Portable Raman Spectrometer as a Screening Tool for Characterization of Iberian Dry-Cured Ham

Abstract

Dry-cured Iberian ham is officially classified into different commercial categories according to the pig’s breed and feeding regime. These reach very different prices, thus promoting labelling fraud and causing great damage to the food sector. In this work, a method based on Raman spectroscopy was explored as a rapid in situ screening tool for Iberian ham samples. A total of 110 samples were analyzed to assess the potential of this technique to differentiate purebred, crossbred, acorn-fed and feed-fed dry-cured Iberian ham. A continuous signal probably due to sample fluorescence was obtained, which hid the Raman scattering signal. Therefore, chemometric treatment was applied in order to extract non-apparent information. High validated classification rates were obtained for feeding regime (83.3%) and breed (86.7%). In addition, an interlaboratory study was carried out to confirm the applicability of the method with 52 samples, obtaining a validated rate above 80%.

Performance of benchtop and portable spectroscopy equipment for discriminating Iberian ham according to breed

“…In this context, the SNV treatment has also been successfully applied in biological samples to eliminate interferences ( Afseth et al, 2006 ; Liland et al, 2016 ), while other studies used curve fitting of the broadband variation with a high-order polynomial based on the Savitzky-Golay method ( Lieber and Mahadevan-Jansen, 2003 ; Chen et al, 2014 ; Wei et al, 2015 ). However, Martín-Gómez et al (2021) were able to discriminate Iberian ham samples using Raman spectra without any mathematical pre-treatment by optimizing their own classification algorithm.…”

“…As far as the application of spectroscopy for Iberian ham classification is concerned, although some studies have addressed the identification of the breed of pork fat or carcasses using NIR spectroscopy equipment (benchtop or portable) ( Horcada et al, 2020 ; Hernández-Jiménez, 2021b ; Pérez-Marín et al, 2022 ), few methods have been proposed to authenticate the final product. Therefore, Martín-Gómez et al (2021) proposed a method based on Raman spectroscopy as a rapid in situ screening tool for Iberian ham samples which classifies the breed correctly in 87% of cases. However, no studies have been made of the feasibility of discriminating Iberian breeds, i.e.…”

Prediction of Carcass Composition and Meat and Fat Quality Using Sensing Technologies: A Review

“…Additionally, Logan et al (2021) correctly classify beef fed long-term grain, short-term grain, grass, and a supplemented grass diet (96%, 85%, 83%, and 83%, respectively), using a handheld Raman spectrometer directly on the carcass subcutaneous fat and PLS-DA. Martin-Gomez et al (2021) used a portable Raman spectrometer in a laboratory and a K-nearest neighbours algorithm to correctly classify 83.3% of dry-cured hams based on pork diet and 77.8% to 100% of dry-cured hams based on breed. Furthermore, Ostovar Pour et al (2020) distinguished beef cuts (rump, Scotch fillet, round, chuck, tenderloin, and T-bone) with 84.4% accuracy, using a portable Raman spectrometer in a laboratory and principal component discriminant function analysis.…”