Individual and combined effects of a-amylase, xylanase, and cellulase on the breadmaking and nutritional properties of steamed bun enriched in wheat bran

The present study investigates the effects of a-amylase (6 and 10 ppm), xylanase (70 and 120 ppm), and cellulase (35 and 60 ppm) on the physicochemical characteristics and nutritional quality of Chinese steamed bun (CSB) incorporated with 15% wheat bran (WB). Compared to the single enzyme, the combined enzymes improved the specific volume of CSB up to the highest value (2.50 mL/g) and decreased the hardness to the minimum value (299.61 g) when the concentration was 6, 120, 35 ppm. Additionally, the combined enzymes (6, 120, and 35 ppm) significantly (p < 0.05) decreased the total dietary fiber from 14.65% to 13.10% and hence increased the area under the reducing sugar release curve during in vitro digestion from 302.12 to 357.26 mg/g. Consequently, enzymes combination can significantly improve the quality of WB CSB, whereas reduce the nutritional value of WB CSB.