Effect of edible coatings on fruit maturity and fungal growth on Berhi dates



Berhi date palm fruits were harvested at the khalal stage, coated with different edible materials: pea starch (PS), zein protein (ZP), pea starch + carnauba wax (PS + CW) and zein protein + carnauba wax (ZP + CW) and stored at 3 or 25 °C for 21 days. Different fruit maturity indicators (colour, firmness, total soluble solids, moisture and tannins) and fungal numbers were monitored during storage. PS and ZP coatings at 3 °C were the most effective in retarding fruit maturation by extending the khalal stage from 7 to >14 days. They were less effective at 25 °C, where the khalal stage was extended only ≤7 days. PS + CW and ZP + CW coatings prevented sample moisture loss, but they accelerated degradation of simple sugars at 25 °C, and this indicated a shift to anaerobic fruit respiration. The PS + CW and ZP + CW coatings, particularly at 3 °C, were the most effective in preventing fungal growth, whereas the PS coating promoted fungal growth.