VALIDATION OF A METHOD FOR DETERMINING FREE AND BOUND POLYPHENOLS IN BARLEY PLANTS BY SPECTROPHOTOMETRY

The article represents the results of a research of the total content and content of free polyphenols in the grain and straw of spring barley (Hordeum vulgare L.). The content of polyphenols was determined by measuring the optical density of solutions containing blue-colored compounds formed between polyphenols of raw plant and molybdenum complexes of the Folin-Ciocalteu reagent. The suitability of the method was confirmed by two characteristics: linearity and repeatability. The study found that the total content and content of free polyphenols in barley straw is higher (21.9±0.6 and 4.78±0.09 mg/g) than in grain (8.7±0.6 and 2.49±0.13 mg/g). The research revealed that the method for determining polyphenols is valid and allows to determine the content of polyphenols in barley plants.