Folate content and stability in commercial beers: Correlations with phenolic compounds

Folate content and stability in commercial beers were investigated using a UHPLC-Q-TOF-MS/MS method. Sixteen commercial beers from a local market contained total folate ranging from 35.0 to 199.6 μg/L, with 5-methyltetrahydrofolate (5-MTHF) as the predominant form (21-70 %). Principal component analysis revealed distinct clustering patterns among beer types and positive correlations between phenolic content and folate levels. During in vitro digestion, beers with higher phenolic content demonstrated enhanced stability of reduced folates, particularly in stout beer containing 493 mg GAE/L phenolics. Under accelerated storage (60 °C, 10 days), all samples showed significant folate degradation despite varying phenolic levels. While total phenolic content remained stable during storage, antioxidant capacity consistently declined across all samples, suggesting complex protective mechanisms beyond simple antioxidant activity. These findings provide valuable insights into folate-phenolic interactions in beer matrices and their implications for nutritional value preservation during processing and storage.