The effect of chitosan and CMC-moringa leaf extracts on peteca spot of 'Eureka' lemon
Lemon (Citrus limon L.) is one of the mostly cultivated citrus fruit in South Africa. In order to enhance shelf-life of citrus fruit during packing and sorting, fruit are coated with commercial synthetic waxes. However, the use of waxes can result in peteca spot (PS) disorder in lemons. The aim of this study was to evaluate the efficacy of chitosan (CH) and carboxymethyl cellulose (CMC) incorporated with moringa leaf extracts (M) on reducing the incidence of peteca spot on 'Eureka' lemon. A total of 500 'Eureka' lemons were harvested from Malowe commercial farm located in KwaZulu-Natal, South Africa. After harvest, fruit were assigned to five coating treatments, namely; control, 1% M+CMC, 1% CMC, 1% CH and 1% M+CH and then transferred into a cold room with delivery air temperature set at 3°C to induce the disorder for a period of 12 weeks. At each sampling week, peteca spot incidence, vitamin C and phenolics were measured. The results showed that PS incidence was significantly affected by coating treatments. Fruit coated with CMC, CH and M+CMC were less susceptible to PS development while control and fruit coated with M+CH showed a high susceptibility to the disorder. Coating treatments significantly affected total phenolic and flavonoid content. The most effective coating treatment was M+CMC followed by CMC and CH. These coating treatments were able to reduce the loss of ascorbic acid during storage and maintain a high concentration of total phenolics and flavonoids of the treated fruit. The results observed in this study demonstrated that either M+CMC, CMC, or CH coating treatments can be used for reducing postharvest PS in 'Eureka' lemons.
Rikhotso, M.M., Magwaza, L.S., Tesfay, S.Z. and Mditshwa, A. (2021). The effect of chitosan and CMC-moringa leaf extracts on peteca spot of 'Eureka' lemon. Acta Hortic. 1306, 209-216
edible coatings, physicochemical properties, citrus