中文摘要：本研究建立了2种区分不同地理起源甜椒的方法。首先，分析了△O8标记的果实水和相应来源地区的水，并同全球水同位素观测网络（GNIP）值进行比对，来源地区的水和GNIP值与辣椒果实水相关性较好，同位素分馏值为-4。其次，应用化合物特异性稳定氢同位素数据对结果进行分类。采用正构烷烃的指纹数据（包括线性鉴别分析和相似性分类法）、核密度平滑数据区分不同来源的甜椒。利用△H2值和正构烷烃的相对组成作为参数对这两种方法进行评估。结果表明，这两种方法对所有样品的灵敏度高，可以较好区分不同地理分布的甜椒。
外文摘要：Two approaches were investigated to discriminate between bell peppers of different geographic origins. Firstly, delta O-18 fruit water and corresponding source water were analyzed and correlated to the regional GNIP (Global Network of Isotopes in Precipitation) values. The water and GNIP data showed good correlation with the pepper data, with constant isotope fractionation of about -4. Secondly, compound-specific stable hydrogen isotope data was used for classification. Using n-alkane fingerprinting data, both linear discriminant analysis (LDA) and a likelihood-based classification, using the kernel-density smoothed data, were developed to discriminate between peppers from different origins. Both methods were evaluated using the delta H-2 values and n-alkanes relative composition as variables. Misclassification rates were calculated using a Monte-Carlo 5-fold cross-validation procedure. Comparable overall classification performance was achieved, however, the two methods showed sensitivity to different samples. The combined values of delta H-2 IRMS, and complimentary information regarding the relative abundance of four main alkanes in bell pepper fruit water, has proven effective for geographic origin discrimination. Evaluation of the rarity of observing particular ranges for these characteristics could be used to make quantitative assertions regarding geographic origin of bell peppers and, therefore, have a role in verifying compliance with labeling of geographical origin.
外文关键词：Isotope ratio mass spectrometry；Gas chromatography；Geographic origin；Food products authenticity；Linear discriminant analysis；Likelihood ratio；Bell peppers；Capsicum annuum
作者：RE De；JC Schoorl；C Cerli等
作者单位：荷兰阿姆斯特丹大学
期刊名称：FOOD CHEMISTRY
期刊影响因子：4.052
出版年份：2016
出版刊次：2
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