RESEARCH OF QUANTITATIVE AND QUALITATIVE CHARACTERISTICS OF GLUTEN OF WHEAT GRAINS DAMAGED BY THE WHEAT BUG
Authors: Stankevych G. , Borta A. 
Published: November 2019

Favorable weather and climate conditions for growing grain are also favorable for the livelihoods and reproduction of pests of grain stocks, and especially for wheat bug (Eurygaster integriceps Put.). Grain damaged by this pest loses its genetically incorporated properties, negative changes occur in the quantity and quality of gluten. Due to the ingestion of bug’s saliva with its special enzymes into the grain, the baking properties of the flour from such grain deteriorate – the dough becomes liquid, sticky, it loses elasticity. Thus, the issue of further effective use of grain damaged by the shield bugis very urgent. This requires information on the dependence of the quantitative and qualitative characteristics of gluten on the content of grains damaged by the wheat bug. The aim of the study was to establish patterns of change in the quantity and quality of gluten depending on the content of grains damaged by the wheat bug, which will increase the efficiency of the formation of batches for further use in the food industry. To achieve this goal, a number of tasks were solved: during the grain harvesting periods of 2015–2018, at the enterprises of the industry, wheat samples were taken with the content damaged by the wheat bug in the range of 0.5...5.0 %, the quantity and quality were determined in them gluten, trends in the quantity and quality of gluten have been established depending on the content of damaged grains and their comparison with published data. The object of the study was the gluten complex of wheat, with various contents of grains damaged by the wheat bug. The subject of research was the quantity and quality of gluten in samples of soft wheat of grades 2–3 of the 2015– 2018 crop samples with various grains damaged by a wheat bug selected at enterprises in the Odessa region. Based on the results of determining the quantity and quality of gluten in samples of the 2015–2018 crop and the available literature data on the quantity and quality of gluten in grain 2005– 2007, a crop with the content of grain damaged by the wheat bug was shown to be 5.0 %, that between the amount of gluten and the content in the grain mass of the grains damaged by the wheat bug, there are no regularities.Existing fluctuations in the amount of gluten are reliably associated with different origins of grain samples grown under different agrotechnological conditions, different protein contents, varietal characteristics of grain and other factors. The regularities of changes in the quality of gluten depending on the content of grain damaged by a wheat bug have been established – with an increase in the content of damaged grains, according to a linear law, the gluten quality index determined on the VDK device also increases. It was also established that the intensity of changes in the quality of gluten significantly depends on the content of grains damaged by the wheat bug; there was a slight increase in the quality index of gluten with the content of damaged grains up to 2.0 %, and its rapid growth with the content of damaged grains from 2.0 % to 5,0 % It is shown that in the studied wheat samples with the content of grains damaged by the wheat bug up to 2.5...2.7 %, the VDK indicator belongs to the 2nd group of gluten quality – satisfactory weak and wheat belongs to 1–3 grades in this indicator. With a further increase in the content of grains damaged the wheat bug, the index of VDK increases and gluten passes to the 3rd group – unsatisfactory weak, and the batch of wheat belongs to the 4th class.