摘要
研究了以刚果红分光光度法测定麦汁及啤酒中的β－葡聚糖，探讨了实验条件，在ｐＨ８．０的条件下，刚果红和水溶性的β－葡聚糖（分子量１０３～１０４）形成有色物质，摩尔吸光系数为９．６４×（１０３～１０４）Ｌ·ｍｏｌ－１·ｃｍ－１，当参加反应的２．０ｍｌβ－葡聚糖溶液中β－葡聚糖的含量为０～１００μｇ时，反应液吸光度的变化符合比耳定律，变异系数１．１％～５．１％，标样的回收率在９０．２％～９８．６％之间，测定麦汁或啤酒中的β－葡聚糖时，变异系数为３．７％左右。
A spectrophotometric method for analysis of soluble B glucan in wort and beer and methods of experiment have been studied in this paper. 2.0ml of B glucan (0￣59mg/L,molecular weight is 10 3￣10 4) mixed with 4.0ml congo red solution (100mg/L in 0.1M pH 8.0 phoshpato buffor) forms a coloured complex.The apparent molar absrptivity of 9.64×10 3￣9.64×10 4 L/mol.cm goes in agreement with Beer′s law. The variation and recovery rate by using this method are within 1.1%￣5.1% and 90.2%￣98.6% respectively.The variation is 3.7% in detecting the soluble B glucan in wort or beer.
