Micronized by-products from debranned durum wheat and sourdough fermentation enhanced the nutritional, textural and sensory features of bread

Abstract

Fractions from debranning of durum wheat (Triticum durum sp.) were subjected to micronization and air fractionation, obtaining coarse (Cf) and fine (Ff) fractions. These fractions mainly differed for particle size, total dietary fiber, protein and fat. Wheat flour (Triticum aestivum sp.) doughs, containing 5% of Cf or Ff, were subjected to fermentation by baker's yeast alone or fermented by Lactobacillus sanfranciscensis DE9 and Lactobacillus plantarum 3DM. White flour doughs, without addition of bran fractions, were also manufactured. The kinetics of growth and acidification of lactic acid bacteria did not differ between sourdoughs with or without Cf or Ff. Breads were manufactured at pilot plant scale. Compared to wheat flour, the addition of micronized bran fractions increased the concentration of free amino acids, total phenols and dietary fiber as well as the phytase and antioxidant activities of doughs. Sourdough fermentation further improved these nutritional features, and enhanced the textural and sensory properties of breads containing bran fractions. In particular, the combination of sourdough fermentation and Cf increased the concentration of functional compounds and decreased the value of hydrolysis index (HI).