Department of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of São Paulo, Av. Professor Lineu Prestes, 580, São Paulo, SP 05508-000, Brazil; Food Research Center FoRC, University of São Paulo, Av. Professor Lineu Prestes, 580, São Paulo, SP 05508-000, Brazil.
Food Res Int. 2024 Nov;196:115040. doi: 10.1016/j.foodres.2024.115040. Epub 2024 Sep 2.
This study aims to enhance understanding of probiotic lactic acid bacteria (LAB) survival in high-hopped beer formulations and their interactions with different yeasts and highlights the fermentation processes, microbial metabolism, and production of distinctive beer flavors. For this, this research used Lacticaseibacillus paracasei F19 (F19), Saccharomycodes ludwigii, and Saccharomyces cerevisiae strains US-05 (US-05) and Kveik (Kveik) for brewing. Bacterial and yeast cultures were prepared, fermented in wort, and analyzed in different hop concentrations (International Bitterness Units - IBU 0, 20, 40). Methods included physicochemical analysis, yeast and bacterial counts, RT-qPCR for gene expression, statistical analysis, and sensory evaluation by sommeliers following BJCP guidelines. Physicochemical analysis showed efficient fermentation across all hop concentrations (IBU 0, 20, 40), with decreasing SG and pH over time due to lactic acid bacteria and yeast metabolism. Higher hop levels (IBU 20 and 40) resulted in less acidic beer, indicating hop interference with bacterial activity. Yeast populations remained stable regardless of hop content, with Saccharomyces cerevisiae and Saccharomycodes ludwigii performing well. Probiotic strain F19 exhibited robust viability in all formulations. Sensory analysis favored higher hop content beers, suggesting consumer acceptance and potential health benefits of probiotic, high-hop beers. Higher hop content hindered sour beer production as only hop-free beers reached low pH levels. Probiotic strain F19 remained viable under high IBU formulations (20 and 40), with these being preferred by sommeliers using BJCP methodology. All yeast strains supported F19 survival. Further studies are needed on gastrointestinal resistance and clinical benefits.
本研究旨在增进对高投麦啤酒配方中益生菌乳酸菌（LAB）存活及其与不同酵母相互作用的理解，并强调发酵过程、微生物代谢和独特啤酒风味的产生。为此，本研究使用了副干酪乳杆菌 F19（F19）、路德酵母和酿酒酵母 US-05（US-05）和 Kveik（Kveik）进行酿造。制备细菌和酵母培养物，在麦汁中发酵，并在不同的啤酒花浓度（国际苦味单位 - IBU 0、20、40）下进行分析。方法包括理化分析、酵母和细菌计数、基因表达的 RT-qPCR、统计分析以及根据 BJCP 指南由侍酒师进行感官评估。理化分析表明，在所有啤酒花浓度（IBU 0、20、40）下均能有效发酵，由于乳酸菌和酵母代谢，SG 和 pH 随时间降低。较高的啤酒花水平（IBU 20 和 40）导致啤酒酸度降低，表明啤酒花干扰了细菌活性。无论啤酒花含量如何，酵母种群均保持稳定，其中酿酒酵母和路德酵母表现良好。益生菌菌株 F19 在所有配方中均表现出较强的生存能力。感官分析倾向于高啤酒花含量的啤酒，表明消费者接受度和益生菌、高啤酒花啤酒的潜在健康益处。较高的啤酒花含量阻碍了酸啤酒的生产，因为只有无啤酒花的啤酒才能达到低 pH 值。益生菌菌株 F19 在高 IBU 配方（20 和 40）下仍能存活，且这些配方受到使用 BJCP 方法的侍酒师的青睐。所有酵母菌株均支持 F19 的存活。需要进一步研究胃肠道抗性和临床益处。
