Determination of fatty acid composition of pork fat by Fourier transform infrared spectroscopy

The fatty acid composition of pork fat determines its processing quality. FTIR spectroscopic methods were evaluated on pork back and breast fat, directly on fat slices and on the fat extracts. Near infrared transmission and middle infrared using an ATR method were developed to determine the fatty acid content in the fat extracts. The results obtained with 80 back and 80 breast samples showed the validity of infrared spectroscopy to estimate SFA (saturated fatty acids), MUFA (monounsaturated fatty acids), PUFA (polyunsaturated fatty acids), C16:0, C18:0, C18:1 and C18:2 contents in fat extracts. Correlation coefficients (R(2)) were around 0.91 and 0.98 for MIR (ATR) and around 0.85 and 0.96 for NIR (transmission). Direct measurements on fat slices by NIR predicted SFA, PUFA, C18:1 and C18:2, although the coefficient correlations were less good; 0.69-0.79. This method though, is easier and faster than other techniques and is accurate enough to discriminate fat samples separated by standard visual and texture classification. Measurements could be made in 1 min.