The influence of rice protein concentrate on the technological process of wheat bread production

Abstract

Bakery products from wheat flour are low in protein and it is inferior and also absorbed at a low level. To solve this problem sources of complete proteins may be introduced into the formulation of bakery products. But animal proteins can be allergens. An alternative can be concentrates, hydrolysates and isolates of proteins of vegetable origin, particularly, obtained from rice. Microbiological, biochemical and conformational changes in dough and bread from wheat flour were influenced by adding rice protein concentrate. Gas-forming capacity of the dough with rice protein concentrate decreased by 8.3–20.8 % compared to the control sample where there was increase of the dosage. Gas formation occurred less intensively in the dough with rice protein concentrate, because fermentation was delayed due to a decrease in the availability of nutrients. The first peak on the gas formation graph in case of the dough with the addition of 4–8 % rice protein concentrate was seen after 65 minutes, in the control sample it was after 60 minutes. When adding 16 % of the additive, the first peak of gas formation was not clearly defined. The second peak of gas formation for control sample was observed after 150 min and for samples with rice protein concentrate a bit later and it was not clearly defined. Infrared spectra showed that relative reflection coefficient of samples with rice protein concentrate was lower both for dough after kneading and after fermentation. The addition of 4 and 8 % rice protein concentrate did not affect the amount of formed sugars, and the addition of 16 % reduced this indicator by 1.6 %. The amount of fermented sugars decreased by 3.0–7.8 %. So, changes during the technological process of bread-making can be followed due to the obtained results for obtaining bread with high protein content.