Departamento Química Analítica, Facultad Ciencias Químicas, Universidad Complutense de Madrid, Madrid 28045, Spain.
Departamento Química Analítica, Facultad Ciencias Químicas, Universidad Complutense de Madrid, Madrid 28045, Spain.
Food Chem. 2018 Nov 30;267:246-254. doi: 10.1016/j.foodchem.2017.06.141. Epub 2017 Jun 27.
A method combining aqueous extraction, reversed-phase high-performance capillary liquid chromatography with photodiode array detection (cLC-DAD) and chemometric tools, was developed to determine phenolic compounds in residual brewing yeast. The effect of temperature, nature of extraction solvent and method for separation of extract solution were studied to optimize the extraction conditions on the basis of total phenolic content (TPC), total flavonoids content (TFC) and antioxidant capacity. Polyphenols were determined by cLC-DAD. Flavonols as rutin and kaempferol, flavonoids as naringin, phenolic acids as gallic acid and antioxidants as trans-ferulic and p-coumaric acids were found and quantified in the brewing residue. Data were subjected to evaluation using multifactor ANOVA and principal component analysis (PCA), both showing that lyophilization pretreatment affects the content of individual polyphenols and that residual brewing yeast contains higher polyphenol amounts than the liquid beer waste. The obtained results suggest that residual brewing yeast could be a source of polyphenols.
建立了一种结合水提、反相高效毛细管液相色谱与光电二极管阵列检测（cLC-DAD）和化学计量学工具的方法，用于测定剩余酿造酵母中的酚类化合物。基于总酚含量（TPC）、总黄酮含量（TFC）和抗氧化能力，研究了温度、提取溶剂的性质和提取液分离方法对提取条件的影响，以优化提取条件。采用 cLC-DAD 测定多酚。在酿造残渣中发现并定量了类黄酮如芦丁和山奈酚、类黄酮如柚皮苷、酚酸如没食子酸和抗氧化剂如反式阿魏酸和对香豆酸。使用多因素方差分析和主成分分析（PCA）对数据进行评估，两者均表明冻干预处理会影响个别多酚的含量，并且剩余酿造酵母中的多酚含量高于液体啤酒废料。研究结果表明，剩余酿造酵母可能是多酚的来源。
