Lipid Class Specific Quantitative Analysis of n-3 Polyunsaturated Fatty Acids in Food Supplements

J Agric Food Chem. 2017 Jan 11;65(1):139-147. doi: 10.1021/acs.jafc.6b03745. Epub 2016 Dec 22.

Abstract

Supplementation products containing n-3 PUFA from marine sources serve a large market. Although the amount of eicosapentaenoic acid and docosahexaenoic acid in the products is provided by the manufacturer, no or little information is available on their lipid pattern. Therefore, we quantitatively analyzed the fatty acid pattern in the lipid fractions triglycerides, phospholipids, ethyl esters, and free fatty acids in supplementation products by means of solid phase extraction and gas chromatography. Twelve products from the European and U.S. markets containing fish, krill, algal, or plant oil were analyzed. Total n-3 PUFA content ranged from 68 g/100 g fat (fish oil) to 42 g/100 g fat (algal oil) to 17 g/100 g fat (krill oil). On the basis of the n-3 PUFA containing lipid class, the supplements can be separated dominantly in ethyl ester, re-esterified triglyceride, triglyceride, and phospholipid containing products. Algae-based products contained natural triglycerides, krill oils a complex mixture of phospholipids, triglycerides, and free fatty acids, and fish oil products either ethyl esters, re-esterified triglycerides, or triglycerides. Even products of the same class and source showed distinct differences in their lipid pattern. A specification of the lipid composition of n-3 PUFA products would allow distinguishing the different (qualities of) supplements.

Keywords: algal oil; fish oil; krill oil; lipid class; n-3 PUFA; plant oil; supplements.

MeSH terms

  • Animals
  • Dietary Supplements / analysis*
  • Euphausiacea / chemistry*
  • Fatty Acids, Omega-3 / analysis*
  • Fish Oils / chemistry*
  • Lipids / chemistry*
  • Phospholipids / analysis
  • Plant Oils / chemistry*
  • Triglycerides / analysis

Substances

  • Fatty Acids, Omega-3
  • Fish Oils
  • Lipids
  • Phospholipids
  • Plant Oils
  • Triglycerides