Application of standard addition to eliminate conjugated linoleic acid andother interferences in the determination of total trans fatty acids in selected food products by infrared spectroscopy

Citation
Mm. Mossoba et al., Application of standard addition to eliminate conjugated linoleic acid andother interferences in the determination of total trans fatty acids in selected food products by infrared spectroscopy, J AM OIL CH, 78(6), 2001, pp. 631-634
Citations number
31
Categorie Soggetti
Agricultural Chemistry
Journal title
JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
ISSN journal
0003021X → ACNP
Volume
78
Issue
6
Year of publication
2001
Pages
631 - 634
Database
ISI
SICI code
0003-021X(200106)78:6<631:AOSATE>2.0.ZU;2-T
Abstract
A novel and rapid (5 min) attenuated total reflection-fourier transform inf rared (ATR-FTIR) spectroscopic method AOCS Cd 14d-99 for the determination of total isolated trans fatty acids, which absorb at 966 cm(-1), was recent ly developed, collaboratively studied, and applied to food products contain ing 1-50% trans fat (as percentage of total fat). Attempts to apply the ATR -FTIR method to biological matrices of low trans fat and/or low total fat c ontent, and to dairy and other products were not satisfactory due to interf ering 1R absorptions in the trans region. One group of interfering compound s with absorption bands near 985 and 948 cm(-1) was the cis/trans positiona l isomers of conjugated linoleic acid (CLA) found in dairy and meat product s from ruminants at levels of <1% (as percentage of total fat). In the pres ent study, we modified the ATR-FTIR method to overcome matrix interferences . This modification, which consisted of applying the standard addition tech nique to the ATR-FTIR determination, was also applied to several food produ cts, namely, dairy products, infant formula and salad oil dressing, which s uccessfully eliminated interfering absorbances that impacted on accuracy. T he presence of <1% CLA in two butter and two cheese products containing 6.8 , 7.5, 8.5, and 10.4% trans fatty acids (as a percentage of total fat) woul d have led to errors of -11.6, 10.4, 17.6 and 34.6%, respectively, in trans fat measurements had the standard addition technique not been used. The ap plicability of ATR-FTIR to the quantitation of food products is discussed.