NIRS technology for fast authentication of vacuum-packed sliced Iberian ham

Objective: This study evaluated the effectiveness of near-infrared spectroscopy (NIRS) for categorising premium and non-premium Iberian ham presented as sliced products in vacuum-sealed packaging. The classification was based on the quality and sensory differences that appear in products derived from animals fed with natural resources (acorn and grass) in extensive systems (premium category), as opposed to those from animals fed with compound feeds (non-premium category).

Methods: A total of 259 sliced and vacuum-packed samples of Iberian hams and three portable near-infrared (NIR) devices were used for this purpose, exploring the best analysis mode (static versus dynamic).

Results: The static mode was the most suitable option for the classification of vacuum-packed sliced Iberian ham according to commercial classification. This approach achieved the highest precision, with 100% sensitivity, specificity, and non-error rate (NER) for two of the NIR sensors during external validation, while minimising sample handling. The third NIR sensor, a very low-cost and miniaturised device, produced more modest results, with 100% sensitivity but 85.71 % specificity and 94.74 % NER, limiting its applicability for samples near the classification threshold.

Conclusion: These results confirm the suitability of NIRS technology for rapid and non-destructive in situ classification of high-value foods, including pre-sliced Iberian ham.