Evaluation of Biochemical Composition and Enzyme Activities in Browned Arils of Pomegranate Fruits

Aril browning disorder threatens production, consumption and exports of pomegranate fruits, because affected fruits cannot be distinguished externally from healthy fruits. This study was conducted to compare mineral, biochemical composition and related enzyme activities in affected brown arils with healthy ones in ‘Malase Saveh’ pomegranate fruits. The results indicated that the level of Cu in the aril and K, Mg and Mn in the peel of healthy fruits was higher than affected ones. The total soluble solids, titratable acidity, total phenolics, total flavonoids, total anthocyanins, antioxidant activity and color parameters (L*, a*, b*, hue and chroma) declined in browned arils of pomegranate, whereas fruit respiration rate and acidity, peroxidase (POD) and polyphenol oxidase (PPO) enzyme activity was higher in browned arils. No difference was found for phenylalanine ammonia lyase (PAL) activity. There were positive correlations between total anthocyanins and both color values and total phenols, and a negative correlation between PPO and POD activities. Overall, nutritional and functional value of these affected fruits is anticipated to be far less than healthy ones.