Effects of Different Harvest Dates on Some Fruit Quality Parameters and Health Promoting Compounds of Morus alba L. and Morus nigra L. Fruit

Mulberries are important fruits in terms of health-promoting compounds such as phenolics, antioxidants and organic acids. However, limited studies have addressed the changes of health-promoting compounds as well as fruit quality parameters during harvest season which have a long duration about two months. This study was conducted to determine whether some bioactive compounds and fruit quality parameters may be changed significantly in this long harvest season. White and black mulberry fruits were collected at commercial maturity stage fifteen day intervals (from 1st July to 1st August) in three locations (Igdir, Tuzluca and Kagizman) in Aras Valley. The content of some selected organic acids and phenolic compounds were analyzed in fresh fruit samples by HPCL/DAD. Antioxidant activity determined also on fresh fruit samples by Spectrophotometer. Fruit weight, width, length, fruit juice pH, titratable acidity (TA) and soluble solid content (SSC) were examined as some fruit quality parameters. Phenolic compounds and antioxidant activity in black mulberries were higher than in white mulberries at all harvest dates in three different locations. Phenolic compound levels and antioxidant activity increased towards the end of harvest season. Some fluctuations were observed organic acid levels during harvest season in Tuzluca and Kagizman locations while the acids increased towards the end of harvest season in Igdir location. Fruit weight, width and length decreased while titratable acidity increased at the end of harvest season in three locations. On the other hand, some fluctuations were observed SSC and fruit juice pH during the harvest season. As a result of the study, contrary to get smaller fruit, content of its phenolic levels and antioxidant activity increased towards the end of harvest season. Late harvested fruits may be more beneficial for human health compared to earlier ones in the same harvesting season.