Predicting liquid loss of frozen and thawed cod from hyperspectral imaging

Abstract

As the ability to appraise the quality of every fish in a delivery in a consistent, objective, and rapid manner has numerous advantages for both sellers and buyers, there has been much research into methods to achieve this. One possible proxy for quality assessment is liquid loss, which correlates with undesirable sensory attributes. This study evaluated whether hyperspectral imaging could predict liquid loss on samples that had undergone a program of freezing and thawing. Vacuum-packaged cod loins were split into two groups, one which was kept chilled and the other that underwent a program of freezing and thawing. Multivariate analysis of the hyperspectral imaging data on the chilled samples could predict liquid loss with good accuracy for samples that underwent no further processing. Analysis of data from the hyperspectral images of the frozen and thawed cod samples also showed a good ability to predict their liquid loss. These results indicate that hyperspectral imaging is a promising method for non-invasive quality monitoring of cod products in different processing states. Also, whereas previous research had been unable to predict sample processing protocols, improvements to the hyperspectral imaging technology now enables identification of samples based on freezing and thawing procedures.