Influence of natural additives on protein complex of bread

Abstract

The study focuses on researching the influence of natural additives on certain technological characteristics of mixtures used for bread production, more particularly the influence of N substances in used raw material on selected qualitative parameters of bread. The blends for bread production to be analysed were prepared by mixing wheat flour with an addition of oat, buckwheat, lentil and chickpea wholegrain flour in different portions (10, 20, 30, 40 and 50 %). The experiment showed that the addition of natural additives worsened the protein complex of the blends used in bread production (worsening also qualitative parameters known as product volume). The loaves prepared with an addition of buckwheat, oat, lentil and chickpea were evaluated to be of a lesser quality from a technological viewpoint when compared with pure wheat loaves. The lower content of gluten forming proteins and the generally changed protein composition of blends due to additives caused a lower percentage of wet gluten content, its lower extensibility and swelling capacity. The sedimentation value (Zeleny index) decreased proportionally with the increase of addition until the level was unsatisfactory for raw material intended for bakery purposes. The N content in experimental loaves was higher than in the reference loaves and it increased according to the selected additive and its portion in the blend (more with the addition of lentil and chickpea, less in case of buckwheat and oat) which is considered as positive from a nutritional point of view. But from the technological point of view the additives did not show any positive influence and caused a lower loaf bread volume. The most significant decrease of the loaf bread volume was found with the addition of 50 % of buckwheat (- 45.6 %). Better results were obtained with a lower portion of the additive: loaf with an addition of 30 % of chickpea (volume decreased by 12.8 %) > loaf with an addition of 30 % of lentil (volume decreased by 8.7 %) > loaf with an addition of 10 % of oat (volume decreased by 14.3 %) > loaf with an addition of 10 % of buckwheat (volume decreased by 22.7 %). Such products can be considered as technologically good or at least satisfactory. To increase the volume of bread loaves, 3 % of vital wheat gluten was added to blends mixed with a portion of 30 % and 50 % of additives. The results were not adequate however. The only exception was buckwheat, where the loaf volume was satisfactory despite the addition of 30 %.