β-环糊精增敏-紫外分光光度法测定啤酒中异α-酸

摘要

啤酒花是一种重要的风味剂，也是酿造啤酒的重要原料。本文采用紫外分光光度法测定了6种不同品牌啤酒中异-酸（iso-α-酸）的含量。试验考察了不同表面活性剂、介质酸度对iso-α-酸紫外吸收的影响。结果表明：iso-α-酸在258 nm处有较强的吸收，方法线性范围在10μg/mL～50μg/mL，相关系R=0.9994， RSD=1.40%（n=5）。通过比较说明β-环糊精（β-CD）对iso-α-酸的增敏作用最强，SDS次之，曲拉通-100最弱。6种不同品牌啤酒中iso-α-酸的含量（μg/mL）依次为：司陶特黑啤酒（130.33）>燕京啤酒（67.45）>哈尔滨啤酒（58.14）>崂山啤酒（39.62）>纯生啤酒（38.76）>雪花啤酒（35.53）。用标准加入法测定其回收率，样品回收率范围在96.30%～104.70%之间，结果满意。%Hops is a kind of important flavour enhancer and raw material of brewing industry. In this article, iso-α-acid content in beer with 6 different brands were measure d through ultraviolet spectrophotometry. The effects of the different surfactants, medium acidity on absorption of α-acid were explored. The results showed that the α-acid had the strong absorption at 258 nm, the linear range of 10μg/mL to 50 g/mL, correlation co-efficent R=0.999 4, the RSD=1.40% (n=5), respectively. The sensitized action with different surfactants forα-acid absorption were as follows:β-CD, the SDS, Brij-35, TritonX-100 and CTMAB. The iso-α-acid contents(g/mL) in beer with 6 different brands were Si Tao Te Hei(130.33)>Yanjing beer(67.45)>Harbin beer(58.14)>Laoshan beer(39.62)>Yanjing pure draft beer(38.76)>Snow Flower beer(35.53). The aver-age recoveries were in the range of 96.30%-104.70%with standard addition method, the results had been sat-isfied for sample determination.