Prediction of fatty acid composition of bovine carcasses using Near Infrared Spectroscopy: measurement site selection
Prédiction de la composition en acides gras des carcasses bovines par spectroscopie proche infrarouge : choix du site de mesure
Résumé
The aim of the study was to determine the best site of bovine carcass for predicting fatty acid (FA) composition using a NIRS (near infrared spectroscopy) portable equipment. Seven tissues (Longissimus thoracis, Infraspinatus, Diaphragma, Rectus abdominis, shoulder subcutaneous adipose tissue (SAT), intercostal SAT and intermuscular fat at the 5th rib) were measured intact on carcasses and after sampling and grinding in liquid nitrogen. In order to have a representative database of French meat FA composition, 78 animals were sampled from different types and rearing systems. FA composition was assessed using gas chromatograph and the spectra were measured at wavelengths between 350 and 2500 nm. For adipose tissue, FA were not correctly predicted from NIRS. However, predictions were more satisfactory for the major FA (C16:0, C18:0, C18:1d9c), total saturated FA and total monounsaturated FA of muscles. They were even higher for ground than intact muscles. The Diaphragma, the fattest muscle (10.2 vs. 5.9% lipids) presented the lowest FA prediction of the four muscles. The three others were very close.