Analysis of ageing and typification of vintage ports by partial least squares and soft independent modelling class analogy
Analysis of ageing and typification of vintage ports by partial least squares and soft independent modelling class analogy
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DOI：
10.1039/an9962101009
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发表时间：
1996-08-01
期刊：
影响因子：
4.2
通讯作者：
Inigueze, M
中科院分区：
文献类型：
--
作者：
Ortiz, MC;Sarabia, LA;Inigueze, M
葡萄酒波特酒是一种在杜罗谷葡萄牙地区生产的数量非常有限的葡萄酒。它在瓶子里陈年非常慢，而且几乎没有分析数据，因此，分析了道氏和格雷厄姆酒窖*对应于1963至1990年12个不同年份的24种葡萄酒的成分，每个样本确定的41个分析参数被用来使用偏最小二乘(PLS)回归预测年份，并使用软独立建模类比(SIMCA)模型来识别酒窖，这两个问题自然属于食品化学计量学领域，提出了对象少于变量的统计困难。因此，不可能应用常规的多元回归和判别分析技术，偏最小二乘模型需要两个潜在变量，可以解释年龄变量97.4%的方差和交叉验证方差的90.2%。对于这两个品牌的特征，SIMCA模型对24个样本中的22个样本进行了正确的分类；它对陶氏葡萄酒的敏感度为83.3%，特异度为91.7%，而对格雷厄姆的古董酒的敏感度和特异度分别为91.7%和100%。
Vintage port is a wine produced in very limited amounts in the Portuguese region of the Douro Valley. It ages very slowly in bottles and few analytical data are available, Thus, the composition of 24 wines from the cellars of Dow's and Graham's,* corresponding to 12 different years between 1963 and 1990, was analysed, Forty-one analytical parameters determined on each sample were used to predict the year using a partial least squares (PLS) regression and to identify the cellar using a soft independent modelling class analogy (SIMCA) model, Both problems fall naturally within the field of food chemometrics and present the statistical difficulty of having fewer objects than variables. It is, therefore, impossible to apply normal multiple regression and discriminant analysis techniques, The PLS model requires two latent variables and explains 97.4% of the variance of the age variable and 90.2% of the cross-validated variance. As for the characterization of both brands, a SIMCA model with two components for each model correctly classified 22 of the 24 samples; it gives a sensitivity of 83.3% and a specificity of 91.7% for Dow's vintage ports, whereas for Graham's vintage ports the sensitivity and specificity are 91.7 and 100%, respectively.