Abstract

Spectroscopic non-targeted methods are gaining ever-growing importance in quality control and authenticity assessment of food products because of their strong potential for identification of specific features of the products by data-driven classifiers. One of the factors hampering the diffusion of spectroscopic non-targeted methods and data-driven classifiers is the lack of harmonized guidelines for their development and validation. In particular, to date, neither conditions to directly compare spectra recorded by different spectrometers nor studies demonstrating the statistical equivalence of the spectra are available. Among the spectroscopic analytical techniques suitable for the development of non-targeted methods, nuclear magnetic resonance (NMR) offers the unique opportunity to generate statistically equivalent signals. In this paper, the feasibility of NMR spectroscopy to generate statistically equivalent NMR signals from a number of different spectrometers was demonstrated for complex mixtures (aqueous extracts of wheat and flour) by organizing an inter-laboratory comparison involving 36 NMR spectrometers. Univariate statistics along with multivariate analysis were exploited to establish unbiased criteria for assessing the statistical equivalence of the NMR signals. The aspects affecting the signal equivalence were investigated, and possible solutions to reduce the extent of the human error were proposed and applied with satisfactory results. This study furnishes the scientific community with an appropriate and easy procedure to validate non-targeted NMR methods and provides error values to be used as a reference for future studies.

中文翻译：

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为数据驱动食品真实性评估的非靶向NMR方法的统一做出的贡献

摘要

光谱非目标方法在食品的质量控制和真实性评估中正变得日益重要，因为它们具有通过数据驱动的分类器识别产品特定特征的强大潜力。阻碍光谱非目标方法和数据驱动分类器扩散的因素之一是缺乏统一的开发和验证指南。特别地，迄今为止，尚无直接比较由不同光谱仪记录的光谱的条件，也没有表明光谱统计等效性的研究。在适用于开发非目标方法的光谱分析技术中，核磁共振（NMR）提供了产生统计等效信号的独特机会。在本文中，通过组织涉及36个NMR光谱仪的实验室间比较，证明了复杂混合物（小麦和面粉的水提取物）中NMR光谱仪从许多不同光谱仪生成统计上等效的NMR信号的可行性。利用单变量统计和多元分析来建立无偏标准，以评估NMR信号的统计等效性。研究了影响信号等效性的方面，并提出了减少人为错误程度的可行解决方案，并得到了满意的结果。这项研究为科学界提供了一种适当且简便的程序，以验证非目标NMR方法，并提供了误差值，可供以后的研究参考。