酒的辐射化学Ⅱ.辐照酒形成的2,3-丁二醇光学异构体的分布

RADIATION CHEMISTRY OF LIQUORS(Ⅱ).DISTRIBUTION OF 2,3-BUTANEDIOL ISOMERS FORMED ON THE IRRADIATION OF LIQUORS

本工作主要研究了辐照酒形成的2,3-丁二醇光学异构体的分布,并与商品酒中2,3-丁二醇异构体分布作了比较。结果指出,虽然某些商品酒中2,3-丁二醇含量高于4000 Gy吸收剂量辐照酒样-1时形成的2,3-丁二醇量,但是两者有不同的光学异构体分布。在辐照酒中,2,3-丁二醇以dl(外消旋体)和meso(内消旋体)形式存在;在商品酒中则以1和meso形式存在。辐照酒样-1中d-2,3-丁二醇含量随吸收剂量增加而增加,在吸收剂量为4330 Gy时,d-2,3-丁二醇的量达7.6ppm,因此其卫生安全性是亟待研究的问题。在N_2饱和的乙醇体系中,G_(2,3-丁二醇)=2.23;在缺氧条件下辐照酒样-1时,G_(2,3-丁二醇)=1.46;在溶解氧可得到某种程度补足的条件下辐照酒样-1时,G_(2,3-丁二醇)=0.35,这不仅表明酒中溶解氧抑制2,3-丁二醇生成,而且酒中其它成分还能与乙醇分子竞争水辐解形成的活性粒子并形成新的辐解产物,因此在评估辐照酒的卫生安全性时必须予以注意。

In this paper. the yield and distribution of 2, 3-butanediol isomersformed during the irradiation of liquors have been investigated and compared withthat of the isomers in some ordinary liquors. It has been found that some commercialliquors also contain 2, 3-butanediol. but there is difference in the distribution oftheir optical isomers. 2, 3-butanediol is in the forms of meso and dl for irradiatedliquor and its ratio(meso/dl)=1. In commercial liquors, 2, 3-butanediol is in theforms of meso and 1 and its ratio(meso/1)≤0 .5. G(2, 3-butanediol) values have been determined in various systems. For liquidethanol saturated with N_2 G(2, 3-butanediol)=2.23, 1. 46 for the irradiated liquorsample-1 without oxygen and 0.35 for the liquor specimen-1 irradiated under thecondition of limited air supply. The results show that (1) the soluble oxygen inliquor can inhibit the formation of 2, 3-butanediol; (2) the other compositions inthe liquor can compete with ethanol molecules in reacting with active species(H, e_(aq)^-,OH etc.) and form some unknowns. Therefore, we must pay attention to the hygienicsatefy of those unknowns in the irradiated liquor.