Borage and evening primrose oil

The paper gives a short overview about the production and composition of borage (Borago officinalis) and evening primrose (Oenothera biennis) oil considering special aspects of the production as cold‐pressed oil. Both oils are characterized by a remarkable amount of γ‐linolenic acid, which has some nutritional advantages. The fatty acid composition of evening primrose oil is dominated by linoleic acid with about 72% and about 13% γ‐linolenic acid, while borage oil consists of twice the amount of γ‐linolenic acid and only 38% linoleic acid. The amount of saturated fatty acids is higher in borage oil. The tocopherol composition of both oils is dominated by γ‐tocopherol, with borage oil containing twice the amount compared to evening primrose oil.     

Oxidative stability of stripped and nonstripped borage and evening primrose oils and their emulsions in water

Oxidative stability of stripped and nonstripped borage and evening primrose oils and their emulsions in water was evaluated. The results indicated that column chromatographic techniques provide an effective means for stripping vegetable oils of their minor components. However, some minor components may be retained in the stripped oils. The minor components in borage and evening primrose oils significantly (P<0.05) influenced their oxidative stability in the dark. In contrast, the behavior of endogenous antioxidants in borage and evening primrose oil-in-water emulsions, according to the “polar paradox” theory, was difficult to evaluate. Correlations existed between peroxide value (PV) and conjugated dienes (CD) (P<0.05) as well as 2-thiobarbituric acid-reactive substances (TBARS) and hexanal content (P<0.01) for most oils and emulsion systems. Therefore, CD and TBARS may generally be used to assess the oxidative stability of borage and evening primrose oils and their oil-in-water emulsions in addition to or in place of PV and headspace volatiles, respectively.     

Formation of 4‐Hydroxy‐2‐Trans‐Nonenal,a Toxic Aldehyde,in Thermally Treated Olive and Sunflower Oils

4‐Hydroxy‐2‐trans‐nonenal (HNE) is a toxic aldehyde produced mostly in oils containing polyunsaturated fatty acid due to heat‐induced lipid peroxidation. The present study examined the effects of the heating time, the degree of unsaturation, and the antioxidant potential on the formation of HNE in two light olive oils (LOO) and two sunflower oils (one high oleic and one regular) at frying temperature. HNE concentrations in these oil samples heated for 0, 1, 3, and 5 hours at 185 °C were measured using high‐performance liquid chromatography. The fatty‐acid distribution and the antioxidant capacity of these four oils were also analyzed. The results showed that all oils had very low HNE concentrations (<0.5 μg g^?1 oil) before heating. After 5 hours of heating at 185 °C, HNE concentrations were increased to 17.98, 25.00, 12.51, and 40.00 μg g^?1 in the two LOO, high‐oleic sunflower oil (HOSO), and regular sunflower oil (RSO), respectively. Extending the heating time increased HNE formation in all oils tested. It is related to their fatty‐acid distributions and antioxidant capacities. RSO, which contained high levels of linoleic acid (59.60%), a precursor for HNE, was more susceptible to degradation and HNE formation than HOSO and LOO, which contained only 6–8% linoleic acid.     

Lipid Composition and Antioxidant Capacity Evaluation in Tilapia Fillets Supplemented with a Blend of Oils and Vitamin E

Since the nutritional value of farm‐raised fish fillets is directly related to the diet provided, we supplemented the diet of Tilapia (Oreochromis niloticus) with a blend of chia (Salvia hispanica L.) oil, tung (Aleurites fordii) oil, and conjugated linoleic acid (CLA) to evaluate the effects on the fatty acid composition. Vitamin E was also added to the diet to improve the antioxidant capacity of tilapia fillets. We observed an increase in α‐linolenic acid content (from 6.56 to 19.03 mg g^?1 of total lipids), as well as the incorporation of CLA and conjugated linolenic acid (CLnA) isomers in the fillets. The addition of vitamin E resulted in the antioxidant capacity improvement of the fillets and higher values were found after 15 feeding days (39.25 µmol TE g^?1 in the Ferric Reducing Ability Power assay). Supplementation proved to be an excellent tool to improve the nutritional value of fish fillets.     

A novel method for the determination of acid value of vegetable oils

The voltammetric behavior of naphthoquinone in the presence of free fatty acids (FFA) at the polypyrrole (PPy)‐modified electrode was investigated in an ethanol/1,2‐dichloroethane (3 : 1) solution containing 0.1 M LiClO₄. A well‐defined new reduction peak appeared at a more positive potential and was higher than that obtained at the bare Pt electrode. Based on the fact that the new reduction peak current showed a good correlation with the concentration of fatty acids, an electroanalytical method for the acid value (AV) of vegetable oils was developed using the PPy‐modified electrode in linear potential sweep voltammetry. The experimental parameters were optimized to obtain a sensitive voltammetric response in this work. A linear calibration graph was obtained in the concentration range of 5.0×10^–6–6×10^–3 M for FFA (R = 0.993), with a sensitivity of 2.41×10^–2 A L/mol and a detection limit of 1.2×10^–6 M (S/N = 3). Each assay of vegetable oil sample took about 80 s. The developed method is applied to the AV determination of six commercial vegetable oils. The results well agreed with those obtained by the titration method. Compared to the conventional titration method, the proposed method is superior in sensitivity and accuracy and requires a small amount of vegetable oil sample, with no pretreatment.     

Physicochemical,Antioxidative, and Sensory Properties of Refined Rapeseed Oils

Physicochemical characteristics, antioxidant capacity (AC), and sensory quality of rapeseed oils available on the Polish market were analyzed and compared. The fatty acid composition (saturated fatty acids = 6.91–7.58%, monounsaturated fatty acids = 64.14–66.14%, and polyunsaturated fatty acids = 27.22–30.17%), color (T420 = 54.5–83.8%), amounts of free fatty acids (0.02–0.07%), primary (PV = 0.04–2.04 meq O₂ kg⁻¹) and secondary (AV = 1.02–3.21) oxidation products, phosphorus (0.38–1.62 mg kg⁻¹), chlorophyll (0.002–0.068 mg kg⁻¹), and polycyclic aromatic hydrocarbons (Σ4PAH = 0.00–2.50 μg kg⁻¹) in the commercial rapeseed oils meet the requirements of the European Food Regulation and Codex Alimentarius standards. Moreover, total phenolic content (TPC = 40.3–467.9 mg SA kg⁻¹) in the studied oils significantly differs from each other. However, the AC of rapeseed oils was analyzed using the novel iron oxide nanoparticle-based (IONP = 5552.1 − 18,510.2 μmol TE/100 g) method and the modified ferric reducing antioxidant power (FRAP = 55.7–280.3 μmol TE/100 g), cupric reducing AC (CUPRAC = 79.6–784.0 μmol TE/100 g), 2,2-diphenyl-1-picrylhydrazyl (DPPH = 185.7–516.7 μmol TE/100 g), and 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS = 465.6–2142.6 μmol TE/100 g) assays. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied for discrimination of the refined rapeseed oils based on fatty acid composition, physicochemical parameters, AC, and sensory properties.     

Canola Proteins Used as Co‐Emulsifiers with Phospholipids Influence Oil Oxidability,Enzymatic Lipolysis,and Fatty Acid Absorption in Rats

The objective of this study is to formulate and characterize oil‐in‐water emulsions with plant‐derived ingredients only, that is, proteins extracted from canola oil bodies, used as co‐emulsifiers with a canola lecithin, and to assess their suitability for food applications. Using the protein extract increases the chemical stability of rapeseed oil emulsions toward oxidation, based on the delay in conjugated diene formation under accelerated storage conditions, and favors pancreatic lipase activity. Bioaccessibility of rapeseed fatty acids is compared in lymph‐duct‐cannulated rats fed oil or emulsion. Fatty acid absorption by the intestine is increased by 78% when the oil is emulsified with canola proteins as co‐emulsifier: 28.7 mg mL^?1 versus 16.1 mg mL^?1 for oil (p < 0.05). In vitro lipolysis results are in overall agreement with fatty acid absorption in vivo. Practical Applications: Results obtained for rapeseed oil emulsified with canola proteins and phospholipids suggest that increased bioaccessibility of n‐3 polyunsaturated fatty acids could be offered in vegan food products.     

Oxidative stability of structured lipids produced from borage (<Emphasis Type="Italic">Borago officinalis</Emphasis> L.) and evening primrose (<Emphasis Type="Italic">Oenothera biennis</Emphasis> L.) oils with docosahexaenoic acid

This study utilized γ-linolenic acid (18∶3n−6; GLA)-rich borage oil (BO) and evening primrose oil (EPO) for the synthesis of structured lipids (SL) and compared the oxidative stability of the products with those of unmodified BO and EPO as controls. Immobilized Novozym 435 lipase from Candida antarctica was used as the biocatalyst for SL production. BO or EPO eas enzymatically modified with docosahexaenoic acid (22∶6n−3; DHA), as the acyl donor, to produce SI. The SI were characterized and their oxidative stabilities evaluated. Among the oils examined, SL gave rise to higher quantities (P≤0.05) of conjugated dienes, TBARS, and headspace volatiles as compared to their unmodified counterparts. Results indicated that modified oils were less stable than their unmodified counterparts. The double bond index (DBI) and methylene bridge index (MBI) of oils decreased (P<0.05) during oxidation in the more unsaturated oils. An attempt was made to correlate various parameters of oxidation with DBI and MBI of oils; correlation coefficients (−r) were within the range of 0.574–0.973. This suggests that indicators such as DBI and MBI can reflect oxidative stability of oils.     

γ-linolenic acid inAnemone spp. seed lipids

γ-Linolenic acid containing oils have been found in seed lipids of a number of plants, but are restricted to certain genera and families,e.g., the Boraginaceae. Some of these oils have found considerable interest for pharmaceutical and dietary use,e.g., borage oil and evening primrose oil in treatment of essential fatty acid and Δ6 desaturase deficiency. Our investigation of the seed lipids of certain Mongolian and other Ranunculaceae has now shown the presnce of unusual fatty acids, including considerable amounts (up to 20%) ofγ-linolenic acid in certain species ofAnemone, whereas this acid was found to be absent in other species ofAnemone. A number of other unusual fatty acids are present inA. rivularis but have not yet been identified. The significance of the presence ofγ-linolenic acid, a Δ6 acid, is discussed in relation to δ5 fatty acids that had been reported to occur in the same plant family.     

A Highly Efficient Automated Flow Injection Method for Rapid Determination of Free Fatty Acid Content in Corn Oils

In the present study, a new flow injection (FI) methodology for determination of free fatty acid (FFA) content in corn oil samples is proposed. The proposed method is based on monitoring the absorbance changes at 580 nm, λ_max, as a result of neutralization of FFA in oil samples by KOH in the reagent. The analyses were performed with a single‐line FI manifold system created by modification of high performance liquid chromatography. The main parameters, such as sample and reagent volumes, reaction coil, reagent concentration and temperature were all optimized. With the newly developed sampling strategy, the oil sample and reagent at micro level were directly injected together without any pre‐treatment. The proposed flow injection analysis method was validated statistically and it was found to be linear (between 0.09 and 1.50 FFA %), accurate (recovery 87.19–122.22 %), and precise (relative standard deviation <1 % for both intra‐day and inter‐day precision). The limit of detection and limit of quantification were found to be 7.41 × 10^?3 and 2.24 × 10^?2 oleic acid %, respectively. The results were also compared with those obtained by the American Oil Chemists Society (Ca‐5a‐40) method using statistical t and F tests, and a significant difference was not observed between the methods at the 95 % confidence level. These results strongly suggest that this method is suitable for automated routine analysis of FFA in edible oils due to its simplicity, reliability, speed, and economy of solvents and sample.     

γ-Linolenic acid concentrates from borage and evening primrose oil fatty acidsvia lipase-catalyzed esterification

γ-Linolenic acid (GLA, all-cis 6,9,12-octadecatrienoic acid) has been enriched from fatty acids of borage (Borago officinalis L.) seed oil to 93% from the initial concentration of 20% by lipase-catalyzed selective esterification of the fatty acids withn-butanol in the presence ofn-hexane as solvent. The immobilized fungal lipase preparation, Lipozyme, used as biocatalyst, preferentially esterified palmitic, stearic, oleic and linoleic acids and discriminated against GLA, which was thus concentrated in the unesterified fatty acids fraction. In the absence of hexane, concentrate containing about 70% GLA was obtained. When the reaction conditions, optimized for borage oil fatty acids, were applied to fatty acids of evening primrose (Oenothera biennis L.) oil, concentrates containing 75% GLA were obtained. From both oils, GLA concentrates were prepared efficiently in short reaction times (1–3 h) at 30–60°C. The process can be applied for the production of GLA concentrates for dietetic purposes.     

Fatty Acid Profiles of Garuga floribunda,Ipomoea pes‐caprae,Melanolepis multiglandulosa and Premna odorata Seed Oils

The fatty acid profiles of the seed oils of four species from four plant families for which no or only sparse information on the fatty acid profiles is available are reported. The four seed oils are Garuga floribunda of the Burseraceae family, Ipomoea pes‐caprae, of the Convolvulaceae family, Melanolepis multiglandulosa of the Euphorbiaceae family, and Premna odorata of the Labiatae (Lamiaceae) family. Linoleic acid is the most abundant in three seed oils, except I. pes‐caprae in which oleic acid is most abundant. These two acids are overall the most abundant in all four seed oils studied. Of the four seed oils investigated, only G. floribunda contains minor amounts of a cyclic fatty acid (dihydrosterculic acid).     

Characterisation of acorn oils extracted by hexane and by supercritical carbon dioxide

Acorn fruit oils from two species of oak, Quercus rotundifolia L. (holm‐oak) and Quercus suber L. (cork‐oak), were extracted by n‐hexane. The acorn fruit of Quercus rotundifolia L. was also extracted by supercritical CO₂ at 18 MPa and 313 K, a superficial velocity of 2.5 × 10^?4 ms^?1, and a particle size diameter of 2.7 × 10^?4 m. The oils were characterised in terms of fatty acids, triglycerides, sterols, tocopherols, and phospholipids. The main fatty acid in both fruit species was oleic acid (about 65%), followed by linoleic acid (about 16.5–17%) and palmitic acid (about 12.1–13.4%). The main triglyceride found in acorn oils was the OOO (oleic, oleic, oleic) triglyceride (33–38%), followed by the POO (palmitic, oleic, oleic) triglyceride (12.6–18.2%). In terms of sterols, the main component in acorn oils of both species was β‐sitosterol (83.5–89%), followed by stigmasterol (about 3%). However, in Quercus suber L., acorn oil was found to consist to 10.2% of campesterol. The amount of cholesterol was low (0.27% for the Quercus rotundifolia L. oil extracted by supercritical fluid extraction, and 0.18% for the oil extracted by n‐hexane). The Quercus suber L. acorn oil presented 0.1% of cholesterol. The total amount of tocopherols in Quercus rotundifolia L. acorn oils was almost the same when the oil was extracted by n‐hexane (973 mg/kg oil) or by supercritical CO₂ (1006 mg/kg oil). The Quercus suber L. acorn oil presented a high value of total tocopherols (1486 mg/kg oil). The supercritical CO₂ did not extract the phospholipids. The amount of phospholipids was very similar for both species of oak acorn oils extracted by n‐hexane. Oxidative stability was also studied, by using the peroxide value and the Rancimat method, revealing that all the oils were significantly protected against oxidation. The influence of storage, under several conditions, on the oxidative stability was also studied. The Quercus rotundifolia L. oil extracted by n‐hexane was better protected against oxidation after a few days of storage at 60 °C.     

Kinetics of supercritical carbon dioxide extraction of borage and evening primrose seed oil

In the present work, high‐pressure extraction of borage (Borago officinalis L.) and evening primrose (Oenothera biennis L.) seed oil, containing the valuable γ‐linolenic acid (GLA), has been investigated. Extraction was performed with supercritical carbon dioxide on a semi‐continuous flow apparatus at pressures of 200 and 300 bar, and at temperatures of 40 and 60 °C. A constant flow rate of carbon dioxide in the range from 0.17 to 0.20 kg/h was maintained during extraction. The extraction yields obtained using dense CO₂ were similar to those obtained with conventional extraction using hexane as solvent. The composition of extracted crude oil was determined by GC analysis. The best results were obtained at 300 bar and 40 °C for both seed types extracted, where the quality of oil was highest with regard to GLA content. The evening primrose seed oil extracted with supercritical fluid extraction was particularly rich in unsaturated fatty acids: up to 89.7 wt‐% of total free fatty acids in the oil. The dynamic behavior of the extraction runs was analyzed using two mathematical models for describing the constant rate period and the subsequent falling rate period. Based on the experimental data, external mass transfer coefficients, diffusion coefficients and diffusivity in solid phase were estimated. Results showed good agreement between calculated and experimental data.     

Effect of Dietary Replacement of Soybean Oil with Different Sources of Gamma‐Linolenic Acid on Fatty Acid Composition of Nile Tilapia

Gamma‐linolenic acid (GLA) plays an important role in the prevention and/or treatment of certain diseases. In this work, we investigate the incorporation of GLA from supplemented feed diets with borage oil (BO) and evening primrose oil (EPO) as substitutes for soybean oil (SO) into the composition of tilapia fillet lipids. High contents of PUFA and n‐6 fatty acids were quantified in fish fillet after 30 days of treatment with SO, BO, and EPO. Feed diets containing BO and EPO were efficient in the incorporation of GLA into fish. Compared to the initial day of the experiment, the increase of GLA was significant (from 6.43 to 13.99 and 15.12 mg g^?1, in lipids of fish treated for 30 days with BO and EPO, respectively). The increase of GLA was also observed in fish which were fed with SO diet (6.43–11.43 mg g^?1). Principal component analysis (PCA) allowed the separation of the treatments and discriminated BO and EPO in a group of fish that received the GLA supplemented diet. In addition to GLA, n‐3 fatty acids were important in the characterization of SO diet and affected the separation of BO and EPO from SO in the PCA score plot.     

Chia seeds as a source of natural lipid antioxidants

Chia (Salvia sp) seeds were investigated as a source of natural lipid antioxidants. Methanolic and aqueous extracts of defatted chia seeds possessed potent antioxidant activity. Analysis of 2 batches of chia-seed oils demonstrated marked difference in the fatty acid composition of the oils. In both batches, the oils had high concentrations of polyunsaturated fatty acids. The major antioxidant activity in the nonhydrolyzed extract was caused by flavonol glycosides, chlorogenic acid (7.1 × 10⁻⁴ mol/kg of seed) and caffeic acid (6.6 × 10⁻³ m/kg). Major antioxidants of the hydrolyzed extracts were flavonol aglycones/kaempferol (1.1 × 10⁻³ m/kg), quercetin (2.0 × 10⁻⁴ m/kg) and myricetin (3.1 × 10⁻³ m/kg); and caffeic acid (1.35 × 10⁻² m/kg). Two methods were used to measure antioxidant activities. Both were based on measuring bleaching ofβ-carotene in the coupled oxidation ofβ-carotene and linoleic acid in the presence of added antioxidants.     

Antioxidant activity of evening primrose phenolics in sunflower and rapeseed oils

Crude ethanol/ethyl acetate extracts of industrial evening primrose (Oenothera biennis L.) seed meal were separated into six fractions using the Sephadex LH‐20 column chromatography and 96% aqueous ethanol as a mobile phase. Their antioxidant activities were tested in sunflower and rapeseed oils by using an Oxidograph apparatus at a temperature of 110 °C. Only the fractions III and IV displayed a pronounced antioxidant activity while the other fractions were either inactive or even pro‐oxidative. The active fractions contained phenolic acids and their esters; gallic acid, methyl and ethyl gallates, protocatechuic acid and its methyl ester were identified by GC/MS. Catechin was present, too, but exhibited only moderate antioxidant activity in sunflower oil.     

Triacylglycerol composition and structure in genetically modified sunflower and soybean oils

Changes in composition were examined in oils extracted from genetically modified sunflower and soybean seeds. Improvements were made to the analytical methods to accomplish these analyses successfully. Triacylglycerols (TAG) were separated on two 300 mm × 3.9 mm 4μ Novapak C18 high-performance liquid chromatography (HPLC) columns and detected with a Varex MKIII evaporative light-scattering detector. Peaks were identified by coelution with known standards or by determining fatty acid composition of eluted TAG by capillary gas chromatography (GC). Stereospecific analysis (fatty acid position) was accomplished by partially hydrolyzing TAG with ethyl magnesium bromide and immediately derivatizing the resulting diacylglycerols (DAG) with (S)-(+)-1-(1-naphthyl)ethyl isocyanate. The derivatized sn-1,2-DAG were completely resolved from the sn-2,3-DAG on two 25 mm × 4.6 mm 3 μ silica HPLC columns. The columns were chilled to −20°C to obtain baseline resolution of collected peaks. The distribution of fatty acids on each position of the glycerol backbone was derived from the fatty acid compositions of the two DAG groups and the unhydrolyzed oil. Results for the sn-2 position were verified by hydrolyzing oils with porcine pancreatic lipase, isolating the resulting sn-2 monoacylglycerols by TLC, and determining the fatty acid compositions by GC. Results demonstrated that alterations in the total fatty acid composition of these seed oils are determined by the concentration of TAG species that contain at least one of the modified acyl groups. As expected, no differences were found in TAG with fatty acid quantities unaffected by the specific mutation. In lieu of direct metabolic or enzymatic assay evidence, the authors’ positional data are nevertheless consistent with TAG biosynthesis in these lines being driven by the mass action of available acyl groups and not by altered specificity of the acyltransferases, the compounds responsible for incorporating fatty acids into TAG.     

Enzymatically Modified Shea Butter and Palm Kernel Oil as Potential Lipid Drug Delivery Matrices

Drug formulations based on lipids can enable a significantly better delivery of a pharmaceutically active substance and thus enhance their bioavailability. However, natural fats and oils usually have properties, which do not allow their direct use for drug delivery. Therefore, we have modified palm kernel oil (PKO) and shea butter (SB) via lipase‐catalyzed transesterification using either glycerol – to create a diglyceride‐enriched lipid – or using hexanoic acid via acidolysis – to alter their fatty acid composition – and hence to improve drug solubility of Celecoxib serving as model compound. The most suitable enzyme was immobilized Thermomyces lanuginosus lipase (Novozyme TL IM). The solubility of Celecoxib as determined in SB, pharmaceutical grade SB, glycerol‐modified SB, hexanoic acid‐modified SB, PKO, glycerol‐modified PKO, and hexanoic acid‐modified PKO. Incorporation of one or two equivalents of hexanoic acid enabled higher Celecoxib solubilization than the diglyceride rich oil. Although structured SB and PKO (15.8 ± 0.4 mg mL^?1) do not differ significantly (p < 0.05) as per the amount of Celecoxib dissolved, the use of the modified oils enhanced Celecoxib solubility in SB (15.5 ± 1.3 mg mL^?1) in comparison to shea butter (7.9 ± 0.5 mg mL^?1). The lipase‐catalyzed modification also improved the miscibility of the oils with surfactants such as Tween 20 and resulted in reduced droplet sizes (<70 nm at oil/surfactant ratios of 1:2 and 1:1) and reduced polydispersity index values of the resulting emulsions. Practical Application: The structured triglycerides synthesized in this work on the basis of natural shea butter oils could function as suppository bases and oil phase in oral and parenteral lipid‐based formulations for improving the solubility and absorption of poorly soluble drugs. As various lipases with distinct selectivity are available for the enzymatic synthesis of structured triglycerides and useful for this purpose, further tailor‐designed formations should be accessible. With the aim of developing novel lipid drug delivery matrices palm kernel oil (PKO) and shea butter (SB) were modified via lipase‐catalyzed transesterification to alter their fatty acid composition and hence to improve drug solubility of the model compound Celecoxib. Incorporation of one or two equivalents of hexanoic acid enabled better Celecoxib solubilization than the diglyceride‐rich oil. Overall, the successful modification process yielded structured lipids with promising miscibility with selected surfactants and potential enhancement of Celecoxib solubility and thus represents a promising approach for the development of novel safe and effective lipid‐based delivery systems.

     

Effect of freezing on quality of sea bass and gilthead sea bream

Freezing is an efficient method of fish preservation. The aim of the present work was to examine the impact of freezing in fatty acid composition and in the in vitro inhibitory activity of sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) fillet lipids against platelet activating factor (PAF). The Bligh and Dyer extraction method and the counter‐current distribution method were used to obtain total, polar and neutral lipids. The fatty acid analysis conducted using the internal standard method and the biological assay on washed rabbit platelets took place calculating the in vitro inhibitory activity of fish lipids against 2.5 × 10^?11 M of PAF. No statistical changes (p<0.05) occurred in fatty acid content of fresh and thawed gilthead sea bream, while fatty acid amount in thawed sea bass was significantly higher (p<0.05) compared to fresh fish. Total lipids of both thawed fish species exhibited stronger anti‐thrombotic activity compared to fresh fish. Freezing preserved fish quality and reinforced the anti‐thrombotic properties of fish oils, since even after 6 months of freezing, fish oils preserve their nutritional value in terms of protecting against cardiovascular diseases. Practical applications: Fish fillets contain high amount of unsaturated lipids that may easily undergo lipid oxidation. Freezing and frozen storage prevent such oxidative changes so fish quality is retained. Fatty acids and PAF‐antagonists in fish are of major importance since they contribute to the nutritional value of fish. The practical application of this work lies on the evaluation of the nutritional value of fish in terms of cardio protection by examining the impact of freezing on the levels of fatty acids and PAF‐antagonists in aquacultured fish fillets.