Through the bottle authentication of red wine using near-IR fluorescence spectroscopy

Abstract

A major unaddressed challenge for food science remains the accurate characterisation of contents in sealed containers with a non-invasive method. This issue is particularly pressing for tackling fraud in the red wine industry, valued at billions of dollars globally, where product authenticity, brand reputation, and consumer trust are paramount. Whilst many techniques exist for authenticating wine externally, to date performing accurate classification of the contents within unopened bottles remains elusive. Using only a single near-infrared optical excitation source operating at a wavelength of 785 nm, in combination with a bespoke geometry to circumvent the confounding signal of the glass, we demonstrate that through-bottle fluorescence spectra can distinguish between twenty different red wines in their original, intact bottles. All twenty wine bottles were correctly classified with linear discriminant analysis (LDA) and principal component analysis (PCA) revealed strong varietal grouping. This non-invasive and rapid technique has the potential to enable on-site, routine wine authentication to combat the growing issue of wine fraud. The geometry itself is applicable across multiple fields for the analysis of other high-value products through their packaging, where authenticity verification is critical.