Effect of postharvest 'wilting' treatment and moringa leaf extract incorporated with carboxymethylcellulose to reduce the incidence of postharvest rind physiological disorders of 'Marsh' grapefruit (Citrus × paradisi)
Rind quality is an important attribute in the fresh produce market, as it determines the consumer willingness to buy the commodity. However, citrus fruit are susceptible to postharvest rind physiological disorders such as chilling injury and rind breakdown. This study investigated the combined effect of 'wilting' moringa-based edible coatings on rind physiological disorders and postharvest quality of 'Marsh' grapefruit. Fruit harvested from the inside canopy (IC) and outside canopy (OC) position of the tree were wilted for 0, 24, 48 or 72 h at 23°C before being dipped into wax or edible coating (EC) constituting moringa leaf extract and carboxymethylcellulose (CMC). The fruit were stored for 9 weeks at 3°C, 95% RH. Thereafter, fruit were kept at room temperature (23°C) for 2 weeks, simulating retail shelf conditions. The study consisted of eight treatments; namely, T1 = citrashine wax, T2 = edible coating, T3 = 24 h & citrashine wax, T4 = 48 h & citrashine wax, T5 = 72 h & citrashine wax, T6 = 24 h & edible coating, T7 = 48 h & edible coating and T8 = 72 h & edible coating. Fruit mass, total soluble solids (TSS), titratable acidity (TA), TSS:TA, BrimA and chilling injury were evaluated at 2 week intervals. Fruit treated with T5 had lower mass loss compared to other treatments. Fruit coated with edible coating not wilted maintained sweetness better than any other treatment. Fruit wilted for 0, 24, 48 and 72 h and coated with edible coating showed higher chilling injury incidence compared to waxed fruit. Overall, results from the current study showed that postharvest wilting for 24, 48 or 72 h or non-wilted grapefruit followed by waxing retained fruit quality. Therefore, combined, these treatments can be used commercially to enhance the appearance and maintain citrus fruit quality during postharvest storage and shelf life. MLE incorporated with CMC were not effectively to reduced chilling injury.
Maphumulo, M.M., Magwaza, L.S., Mditshwa, A. and Tesfay, S.Z. (2021). Effect of postharvest 'wilting' treatment and moringa leaf extract incorporated with carboxymethylcellulose to reduce the incidence of postharvest rind physiological disorders of 'Marsh' grapefruit (Citrus × paradisi). Acta Hortic. 1306, 217-224
citrus, organic edible coating, physio-chemical, chilling injury