New insights into influence of green composite modification on the structure, digestive, and physicochemical properties of rice flour

How to reduce the digestibility of rice flour (RF) using efficient and green technologies has attracted increasing attention from food industry and consumers alike. In this study, the structural, digestive, and physicochemical properties of RF under green treatments of annealing (ANN), pullulanase debranching (PUL), double enzyme (DE), PUL combined with ANN (PA), DE combined with ANN (DA) were investigated. The results showed the resistant starch content of RF increased from 5.00 % to 16.56 % after DA treatment and the digestibility of PA-RF was reduced significantly (P < 0.05), which indicated that composite modification could reduce the digestibility more effectively. SAXS and FTIR results suggested that DA-RF had the densest starch structure and the most ordered protein secondary structure. Furthermore, PA, DA treatments could change the thermal stability, water solubility, and swelling power of RF significantly, while these properties of ANN-RF were relatively close to those of RF. These results suggest that composite modification could be used as the new effective strategy to reduce RF digestibility and expand RF applicability.