Influence of cooking techniques on whole grains quality, nutrition, safety and structural changes

Whole grains (WGs) are important sources of dietary fiber (DF), vitamins, and phytochemicals and play an important role in improving metabolic health and preventing chronic diseases. However, despite their substantial health benefits, the application of WGs in staple foods and their consumer acceptance remain limited, mainly because the bran layer adversely affects product texture, palatability, cooking time, and processing adaptability. Therefore, optimizing cooking methods is an important strategy for balancing palatability, nutritional value, and consumer needs. This review discusses key structural changes occurring during WG cooking, including water migration, starch gelatinization and retrogradation, protein network reorganization, and dietary fiber transformation, with particular emphasis on three representative cooking approaches: hydrothermal cooking, represented by steaming and boiling; dry-heat cooking, represented by baking; and extrusion cooking. These three approaches offer distinct advantages in texture softening, flavor and crispness development, and rapid structural reorganization and large-scale production, respectively. Their selection should therefore take into account product characteristics as well as nutritional and digestive requirements. Building on this comparison, the review further summarizes biological pretreatments, including germination, fermentation, and enzymatic hydrolysis, as well as physical pretreatments such as superfine grinding, microwave treatment, and superheated steam treatment, and outlines their combined applications with cooking processes. Finally, future research may integrate multi-omics approaches to deepen the mechanistic understanding of structural transformations and advance the development of precision nutrition design and intelligent processing technologies.