Effect of β-glucanase on the processing quality and nutritional characteristics of highland barley steamed bread

The high-fiber content in traditional barley steamed bread contributes to a coarse texture, reduced product size, and limited digestibility, which can negatively impact consumer acceptance. To address these issues, we explored the use of β-glucanase (BGS) to enzymatically modify the native fiber in two highland barley (HB) varieties, namely Kunlun-14 (KHB) and Zangqing-18 (NHB). We evaluated the impact of varying BGS concentrations (0.02–0.1%) on the processing quality, nutritional attributes, and flavor profile of steamed bread. Parameters, such as volume, color, textural properties, starch digestibility, and sensory characteristics, were assessed to guide the development of staple foods that align with the health-oriented preferences of consumers. The experimental group exhibited a significant reduction in β-glucan content by up to 40%, along with higher starch digestibility, specific volume, and elasticity values than those of the control group. Conversely, hardness and chewiness decreased markedly (e.g., by 66% in the NHB variety), and the textural qualities and palatability improved in a concentration-dependent manner. Flavor profiling via gas chromatography-ion mobility spectrometry revealed increased levels of alcohols and ketones, whereas characteristic aromas of barley—such as fruity, grassy, and floral notes—became more pronounced in the steamed bread. Collectively, these findings suggest that BGS is an effective enzymatic improver of cereal-based products, particularly those rich in β-glucan, demonstrating its potential for functional food applications. • BGS effectively modifies native β-glucan in highland barley. • Enzymatic treatment improves steamed bread texture and palatability. • BGS enhances starch digestibility in high-fiber steamed bread. • The process boosts fruity, grassy, and floral aromas in the bread. • Offers a viable strategy for functional, high-fiber staple foods.