Modification of highland barley starch properties via germination-induced amylase activation and amylopectin reduction

To investigate the impact of germination on the development of deep-processed products from highland barley starch, this study systematically examined changes in the structure, composition, physicochemical properties, and related enzyme activities of starch during germination. After 72 h of germination, the contents of total starch and amylopectin in highland barley starch decreased significantly ( p  < 0.05). The activities of α-amylase and β-amylase increased dramatically by 19.6-fold and 6.3-fold, respectively. Concurrently, the gelatinization enthalpy ( ΔH ) of the starch decreased significantly, whereas the syneresis rate showed a significant increase ( p  < 0.05). Correlation analysis revealed that the germination treatment enhanced the activities of α-amylase and β-amylase in highland barley, which promoted the enzymatic degradation of amylopectin. This led to a significantly increased starch solubility, syneresis rate, and initial gelatinization temperature( T 0 ), while decreasing starch transparency, termination gelatinization temperature ( T c ), peak temperature ( T p ), and Δ H . The results demonstrate that germinated highland barley starch is suitable for noodle products.