Effects of carnauba wax and temperatures during storage on antioxidants and granulation in 'Manee-Esan' pomelo

Pomelo is an economic fruit in Thailand. 'Manee-Esan' is a new promising pomelo cultivar of northern Thailand. The problem of pomelo during storage and export is the decrease in quality of the products and them becoming unacceptable to consumers. The use of coating and the control of storage temperature have been used to prolong shelf life of fresh fruits. The aim of this study was to investigate the effect of carnauba wax and temperatures during storage on antioxidants and granulation in 'Manee-Esan' pomelo. Experiments were conducted based on a 3×2 factorial in a completely randomized design. Three carnauba wax concentrations (0, 20 and 25%) and two storage temperature (10 and 25°C) were used. Samples were randomly collected every 15 days. The results showed that phenolic, flavonoid, β-carotene and anthocyanin content tended to decrease after long storage times. Moreover, granulation in 'Manee-Esan' pomelo was raised during storage. Granulation was highest with carnauba wax at 0% and storage at 25°C, followed by 20%/10°C, 20%/25°C, 25%/25°C, 0%/10°C, 25%/10°C; granulation values (%) were 25.0, 17.0, 16.4, 15.9, 9.5 and 2.7, respectively. When 'Manee-Esan' pomelo fruits were coated with carnauba wax 25% and stored at 10°C, storage life could be extended to 135 days compared to only 45 days for the control (0% carnauba wax/25°C).