Combined influence of bitterness and alcohol content on the microbiological stability, antioxidant capacity, and bioactive compounds of UV-LED treated beers: A non-thermal processing approach

作者：Oscar Cavieres, Agustín Zavala, Mariela Labbé, Fernando Salazar · 发表于：LWT · 年份：2025 · DOI：10.1016/j.lwt.2025.118146 · 研究领域：Fermentation and Sensory Analysis、Phytochemicals and Antioxidant Activities、Postharvest Quality and Shelf Life Management

Although beer has antimicrobial properties, it remains susceptible to contamination by acetic acid bacteria (AAB) and lactic acid bacteria (LAB), such as Acetobacter aceti and Levilactobacillus brevis . This study investigates the combined effects of UV-LED treatment, bitterness level (IBU), and alcohol content (ABV) on the microbiological stability, bioactive compounds, and antioxidant capacity of beers. American pale ale samples with varying bitterness and alcohol levels were brewed using different malts and yeasts. Samples were treated with 278 nm UV-LEDs at 90 % power, applying doses of 149, 298, and 448 mJ/cm 2 . The highest factor levels (5.4 ABV, 41 IBU, 448 mJ/cm 2 ) achieved the greatest microbial reductions: 1.9 ± 0.7 log reductions for A. aceti and 8.5 ± 0.1 log reductions for L. brevis , significantly different from untreated samples (∼1 × 10 8 CFU/ml, p < 0.05). Total phenol content (TPC) was unaffected by UV treatment, influenced only by bitterness and alcohol, with the highest value (538.7 ± 31.4 μg EAG/ml) in 5.4 ABV and 41 IBU beers. However, total flavonoids content (TFC) and antioxidant capacity (AC) significantly increased at 298 and 448 mJ/cm 2 . These findings suggest that UV-LED treatment effectively stabilizes low alcohol beers, improving their microbiological safety while enhancing phenolic content and antioxidant properties.