麦芽中超前絮凝因子多糖的提取与性质研究

Purification and characterization of a polysaccharide in malt inducing premature yeast flocculation

啤酒发酵中的超前絮凝现象(PYF,premature yeast flocculation)主要由麦芽中的多糖引起。本文将麦芽汁进行醇沉、Sevag去蛋白、超滤、DEAE-Sephadex A-25及Sephadex G-100柱层析等一系列分离,提取得到一种分子量在10000Da以上的多糖物质PYFⅠ-Ⅰ,酵母超前絮凝活力测定及聚集沉淀后的酵母形态均能证实该多糖能显著促进酵母絮凝。对其性质进行研究发现,该多糖为糖蛋白,糖含量和蛋白质含量分别为58.3%、3.8%。这种多糖物质的发现为进一步研究啤酒发酵中的PYF现象奠定了基础。

Premature yeast ftocculation （PYF）in beer brewing due to the presence of a malt polysaccharide. A polysaccharide which named PYF I- I and its molecular weight was more than 10000 Da. was purified after sedimented by ethanol, remove of protein, ultrafiltration, Chromatography by DEAE-Sephadex A-25 and Sephadex G-100 .The polysaccharide accelerated the flocculation of yeast apparently.The polysaccharide was identified as a protein containing polysaccharide by experiment,the content of polysaccharides and proteins was 58.3% and 3.8%.The discovery of the polysaccharide will do good to the further study of PYF in beer brewing.