عنوان مقاله [English]
Background and Objectives
Pomegranate (Punica granatum L.) is one of the most important fruit that grown on commercial scale in Iran and is gaining a lot of popularity worldwide in recent years owing to its high economic, nutraceutical and therapeutic values. Chilling injury and weight loss are the most important limiting factors for pomegranate fruit storing. Application of an edible coating such as carnuba wax on the fruit surface imparts a glossy appearance and better color, reduces fruit weight loss, extends storage life, and prevents microbial spoilage, which is extremely important to perishable fruit. Edible coatings create a modiﬁed atmosphere around the fruit by providing a semipermeable barrier to water vapor and gases, and their use offers an effective alternative to ﬁlm packaging due to their environmentally friendly characteristic
Material and Methods
In order to evaluate the effect of carnuba wax on pomegranate fruit storage, an experiment was conducted in a factorial design based on completely randomized with four replications. The treatments included of carnuba wax in three concentrations 0, 0.5% and 1% and storage time in 3 levels (0, 45 and 90 days). After immersion and drying, the fruits were packed in plastic baskets and kept in cold room at 4 ± 1 ° C with 85 ± 5% of relative humidity., In each sampling removal, quantitative and qualitative characteristics such as, weight loss (%), electrolyte leakage (percentage), chilling index, tissue firmness, total acidity, pH, Color indices (Aril and skin), fruit flavor, anthocyanin, skin freshness and fruit overall acceptance.
The results showed that carnuba wax was able to prevent weight loss until the end of storage period (90 days), but controlled ion leakage until 45 days of storage. The skin firmness of fruits and arils were higher in carnuba than control samples. Increasing the concentration of carnuba wax resulted to lower vitamin C but did not affect the antioxidant capacity. According to the panellists', the flavor, skin freshness and the appearance of pomegranate fruits in both carnuba treatments were better than the control sample.
The results of this study showed that carnuba-coated fruit has protective quantitative and qualitative characteristics during cold storage. Exogenous application of carnauba wax showed improvement in pomegranate storability at 4 C, which otherwise leads to occurrence of chilling injury and reduction in quality. The treatment with carnauba wax preserves fruit weight, total acidity and skin freshness. Pomegranate carnuba-coated fruit exhibited signiﬁcantly lower chilling rate as compared to the control. According to the results carnuba 0.5% was able to maintain most qualitative and quantitative properties of pomegranate fruit until 90 days in 4°C.