DETERMINATION OF VITAMIN CONTENT IN THE LEAVES OF RED RASPBERRY (RUBUS IDAEUS L.) BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY
Annotatsiya
Abstract. The article reports the profile of water-soluble vitamins in the leaves of red raspberry (Rubus idaeus L.) grown in the Bostanlyk district of the Tashkent region, determined by high-performance liquid chromatography (HPLC). The analysis was performed on an Agilent 1260 system with a diode-array detector, an Eclipse XDB-C18 column and a gradient mobile phase of acetonitrile and buffer solution (pH 2.92). Six of the seven target vitamins were found in the leaves: ascorbic acid – 44.451; pyridoxine (B6) – 40.549; cobalamin (B12) – 4.525; folic acid (B9) – 3.649; riboflavin (B2) – 3.251 and nicotinic acid (PP) – 0.377 mg/100 g. Thiamine (B1) was below the limit of detection. The total vitamin content reached 96.80 mg/100 g, of which 87.8 % was contributed by ascorbic acid and pyridoxine. The results provide a basis for evaluating raspberry leaves as a domestic raw material for vitamin herbal teas and dietary supplements and for their standardization. Keywords: Rubus idaeus L., red raspberry, leaf, water-soluble vitamins, ascorbic acid, pyridoxine, HPLC, diode-array detector, standardization.