EQUIPMENT AND SCIENTIFIC STUDIES OF EXPERIMENTAL DATA ON STORAGE OF WHEAT GRAIN

Abstract

A complex of technical solutions is presented which makes it possible to study the influence of external factors on changes in the indicator of fat acidity value (FAV) and a range of other parameters characterizing the quality of preservation of long-term stored wheat grains in South Russia. Storage conditions (natural climatic, model) and also the effect of dust suppression treatment of grain by oil glazing that is carried out in some grain terminals in the South of Russia were taken as controlled external factors. New data has been obtained on changes in parameters of food suitability of the wheat grains during storage under model conditions with varying degrees of severity of climatic conditions in South Russia. After 6 months of storage the most considerable changes in FAV value were found for 4th class of wheat stored in natural climatic conditions with intensive insolation, the increase was 1.7 mg KOH/1 g of fat (from 7.3 mg KOH/1 g of fat up to 9.0 mg KOH/ 1g of fat). Minimum changes in the same parameter for the same storage period were observed for the wheat of the 3rd class stored in a thermostat at a stable high temperature of 35 ºС (from 11.6 mg KOH/1 g of fat to 11.5 mg KOH/1 g of fat). For wheat of the 4th class, the changes were 0.7 mg KOH/1 g of fat (from 7.8 mg KOH/1 g fat to 8.5 mg KOH/1 g of fat). Analyzes of stored wheat grains subjected to dust suppression by the oil glazing showed similar results, which allows us to state the absence of a significant effect of oil glazing on changes in wheat properties during its storage.Based on the results of the experimental analysis and a generalization of the data obtained an assumption was made on the possible reasons for the lack of pronounced trends in the data for the expected increase of FAV value in food suitability of the wheat grain when it is stored under typical model conditions of South Russia. The likely reason for this is the corresponding moisture state of grain, the water activity of grain was about 0.45. Such a low value was due, in particular, to the fact that samples of model-stored grain had a limited volume and do not reproduce the mass transfer processes that involve deep layers of the grain mass (because of the mass absence), which takes place during storage of grain in an industrial environment. The tools were proposed for the operational monitoring of the moisture state of wheat grain during storage. Moreover, a plan has been developed to expand the field of modelling storage processes in terms of varying the moisture state of the stored wheat grain samples with an assessment of the influence of moisture state on the dynamics of changes in the parameters to be controlled.