Jaehrig Silke C, Rohn Sascha, Kroh Lothar W, Fleischer Lutz-G, Kurz Tomas
Department of Food Process Engineering, Institute of Food Technology and Food Chemistry, Technische Universitaet Berlin, Amrumer Strasse 32, D-13353 Berlin, Germany.
J Agric Food Chem. 2007 Jun 13;55(12):4710-6. doi: 10.1021/jf063209q. Epub 2007 May 22.
(1-->3),(1-->6)-Beta-D-Glucan, a cell wall polysaccharide in many microorganisms, fungi and algae, is a well-known biological response modifier. Recently, it was found that (1-->3)-beta-D-glucan from Saccharomyces cerevisiae also exhibits antioxidative capabilities. In this study the antioxidative activity of the cell wall fractions of brewer's yeast was investigated. Particular emphasis was put on the question to which extent glucan is responsible for the antioxidative activity of the cell walls and how the other cell wall components might contribute. For the experiments yeast cell walls from brewery fermentations were used. Glucan was isolated by a three-step extraction procedure including a combination of hot water and enzymatic treatment. The level of (1-->3),(1-->6)-beta-D-glucan in the cell walls was analyzed enzymatically. The antioxidant activity was determined by electron paramagnetic resonance spectrometry and Trolox equivalent antioxidant capacity assay. The results show that the antioxidative activity of yeast cell wall proteins exceeds that of beta-glucan greatly. Especially aromatic side chains and free thiols from denatured proteins seem to work as antioxidants.
（1→3），（1→6）-β-D-葡聚糖是许多微生物、真菌和藻类细胞壁中的一种多糖，是一种著名的生物反应调节剂。最近发现，来自酿酒酵母的（1→3）-β-D-葡聚糖也具有抗氧化能力。在本研究中，对啤酒酵母细胞壁组分的抗氧化活性进行了研究。特别关注的问题是，葡聚糖在多大程度上负责细胞壁的抗氧化活性，以及其他细胞壁成分可能如何发挥作用。实验使用了啤酒发酵过程中的酵母细胞壁。通过包括热水和酶处理相结合的三步提取程序分离葡聚糖。用酶法分析细胞壁中（1→3），（1→6）-β-D-葡聚糖的含量。通过电子顺磁共振光谱法和Trolox等效抗氧化能力测定法测定抗氧化活性。结果表明，酵母细胞壁蛋白质的抗氧化活性大大超过β-葡聚糖。特别是变性蛋白质中的芳香侧链和游离巯基似乎起到了抗氧化剂的作用。
