Near infrared spectroscopy (Vis-NIRS) applied to differentiation between chilled and frozen/thawed meat

The ability of Vis-NIRS to differentiate between only chilled and frozen and thawed meat from pork, lamb, beef and goat is investigated in this study. Samples were purchased as retail ready package from seven different local supermarkets. Partial least squares discriminant analysis and double cross-validation were used for analysis of the data. The discrimination between the two groups achieved an accuracy of 93%. There is 92% probability that a chilled sample is predicted correctly as chilled and 96% that frozen/thawed is a true frozen/thawed event, which demonstrates reasonable performance, i.e. independent of the species (pork, lamb, beef and goat) and source. It was possible to detect the difference between only chilled and frozen/thawed meat. The regression coefficients suggest that the differences between the two treatments are likely to be associated to changes in structure and chemical composition of samples due to the process of freezing/thawing.