Determination of fatty acid composition of pig fat by near infrared reflectance spectroscopy

Abstract

Near infrared spectroscopy has been used in a wide range of agricultural sciences as an analytical tool to replace traditional wet chemistry. The current study was designed to investigate its possibilities for use as a technique in determining fatty acid profiles of pig fat.This study was carried out as part of a larger study examining influences of dietary fat sources on pig carcass and meat quality. Samples of the outer layer of pig fat from 52 animals was freeze dried then extracted with petroleum ether (40-60) for eight hours in a Soxhlet apparatus. This known quantity of fat was dissolved in 50 ml chloroform and a sub sample scanned in to the NIRS (Figure 1 shows a typical spectra). A sample of this chloroform solution was also methylated and the fatty acid profile determined by gas liquid chromatography. Values for each sample were determined for; total weight of fat, weight of: myristic, palmitic, palmitoleic, stearic, oleic, linoleic and linolenic fatty acids, as well as the total weight of saturated fatty acids (myristic + palmitic + stearic), total weight of monounsaturated fat (palmitoleic + oleic) and total weight of polyunsaturated fat (linoleic + linolenic).