Seasonal variation in the fatty acid composition of three Mediterranean fish – sardine (Sardina pilchardus), anchovy (Engraulis encrasicholus) and picarel (Spicara smaris)

The total fat contents and the fatty acid compositions of three common Mediterranean fish, namely sardine (Sardina pilchardus), anchovy (Engraulis encrasicholus) and picarel (Spicara smaris) were determined at bimonthly intervals for a one-year period. The purpose of this work was to study the seasonal variation of the fatty acids in the three fish that are some of the best sources of n − 3 fatty acids. The fat and fatty acid content of the investigated fish species show a significant seasonal dependency. Two of the fish (anchovy and picarel) have the highest fat content during the late winter – spring period. On the other hand, sardine shows the highest fat concentrations during the spring-early summer period. The fish that showed the highest variation in fatty acid composition was the anchovy. The sardine was found to be the best source of n − 3 fatty acids during the one-year period (35.35 g/100 g fatty acids). Finally the picarel had the highest oleic acid content (on average, 13.89/100 g fatty acids).     

Oxidative stability of oil from blubber of harp seal (Phoca groenlandica) as assessed by NMR and standard procedures

Oils from seal blubber and cod liver were extracted, refined and bleached in a laboratory scale process. Oxidative stability of oils was evaluated over a 16-day period under accelerated oxidation conditions at 65°C. Peroxide value (PV), contents of conjugated dienes (CD) and trienes (CT), 2-thiobarbituric acid reactive substances (TBARS) and p-anisidine values (AnV) were determined. In addition, NMR spectroscopy was used to monitor relative changes in the proton pattern of the fatty acids of oils during storage. Cod liver oil showed higher PV, CD, CT and TBARS values as compared with seal blubber oil. The ratio of aliphatic to olefinic protons in both oils determined by NMR spectroscopy increased steadily over the entire length of the storage period, indicating progressive oxidation of unsaturated fatty acids in both oils. A significant correlation (P ≤0·05) was found between these ratios and TOTOX values (2PV + AnV) for both oils, thus suggesting that NMR methodology can be used as an effective means to simultaneously estimate both primary and secondary oxidation changes.     

Production of n − 3 polyunsaturated fatty acid concentrate from sardine oil by lipase-catalyzed hydrolysis

The production of n − 3 polyunsaturated fatty acids (n − 3 PUFAs) concentrate from oil extracted from Pacific sardines (Sardinops sagax) was studied using lipase-catalyzed hydrolysis. Commercially available microbial lipases, from Candida Rugosa (CR), Candida cylindracea (CC), Mucor javanicus (MJ), and Aspergillus niger (AN) were used for enzymatic hydrolyses with extracted sardine oil, run at 37 °C with constant stirring for 1.5, 3, 6, and 9 h. Fatty acid composition analysis by gas chromatography showed that the refined unhydrolyzed oil contained 26.86% of eicosapentaenoic acid (EPA) and 13.62% of docosahexaenoic acid (DHA) (wt/wt%). CR lipase was the most effective in concentrating n − 3 PUFA. Hydrolysis with 250 U CR lipase increased EPA concentration to a relatively constant level of 33.74% after 1.5 h. DHA levels were also significantly increased from 13.62% to 29.94% with 500 U after 9 h. Compared to CR and CC lipases, MJ and AN lipases resulted in low n − 3 PUFA concentration. Triacylglycerol levels decreased significantly as reaction time progressed.     

Enriching the egg yolk in n − 3 fatty acids by feeding hens with diets containing horse fat produced in Uruguay

The present study was conducted to evaluate the ability of horse fat produced in Uruguay, compared with other lipid sources supplemented in the diet of laying hens, to modify the lipid composition and the n − 6/n − 3 fatty acid ratio of the produced eggs. For this purpose, 60 laying hens (Gallus domesticus) were fed for 30 days with five experimental diets (12 hens/diet) containing 3% sunflower oil (SO), rice oil (RO), beef tallow (BT), pressed-fat (PF), obtained by pressing fat from bovine viscera, and horse fat (HF) obtained from horse bone medulla. Throughout the trial, feeding rate, shell index, weight and total lipid contents of eggs, were not affected by the different diets. Feeding on the SO and RO diets significantly increased the amount of linoleic acid of the egg, although it was lower in the RO than in the SO eggs. Diet BT did not affect the saturated fatty acid content of the yolks. The diets with animal fats containing 18:3n − 3 (diets PF and HF), resulted in a significant increase in the n − 3 fatty acid contents of the eggs, through an increase of linolenic (18:3n − 3) and docosahexaenoic acid (DHA, 22:6n − 3) contents. Eggs from hens fed the HF diet showed increased linolenic acid (46 mg/yolk) and DHA (71 mg/yolk, 1.7% of total fatty acids) contents. These levels were obtained after two weeks of feeding. Moreover, the fatty acid profiles of eggs from treatment HF were not significantly affected by thermal treatment of the yolks. In conclusion, the fat from horse bone medulla, as produced in Uruguay, can be considered as a suitable lipid source for diets of laying hens, to modify the nutritional composition of the eggs in n − 3 PUFA content, especially DHA, and consequently, the n − 6/n − 3 fatty acid ratio.     

Nutritional and sensory aspects of light lamb meat enriched in n−3 fatty acids during refrigerated storage

Fatty acid content and sensory characteristics of meat from light lambs fed three diets supplemented with different sources of n−3 fatty acids (fish oil, extruded linseed and extruded linseed plus microalgae) and a control diet during refrigerated storage have been studied. The meat from lambs fed linseed diets had the highest levels of C18:3 n−3, while animals fed fish oil had the highest long-chain n−3 polyunsaturated fatty acids (PUFA). Thus, 100 g of meat from lamb fed the fish oil diet provided 183 mg of long-chain n−3 PUFA, representing 40% of the daily recommended intake. The levels of n−3, n−6 and long-chain n−3 PUFA decreased during a 7-day storage period. The meat from lambs fed the fish oil diet had high scores of fish odour and flavour and rancid odour and flavour and the lowest overall liking. Rancid odour and flavour increased after storage, mainly in supplemented groups.     

Chemical composition characteristics of the longissimus and semimembranosus muscles for pigs from New Zealand and Singapore

A range of composition characteristics of the longissimus (LL) and semimembranosus (SM) muscles were compared between pigs raised in intensive and extensive production systems in New Zealand (NZ), and pigs raised in an intensive system in Indonesia for supply to the Singapore market (n = 8/group). Ultimate pH was slightly higher for the Singaporean LL muscles (P < 0.05), while LL muscle of the NZ extensive group was redder (higher a^∗ values) and contained more fat (P < 0.05). Muscle iron levels were highest for the NZ extensive group and lowest for a lighter group within the Singapore pigs (P < 0.05). Differences in fatty acid concentrations, which were also measured in a sample of the belly cut, could largely be attributed to the effects of diet, with higher levels of alpha linolenic acid for the NZ extensive group (P < 0.05) due to linseed in the diet, and much higher levels of linoleic acid and the P:S ratio for the Singapore group (P < 0.05). Some statistically significant differences in amino acid concentrations were shown between muscles and groups, but they were not large. With respect to compounds with potential bioactive properties, coenzyme Q_10, and taurine levels were higher in pork from NZ pigs, and carnosine levels were highest for the NZ intensive group (P < 0.05). The LL muscle contained more coenzyme Q₁₀ and taurine, but less carnosine than the SM muscle (P < 0.001). It is concluded that some of these composition differences in the pork from the muscles and groups compared may be of commercial importance, but several are likely to have been due to dietary or weight differences.     

Heterotrophic growth and nutritional aspects of the diatom Cyclotella cryptica (Bacillariophyceae): Effect of some environmental factors

To investigate the nutritional value of the diatom Cyclotella cryptica (Reimann, Lewin, and Guillard) as an alternative feed for use in the aquaculture industry, the heterotrophic growth characteristics and resultant fatty acid profile of the microalga were studied when cultivated under a variety of controlled salinity and temperature conditions. In addition, the effects of pH on the growth characteristics were also studied. The maximum specific growth rate was affected by initial pH and cultivation temperature, but not by salinity. The optimal pH and temperature ranges for growth were 7.2 to 8.1 and 22.5 to 25.0 °C, respectively. Lipid accumulation and the fatty acid composition were also affected by cultivation temperature and salinity. The optimal temperature range and salinity level for lipid accumulation were 18.0 to 25.0 °C and 11.2 psu, respectively. In all cases the fatty acid distribution was similar, with the most abundant fatty acids being palmitic acid (16:0), palmitoleic acid (16:1 n-7), stearidonic acid (18:4 n-3, SDA), eicosapentaenoic acid (20:5 n-3, EPA), and decosahexaenoic acid (22:6 n-3, DHA).     

Development of dry fermented sausages rich in docosahexaenoic acid with oil from the microalgae Schizochytrium sp.: Influence on nutritional properties,sensorial quality and oxidation stability

Significant enrichment of dry fermented sausages in n−3 polyunsaturated fatty acids (PUFA) was achieved by incorporating algae oil from Schizochytrium sp. into an emulsion that partially substituted pork backfat from the traditional formulation. Two different levels of substitution were initially tested, both including BHA and BHT as antioxidants: (15% and 25%). A triangular test showed that products with 25% substitution were not sensorially acceptable. Sausages with 15% substitution supplied 1.30 g/100 g product of docosahexaenoic acid (DHA), with an interesting n−6/n−3 ratio of 2.62. No signs of oxidation were detected at the end of the ripening process, with low values of TBARs (<0.2 mg/kg), peroxides (<2 meq O₂/kg fat) and volatile aldehydes. Storage of these sausages under vacuum during 30 days totally guaranteed their stability, whereas after 90 days certain degree of oxidation was detected, only by means of aldehydes analysis. Hexanal, nonanal and dienals increased, whereas no increment in TBARs or peroxides were observed. Aerobical storage of these sausages was not viable due to a high oxidation susceptibility of the new formulation, despite the use of antioxidants.     

Effects of feeding flaxseed or sunflower-seed in high-forage diets on beef production,quality and fatty acid composition

Yearling steers were fed 70:30 forage:concentrate diets for 205 d, with either grass hay (GH) or red clover silage (RC) as the forage source, and concentrates containing either sunflower-seed (SS) or flaxseed (FS), each providing 5.4% oil to diets. Feeding diets containing SS versus FS significantly improved growth and carcass attributes (P < 0.05), significantly reduced meat off-flavor intensity (P < 0.05), and significantly increased intramuscular proportions of vaccenic (t11-18:1), rumenic (c9,t11-CLA) and n − 6 fatty acids (FA, P < 0.05). Feeding diets containing FS versus SS produced significantly darker and redder meat with greater proportions of atypical dienes (P < 0.05). A significant forage × oilseed type interaction (P < 0.05) was found for n − 3 FA, α-linolenic acid, and conjugated linolenic acid, with their greatest intramuscular proportions found when feeding the RC-FS diet. Feeding GH versus RC also significantly improved growth and carcass attributes, sensory tenderness (P < 0.05) and significantly influenced intramuscular FA composition (P < 0.05), but overall, forage effects on FA profiles were limited compared to effects of oilseed.     

Chemical composition,fatty acid content and antioxidant potential of meat from goats supplemented with Moringa (Moringa oleifera) leaves,sunflower cake and grass hay

The present study determined the chemical composition, fatty acid (FA) content and antioxidant capacity of meat from goats supplemented with Moringa oleifera leaves (MOL) or sunflower cake (SC) or grass hay (GH). The meat from goat supplemented with MOL had higher concentrations of total phenolic content (10.62 ± 0.27 mg tannic acid equivalent E/g). The MOL significantly scavenged 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic-acid (ABTS) radical to 93.51 ± 0.19% (93.51 ± 0.19%) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical to 58.95 ± 0.3% than other supplements. The antioxidative effect of MOL supplemented meat on catalase (CAT), reduced glutathione (GSH), superoxide dismutase (SOD) and lipid oxidation (LO) was significantly (P < 0.05) higher than other meat from goat feed on grass hay or those supplemented with sunflower seed cake. The present study indicated that the anti-oxidative potential of MOL may play a role in improving meat quality (chemical composition, colour and lipid stability).     

Characterisation of a novel monomeric lectin (AML) from Astragalus membranaceus with anti-proliferative activity

A novel lectin (AML) was isolated from the roots of a Chinese herb Astragalus membranaceus (Fisch.) Bunge, using a combination of ammonium sulphate fractionation and affinity chromatography. AML was found to be a monomeric protein with a molecular mass of 31.5 kDa. Biochemical characterisation revealed that it is a glycoprotein containing 10.7% neutral sugars. The N-terminus of AML was blocked but amino acid sequences of internal tryptic peptides showed moderate sequence identities with some other known lectins. Amongst the various carbohydrates tested, the lectin was best inhibited by d-galactose and its derivatives with pronounced preference for o-nitrophenyl-β-d-galactopyranoside (8.3 mM). The lectin was stable in the pH range of pH 5.0–12.0 and temperatures up to 55 °C for 30 min. AML inhibited the proliferation of HeLa and K562 cell lines. Thus, the lectin displays a high potential for antitumour activity.     

Isolation,characterization and antioxidant capacity assessment of the bioactive compounds derived from Hypoxis rooperi corm extract (African potato)

The rhizome of the plant Hypoxis rooperi (“African potato”) is known for its traditional and ethnomedical uses in the treatment of benign prostatic hyperplasia and other diseases. We have characterized an extract derived from H. rooperi, isolated its major bioactive compound, hypoxoside, and obtained its aglycone, rooperol, by enzymatic digestion. Absorption, fluorescence emission and bidimensional NMR complete spectral data of these compounds were obtained. The antioxidant capacity of both compounds was fully analyzed through the thiobarbituric acid reactive substances (TBARS) and Trolox equivalent antioxidant capacity (TEAC) assays, and it was compared to catechins and olive biophenolics. Both compounds showed a strong antioxidant capacity, although rooperol exhibited a higher antioxidant activity against lipid peroxidation which correlated to its strong affinity for phospholipid membranes as derived from its extremely high lipid/water partition coefficient (K_p = 3.4 × 10⁴). The study of the lipophilic (EtOH) and hydrophilic (water) TEAC values revealed that more hydrophobic compounds, had greater lipophilic TEAC values than hydrophilic ones, probably indicating that lipophilic TEAC assay may be more reliable for these compounds. The H. rooperi extract also showed higher antioxidant efficacy compared to other strong antioxidant herbal extracts, such as olive leaf or green tea. Moreover, neither evidence of acute oral toxicity nor adverse effects were observed when the H. rooperi commercial extract containing 45% hypoxoside was used at a dosage of 2000 mg/kg. The results obtained in this work may contribute to understanding the biological activity described for these dicatechols and the African potato extract for food and cosmetic applications.     

Açaí (Euterpe oleraceae) ‘BRS Pará’: A tropical fruit source of antioxidant dietary fiber and high antioxidant capacity oil

This article reports a study of the concentrations of dietary fiber (DF) and antioxidant capacity in fruits (pulp and oil) of a new açaí (Euterpe oleraceae) cultivar—‘BRS-Pará’, with a view to determine the possibility of using it as a source of antioxidants in functional foods or dietary supplements. Results show that ‘BRS-Pará’ açaí fruits has a high content of DF (71% dry matter) and oil (20.82%) as well as a high antioxidant capacity in both defatted matter and oil. ‘BRS-Pará’ Açaí fruits can be considered as an excellent source of antioxidant dietary fiber. Antioxidant capacity of açaí ‘BRS-Pará’ oil by DPPH assay was higher (EC₅₀ = 646.3 g/g DPPH) than extra virgin olive oil (EC₅₀ = 2057.27 g/g DPPH). These features provide açaí ‘BRS-Pará’ fruits with considerable potential for nutritional and health applications.     

Mycosporine-like amino acid composition of the edible red alga, Palmaria palmata (dulse) harvested from the west and east coasts of Grand Manan Island,New Brunswick

The oxygen radical absorbance capacity (ORAC), antiproliferative activities and mycosporine-like amino acid (MAA) profiles of methanol extracts from two grades of dulse harvested from locations varying in UV-exposure (west vs east coasts of Grand Manan Island, NB) were determined in the present study. MAAs confirmed by LC/MS in both grades 1 (low-UV) and 2 (high-UV) dulse were palythine, shinorine, asterina-330, palythinol and porphyra-334; usujirene was present only in grade 2 dulse. ORAC values of grade 1 and 2 dulse extracts were 36.42 and 38.78 μmol Trolox/g extract. B16-F1 murine skin melanoma cell proliferation was inhibited (p < .05) by 68.5% and 91.9% by grade 1 and 2 dulse extracts at 6.0 mg/mL. The antiproliferative efficacy of grade 2 dulse was greater (p < .05) than grade 1 from 0.375 to 6.0 mg/mL. MAA differences between the grade 1 and 2 dulse extracts likely influenced the antiproliferative efficacies, despite the similar ORAC values.     

Inhibition of fish oil oxidation and the radical scavenging activity of New Zealand seaweed extracts

This study describes the potential use of New Zealand seaweed extracts as antioxidants in fish oils. The extracts from two brown seaweeds (Ecklonia radiata, Macrocystis pyrifera) and two red species (Champia sp. and Porphyra sp.), were added to hoki (Macruronus novaezelandiae) oil and assessed by production of oxidation products in an elevated temperature (60 °C) storage trial. Antioxidant assays ORAC and DPPH were conducted to elucidate the radical scavenging activity of the seaweed extracts. The results showed that all the lipid-soluble seaweed extracts had some antioxidative capacity, with brown algae generally outperforming red algae species. Extracts from E. radiata performed best with significantly lower primary, secondary and total oxidation products, and higher DPPH radical scavenging ability than the commercial antioxidant, BHT. This study demonstrated the potential of brown algae seaweed extracts, in particular E. radiata, for use as antioxidants in fish oil products.     

Purification and characterisation of a novel antioxidant protein molecule from Phyllanthus niruri

The herb Phyllanthus niruri is known to possess antioxidant activity, but the nature of the responsible active principle(s) is not well defined. The present study reports the purification and characterisation of a 35 kDa antioxidant protein molecule from this herb using a bioassay in which oxidative stress was introduced in hepatocytes with the help of a suitable free radical inducer, tertiary butyl hydroperoxide (TBHP), and the prevention of that stress was monitored using the protein fraction(s) obtained at each step of the purification. Partial amino acid sequence of this protein revealed its unique structural features. The purified protein possesses potent radical-scavenging activity, enhances intracellular antioxidant power and protects the TBHP-induced alterations of the cytoprotective and antioxidant molecules, as well as other parameters used in this particular study. Combining, data suggest that the antioxidant activity of Phyllanthus niruri is at least partly due to this unique protein molecule.