Determination of Primary Metabolites, Vitamins and Minerals in Black Mulberry (Morus nigra) Berries Depending on Altitude

Abstract

This research was conducted to examine the effect of altitude on primary metabolites (soluble solids, total sugars, invert sugars, individual invert sugars (glucose, fructose, sucrose), total acidity, pH, organic acids (citric acid, malic acid), vitamins (C, A, B1, B2, B3) and mineral contents (K, P, Ca, Mg, Na, Fe, Cu, Zn, Mo)) in black mulberry (Morus nigra) berry extracts. The experiment was performed at three locations: Location 1—(187 m altitude), Location 2—(271 m altitude) and Location 3—(493 m altitude). High performance liquid chromatography (HPLC) was employed for the identification of individual invert sugars, organic acids and vitamins (A, B1, B2, B3) in berry extracts. Vitamin C was evaluated by spectrophotometry, whereas the mineral contents were determined by flame atomic absorption spectrophotometry. The contents of primary metabolites, vitamins and minerals varied widely depending on altitude. The synthesis and accumulation of the tested parameters changed with increasing altitude. The highest levels of sugars were found in Location 3, whereas the values of acids, vitamin A and the minerals Na, Mo and Fe were higher in Location 1. The accumulation of macronutrients K and P, and vitamins C and B3 was most intensive in Location 2. Altitude had no effect on the contents of vitamin B1 and B2, and the micronutrients Cu and Zn. The results suggest that black mulberry fruits are rich in primary metabolites, vitamins and minerals, and that altitude has an important effect on the synthesis of the tested parameters in the fruits.