Study of technological properties of rye and wheat flour

Abstract

In the production of sourdoughs and doughs for baking bread, the main raw material is flour. To obtain a high-quality product, low-grade flour shall not be used; it must be of high activity, that is, it must have elastic gluten, high water-absorbing and gas-forming ability and low enzyme activity. All these factors give the dough certain structural-mechanical properties during ripening of the sourdough and dough, standing and baking. For the study, two samples (sample 1 and sample 2) of rye flour from producers in the Kyiv and Kirovograd regions and one sample of wheat flour (sample 3) from producers in the Kyiv region were selected. Sensorial indicators were determined in the samples, namely aroma, color, crunch, taste, pest infestation, physical and chemical indicators: humidity, grind size, acidity. The quality of the raw materials used in the study was analyzed using generally accepted and special methods. The flour samples 2 and 3 have shown the highest protein content, namely 8,9 % and 11,1 %, respectively, the lowest protein content 8,4 % was in sample 1. The energy value of wheat flour was 50,24 kcal and 42,58 kcal than in samples 1 and 2, respectively. A sensorial assessment of flour samples showed that all samples were free of foreign odors, had a pleasant aroma, and had a color characteristic of the nature of the grain, no mechanical impurities were observed. All types of flour had a uniform degree of grinding. Wheat flour showed the lowest dispersion (largest coarseness), and rye flour of both brands had high dispersion, its effect upon the quality of the finished product being positive. Rye flour samples had 11,1-13,4 % higher water absorption coefficient compared to wheat flour. The acidity of rye flour was higher than that of wheat flour. The total gas formation during 5 hours of fermentation for sample 3 was 1430 cm 3 of CO 2 per 100 g of flour; for rye flour, sample 2 was 678 cm 3 of CO 2 per 100 g of flour. Therefore, for the development of sourdough technology based on rye flour, coarse rye flour from the manufacturer’s plant in the Kirovograd region shall be recommended, which was the optimal in terms of granulometry, contained more starch, monosaccharides, disaccharides and protein, was optimal in terms of technological properties and had greater water absorption capacity than wheat flour.