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BACKGROUND: Wheat is an important food crop, and its characteristics vary depending on the region of cultivation; different environments have varying effects on the composition of the grains. We previously reported the effects of environmental factors on wheat grain cell wall composition and structure. The variations in the structure of aleurone cell walls between different wheat samples were examined to determine the effects of aleurone cell walls on grain starch digestion properties. Ten different varieties of wheat grains with different aleurone cell wall structure and composition constituted a simple research system used to investigate their effect on the starch digestion of bread. RESULTS: The aleurone cell wall thickness ranged from 3.05 μm to 4.67 μm, and the arabinose to xylose ratio of water‐extractable arabinoxylan was in the range 0.79–0.97. With the increase in arabinoxylans content or cell wall thickness, the total digestibility of starch within the bread decreased; this phenomenon may be related to the changes in the interaction between polysaccharides and starch granules in this process. CONCLUSION: The results of the present study showed that the wheat cell wall structure has a great impact on starch hydrolysis, indicating that the change in the digestibility of starch in flour and bread may be a result of changes in the cell wall structure leading to different combinations, thus affecting digestibility. The present study showed that the cell wall combines the starch granules during the bread‐making process; thus, the diffusion of enzymes through the cell wall was hindered. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Summary: Aleurone represents a fraction of the outer endosperm in wheat kernels composed of a single‐cell layer containing a variety of nutrients, including dietary fibre (mainly arabinoxylan, β‐glucan, and cellulose), proteins, minerals, vitamins, and antioxidants (ferulic acid). In this study, aleurone‐rich fraction (0%–100%) was added to wheat flour to examine the microstructure of the bread and the crystal structure of the starch after the addition using scanning electron microscopy and X‐ray diffraction. The maximum in vitro hydrolysis rate of bread with 10%–100% aleurone‐rich fraction addition ranged from 35.69% to 65.93%, which was significantly lower than that of white bread (68.76%). Low‐field nuclear magnetic resonance revealed an increase in the amount of bound water in bread after the addition of the aleurone‐rich fraction. Further, bread containing the aleurone‐rich fraction had a higher antioxidant capacity, as evaluated by DPPH• and •OH scavenging activity. Therefore, these results indicate that the aleurone‐rich fraction may be a beneficial ingredient for the manufacture of low‐calorie and high‐fibre foods. [ABSTRACT FROM AUTHOR]