Fat by Gas Chromatography Test

Method description

This analysis defines the breakdown of fat in terms of Total Fat, Saturated Fat, Monounsaturated Fat, Polyunsaturated Fat and Trans Fat. Total fat is reported as triglycerides; saturated, monounsaturated and trans fat are reported as fatty acids (as per NLEA regulations).

Lipids are extracted from food stuffs by conventional Mojonnier techniques. The resulting residues are then transesterified to form fatty acid methyl esters (FAMEs). The FAMEs are then quantitated using capillary column gas chromatography.

Acceptable matrices

All foods and food products

Unacceptable matrices

Non-food matrices

Limit of quantitation

0.01%

Equipment

Gas Chromatography – FID

Method reference

AOAC 996.06 (see also 920.39C, 983.23, 933.05, 948.15 Fat in various food stuffs) House, S.D. et. al. JAOAC Intl, 77, No. 4 (1991), 960. DeVries, J.W. et.al. JAOAC Intl, 82, No 4 (1999), 1146

Reportable unit

%

Sample size requirements

10 grams

Information required by submitter

For efficiency in processing your sample for analysis, please let your customer service representative know if your sample contains a large percentage of any one particular fatty acid.

Additional information

This test is ISO/IEC 17025 accredited through A2LA, Certificate # 2769.01.

The testing method assumes the presence of fat as a triglyceride and calculates total fat using the measured FAME values and an assumed glycerin backbone.  As the method is designed to measure triglyceride content, the accuracy of the total fat value may be affected in samples containing significant levels of monoglycerides, diglycerides and phospholipids.

There are two Fat tests which should be ordered for Dairy products with regard to food labeling. The first test is Fat by Gas Chromatography which is used for the Nutrition Facts Panel values for listed fats. The second test is Fat Dairy which is total fat determined by the Roese-Gottlieb official method (gravimetric). This Fat Dairy, Roese-Gottlieb, method is required by the Code of Federal Regulations (CFR) for use in labeling milk-fat content. This would be for the (skim, whole, low, etc.) labeling claim for milk fat that goes on the front of the product package.

This method includes specific calculations appropriate for nutrition labeling under the NLEA regulations. Total fat is calculated as triglycerides.

The sum total of Omega 3 fatty acids DHA and EPA are calculated separately and highlighted in this report.