Determination of fatty acid composition of intramuscular fat in sheep by Near Infrared Transmission Spectroscopy (NIT) and their importance for the meat production

In the present study the precision of Near Infrared Transmission Spectrosco py (NIT) in the measurement of fatty acid composition of ovine intramuscula r fat using gas chromatography as reference was examined. A total of 81 fem ale lambs of various genetic backgrounds were involved in these measurement s. The animals were slaughtered at the age of 104 days with an average live weight of 30.7 kg. After slaughtering, two samples were taken fi om each a nimal (m. longissimus dorsi and nz. semimembranosus) for analysis. Altogether 40 fatty acids were identified by gas chromatography. Individual calibration for NIT measurement was performed for 15 of these. All 40 fatt y acids identified were then grouped by chain length and degree of saturati on and a separate calibration was performed for each group. There was good agreement between reference analysis by gas chromatography and NIT analysis (r = 0.57-0.90). With NIT, the standard error of prediction for each fatty acid depended on its individual concentration and ranged from 0.4 to 47.8 mg/100 g meat. These results demonstrate that it is possible to measure the content of individual fatty acids and the content of various classes of fa tty acids by NIT with high precision. This technique represents a practical and quick alternative to analysis by gas chromatography.