Morphological, physicochemical and antioxidant comparison of medicinal date-plum fruit (Diospyros lotus L.) in three regions of Hyrcanian forests

The Hyrcanian forests, located along the southern shores of the Caspian Sea, are a unique and ancient ecosystem. To preserve the genetic reserves of these forests, it is essential to examine the diversity of their medicinal plants , including the date-plum or wild persimmon (Diospyros lotus L.). The aim of this research was to evaluate the native date-plum fruit harvested from three regions of the Hyrcanian forests including Gorgan, Aliabad, and Behshahr in terms of morphological, physicochemical, and antioxidant traits. to do so, fruit samples were collected and evaluated in November 2021 during commercial-local harvest. The obtained results showed that the highest fruit weight, diameter, and volume were recorded in samples collected from Behshahr, while the lowest weight, length, diameter, and fruit volume were observed in fruits belonging to Gorgan. This research indicated that fruits collected from Behshahr were more elongated compared to those collected from Gorgan and Aliabad. The comparison of qualitative traits confirmed that the highest acidity and vitamin C content were observed in Behshahr and the highest pH and total soluble solids were recorded in the fruit samples of Gorgan. The maximum total phenol and flavonoid were related to Aliabad and Behshahr. Finally, the highest total anthocyanin and antioxidant capacity were observed in Gorgan. Furthermore, this study found that fruit weight had a significant positive correlation with acidity while it showed a significant negative correlation with pH and antioxidant capacity. Also, fruit acidity had a significant negative correlation with antioxidant capacity and total anthocyanin. In contrast, pH and total soluble solids showed a significant positive correlation with total anthocyanin. In general, a great diversity was observed among the medicinal fruit of the wild date-plum collected from the three investigated regions in Hyrcanian forests with regard to the morphological, physicochemical, and antioxidant activity.