The effect of Zinc oxide, Talk and Kaolin on biochemical and quality parameters of pomegranate fruits cv. Malas saveh

Sunburn is one of the most important problems in pomegranate cultivation, which results in reduced yield and fruit quality. This study was conducted to evaluate the effect of antiperspirant application on quality and biochemical properties of pomegranate fruits in Qom. The experiment was conducted as a completely randomized design with nine treatments and three replications. Treatments were talc (T), zinc oxide (ZnO), kaolin (K), zinc oxide+talc (ZnT), talc+kaolin (TK), zinc oxide+kaolin (ZnT), zinc oxide+talc+kaolin (ZnTK), shading with 50% light passing and control (sprayed with water). The results showed that the fruit quality characteristics were significantly affected by treatments. The highest fruit skin thickness was observed in control and the lowest was seen in ZnT treatment. ZnK treatment resulted in highest aril length, but the other treatments had no effects on aril diameter, length and diameter of pomegranate kernel. The highest fruit skin phenol content was seen ZnTK treatment and the other treatments were almost at similar significant levels. The lowest pH of the skin and aril peroxidase were observed in the Shading and the combination of talc, kaolin and zinc oxide had the highest peroxidase activity. ZnK enhanced laccase activity by 77% compared to control. The highest and lowest lipoxygenase activity were measured in ZnTK and kaolin treatments, respectively. Because of its good peroxidase level and lower lipoxygenase and laccase activity, the zinc oxide seems to be a good treatment for increasing the quality of pomegranate fruits.