Multi-needle injectors can potentially add large amounts of water rapidly to meat and fish. In order to hold in this water during freeze thawing and cooking of the meat, strong water holding agents have to be added such as salt, polyphosphates, hydrolysed collagen proteins, and vegetable gelling agents. The process can be used fraudulantly, unless the ingredients are declared according to labelling legislation. Brazilian researchers have developed a rapid method based on Raman spectroscopy and chemometrics to determine the presence of salt, sodium tripolyphosphate, and carageenan. One hundred and sixty five samples of beef injected with single, binary and tertiary mixtures of the three water holding agents were prepared. Raman spectra were run on all the samples, using 112 of them as the training set and the other 53 as the test set. The best PLS-DA model was built with 4 latent variables and successfully discriminated adulterated samples at relatively low rates of false negative and false positive results, which varied from 8.0 to 11.7%.
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