RVA and Farinograph Properties Study on Blends of Resistant Starch and Wheat Flour

Resistant starch (RS) is the undigested starch that passes through the small intestine to the large intestine. As a functional low calorie additive, it has special applications in the food industry. Rapid visco analysis (RVA) and the Brabender farinograph were used to study the pasting properties and the viscoelasticity of blends of RS (RS3 and RS2) and three wheat flours. The wheat flours represented strong gluten wheat (SGW), intermediate gluten wheat (IGW), and weak gluten wheat (WGW) flours, at different levels of RS substitution (0, 5, 10, 15, and 20%). The influence of RS3 on the control wheat flours and RS-wheat flour blends were consistent with those of RS2. The peak, trough, and final viscosities of RS3-wheat flour blends were higher than those of the corresponding RS2-wheat flour blends. The peak, trough, breakdown, final, and setback viscosities of wheat-RS blends decreased with an increase in resistant starch contents from 0 to 20% in the blends. The 0-20% RS-wheat flour blends were all able to form doughs. The dough development times, dough stabilities, dough breakdown times, and farinograph quality numbers for the RS-wheat flour blends decreased as the RS proportion in the blends increased. The values for RS-SGW flour blends were the highest, followed by RS-IGW and then RS-WGW flour blends. The water absorption values for RS-wheat flour blends and the mixing tolerance index for RS-WGW flour blends were found to increase significantly with an increasing proportion of RS from 0 to 20%, but the mixing tolerance index for RS-SGW and RS-IGW flour blends showed no significant differences amongst the different ratios. Correlation analysis showed that the Farinograph quality number was highly positively correlated with dough breakdown time, dough stability, and dough development time (r= 1.000, 0.958, 0.894), and highly negatively correlated with the mixing tolerance index (r=-0.890). Data from this study can be used for the development of dough-based products. It also provides a basis for RS-wheat flour blends and quality evaluation in the food industry.