价键原子指数用于酱香型习酒香气成分保留性质研究

Retention properties study of applying valence bond atomic index to aroma components in Xi Baijiu

酱香型习酒是一种风味极其独特的酱香型白酒,具有风味醇厚、幽雅细腻和回味悠长的香气,香气成分繁多而复杂.为探究酱香型白酒的主要挥发性物质的组成及香气风味成分的差异,研究建构酱香型习酒香气成分保留指数的定量结构-保留相关性模型,根据酱香型习酒香气成分分子中原子的空间与电性结构,基于拓扑理论,提出了一种新的结构参数-价键原子指数~mA.另计算了酱香型习酒香气成分的电拓扑状态指数(Em),优化筛选了指数中的~0A、E_(1)、E_(2)、E_(14),将4种结构参数作为神经网络三层结构的输入节点数,色谱保留指数作为三层结构的输出节点数,网络结构采用4-12-1方式.建立的预测香气成分保留指数模型的相关系数达到0.9965,计算得到的酱香型习酒香气成分保留指数RI预测值的平均相对误差为1.41%.结果表明,酱香型习酒挥发性香气成分的保留指数,与价键原子指数和电拓扑状态指数之间具有很好的非线性关系,非氢原子结构及—CH_(3)、>CH_(2)、—O—等基团,是影响酱香型习酒香气成分保留指数的主要因素.

Sauce-flavor Xi Baijiu was a kind of sauce-flavor liquor with mellow flavor,elegant and long aftertaste,with various and complex aroma ingredients.In order to study the differences of the main volatile substances composition and aroma flavor composition of sauce-flavor Chinese Baijiu,a quantitative structure-retention relationship(QSRR)model of the GC retention index of aromatic ingredients in sauce-flavor Xi Baijiu was established.Moreover,a novel structure parameter-valence bond atomic index mA was derived based on molecular topology theory and the spatial and electrical structure of atoms in the aroma components molecules of sauce-flavor Xi Baijiu.The electrical topological state index(Em)of aroma molecules of sauce-flavor Xi Baijiu was calculated,and 0A,E_(1),E_(2),E_(1)4 were optimized screened.The four structure parameters were taken as input layer nodes,while the GC retention index was used as output layer nodes of the three-layer(4-12-1)structure,a neural network was constructed.The correlation coefficient was 0.9965.The mean relative error between the predicted value and the literature value of retention index RI was only 1.41%.The results showed that there was good non-linear relationship between the retention index,valence bond atomic index and electrical topological state index.Non-hydrogen atomic structure and–CH_(3),>CH_(2),–O–iso-group fragments were the main factors affecting the GC retention index of aromatic ingredients in sauce-flavor Xi Baijiu.