Effects of protein and transglutaminase on the preparation of gluten-free rice bread

Abstract

Effects of transglutaminase (TGase) and proteins such as whey protein, caseinate, and soy protein on the preparation of gluten-free rice breads using non-waxy rice flour were investigated. Rice flour (about 12% moisture content) was prepared from dry milling of dried grain after rice got soaked. Unlike general dry milled flour, newly developed rice flour increased water binding capacity (WBC), swelling power, and peak viscosity. Soy protein increased WBC but other proteins slightly decreased with the increase of levels. Lightness decreased and yellowness increased with the addition of whey and soy protein. All pasting viscosities decreased with the addition of protein. The TGase improved the network structure of rice batter. The 2nd proof time of rice batter with protein was shortened by 4–9 min with the addition of TGase. The specific volumes of rice breads with whey and soy protein also increased. TGase and protein additions decreased the hardness of rice bread. Sensory test showed that roasted flavor, volume, air cell homogeneity, and overall quality were significantly different (p<0.05) with protein and TGase additions.