Exploring the effects of barley (Hordeum vulgare L.) germination on chemical composition, phytic acid, and potential malt prebiotic properties

Abstract

Germination is a complex process that triggers physical, chemical, and structural changes in grains, including macromolecule hydrolysis such as fiber components like β-glucans, and phenolic compound liberation, which may exhibit prebiotic effects. This work studies the impact of varied germination conditions on barley chemical composition, phytic acid content, and phenolic compound profile to obtain a potential prebiotic source. A combination of two temperatures (20 and 25°C) and times (35 and 72 h) was evaluated. Ungerminated barley and malt obtained under traditional brewing conditions (20°C for 95.5 h) were also analyzed. Bifidobacterium animalis subsp. lactis INL1 and B. lactis BB-12® were used to assess the potential prebiotic capacity. Barley germination at 25°C for shorter times (35–72 h) induced less starch, sugars, and β-glucans degradation than brewing malt. However, only brewing malt effectively reduced the content of phytic acid. Germination at 25°C produced a higher release of phenolic compounds. Malt obtained after germination at 20°C for 35 h was sufficient to produce a fermentable substrate by probiotic bacteria and did not stimulate pathogen-like strains. These results highlight the prebiotic potential of barley malt and uncover previously unexplored properties of this cereal, laying the groundwork for further investigation.