Wheat-rye bakery products with soy okara

Abstract

The enrichment of mass-produced varieties of bakery products, such as wheat and rye, is an urgent task at the present time. The use of soy okara for this purpose is due to its rich chemical composition and high ability to swell and bind moisture. The purpose of the research was to determine the effect of replacing dry soy okara flour on the properties of semi-finished products and the quality of wheat-rye bakery products. The technological properties of okara, flour and their mixtures were determined by the indicators of water binding capacity, the degree of swelling, the quantity and quality of gluten and the number of drops. Soy okara was added in an amount of 3–12% in increments of 3% instead of flour. Okara was not added to the control sample. In the test, the acidity was determined by titration, the maximum shear stress and adhesion on the device Structurometer ST-1. The quality of the finished bread was evaluated according to the indicators of the mass fraction of moisture, porosity, specific volume, organoleptic indicators by standard and generally accepted methods. The preservation of the freshness of bakery products was assessed by the change in the moisture content of the crumb and its swelling during storage. It was found that in soy okara, the water binding capacity and the degree of swelling are higher than in flour by 2,45–2,8 times and 20–25%, respectively. The introduction of soy okara helps to reduce the amount of raw gluten by 0,45–1,8%, the IDC­index by 2–8 units of the device, and also reduces the number of drops by 8–35 seconds compared to the control. As a result of the conducted studies, it was found that the moisture, acidity, viscosity increases in the experimental samples of the test with soy okara and the adhesion decreases accordingly by 1,8–5,2%, 0,1–0,7%, 7,2–28,8%, 2,3–11,2%. The introduction of 9% soy okara instead of flour does not reduce the quality of finished products. At the same time, the yield increases by 13,7%, the freshness retention period by 24 hours, the calcium and fiber content increases by 20,3% and 4 times, respectively, the biological value increases by 3%, and the energy value decreases by 10% compared to the control.