Effect of dietary fibre waste originating from food production on the gluten structure in common wheat dough

Abstract

At present, the use of by-products from plant food production is gaining more interest because these products contain a large amount of valuable nutritional compounds e.g. dietary fibre, proteins, polyphenols, unsaturated fatty acids, vitamins. The by-products improve both the nutritional profile and the health-promoting properties of bakery products but simultaneously impair some technological properties, which is strongly related to the structure of the gluten network. FT-IR spectroscopy was used to determine changes in the gluten structure through the addition of by-products from the vegetable industry and cold oil pressing production. The supplements were added to the common wheat dough in the amounts of 3, 6, 9 and 12%. Analysis of the spectra indicates that changes in the gluten structure and the distribution of water populations are connected with the type of technological process from which the supplement originated and hence its chemical composition. Vegetable supplements cause the formation of aggregated structures such as pseudo-β-sheets, whereas gluten samples modified by oil supplements contain mainly basic secondary structures i.e. α-helices, β-turns and antiparallel-β-sheets. With regard to the water populations, oil supplements do not affect them or affect them slightly. Vegetable supplements lead to the formation of a weaker gluten network. This is observed in the form of a decrease in the number of strong hydrogen bonds.