BIOCHEMICAL COMPOSITION OF SEEDS OF EARLY-MATURING SOYBEAN VARIETIES AND ITS VARIABILITY DEPENDING ON THE VARIETAL CHARACTERISTICS AND METEOROLOGICAL CONDITIONS OF VEGETATION PERIOD

Soy is one of the most valuable agricultural crops, the protein composition of which includes essential amino acids, similar in composition to animal proteins, and fat in its composition predominates sunflower and olive. Comparative study of biochemical composition of soybean seeds of the Northern ecotype depending on varietal characteristics and meteorological conditions of the growing season. Perennial field experiments (2002-2019) were carried out on the experimental field of the plant growing laboratory of RSAU–MSHA named after K. A. Timiryazev. The objects of study were soybean varieties of the Northern ecotype – Svitlaya, Mageva, and Okskaya. Biochemical analysis of seeds was performed in the laboratory of research of technological properties of agricultural materials FSBSI FSAC VIM. The seeds of Northern ecotype soybean varieties contain 40.6-41.2 % protein and 19.4-19.9 % fat. Protein is characterized by a high content of sum of essential amino acids (63.10-63.98 %), including – histidine (7.2–7.7 %), lysine (7.7–7.8 %), tryptophan (by 4.6–4.9 %), arginine (8.4–8.8%), threonine (more than 4.0 %), phenylalanine (to 3.5 %). It was established that in comparison with traditional (southern) varieties, the seed fat of soybean varieties of the Northern ecotype is characterized by a higher content of palmitic acid (11.0–11.3 %) and significantly lower content of oleic acid (10.0–12.0 %). At the same time, according to the content and ratio of polyunsaturated fatty acids (linoleic and linolenic), it is close to the fat of food grades. Under conditions of excessive moisture, a high content of saturated palmitic fatty acid was observed, and in arid conditions – unsaturated fatty acids – oleic, linoleic and linolenic. Analysis of the quantitative and qualitative components of protein and fat of soybean varieties of Northern ecotype gives grounds to recommend their use not only for feed, technical, but also for food purposes.