SOURDOUGH TYPE II IMPROVE BREAD QUALITY
Sourdough technology has acquired a great interest in breadmaking process. Three types of sourdough are known, where: (I) natural fermentation by flour microorganism, also called as levain; (II) induced fermentation through the use of starters (yeast and lactic acid bacteria); and (III) freeze-dried powder from sourdough type I or II. The aim of this work was to produce sourdough type II (using only yeast as starter culture) and its use in breadmaking. Sourdough was developed through the fermentation at 28°C during 13 days, by feeding at every 2 days, using refined wheat flour or wholemeal (80:20 refined wheat flour:wheat bran). Four samples of bread were produced, where: B1 (control sample with refined wheat flour); B2 (10% of refined wheat flour sourdough); B3 (control sample with wholemeal); and B4 (10% of wholemeal sourdough). The results were evaluated by Student t-test (P≤0.05). For B1 and B2 no difference was observed for specific volume and parameters luminosity and hue of instrumental color. Nevertheless, the chroma value was higher for B1 (17.32±0.12) in relation to B2 (15.97±0.36) (P≤0.05), indicating a yellowness tendency for control sample of refined flour. The firmness was lower for B2 (5.87±0.62N) with sourdough when compared to B1 (7.19±0.39N). For the integral bread, no difference was observed for instrumental color, but the loaves with wholemeal sourdough showed a higher specific volume (B4=2.68±0.12kg/L and B3=2.31±0.03kg/L) and lower firmness (B4=11.07±1.02N and B3=12.79±0.37N) (P≤0.05). Regarding color difference, refined wheat flour sourdough showed value of 1.37 and wholemeal sourdough showed value of 0.52, indicating that the consumers probably not perceive these difference by the naked eye, because these differences could be observed only by values higher than 3.00. The use of sourdough resulted in bread with better technological characteristics, with higher specific volume and lower firmness, without color difference between the refined or wholemeal loaves.