Black cumin oil-enriched edible coating application improves the storability of fresh loquat fruits

This study was conducted to determine the effects of edible coatings (EC) and black cumin oil-enriched edible coatings on the storability of fresh loquat fruits. The edible coating was prepared by heating a mixture of diluted corn starch (2% w/v) and glycerol (0.5% v/v) in distilled water at 90-95°C for 30 min. The same procedure was followed for the black cumin oil (0.5%) enriched edible coating preparation, while distilled water was used as a control. The freshly harvested fruits were pre-selected to eliminate damaged and unripe fruits. Then the fruits were separated into three groups, each with 90 fruits. These three treatments were applied by dipping the fruits for 60 min. After dipping, the fruits were air-dried for 30 min and packed in plastic boxes. A total of 15 boxes were used for each treatment, and six fruits were put in each box. The boxes were stored at 4.0±1.0°C and 90-95% relative humidity for 35 days. Three boxes (replications) from each treatment were taken from the cold chambers at 7-day intervals for quality evaluation. According to the results obtained, the edible coating (EC) application alone or in combination with black cumin oil was noted to have an important influence on the prevention of weight loss, disease severity and fruit browning during 35 days of storage. These treatments were also noted to increase the ascorbic acid content of the fruits and delay the reduction of titratable acidity. The improved maintenance of the fruit quality was also associated with the reduced respiration rate in the treated fruits. Overall results suggested that the enrichment of edible coatings with black cumin oil provides higher efficacy in preserving the storage quality of fresh loquat fruits.