Abstract

Growth tests in beers supplemented with specific chemical substances were conducted to investigate the growth control method of beer-spoilage bacteria. Lactobacillus brevis and Pectinatus frisingensis were inoculated into beers in which the pH was set and chemical substances had been added to form a matrix. Supplementation of the beer with hop bitter compounds (iso-α-acids, α-acids, or SO₂), had an inhibitory effect on the growth of the tested strains in beer. Furthermore, the growth inhibiting compounds had a synergistic effect when used simultaneously. Two-way repeated measures analysis of variance showed that the interaction effects of combinations of iso-α-acids and α-acids in addition to α-acids and SO₂ on the growth of L. brevis and P. frisingensis in beer were highly significant. To verify the contribution degree of pH, iso-α-acids, α-acids, and SO₂ on the growth of L. brevis and P. frisingensis, growth test results using a combination of these factors set at different levels were subject to stepwise regression. The contributions of undissociated α-acids, undissociated SO₂, and multiplications of undissociated α-acids and undissociated SO₂ were especially high in the control of L. brevis growth. The contributions of pH, undissociated SO₂, and multiplications of pH and undissociated iso-α-acids were especially high in the control of P. frisingensis growth. The difference in the contributions of antibacterial compounds between L. brevis and P. frisingensis may be due to the difference in the cell wall/membrane structure. Such factorial analysis may be useful for parameter setting in future product designs and process adjustments.

摘要

对添加特定化学物质的啤酒进行生长试验，探讨啤酒腐败菌的生长控制方法。将短乳杆菌和弗里辛梳齿菌接种到设定了 pH 值并添加化学物质形成基质的啤酒中。在啤酒中添加啤酒花苦味化合物（异α-酸、α-酸或SO ₂），对啤酒中测试菌株的生长具有抑制作用。此外，同时使用生长抑制化合物时具有协同效应。双向重复测量方差分析表明，异-α-酸和异-α-酸组合的相互作用效应除α-酸和SO _2外， α-酸对啤酒中短乳杆菌和弗里辛对虾的生长均具有高度显着性。为了验证pH、异α-酸、α-酸和SO _2对短乳杆菌和弗里辛对虾生长的贡献程度，将这些因素组合在不同水平上的生长测试结果进行逐步分析。回归。未解离的α-酸、未解离的SO ₂的贡献以及未解离的α-酸和未解离的SO _2的倍增对短乳杆菌生长的控制特别高。_{pH值、未解离的SO 2}以及pH值和未解离的异-α-酸的倍增在控制弗里辛对虾生长方面的贡献尤其高。短乳杆菌和弗里辛巴氏杆菌之间抗菌化合物贡献的差异可能是由于细胞壁/膜结构的差异所致。这种因子分析可能对未来产品设计和工艺调整中的参数设置有用。