Integrative LC-MS and GC-MS Metabolic Profiling Unveils Dynamic Changes during Barley Malting

ABSTRACTMalting, a crucial process for beer production, involves complex biochemical transformations affecting sensory attributes and product quality. Despite extensive research on storage carbohydrates and proteins involved in malting, a detailed understanding of metabolic alterations during this process remains elusive, limiting our ability to assess and enhance malt quality. Our study employed untargeted GC-MS and LC-MS metabolite profiling to elucidate these changes across six malting stages: dry seed, post-steeping (DOG0), germination (DOG1, DOG3, DOG5), and kilning. We identified a total of 4980 known metabolites, with approximately 82% exhibiting significant changes. Statistical analysis revealed stage-dependent metabolic shifts, with most significant shifts occurring from DOG1 to DOG3 and during kilning. Dynamic changes in various chemical classes and metabolic pathways provide insights into processes critical for malt quality and beer production. Additionally, metabolites associated with antimicrobial properties and stress responses were identified, underscoring the interplay between barley and microbial metabolic processes during malting.HighlightsGC-MS and LC-MS profiling were performed to track metabolic changes during malting.Identified 4980 known compounds belonging to 346 chemical classes during malting.Many microbial metabolites demonstrated increased abundance in finished malt.The most significant metabolic shifts occurred during early germination and kilning.