’s orchard and coated with aloe gel and cactus mucilage each at 0, 25, 50, and 75% and with their possible combinations. The experiment was laid out in completely randomized design (CRD) with three replications consisted of treatments arranged in factorial combinations. The results revealed the significant effect of coating with aloe gel and cactus mucilage on most parameters considered. Marketability of fruits was significantly influenced by interaction (aloe gel x cactus mucilage x storage period) and (aloe gel x cactus mucilage, aloe gel x storage period and cactus mucilage x storage period). Weight loss was also significantly affected by interaction of two coatings with storage period. The highest marketability (90, 84.31 and 66.67%) on 8th, 12th and 16th respectively were obtained from fruits coated with combination of aloe gel and cactus mucilage at 75% concentration level while the lowest( 76.67,45.24 and 33.33% on respective day ) obtained from control. The minimum fruits weight loss was obtained from 75% aloe gel and cactus mucilage throughout storage period. The interaction of aloe gel coating and storage period significantly influenced TSS, TA and sugar to acid ratio, while the interaction of cactus mucilage and storage period had significant effect only on TSS of mango juice. The incidence and severity of alternaria rot and anthracnose diseases were significantly reduced in fruits coated with aloe gel while coating fruits with cactus mucilage only significantly reduced alternaria rot incidence. The aloe gel had significant effect on all sensory attributes while cactus only on color, appearance and over all acceptances but the interaction of two did not. Generally, coating of fruits with aloe gel and cactus mucilage at possible combination of 50 and 75% had a tendency to maintain high percentage marketability and extend shelf life. Likewise, both coatings at 50 and 75% concentration level alone provided high percentage marketability, extend shelf life, retard quality deterioration, reduce weight loss and keep good appearance. Therefore, coating of mango fruits with these extracts in combination and alone at higher concentrations could be used as alternative postharvest loss management of mango fruits. However, work requires replication in terms of cultivars, harvesting stage and different types of coatings