Effect of Hot Air Treatment on Physio-Chemical Properties of Pomegranate Arils

Hot air treatment has been applied on a wide range of horticultural crops to control postharvest decay and to maintain quality characteristics. To evaluate the effect of hot air treatment on physio-chemical properties of pomegranate arils, an experiment was carried out in a factorial experiment using a completely randomized design with four replications in ۲۰۱۵. About ۲۰۰ g of ‘‘Rabab-e-Neyriz’’ pomegranate arils were placed in ۳۵۰ mg polypropylene boxes with three holes on top for ventilation. Boxes were heated at ۳۵ °C, ۴۰ °C and ۴۵ °C and ۸۰% relative humidity for ۳۰, ۶۰, and ۱۲۰ min in oven. After being cooled at an ambient temperature, boxes were stored at ۵ °C (RH= ۷۰-۸۰%) for ۱۵ days. The scored results of decay assay showed that heated “Rabab” arils at ۳۵ °C till ۴۵ °C decayed lesser than those untreated during storage period. Hot air temperature at ۴۵ °C for ۱۲۰ min resulted in the highest weight loss at the end of storage period. The highest total soluble solids content was belonged to the arils heated at ۴۵ °C for ۳۰ min. Hot air treatments increased pH and TSS/TA ratio of aril juice. Hot air temperature treatment decreased antioxidant activity, total phenolic compounds and total anthocyanin of arils during storage period, whilst hot air treatment had no significant effect on color values. Generally, the application of mild heat treatments could be considered as a non-contaminant postharvest tool to maintain functional and nutritive properties of arils during postharvest storage.

Keywords:

Antioxidant activity , Anthocyanin content , Heat treatment , pomegranate