CHANGES IN QUALITY OF AMARANTH GRAIN IN THE PROCESS OF POST-HARVESTING PROCESSING AND STORAGE

Abstract

One of the ways to solve the problem of deteriorating human health can be the widespread use of plant products, among which the most valuable are vegetable oils, including amaranth oil. It contains a complex of vitamins, micro- and macroelements, unsaturated fatty acids and essential amino acids and a unique natural biologically active substance, squalene, which performs a number of key functions in the human body. However, post-harvest processing of amaranth grain, in particular drying, and its subsequent storage in different conditions can significantly impair its valuable natural properties. The research presents the results of studies of changes in the chemical composition and microbiological characteristics of amaranth grain in the process of drying and storage in different conditions, which will ensure its guaranteed quality during storage. The effect of drying amaranth to humidity of 9% at temperatures of 50 °С and 60 °С , has been studied on the total amount of saponified substances, content of squalene, linolenic, linoleic, oleic, palmitic and stearic acids, which were determined by gas – liquid chromatography. It has been found that after drying amaranth grain there is a decrease in the content of saponified substances by 10% and squalene by 14% compared to freshly harvested grain, and the content of free fatty acids in the unsaponified fraction remains unchanged. When storing amaranth during the year at temperatures of +5 °С, +15 °С and +25 °С and relative humidity of 55% and 75%. Changes in the content of such basic indicators of grain quality as protein, starch, fiber, fat, ash, as well as acid number and acidity of fat were determined. At the same time, the protein content decreased by 13.5%, starch by 8.7%, fat by 29.0%. The content of fiber and ash has not changed. Under the same storage conditions, there was also a significant deterioration in the quality of fat -acid number increased by 6.9 times, the acidity of the alcohol extract by 2.9 times. When storing amaranth at a temperature of +5 °С and a relative humidity of 55%, the decrease in the content of the main components was significantly smaller and amounted to 8.1% for protein, 2.9% for starch and 4.2% for fat. Under the same conditions, the activity of microorganisms is significantly reduced, which allowed to recommend these storage conditions for industrial use.