Assessment of lipid composition and eicosapentaenoic acid/docosahexaenoic acid bioavailability in fish oil obtained through different enrichment methods

Assessment of cooking methods and freezing on the nutritional value and health risks of heavy metals in four fish species consumed in Douala, Cameroon

The effects of smoking, boiling and freezing on the nutritional value and health risks of heavy metals in four fish species consumed in Douala was investigated. Fish samples from Cyprinus carpio, Arius parkii, Ethmalosa fimbriata and Polydactilis quadrifilis were collected at the Douala Fishing seaport, carried to the laboratory, washed with distilled water and processed. Proximate composition, mineral content, heavy metals and lipid quality were analyzed using AOAC standard methods. Estimated Daily Intake (EDI), Targeted Hazard Quotient (THQ), Hazard Index (HI) and Carcinogenic Risk (CR) were used to estimate the human health risk. Results showed that smoking and boiling increased significantly (P < 0.05) protein and ash levels. Lipid were reduced significantly (P < 0.05) with boiling and freezing compared to raw and smoked sample. Smoking increased significantly (P < 0.05) cadmium, lead, mercury and arsenic contents compared to boiling and freezing. EDI values of cadmium in all species of fish smoked were not acceptable for human consumption. THQ values of mercury in raw, smoked, boiled and frozen were not acceptable for human consumption. HI suggested a non potential carcinogenic effect for all fish while CR for cadmium and arsenic suggested a carcinogenic health risk for Arius parkii (smoked and boiled). All treatment decreased significantly (P < 0.05) iodine value and increased acid, peroxide, anisidine values, thiobarbituric acid reactive substances and total oxidation index compared to raw fish. Boiling was the best cooking method compared to smoking.

Discrimination between the Triglyceride Form and the Ethyl Ester Form of Fish Oil Using Chromatography-Mass Spectrometry

Although the triglyceride form is the natural form of fish oil found in fish, the ethyl ester form of fish oil, which is used during processing to save costs, is also present on the market. In this study, fatty acids and lipids were determined using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-linear ion trap mass spectrometry (LC-LIT/MS), respectively, according to developed methods. The identification of fatty acids was based on the mass spectral characteristics and equivalent chain lengths. However, the fatty acid contents of both forms of fish oils are quite similar. The application of the LC-LIT/MS method for the structural characterization of triacylglycerols (TAGs) and the mechanism of LIT/MS fragmentation are also discussed. Neutral losses of CH2=CH2 (m/z 28) and CH3CH2OH (m/z 46), which are LIT/MS characteristics of ethyl ester from fish oil, were found for the first time. The triglyceride form of fish oils was easily and accurately identified using fingerprint chromatography. In conclusion, lipid analysis combined with LC-LIT/MS showed an improved capability to distinguish between types of fish oil.

Fish Oil Supplementation Modifies the Proteome, Lipidome, and Function of High-Density Lipoprotein: Findings from a Trial in Young Healthy Adults

BACKGROUND

Fish oil with the ω-3 fatty acids EPA and DHA is an FDA-approved treatment of patients with severe hypertriglyceridemia. Furthermore, EPA is an FDA-approved treatment of patients with high risk of cardiovascular disease (CVD); however, the cardioprotective mechanisms are unclear.

OBJECTIVES

We aimed to determine if fish oil supplementation is cardioprotective due to beneficial modifications in HDL particles.

METHODS

Seven fish oil naïve subjects without a history of CVD were recruited to take a regimen of fish oil (1125 mg EPA and 875 mg DHA daily) for 30 d, followed by a 30-d washout period wherein no fish oil supplements were taken. HDL isolated from fasting whole blood at each time point via 2-step ultracentrifugation (ucHDL) was assessed for proteome, lipidome, cholesterol efflux capacity (CEC), and anti-inflammatory capacity.

RESULTS

Following fish oil supplementation, the HDL-associated proteins immunoglobulin heavy constant γ1, immunoglobulin heavy constant α1, apolipoprotein D, and phospholipid transfer protein decreased compared to baseline (P < 0.05). The HDL-associated phospholipid families sphingomyelins, phosphatidylcholines, and phosphatidylserines increased after fish oil supplementation relative to baseline (P < 0.05). Compared to baseline, fish oil supplementation increased serum HDL's CEC (P = 0.002). Fish oil-induced changes (Post compared with Baseline) in serum HDL's CEC positively correlated with plasma EPA levels (R2 = 0.7256; P = 0.015). Similarly, fish oil-induced changes in ucHDL's CEC positively correlated with ucHDL's ability to reduce interleukin 10 (R2 = 0.7353; P = 0.014) and interleukin 6 mRNA expression (R2 = 0.6322; P =0.033) in a human macrophage cell line.

CONCLUSIONS

Overall, fish oil supplementation improved HDL's sterol efflux capacity through comprehensive modifications to its proteome and lipidome.