13C NMR Spectra of TAG: An Easy Way to Distinguish Milks from Different Animal Species

In order to differentiate milks from different species, we carried out a comparative analysis of triacylglycerols from cow, buffalo, goat, and sheep’s milk fat based on 13C nuclear magnetic resonance (NMR) experiments. NMR spectroscopy, although less sensitive than other techniques, does not require an extensive chemical manipulation of samples, and can easily highlight the different content of short chain acyl groups in the four milk species. The resonances were assigned and quantified, and by using only three NMR parameters in data clustering with fuzzy logic analysis, we were able to separate goats’ milk from sheep’s milk, and both from cows and buffaloes’ milks. This appears to be an important result considering the easiness and rapidity with which milk identification can be obtained. From 13C spectra of triacylglycerols the positional distribution of fatty chains on glycerol carbon atoms can also be easily evaluated. In particular, analysis of positional distribution of monounsaturated fatty acids revealed that it may be species specific, and we are currently analyzing larger data sets in order to use this parameter as a suitable approach to the solution of milk authenticity issue.