LAUSR

BACKGROUND Quinoa is a good gluten-free resource for food processing especially bread making which can improve and prevent the development of complications associated with celiac disease (CD). However, lack of gluten affected quinoa bread quality. Previous researches showed soy protein isolate (SPI) could improve gluten-free bread quality to some extent. Therefore, this study investigated the effects of SPI on the physical properties of quinoa dough and gluten-free bread quality characteristics. RESULTS Results showed that, with appropriate soy protein isolate (SPI) substitution, the farinograph properties of quinoa flour significantly improved (P<0.05). And the sample with 8% SPI substitution showed the better development time (DT, 3.30±0.20 min), stability time (ST, 8.80±0.10 min), softening degree (SD, 8.80±0.10 FU) which were close to those of wheat flour, although more water absorption (WA, 76.40±2.10%) was needed than wheat flour (66.30±3.10%). And the extensograph properties of quinoa flour also significantly improved after 8% SPI substitution (P<0.05). Furthermore, SPI substitution increased G' moduli of quinoa dough and decreased tanδ to some extent, providing better rheological properties nearly close to the wheat dough. SPI substitution also improved the quality and texture of quinoa bread and reduced the gap with wheat bread. When SPI substitution was 8%, the specific volume, hardness and springiness of quinoa bread were 2.29±0.05 ml/g, 1496.47±85.21 g and 0.71±0.03%, respectively. CONCLUSIONS These results suggested that SPI substitution will be an effective way to develop higher-quality gluten-free bread. This article is protected by copyright. All rights reserved.