Evaluation of gas chromatographic and fourier transform infrared spectroscopic methods for the determination of trans-fat levels in the diets of laying hens and their eggs
Fusco, Robert Louis
MetadataShow full item record
Five groups of 10 single comb white leghorn hens were fed different diets (standard corn/soy laying rations supplemented with edible oils) to ascertain the effect of trans-fat deposition in eggs. Trans-fat contents of the feeds and eggs were determined by gas chromatography (GC) and Fourier transform infrared (FTIR) spectroscopy. Diets devoid of hydrogenated oils contained no detectable levels of trans-fats. Feeds supplemented with tallow, shortening, or their combination contained 2.78±0.08, 3.25±0.03, and 2.85±0.05 g/100-g dietary fat, and 3.33±0.32, 4.16±0.03, and 3.52±0.05 g/100-g dietary fat as assessed by GC and FTIR, respectively. Eggs from hens fed these latter diets contained 0.68±0.05, 0.81±0.05, and 0.76±0.04 g/100 g dietary fat, by GC, but were below the 1% detection limit of FTIR. Nearly 25% of trans-fats in the diets accumulated in the eggs. Supplementation of edible oils did not appreciably increase trans-fat levels in the eggs. Data acquired by these methods correlated well, r=0.98.