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

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.

Krill Oil Has Different Effects on the Plasma Lipidome Compared with Fish Oil Following 30 Days of Supplementation in Healthy Women: A Randomized Controlled and Crossover Study

“…In all these studies, including the present study, it was difficult to exactly balance the contents of EPA and DHA between KO and FO arms, but in general, all studies had similar EPA contents. Another difference between published studies could be due to differences between supplements, in terms of the proportions of lipid classes (TG and PC in particular) in the KO [23]. In the present study, the increased plasma omega-3 levels over 30-days of KO treatment suggests a sustained maintenance of higher EPA levels due to homeostatic regulation balancing absorption into plasma with excretion in faeces and equilibration in tissues such as liver, muscle, and adipose and beta-oxidation of the EPA.…”

Modulation of the endogenous omega-3 fatty acid and oxylipin profile in vivo—A comparison of the fat-1 transgenic mouse with C57BL/6 wildtype mice on an omega-3 fatty acid enriched diet

“…The n3-PUFA rich diet (STD+n3) was the same diet containing 1% EPA and 1% DHA as ethyl esters (10% each in fat). Ethyl ester are generated during the purification and concentration of fish oil and thus represent together with the re-esterified triglycerides the most important class of supplementation products [ 40 ]. The fat content, peroxide value and the fatty acid composition of the experimental diets can be found in the supplementary information ( S1 Table ).…”

Comprehensive study of the composition of fish fat extracts and quantitative criteria for distinguishing standardized omega-3 polyunsaturated fatty acids extracts

“…Все вышесказанное обусловливает необходимость проведения исследований химического состава различных экстрактов ω3 ПНЖК на основе жира рыб [3,4] и др. с целью установления реальных показателей количественного и качественного состава препаратов и БАД на основе ω3 ПНЖК, реально используемых во врачебной практике.…”