| Abstrakt: |
Introduction. The purpose of the research is to determine the influence of water activity indicator on the quality of wheat flour and modified wheat flour. Research methodology. Samples of wheat flour obtained from wheat grain of different starch polymer composition and component composition were using. The water activity index for wheat flour and modified according to ISO 18787:2017 was determined. In the bread recipe, 10% of flour was replaced by modified wheat flour. Determined the effect of improved formulation on the shelf life of loaves. Research results. The highest value of enthalpy and water activity is for flour, which has a base ratio of amylose and amylopectin. Softening of the structure and weakening of the starch-protein matrix bonds reduces the enthalpy by 2.3 J/g and the activity of water. The lowest value of enthalpy and water activity has flour, which contains only amylopectin in the starch granules. It should be noted, that the increased composition of micro- and macronutrients flour leads to a decrease in enthalpy of 3.7 J/g. Studies have shown that the physical modification of wheat flour leads to a change in water activity of the samples. In particular, is reduced from 0.619 to 0.591. At the same time, the change in the structure of starch granules leads to an increase in water activity for flour samples: confectionery – from 0.477 to 0.585, type “waxy” – from 0.542 to 0.570, enriched with micro- and macronutrients – from 0.491 to 0.597. The use of ingredients with a reduced rate of aw shows an inhibitory ability to develop potato disease and micromycetes, which prolongs the storage of bread loaves for 1–2 days. The change in the component composition of the flour after its modification significantly affected its technological quality. The use of such a product in the production of food products helps to extend their shelf life, and, accordingly, for a long time to promote the preservation of organoleptic properties and to show stability to the action of microorganisms. Samples of flour differ in the composition of carbohydrates (p <0,001), proteins (p <0,01), fats (p <0,05). Therefore, with temperature modification there are structural changes of the main components with the formation of simpler ones. Conclusions. The water activity index for native wheat flour is in the range of 0.491–0.619 and for modified wheat flour in the range of 0.570–0.597. [ABSTRACT FROM AUTHOR] |
