POPs and PAHs in fish oil-based food supplements at the Czech market.

The objectives of this study were to assess concentrations of three groups of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) in 44 fish oil-based food supplements, to estimate their daily intake by consumers and, to evaluate the compliance of the oil samples with the oil origin declarations (cod liver oil or fish oil). The concentrations of ∑PCBs (7 congeners), OCPs (19 compounds, represented mainly by ∑DDTs), ∑PBDEs (10 congeners), and ∑PAHs (16 compounds) found in samples ranged between 0.15-55.7 µg kg-1, 0.93-72.8 µg kg-1, 0.28-27.5 µg kg-1, and 0.32-51.9 µg kg-1, respectively. Besides, the authenticity of the oils was assessed based on the fingerprints obtained by DART-HRMS, an ambient mass spectrometry technique. Four samples declared as fish oil were probably prepared from cod liver oil, which is much cheaper. Furthermore, these samples contained elevated concentrations of halogenated POPs when compared to supplements produced from fish oil.

Direct immersion thin film solid phase microextraction of polychlorinated n-alkanes in cod liver oil.

A thin film-solid phase microextraction (TF-SPME) method was developed to test for 5 individual polychlorinated n-alkanes (PCAs) from commercial cod liver oil samples. This was accomplished by preparing a novel aluminum supported, hydrophilic-lipophilic balance/polydimethylsiloxane (HLB/PDMS) TF-SPME device that enabled direct immersion extraction from fish oil. Matrix-matched calibration gave a linear range from 0.075 µg/g to 0.75 µg/g with method limits of quantitation (MLOQ) ranging from 0.07 µg/g to 0.217 µg/g in oil. Standard addition calibration was performed using other fish oils demonstrating comparable slope to the external calibration. As a proof of concept, four fish oil brands were tested for contaminants; 1,1,1,3-tetrachlorodecane, 1,2,9,10-tetrachlorodecane, 1,2,13,14-tetrachlorotetradecane, and 1,1,1,3,14,15-hexachloropentadecane were detected above the MLOQ but below the range provided by the Stockholm Convention. This method provides an effective approach for cleanup and preconcentration of PCAs from oily matrices using inexpensive, and reusable microextraction devices that limit environmental impact of the sample preparation protocol.

Preparation of PLA/chitosan nanoscaffolds containing cod liver oil and experimental diabetic wound healing in male rats study.

Diabetes mellitus is one of the most common metabolic disorders. One of the important metabolic complications in diabetes is diabetic foot ulcer syndrome, which causes delayed and abnormal healing of the wound. The formulation of nanoscaffolds containing cod liver oil by altering the hemodynamic balance toward the vasodilators state, increasing wound blood supply, and altering plasma membrane properties, namely altering the membrane phospholipids composition, can be effective in wound healing. In this study, electrospinning method was used to produce poly lactic acid/chitosan nanoscaffolds as a suitable bio-substitute. After preparing the nanoscaffolds, the products were characterized with dynamic light scattering (DLS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Also optical properties of polymer and comparison between adsorption between single polymer and polymer-drug calculated with UV-Vis spectra. The structure and functional groups of the final products were characterized by Fourier-transform infrared spectroscopy (FT-IR) and energy dispersive spectroscopy (EDAX) as elemental analysis. The results showed that the optimum formulation of cod liver oil was 30%, which formed a very thin fiber that rapidly absorbed to the wound and produced significant healing effects. According to the results, poly lactic acid/chitosan nanoscaffolds containing cod liver oil can be a suitable bio-product to be used in treating the diabetic foot ulcer syndrome.

Monochloropropanediol esters and glycidyl esters in dietary supplements based on fish oils.

Dietary supplements based on fish oils might be contaminated with thermal processing contaminants, which are generated during the fish oil deodorisation. In the study, 30 samples of dietary supplements were analysed in terms of the occurrence of 3-monochloropropane-1,2-diol esters (3-MCPDE), 2-monochloropropane-1,3-diol esters (2-MCPDE) and glycidyl esters (GE). The results showed that the highest levels of 3-MCPDE (mean: 1461 µg kg-1) as well as 2-MCPDE (mean: 357 µg kg-1) were observed in the products containing shark liver oil. In the case of GE, they were mainly detected in the supplements including shark liver and cod liver oils. Although the results indicated that the consumption of the investigated supplements constituted no more than 1% of tolerable daily intake (TDI), the occurrence of MCPDE and GE in fish oil dietary supplements with a special attention to the origin of ester precursors should be thoroughly investigated in further studies.

Dioxin-like polybrominated biphenyls (PBBs) and ortho-substituted PBBs in edible cod (Gadus morhua) liver oils and canned cod livers.

This study investigates the occurrence of polybrominated biphenyls (PBBs), a legacy flame retardant, in fishery products such as medicinal grade cod liver oils and canned liver products, sourced from the North Atlantic during 1972-2017. It also assesses the dietary and supplementary (the oils were commonly administered as dietary supplements to children and youth) intake of PBBs from these products. Summed ortho-PBB concentrations ranged from 770 to 1400 pg g-1 fat in the oils and from 99 to 240 pg g-1 whole weight in canned livers, with PBB-49, 52, 101 and 153 accounting for most of these levels. Among the more toxic non-ortho-PBBs, PBB-126 and PBB-169 were not detected, but PBB-77 concentrations ranged from 0.6 to 5.78 pg g-1 fat in the oils and 0.06-0.126 pg g-1 whole weight in canned livers. During 1972-1993, PBB contamination levels were similar for cod liver oils from the Baltic Sea and other North Atlantic regions, but over the timescale of the study, Baltic Sea products appear to show a decline in PBB concentrations. As PBB-77 was the only dioxin-like PBB detected in the samples, the corresponding supplementary (oils, 1972-2001) and dietary (cod liver from 2017) intakes were very low, at < 0.001 pg TEQ kg-1 bm d-1 (or < 0.01 pg TEQ kg-1 bm d-1 upper bound) for the sum of all the measured dioxin-like PBBs -four to six orders of magnitude lower than that arising from other dioxin-like contaminants that were shown to occur in these products, from earlier studies.

Oxidative stability of cod liver oil in the presence of herring roe phospholipids.

The aim of this research was to investigate the effect of herring roe phospholipids (PLs) on the oxidative stability of cod liver oil during storage. The effect of PLs on the oxidative stability of cod liver oil was assessed in terms of peroxide value, free fatty acids, secondary oxidation products and pyrrolisation. The results show that the PV was lower in cod liver oil containing PLs (P < 0.05) than in the control without PLs. Benzaldehyde, 2,5-dimethylpyrazine, 2-methyl-2-pentenal, 1-penten-3-ol and 3-methylbutanal were the main volatiles. In addition, significant pyrrolisation was observed after 28 days when PLs were added to cod liver oil. The results suggested that cod liver oil with dispersed PLs was oxidized during storage followed by non-enzymatic browning reactions. The findings indicated that the ratio between pyrroles formed and α-tocopherol may influence the formation of new peroxides and secondary oxidation products.

Lipase-catalyzed selective enrichment of omega-3 polyunsaturated fatty acids in acylglycerols of cod liver and linseed oils: Modeling the binding affinity of lipases and fatty acids.

Present study employed molecular modeling method to elucidate the binding affinity of lipases with fatty acids of different chain lengths; and investigated the effects of lipases positional and fatty acids specificity on omega-3 polyunsaturated fatty acids (ω-3 PUFAs) enrichment in cod liver and linseed oils. Among the lipases studied, molecular modeling showed the active sites of Candida rugosa lipase (CRL) had a low C-Docker interactive energy for saturated (SFA) and monounsaturated (MUFA) fatty acids which predicted CRL to have highest preferences to selectively hydrolyze resulting in efficient enrichment of ω-3 PUFAs. Verification experiments showed the SFA and MUFA in the acylglycerol fraction includes monoacylglcyerols (MAG), diacyglycerols (DAG), and triacylglycerols (TAG) of CRL-hydrolyzed cod liver oil decreased from the initial 25.21 to 16.88% and 45.25 to 32.17%, respectively. In addition, CRL-hydrolyzed cod liver oil demonstrated 88.36% of ω-3 PUFAs enrichment. The regio-distribution of fatty acids in CRL-hydrolyzed cod liver oil were not significantly different than that of cod liver oil indicating the ω-3 PUFAs enrichment was due to fatty acids selectivity and not positional selectivity of CRL.

Stability of compounded trilostane suspension in cod liver oil.

Trilostane is a synthetic steroid analog used to treat canine hyperadrenocorticism. For small dogs, the dose found in commercially available dosage forms of trilostane is sometimes too high. Compounding trilostane in a liquid diluent provides an option for more precise dosing and adjustments, and can be easier to administer, versus a tablet or capsule. Trilostane suspends well in cod liver oil, which is generally palatable to dogs. The stability of a compounded trilostane suspension in cod liver oil stored at room temperature was investigated for 90 days. Compounded trilostane retained stability, defined as maintaining 90-105% labeled value, for 60 days when stored in amber glass bottles. However, drug potency fell >10% below the labeled value when stored in amber plastic bottles after 7 days.

Lipase-Catalyzed Transesterification of Egg-Yolk Phophatidylcholine with Concentrate of n-3 Polyunsaturated Fatty Acids from Cod Liver Oil.

Phospholipids containing PUFAs are important vehicles for their delivering to the targeted tissues. In our research project we established enzymatic methods for the enrichment of natural egg-yolk PC with n-3 PUFAs. Instead of synthetic PUFA ethyl esters, the new strategy was developed using polyunsaturated fatty acids enriched fraction (PUFA-EF) from cod liver oil as the natural acyl donors. PUFA-EF was produced by urea-complexation and contained 86.9% PUFA including 8.5% stearidonic acid (SDA; 18:4(n-3)), 26.7% EPA, and 45.2% DHA. The transesterification of PC with PUFA was catalyzed by lipases. After screening of enzymes the effect of reaction medium; molar ratio of substrates and etc. was investigated. The highest incorporation of PUFA was 45.6%; including 36.8% DHA and 5.8% EPA at the following reaction conditions: hexane; 55 °C; PUFA-EF/PC acyl ratio of 10; 48 h of reaction time and lipase B from Candida antarctica as a biocatalyst (20% of enzyme load).

Tunable adhesion of superoleophilic/superhydrophobic poly (lactic acid) membrane for controlled-release of oil soluble drugs.

Superhydrophobic membranes with tunable adhesion have attracted intense interests for various engineering applications. In this work, superhydrophobic sustainable poly (lactic acid) (PLA) porous membrane with tunable adhesive force from 101µN to 29µN was successfully fabricated via one-step phase separation method. The incorporation of Perfluoro-1-decene (PFD) into the PLLA/PDLA membrane via the in situ polymerization can facilely tune the PLLA/PDLA stereocomplex crystallization during phase inversion, which consequently caused the unique morphology blooming evolution from bud to full-blown state. The resulted membrane showed tunable pore size, porosity, surface area, surface roughness and superhydrophobicity, which enabled the membrane with controlled-release of oil soluble drugs.

Topical Formulation Comprising Fatty Acid Extract from Cod Liver Oil: Development, Evaluation and Stability Studies.

The purpose of this study was to develop a pharmaceutical formulation containing fatty acid extract rich in free omega-3 fatty acids such as eicosapentaenoic acid and docosahexaenoic acid for topical use. Although the health benefits of cod liver oil and other fish oils taken orally as a dietary supplement have been acknowledged and exploited, it is clear that their use can be extended further to cover their antibacterial properties. In vitro evaluation showed that 20% (v/v) fatty acid extract exhibits good activity against strains of the Gram-positive bacteria Staphylococcus aureus, Enterococcus faecalis, Streptoccoccus pyogenes and Streptoccoccus pneumonia. Therefore, free polyunsaturated fatty acids from cod liver oil or other fish oils can be used as safe and natural antibacterial agents. In this study, ointment compositions containing free fatty acids as active antibacterial agents were prepared by using various natural waxes and characterized. The effects of different waxes, such as carnauba wax, ozokerite wax, laurel wax, beeswax, rice bran wax, candelilla wax and microcrystalline wax, in the concentration range of 1% to 5% (w/w) on the ointment texture, consistency and stability were evaluated. The results showed significant variations in texture, sensory and rheological profiles. This was attributed to the wax's nature and chain composition. Microcrystalline wax gave the best results but laurel wax, beeswax and rice bran wax exhibited excellent texturing, similar sensory profiles and well-balanced rheological properties.

Various Acylglycerols from Common Oils Exert Different Antitumor Activities on Colorectal Cancer Cells.

Colorectal cancer is one of the leading causes of death in Western countries; therefore, the implementation of healthy dietary habits in order to prevent its occurrence is a desirable action. We show here that both free fatty acids (FFAs) and some acylglycerols induce antitumoral actions in the colorectal cancer cell line HT-29. We tested several C18 polyunsaturated fatty acid-enriched oils (e.g., sunflower and Echium) as well as other oils, such as arachidonic acid-enriched (Arasco®) and docosahexaenoic acid-enriched (Marinol® and cod liver oil), in addition to coconut and olive oils. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test indicated inhibitory effects on HT-29 cells viability for FFAs, and monoacylglycerol and diacylglycerol (DAG) species, while the lactate dehydrogenase test proved that FFAs were the more effective species to induce membrane injury. Conversely, all species did not exhibit actions on CCD-18 normal human colon cells viability. Furthermore, transmission electron microscopy showed the presence of necrosis and apoptosis, while the monoacylglycerol lipase (MAGL) inhibition test demonstrated high activity for 2-monoacylglycerols derived from Arasco and sunflower oils. However, different monoacylglycerols and DAGs have also the potential for MAGL inhibition. Therefore, checking for activity on colon cancer cells of specifically designed acylglycerol-derivative species would be a suitable way to design functional foods destined to avoid colorectal cancer initiation.

Formation of reactive aldehydes (MDA, HHE, HNE) during the digestion of cod liver oil: comparison of human and porcine in vitro digestion models.

In this work, we investigated lipid oxidation of cod liver oil during gastrointestinal (GI) digestion using two types of in vitro digestion models. In the first type of model, we used human GI juices, while we used digestive enzymes and bile from porcine origin in the second type of model. Human and porcine models were matched with respect to factors important for lipolysis, using a standardized digestion protocol. The digests were analysed for reactive oxidation products: malondialdehyde (MDA), 4-hydroxy-trans-2-nonenal (HNE), and 4-hydroxy-trans-2-hexenal (HHE) by liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS), and for free fatty acids (FFA) obtained during the digestion by gas chromatography-mass spectrometry (GC-MS). The formation of the oxidation products MDA, HHE, and HNE was low during the gastric digestion, however, it increased during the duodenal digestion. The formation of the oxidation products reached higher levels when digestive juices of human origin were used (60 µM of MDA, 9.8 µM of HHE, and 0.36 µM of HNE) [corrected] compared to when using enzymes and bile of porcine origin (0.96, and 1.6 µM of MDA; 0.16, and 0.23 µM of HHE; 0.026, [corrected] and 0.005 µM of HNE, respectively, in porcine models I and II). In all models, FFA release was only detected during the intestinal step, and reached up to 31% of total fatty acids (FA). The findings in this work may be of importance when designing oxidation oriented lipid digestion studies.

Enrichment of omega-3 fatty acids in cod liver oil via alternate solvent winterization and enzymatic interesterification.

Enrichment of omega-3 fatty acids in cod liver oil via alternate operation of solvent winterization and enzymatic interesterification was attempted. Variables including separation method, solvent, oil concentration, time and temperature were optimized for the winterization. Meanwhile, Novozyme 435, Lipozyme RM IM and Lipozyme TL IM were screened for interesterification efficiency under different system air condition, time and temperature. In optimized method, alternate winterization (0.1g/mL oil/acetone, 24h, -80°C, precooled Büchner filtration) and interesterification (Lipozyme TL IM, N2 flow, 2.5h, 40°C) successfully doubled the omega-3 fatty acid content to 43.20 mol%. (1)H NMR was used to determine omega-3 fatty acid content, and GC-MS to characterize oil product, which mainly contained DHA (15.81 mol%) and EPA (20.23 mol%). The proposed method offers considerable efficiency and reduce production cost drastically. Oil produced thereof is with high quality and of particular importance for the development of omega-3 based active pharmaceutical ingredients.

The ability of in vitro antioxidant assays to predict the efficiency of a cod protein hydrolysate and brown seaweed extract to prevent oxidation in marine food model systems.

BACKGROUND: The ability of different in vitro antioxidant assays to predict the efficiency of cod protein hydrolysate (CPH) and Fucus vesiculosus ethyl acetate extract (EA) towards lipid oxidation in haemoglobin-fortified washed cod mince and iron-containing cod liver oil emulsion was evaluated. The progression of oxidation was followed by sensory analysis, lipid hydroperoxides and thiobarbituric acid-reactive substances (TBARS) in both systems, as well as loss of redness and protein carbonyls in the cod system. RESULTS: The in vitro tests revealed high reducing capacity, high DPPH radical scavenging properties and a high oxygen radical absorbance capacity (ORAC) value of the EA which also inhibited lipid and protein oxidation in the cod model system. The CPH had a high metal chelating capacity and was efficient against oxidation in the cod liver oil emulsion. CONCLUSION: The results indicate that the F. vesiculosus extract has a potential as an excellent natural antioxidant against lipid oxidation in fish muscle foods while protein hydrolysates are more promising for fish oil emulsions. The usefulness of in vitro assays to predict the antioxidative properties of new natural ingredients in foods thus depends on the knowledge about the food systems, particularly the main pro-oxidants present.

Extraction of trace elements by ultrasound-assisted emulsification from edible oils producing detergentless microemulsions.

The aim of this study is to develop a new method for the extraction and preconcentration of trace elements from edible oils via an ultrasound-assisted extraction using ethylenediaminetetraacetic acid (EDTA) producing detergentless microemulsions. These were then analyzed using ICP-MS against matrix matched standards. Optimum experimental conditions were determined and the applicability of the proposed ultrasound-assisted extraction method was investigated. Under the optimal conditions, the detection limits (µg kg(-1)) were 2.47, 2.81, 0.013, 0.037, 1.37, 0.050, 0.049, 0.47, 0.032 and 0.087 for Al, Ca, Cd, Cu, Mg, Mn, Ni, Ti, V and Zn respectively for edible oils (3Sb/m). The accuracy of the developed method was checked by analyzing certified reference material. The proposed method was applied to different edible oils such as sunflower seed oil, rapeseed oil, olive oil and cod liver oil.

Steroidogenic differential effects in neonatal porcine Leydig cells exposed to persistent organic pollutants derived from cod liver oil.

Seafood products, including fish and fish oils, are major sources of persistent organic pollutants (POPs) which may cause endocrine disruption related to reproductive dysfunction in males. Primary porcine neonatal Leydig cells were exposed to three extracts of POPs obtained from different stages in production of cod liver oil dietary supplement, in the absence and presence of luteinizing hormone (LH). No reduced viability was observed and all POP extracts showed increased testosterone and estradiol levels in unstimulated cells and decreased testosterone and estradiol secretion in LH-stimulated cells. A decrease in central steriodogenic genes including STAR, CYP11A1, HSD3B and CYP17A1 was obtained in both culture conditions with all POP extracts. We implicate both small differences in composition and concentration of compounds as well as "old" POPs to be important for the observed steroidogenic effects.

Cod liver oil ameliorates sodium nitrite-induced insulin resistance and degradation of rat hepatic glycogen through inhibition of cAMP/PKA pathway.

AIMS: Sodium nitrite is used to inhibit the growth of microorganisms and is responsible for the desirable red color of meat; however, it can be toxic in high quantities for humans and other animals. Moreover, glycogen, a branched polysaccharide, efficiently stores and releases glucose monosaccharides to be accessible for metabolic and synthetic requirements of the cell. Therefore, we examined the impact of dietary sodium nitrite and cod liver oil on liver glycogen. MAIN METHODS: Thirty-two Sprague-Dawley rats were treated daily with sodium nitrite (80 mg/kg) in the presence/absence of cod liver oil (5 ml/kg). Liver sections were stained with Periodic acid-Schiff. Hepatic homogenates were used for measurements of glycogen, cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), glycogen synthase, glycogen synthase kinase, pyruvate carboxylase, fructose 1,6-diphosphatase, glucose 6-phosphatase, phosphodiesterase and glycogen phosphorylase. Glucose, pyruvate tolerances and HOMA insulin resistance were also determined. KEY FINDINGS: Sodium nitrite significantly increased plasma glucose and insulin resistance. Moreover, sodium nitrite significantly reduced hepatic glycogen content as well as activities of glycogen synthase, glycogen synthase kinase-3, and phosphodiesterase. Sodium nitrite elevated hepatic cAMP, PKA, pyruvate carboxylase, fructose 1,6-diphosphatase, glucose 6-phosphatase and phosphorylase. Cod liver oil significantly blocked all of these except pyruvate carboxylase, fructose 1,6-diphosphatase and glucose 6-phosphatase. SIGNIFICANCE: Sodium nitrite inhibited liver glycogenesis and enhanced liver glycogenolysis and gluconeogenesis, which is accompanied by hyperglycemia and insulin resistance through the activation of cAMP/PKA and the inhibition of phosphodiesterase. Cod liver oil blocked the sodium nitrite effects on glycogenesis and glycogenolysis without affecting gluconeogenesis.

Comparison of optimized long echo time STEAM and PRESS proton MR spectroscopy of lipid olefinic protons at 3 Tesla.

PURPOSE: To investigate the response of lipid olefinic protons (≈ 5.35 ppm) as a function of STEAM (Stimulated Echo Acquisition Mode) mixing time (TM), and echo time (TE), to find values that resolve the olefinic resonance from water in vivo while retaining sufficient olefinic signal. MATERIALS AND METHODS: PRESS (Point RESolved Spectroscopy) and STEAM experiments with varying timing parameters (TE and also TM for STEAM) were conducted on nine oils (almond, canola, cod liver, corn, linseed, peanut, sesame, sunflower, and walnut oil), and on vertebral bone marrow in vivo at 3 Tesla (T). Olefinic and methylene (methyl + methylene in vivo) peak areas were measured. RESULTS: Optimal STEAM parameters were found to be TM = 20 ms and TE = 100 ms. The STEAM olefinic/methylene area ratios (ranging between 0.1 and 0.4) calculated for each oil correlated well with ratios deduced from oil compositions in the literature (R(2) = 0.975). The optimized STEAM sequence resolved the olefinic peak from water in vivo and yielded on average 1.91 times more olefinic signal compared with a previously optimized PRESS (TE = 200 ms) sequence tailored for the same purpose. Olefinic/(methyl + methylene) area ratios obtained with optimized STEAM and PRESS in vivo were linearly correlated (R(2) = 0.972). CONCLUSION: A STEAM sequence with TE = 100 ms and TM = 20 ms provides an alternative to the previously optimized PRESS (TE = 200 ms) sequence for determining relative amounts of lipid unsaturation at 3T.

Cod liver oil in sodium nitrite induced hepatic injury: does it have a potential protective effect?

OBJECTIVES: Exposure to sodium nitrites, a food additive, at high levels has been reported to produce reactive nitrogen and oxygen species that cause dysregulation of inflammatory responses and tissue injury. In this work, we examined the impact of dietary cod liver oil on sodium nitrite-induced inflammation in rats. METHODS: Thirty-two adult male Sprague-Dawely rats were treated with 80 mg/kg sodium nitrite in presence/absence of 5 ml/kg cod liver oil. Liver sections were stained with hematoxylin/eosin. We measured hepatic tumor necrosis factor (TNF)-α, interleukin-1 beta (IL)-1ß, C-reactive protein (CRP), transforming growth factor (TGF)-ß1, and caspase-3. RESULTS: Cod liver oil reduced sodium nitrite-induced hepatocyte damage. In addition, cod liver oil results in reduction of hepatic TNF-α, IL-1ß, CRP, TGF-ß1, and caspase-3 when compared with the sodium nitrite group. DISCUSSION: Cod liver oil ameliorates sodium nitrite-induced hepatic injury via multiple mechanisms including blocking sodium nitrite-induced elevation of inflammatory cytokines, fibrosis mediators, and apoptosis markers.