Some physico-chemical characteristics of mulberry (Morus alba, Morus laevigata, Morus nigra) species grown in western Turkey

Abstract

Fruit colour of mulberry may be white, purple (Morus alba), black (Morus nigra) or red (Morus laevigata and Morus rubra) when they are ripe. Recently, black coloured mulberry species received a great importance due to higher contents of phenolic compounds and having a unique delicious refreshing taste. Dark coloured mulberries have been used as a folk remedy to treat many diseases such as hypertension, arthritis and anemia, diabetes and cancer. In this study, physico-chemical properties (fruit weight, fruit diameter, fruit length, stalk length, fruit juice colour, total soluble solid contents, pH, titratable acidity, antioxidant activitiy, total phenolic and total flavonoid contents) of white, purple (both Morus alba L.), dark red (Morus laevigata Wall.) and bright black (Morus nigra L.) mulberry fruits grown in the West Mediterranean Region of Turkey were investigated. While the largest fruits were noted in dark red mulberry plants, the smallest one was the white mulberry fruit. The highest total soluble solid contents (TSS) were obtained in fruits of black mulberry (20.10%), while it was lowest in dark red coloured mulberry (9.23%). The total acidity contents of mulberry species was between 0.12 (white mulberry) and 1.73% (black mulberry). The highest total phenolic contents and antioxidant activity were found both in black mulberry (270 mg of gallic acid equivalent (GAE) 100 g-1 fresh weight; 6.79 mg fresh weight) and in dark red mulberry (265.5 mg GAE 100 g-1 fw; 6.64 mg fresh weight). The highest amount of total flavonoid was also observed in black mulberry fruits (mg catechin equivalent 100 g-1 fresh weight). The results showed that black mulberry species had higher bioactive contents compared to other mulberry species.