Mid-infrared spectroscopy as a new tool for the evaluation of fish freshness

• Published in: International journal of food science & technology 2007, Vol.42 (1), p.57-64
• Main Authors: Karoui, Romdhane, Lefur, Bruno, Grondin, Christel, Thomas, Emilie, Demeulemester, Claude, Baerdemaeker, Josse De, Guillard, Anne-Sophie
• Format: Article
• Language: English
• Subjects: accuracy; adulterated products; Biological and medical sciences; calibration; Chemometry; differentiation; discriminant analysis; fish; food analysis; Food industries; food quality; freeze-thaw cycles; fresh fish; freshness; frozen fish; Fundamental and applied biological sciences. Psychology; infrared spectroscopy; mid-infrared; principal component analysis; qualitative analysis; raw fish; thawing; validity
• ISSN: 0950-5423; 1365-2621
• DOI: 10.1111/j.1365-2621.2006.01208.x

Frozen fish usually have a much lower market price than fresh fish, hence, adulteration could occur. This paper focuses on the use of mid-infrared (MIR) spectroscopy combined with chemometric tools to determine whether fish has been frozen-thawed. A total of twenty-four fish samples (fresh fish (n = 12) and frozen-thawed fish (n = 12)) were investigated. The principal component analysis and the factorial discriminant analysis were applied to the three spectral regions in the MIR of 3000-2800 cm⁻¹, 1700-1500 cm⁻¹ and 1500-900 cm⁻¹. Within the 1500-900 cm⁻¹ spectral region, correct classification (CC) of 100% and 75% was observed for the calibration and validation spectra, respectively. Improved classification was obtained from the 3000-2800 cm⁻¹ spectral region, with CC of 100% and 87.5% of the calibration and validation spectra, respectively. It can be concluded that the 3000-2800 cm⁻¹ and 1500-900 cm⁻¹ spectral regions may provide useful fingerprints allowing the differentiation between fresh and frozen-thawed fish. These regions can be considered as a reliable indicator of fish freshness.