Effects of rootstock, storage temperatures, and edible coatings on fruit quality and storage performance of finger lime (Citrus australasica)

Finger lime fruit are susceptible to chilling injury, which can shorten postharvest storage life, reduce fruit quality, and compromise marketability. In this study, we investigated the effects of rootstock selection on finger lime tree performance and fruit quality, identified an optimal fruit storage temperature, and evaluated the efficacy of some edible coatings in maintaining postharvest fruit quality. Trees of ‘DPI 50-36’ grafted onto US-802 rootstock developed the largest canopy volume, followed by Volkamer lemon, whereas trees on Kuharske rootstock produced smaller trees. However, both US-802 and Kuharske yielded heavier fruit at harvest and maintained a higher percentage of marketable fruit during storage than those on Volkamer lemon. Storage temperature had a pronounced effect on both ‘DPI 50-36’ (white pulp) and ‘UF SunLime’ (red pulp) fruit quality, with fruit of both cultivars stored at 10 °C outperforming those stored at 5 °C. Fruit held at 10 °C exhibited reduced weight loss, lower incidence of peel physiological disorders, reduced puncture resistance, improved peel Citrus Color Index (CCI), and higher marketable yield. For both ‘DPI 50-36’ and ‘UF SunLime’ finger lime fruit, coconut oil (CO) and zein-based (AK) coatings effectively reduced weight loss and minimized physiological disorders compared with uncoated controls. Coating treatments did not significantly affect peel or pulp CCI, nor did they alter juice biochemical characteristics in either pulp color type. Overall, storing finger lime fruit at 10 °C with either CO or AK coatings effectively maintained fruit quality by limiting physiological deterioration, enabling both white and red pulp types to be stored successfully for up to 21 d, followed by 7 to 14 d at 20 °C, while retaining high marketability and excellent fruit quality.