Effects of different pretreatment methods on the dough properties, bread flavor and

Highland barley is rich in nutrients, however, its application in bread products is limited due to its poor processing quality. Therefore, physical modification of highland barley is required to improve its processing properties. This study investigated the effects of four pretreatment methods-traditional stir-frying, steam explosion, microwave, and far-infrared baking-on the dough properties and final bread quality of black highland barley. The results indicated that all four pretreatments decreased free water content in the dough and improved its rheological properties. Meanwhile, the protein structure and aggregation state were altered, and treatment-specific changes in free sulfhydryl groups and intermolecular interactions were observed. Microstructural observations revealed that the treated dough samples exhibited looser and more fragmented gluten network structures, with steam explosion treatment notably preserving network continuity and starch encapsulation. Regarding bread quality, pretreatments significantly modified textural properties and enhanced flavor compound diversity, with steam explosion treatment showing the most pronounced flavor enhancement effects. In terms of digestibility, pretreatments reduced the maximum starch digestibility and the content of rapidly digestible starch while increasing the resistant starch content, which consequently lowered the estimated glycemic index of all pretreated breads. Overall, this research provides a theoretical foundation for utilizing pretreatments to improve dough properties and reduce bread digestibility, offering scientific support for developing nutritionally enhanced functional products.