Evaluation of Authenticity of Iranian Olive Oil by Fatty Acid and Triacylglycerol Profiles

For evaluation of the authenticity of Iranian olive oil, samples from many Iranian olive oil producers especially north of Iran in the production year 2007 were collected. The fatty acid and triacylglycerol compositions were measured. The most recent calculation methods including ∆ECN the difference between the actual and theoretical ECN42 (equivalent carbon number), triglyceride content and R of olive oils according to IOOC methods were applied. On the basis of our results, we were able to classify the olive oils into the extra virgin, virgin olive and olive oil categories. The important fatty acids are oleic, palmitic and linoleic acids and their main triacylglycerols are OOO, POO, OOL, PLO, SOS plus POP, and OLL, respectively. On the basis of the triacylglycerol results, experimental ECN48, ECN46, ECN50, ECN44 and ECN42 were obtained. By using the fatty acids results and a computer program, the theoretical ECN42 and ECN44 were calculated. Then R values, being the ratio of r ECN42/r ECN44 for authenticity of all olive oils and ∆ECN for determining categories of olive oils, were defined. The results of olive oil samples were in the accepted limits of Codex and IOOC. Finally we suggest that the R and ∆ECN can be used in identification of adulteration of olive oils and also they are useful from the point of view of authenticity and classification.     

Erucic Acid is Differentially Taken up and Metabolized in Rat Liver and Heart

Because X-linked adrenoleukodystrophy is treated using erucic acid (22:1n-9), we assessed its metabolism in rat liver and heart following infusion of [14-¹⁴C]22:1n-9 (170 Ci/kg) under steady-state-like conditions. In liver, 2.3-fold more tracer was taken up as compared to heart, accounted entirely by increased incorporation into the organic fraction (4.2-fold). The amount of tracer entering the aqueous fraction, which represents β-oxidation, was not different between groups; however a significantly elevated proportion of tracer was in the heart aqueous fraction. In both tissues, 76% of the radioactivity found in the organic fraction was esterified in neutral lipids, while only about 10% was found esterified into phospholipids. In liver, 56% of lipid radioactivity was found in cholesteryl esters, whereas in heart 64% was found in triacylglycerols. Because 22:1n-9 can be chain shortened, we assessed tracer metabolism using phenacyl fatty acid derivatives esterified from saponified esterified neutral lipid (triacylglycerol/cholesteryl ester) and phospholipid fractions. In heart esterified neutral lipids, 75% of tracer was recovered as 22:1n-9 and only 10% as oleic acid (18:1n-9), while in liver only 25% of the tracer was recovered as 22:1n-9, while 50% was found as stearic acid (18:0) and 10% as 18:1n-9. In liver and heart phospholipids, the tracer was distributed amongst the n-9 fatty acid family. Thus, 22:1n-9 under went tissue selective metabolism, with conversion to 18:0 the dominant pathway in the liver presumably for export in the neutral lipids, while in heart it was found primarily as 22:1n-9 in neutral lipids and used for β-oxidation.     

Alteration of Serum Phospholipid n-6 Polyunsaturated Fatty Acid Compositions in Nonalcoholic Fatty Liver Disease in the Japanese Population: A Cross-Sectional Study

We performed a cross-sectional study on 215 Japanese employees aged 20–68 years to investigate the association between NAFLD and serum phospholipid fatty acid composition. NAFLD was diagnosed by ultrasonography. The fatty acid composition between the control and NAFLD groups was compared, and the inverse probability of treatment weighting (IPTW) was performed to eliminate each confounding effect of sex, smoking status, BMI, insulin resistance, dietary cholesterol, and salt intake. A receiver operating characteristic (ROC) curve analysis was performed to evaluate the NAFLD prediction accuracy of fatty acids. Seventy-one subjects were diagnosed with NAFLD. Their serum phospholipid dihomo-γ-linolenic acid (DGLA) level was significantly higher after adjusting for each variable using IPTW. In the ROC analysis, the ratio of ARA to DGLA had an area under the curve (AUC) of 0.763. By combining the ratio of ARA to DGLA with the ratio of AST to ALT, AUC increased to 0.871. In conclusion, NAFLD subjects in a Japanese working population have higher serum phospholipid DGLA. Results of the IPTW and ROC analysis indicated that serum PL DGLA and the ratio of ARA to DGLA provide diagnosis information on the fatty liver that is different to AST and ALT and improve the accuracy of fatty liver prediction, owning potential value as serum biomarkers.     

Longitudinal Assessment of Erythrocyte Fatty Acid Composition Throughout Pregnancy and Post Partum

Transfer of fatty acids from mother to fetus during pregnancy is a requirement for optimal fetal growth. We report a longitudinal study of full maternal erythrocyte fatty acid profile assessed at each trimester of pregnancy [mean 12.5 (range 8–14), 26.1 (24–28) and 35.5 (33–38) weeks’ gestation] and in the post partum period [18.1 (12–26) weeks]. The study recruited healthy women (n = 47) from routine antenatal clinics at the Princess Royal Maternity Unit, Glasgow, Scotland. There were increases in 16:1n7 (22%, p = 0.0005), 24:1n9 (13%, p = 0.0032), 22:5n6 (25%, p = 0.0003), 18:3n3 (41%, p = 0.0007) and 22:6n3 (20%, p = 0.0005) concentrations during pregnancy. The greatest increases took place between gestations at sampling of 12.5 and 26.1 weeks. The change in 16:1n7 concentration between gestations at sampling of 12.5 and 35.3 weeks was negatively associated with maternal booking body mass index (r = −0.40, p = 0.006). The change in 22:6n3 concentration was correlated with the change in 24:1n9 (r = 0.70, p < 0.001). In samples taken four months post partum, 14:0 concentration was lower (29%, p = 0.0002) and 24:0 concentration (15%, p = 0.0009) and n6/n3 ratio (11%, p = 0.0019) were higher than at a gestation at sampling of 12.5 weeks. In conclusion, several fatty acids are specifically mobilised during pregnancy. The correlation between maternal 22:6n3 and 24:1n9 suggests that mobilisation of these fatty acids may be coordinated. The inverse relationship between 16:1n7 and maternal central obesity warrants further investigation.     

Fatty Acids in Liver,Muscle and Gonad of three Tropical Rays including Non-Methylene-Interrupted Dienoic Fatty Acids

Scientific investigation of lipids in Elasmobranchs has been conducted mainly on shark species. Because rays seem to be neglected, this study was performed to examine the complete fatty acid (FA) composition with a particular interest for long-chain polyunsaturated FA (PUFA) content in different tissues of three ray species including parts usually discarded. The total FA and PUFA profiles of total lipids were determined in muscle, liver, and gonad of Rhinobatos cemiculus, Rhinoptera marginata, and Dasyatis marmorata, the most often caught ray species from the East Tropical Atlantic Ocean. Fifty FA were characterized as methyl esters and N-acyl pyrrolidides by gas chromatography/mass spectrometry, showing significant levels of 20:5n-3 (EPA) (up to 5.3%) and 22:5n-3 (DPA) (up to 7.3%), high levels of 20:4n-6 arachidonic (ARA) (4.8–8.6% of total FA) and 22:6n-3 (DHA) (up to 20.0%). The results show that muscle, liver and gonad of rays can provide high amounts of essential PUFA, specially DHA, for direct human nutrition or the food processing industry. High proportions of DHA were particularly found in all samples of R. cemiculus (11.6–20.0%), and in muscle and liver of D. marmorata (11.1–16.1%). Regarding the high amounts of (n-3) PUFA, this study shows that these rays deserve a better up-grading, including the normally discarded parts, and describes the occurrence of unusual NMID FA in all tissues studied. Five non-methylene-interrupted dienoic fatty acids (NMID FA) (0–3.4%) were reported, including previously known isomers, namely 20:2 Δ7,13, 20:2 Δ7,15, 22:2 Δ7,13, 22:2 Δ7,15, and new 22:2 Δ6,14. These acids are quite unusual in fish and unprecedented in rays. The 22:2 Δ6,14 acid occurred in gonads of male specimens of R. cemiculus at 2.9%.     

Seasonal Variation of the Chemical Content and Fatty Acid Composition of Mantle and Tentacle of Male and Female Sepia officinalis

The goal of this study was to evaluate the chemical composition and the fatty acid profile of mantle and tentacle of male and female Sepia officinalis, sampled at four seasons from the Mediterranean sea of Tunisia. S. officinalis were found to be rich in glycogen, protein and oil, and significant differences were observed between samples. The level of saturated fatty acid and unsaturated fatty acid showed significant variability among sex and during seasons. DHA and EPA, as polyunsaturated fatty acids, were the most abundant in all samples (14.8–27.8 % and 10.4–18.3 %, respectively). Oleic acid was the most abundant monounsaturated fatty acids (1.63–4.52 %). Σn3 and Σn6 was remarkably different between seasons and among sex. This study could be suitable for the development of reliable guide of fatty acid accumulation in cephalopod.     

Oil Content and Fatty Acid Composition in Seeds of Three Safflower Species

Seeds of six safflower (C. tinctorius L.) genotypes and 19 accessions of two wild species were analyzed for oil and fatty acid composition. Oil content ranged from 29.20 to 34.00, 20.04 to 30.80 and 15.30 to 20.80% in C. tinctorius, C. oxyacantha Bieb. and C. lanatus L., respectively. The main fatty acids of oleic, linoleic, palmitic and stearic acids composed 96–99% of the total fatty acids in all species. The sum of myristic, palmitoleic, arachidic, and behenic fatty acids in oil of the species ranged from 0.43 to 0.57%. The oleic acid in seed oil of C. tinctorius, C. oxyacantha and C. lanatus ranged from 12.24 to 15.43, 14.11 to 19.28 and 16.70 to 19.77%, respectively. The corresponding ranges for linoleic acid were 71.05 to 76.12, 63.90 to 75.43 and 62.47 to 71.08%. Palmitic acid in seed oil varied from 5.48 to 7.59% in C. tinctorius, 6.09 to 8.33% in C. oxyacantha and 7.44 to 8.78% in C. lanatus. The stearic acid of the seed oil showed a variation of 1.72 to 2.86, 2.50 to 4.87 and 3.14 to 4.79% in genotypes of these species, respectively. The fatty acids composition of oil among the cultivated and wild species were not considerably different, indicating that seed oil of the wild safflower is possibly suitable for human consumption and industrial purposes.     

Influence of Fatty Acid Profile of Total Parenteral Nutrition Emulsions on the Fatty Acid Composition of Different Tissues of Piglets

Total parenteral nutrition (TPN) studies in human babies of very-low-birth-weight suggest that the lipid emulsions currently available are not optimum for neonatal nutrition. Since fatty acid metabolism in human and pigs is very similar, the present study examines how lipid emulsions used in clinical TPN (i.e. ClinOleic, Intralipid, Lipofundin or Omegaven), with different fatty acid compositions, administered to neonatal piglets for 7 days, influenced their tissue fatty acid composition as compared to those enterally fed with a sow milk replacer. A positive linear relationship was found between the proportion of all individual fatty acids in the lipid emulsions or in the milk replacer versus those in plasma, skeletal muscle, subcutaneous fat, liver, heart, pancreas, stomach or intestine total lipids or in brain phospholipids, the latter showing the lowest correlation coefficient. With the exception of brain, the proportion of either oleic acid or alpha-linolenic acid in the individual tissues was correlated with those present in the corresponding lipid emulsion or milk replacer, whereas the proportion of linoleic acid correlated significantly with all the tissues studied. With the exception of brain phospholipids, both eicosapentaenoic and docosahexaenoic acids were higher in the tissues of piglets receiving Omegaven than in all other groups. In conclusion, with the exception of the brain, fatty acid composition of plasma and different tissues in piglets are strongly influenced by the fatty acid profile of TPN emulsions. Fatty acid composition of brain phospholipids are, however, much less influenced by dietary composition, indicating an active and efficient metabolism that ensures its appropriate composition at this key stage of development.     

Determination of the Fatty Acid Composition in Tree Peony Seeds Using Near-Infrared Spectroscopy

Tree peonies (Paeonia Sect Moutan DC) are an emerging oil crop because of their high oil and α‐linolenic acid (ALA) content. This research was to investigate the potential use of near infrared reflectance spectroscopy (NIRS) for estimating the major fatty acids contents, such as palmitic acid (C16:0), oleic acid (C18:1), linoleic acid (C18:2) and linolenic acid (C18:3) in tree peonies. A total of 115 small seed samples and 447 single seeds were selected to calibrate the predictive models. NIRS absorbance spectra were collected using a Fourier transform near infrared (FT‐NIR) spectrometer for the small seed samples, and acousto‐optic tunable filter‐near infrared (AOTF‐NIR) for the single seed samples. Statistical analysis was performed with partial least squares (PLS). For the husked samples, C18:3, C18:1 and C18:2 showed the highest correlation coefficient of validation (R_v; = 0.9756, 0.9467 and 0.8485, respectively) and the ratio of performance to deviation (RPD; = 3.58, 1.91 and 2.17, respectively); however, C16:0 did not reach expectations (R_v = 0.7783, RPD = 1.32). For intact samples, C18:3 showed the best prediction (R_v = 0.9096, RPD = 3.14), followed by C18:2 (R_v = 0.8479, RPD = 1.96). The results for C18:1 were poor (R_v = 0.7237, RPD = 1.70). For single seeds, only the results for C18:3 (R = 0.9150, RPD = 1.73) were good in the husked seed samples. It was concluded that NIRS can be used to rapidly assess the content of the major fatty acids in small samples.     

Acetate Treatment Increases Fatty Acid Content in LPS-Stimulated BV2 Microglia

Acetate supplementation increases plasma acetate, brain acetyl-CoA, histone acetylation, phosphocreatine levels, and is anti-inflammatory in models of neuroinflammation and neuroborreliosis. Although radiolabeled acetate is incorporated into the cellular lipid pools, the effect that acetate supplementation has on lipid deposition has not been quantified. To determine the impact acetate-treatment has on cellular lipid content, we investigated the effect of acetate in the presence of bacterial lipopolysaccharide (LPS) on fatty acid, phospholipid, and cholesterol content in BV2 microglia. We found that 1, 5, and 10 mM of acetate in the presence of LPS increased the total fatty acid content in BV2 cells by 23, 34, and 14 % at 2 h, respectively. Significant increases in individual fatty acids were also observed with all acetate concentrations tested with the greatest increases occurring with 5 mM acetate in the presence of LPS. Treatment with 5 mM acetate in the absence of LPS increased total cholesterol levels by 11 %. However, neither treatment in the absence of LPS significantly altered the content of individual phospholipids or total phospholipid content. To determine the minimum effective concentration of acetate we measured the time- and concentration-dependent changes in histone acetylation using western blot analysis. These studies showed that 5 mM acetate was necessary to induce histone acetylation and at 10 mM acetate, the histone acetylation-state increased as early as 0.5 h following the start of treatment. These data suggest that acetate increases fatty acid content in LPS-stimulated BV2 microglia that is reflected by an increase in fatty acids esterified into membrane phospholipids.     

Heart-Cut Two-Dimensional Countercurrent Chromatography for the Isolation of a Furan Fatty Acid Triacylglycerol from Latex Gloves and Identification of Further Lipid Compounds

Hevea brasiliensis latex from specific genotypes such as RRIM501 or PB235 is one of the richest natural sources of furan fatty acid 9-(3-methyl-5-pentylfuran-2-yl)-nonanoic acid (9M5), which is mainly present in the form of triacylglycerols. In this study, we successfully isolated a triacylglycerol esterified with three 9M5 molecules (tri-9M5) with a purity of 97% from the lipid extract of latex gloves by means of countercurrent chromatography (CCC). The gas chromatography with a mass spectrometry (GC/MS) spectrum of tri-9M5 not only featured the diagnostic fragment ion [M-RCOO]⁺ of triacylglycerols but also a fragment ion shifted by 16 Da to higher mass which corresponded with [M-RCO]⁺. [M-RCO]⁺ was only detected in triacylglycerols substituted with at least one furan fatty acid. Additionally, five γ-tocotrienyl fatty acid esters (γ-T₃-FA esters), namely, γ-T₃-16:0, γ-T₃-18:0, γ-T₃-18:1n-9, γ-T₃-18:2n-6 and γ-T₃-20:0, were detected in the sample. Contributions of γ-T₃-FA esters with 18:1n-9 and 18:2n-6 which co-eluted in GC/MS could be calculated after mathematical correction for contributions of the ¹³C₂ isotope peak of γ-T₃-18:2n-6 to γ-T₃-18:1n-9. This was necessary for quantitation of these two γ-T₃-FA esters. Improved separation of the γ-T₃-FA esters could be achieved by the novel heart-cut recycling CCC mode (four cycles). Sterols detected in disposable latex gloves were β-sitosterol, Δ⁵-avenasterol, and stigmasterol along with small quantities of 24-methylene-cycloartenol and Δ⁵-citrostadienol.     

Streptozotocin-Induced Diabetes Partially Attenuates the Effects of a High-Fat Diet on Liver and Brain Fatty Acid Composition in Mice

The current study addresses the effects of a high-fat diet on liver and brain fatty acid compositions and the interaction of that diet with diabetes in a type 1 mouse model. Adult, male, normal and streptozotocin-induced diabetic C57BL/6 mice were fed standard (14 % kcal from fat) or high-fat (54 % kcal from fat, hydrogenated vegetable shortening and corn oil) diets for 8 weeks. Liver and whole brain total phospholipid fatty acid compositions were then determined by TLC/GC. In the liver of non-diabetic mice, the high-fat diet increased the percentages of 18:1n-9, 20:4n-6, and 22:5n-6 and decreased 18:2n-6 and 22:6n-3. Diabetes increased 16:0 in liver, and decreased 18:1n-7 and 20:4n-6. The effects of the high-fat diet on liver phospholipids in diabetic mice were similar to those in non-diabetic mice, or were of smaller magnitude. In the brain, the high-fat diet increased 18:0 and 20:4n-6 of non-diabetic, but not diabetic mice. Brain 22:5n-6 acid was increased by the high-fat diet in both non-diabetic and diabetic mice, but this increase was smaller in diabetic mice. Diabetes alone did not alter the percentage of any individual fatty acid in brain. This indicates that the effects of a high-fat diet on liver and brain phospholipid fatty acid compositions are partially attenuated by concomitant hyperglycemia with hypoinsulinemia.     

棉籽酸化油的理化性质及脂肪酸组成分析

采用气相色谱法分析了棉籽酸化油的脂肪酸组成,并对其理化性质进行了研究。分析结果表明,棉籽酸化油的含油率为91.33%,酸值为144.35mgKOH/g,碘值为116.58gI2/100g,皂化值为199.80mgKOH/g;其主要脂肪酸为棕榈酸(21.29%)、硬脂酸(2.29%)、油酸(23.72%)、亚油酸(50.23%)和亚麻酸(0.39%),其中不饱和脂肪酸的含量高达74%,具有很高的工业利用价值。     

Rapid Preparation of Fluorescent 9-Anthrylmethyl Esters for Fatty Acid Analysis of Small Amount of Triacylglycerols

This paper proposes a one-step method for preparation of fluorescent 9-anthrylmethyl esters from triacylglycerols (TAG) ranging in amount from 0.1 to 5 μg. It involves base-catalyzed transesterification using potassium 9-anthracenemethoxide, prepared by proton exchange between 9-anthracenemethanol and potassium tert-butoxide. Transesterification for 10 min at room temperature gave the fatty acid 9-anthrylmethyl esters in nearly maximal yields (82–85%). The products could be analyzed by reversed-phase HPLC without purification. Excellent linear relationships were observed for standard curves of 10–250 pmol of TAG standards (16:0, 19:0, 18:2 and 22:6), and differences in the slopes were less than 5% among the standards. Almost consistent compositions of the esters were observed for the products formed from 0.5 to 5 μg or less of fish oils TAG, and they were similar to those obtained by HPLC of ordinary multi-step synthesis products and by GLC of methyl esters. The present method is a great improvement of derivatization time, and is powerful for fatty acid analysis of small amounts of natural TAG.     

Seasonal Variations of Lipid Content and Composition in <Emphasis Type="Italic">Perna viridis</Emphasis>

The total lipid content, composition of main lipid classes, composition of sterols and composition of fatty acids in the main glycerolipids of Perna viridis were analyzed through four seasons using TLC-FID and GLC. Mussel samples were collected during different seasons between 2003 and 2004 from Shengsi Island, Zhejiang Province, China and stored frozen prior to freeze-drying and lipid extraction. Ten grams of dried mussel powder of each season were analyzed. Total lipid content ranged from 14.5 g/100 g in spring month to 7.8 g/100 g dried mussel powder in autumn month. The predominant lipid in spring month was triacylglycerol (TAG), however, in the other three seasons the phospholipids (PL) was the main lipid class. The most abundant fatty acid in TAG, PL and phosphatidylcholine (PC) was 16:0, with the summer samples having the highest proportion (24-30% of total fatty acid) and winter the lowest (14-22%). In phosphatidylethanolamine (PE), the spring samples had the highest proportions of 16:0. The predominant polyunsaturated fatty acids (PUFA) were 22:6n-3 and 20:5n-3 in TAG, PL, PE and PC (25-40%). The proportions of 22:6n-3 and 20:5n-3 were higher in spring than in other seasons in PL and PE. There were nine sterols identified, with cholesterol being the predominant sterol, and other main ones were desmostersol/brassicasterol and 24-methylenecholesterol. Proportions of other fatty acids in different lipid fractions and the sterol compositions as well also varied seasonally. There were subject to the seasonal variations. Differences in lipid content and composition, fatty acid composition in different lipid fractions may be caused by multiple factors such as lifecycle, sex, variation of plankton in different seasons and temperature, which could influence physiological activities and metabolism.     

环氧油脂肪酸组成分析研究

通过薄层色谱、气相色谱、色质联用等技术,首次得到了油脂环氧化反应期间的脂肪酸环氧化反应规律:开始反应阶段,高含量不饱和脂肪酸反应速率高于低含量不饱和脂肪酸;环氧化反应期间,多不饱和脂肪酸首先生成单环氧酸,之后再逐渐生成二环氧酸,最后生成三环氧酸;富含亚麻酸的油脂环氧化反应时有更易于开环反应的趋向,其次是富含亚油酸的油脂,再次是富含油酸的油脂.实验结果表明,不同环氧油原料在进行环氧化反应时需要控制不同的反应条件,以避免开环副产物量的增加,从而制备得优质环氧油产品.     

Gut Microbial Fatty Acid Metabolites Reduce Triacylglycerol Levels in Hepatocytes

Hydroxy and oxo fatty acids were recently found to be produced as intermediates during gut microbial fatty acid metabolism. Lactobacillus plantarum produces these fatty acids from unsaturated fatty acids such as linoleic acid. In this study, we investigated the effects of these gut microbial fatty acid metabolites on the lipogenesis in liver cells. We screened their effect on sterol regulatory element binding protein‐1c (SREBP‐1c) expression in HepG2 cells treated with a synthetic liver X receptor α (LXRα) agonist (T0901317). The results showed that 10‐hydroxy‐12(Z)‐octadecenoic acid (18:1) (HYA), 10‐hydroxy‐6(Z),12(Z)‐octadecadienoic acid (18:2) (γHYA), 10‐oxo‐12(Z)‐18:1 (KetoA), and 10‐oxo‐6(Z),12(Z)‐18:2 (γKetoA) significantly decreased SREBP‐1c mRNA expression induced by T0901317. These fatty acids also downregulated the mRNA expression of lipogenic genes by suppressing LXRα activity and inhibiting SREBP‐1 maturation. Oral administration of KetoA, which effectively reduced triacylglycerol accumulation and acetyl‐CoA carboxylase 2 (ACC2) expression in HepG2 cells, for 2 weeks significantly decreased Srebp‐1c, Scd‐1, and Acc2 expression in the liver of mice fed a high‐sucrose diet. Our findings suggest that the hypolipidemic effect of the fatty acid metabolites produced by L. plantarum can be exploited in the treatment of cardiovascular diseases or dyslipidemia.     

Fingerprinting Krill Oil by 31P, 1H and 13C NMR Spectroscopies

The detailed analysis of krill oil is of importance to be able to differentiate other oils, identify adulterated products, and provide the highest quality associated with its beneficial health effects. The objective of this study was to demonstrate the usefulness of the combination of ³¹P, ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopies to characterize the krill oil profile. It was found that in contrast to fish oil, where eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) fatty acids are found in triacylglycerol, krill oil is characterized by a more asymmetric fatty acid distribution with a higher polyunsaturated fatty acids PUFA content in the sn‐2 position of phospholipids and lower amounts in triacylglycerol. Besides the typical asymmetric fatty acid composition, several other markers were investigated for krill oil origin test. The validation of the ³¹P NMR spectroscopic method regarding major phospholipid species was performed according to the Good Laboratory Practice (GLP) and International Council for Harmonisation (ICH) guidelines. The method was characterized by high sensitivity, accuracy, and reproducibility. Interlaboratory testing showed satisfactory robustness regardless of the type of NMR equipment used by different laboratories. High‐resolution NMR spectroscopy has proven to be a convenient and exact method for providing a characteristic fingerprint of krill oil. By this technique, clear distinctions to other oils can be made through qualitative and quantitative analysis of krill oil.