Comparative analysis of the fatty acid and sterol profiles of widely consumed Mediterranean crustacean species

Comparative analysis of FA, NL and sterol profiles in the Nephropsnorvegicus (langoustine), Palinurusvulgaris (lobster) and Penaeuskerathurus (shrimp) muscle and cephalothorax showed that C16:0, C16:1ω-7, C18:0, C18:1ω-9, C20:4ω-6, EPA and DHA were found to be their major FA. Highest EPA occurred in langoustine muscle TL, DHA in both shrimp tissues TL while C20:4ω-6 in lobster muscle and cephalothorax TL. Muscle and cephalothorax NL consisted mainly of sterols (42.5–54.4% and 13.7–43.1%) and triacylglycerols (35.4–45.8% and 44.6–59.4%). Cholesterol was the major sterol (70.90–98.58% and 97.10–98.31% of total sterols in muscle and cephalothorax respectively) followed by avenasterol (0.18–20.32% and 0.07–0.70%) and β-sitosterol (0.29–7.30% and 0.23–0.75%). Lower concentrations of brassicasterol, stigmasterol, Δ7-stigmasterol, campesterol and campestanol were also found. The examined crustaceans muscle (edible part) was found to be a good ω-3 PUFA source for the consumers, while the cephalothorax (which is usually discarded) could be used effectively as a source for ω-3 PUFA production.     

利用微藻培养生产多不饱和脂肪酸研究进展

多不饱和脂肪酸(PUFA),尤其是二十碳五烯酸(EPA)和二十二碳六烯酸(DHA)在营养和医学领域有着重要作用。目前PUFA主要从鱼油中提取,工艺复杂,价格昂贵。微藻中含有丰富的多不饱和脂肪酸,利用微藻生产多不饱和脂肪酸具有广阔的前景。本文综述了微藻培养生产PUFA的研究进展,包括生理作用、合成途径、来源分布及培养方式等。     

Effect of dietary linseed on the nutritional value and quality of pork and pork products: Systematic review and meta-analysis

Nutritional quality of pork is a significant factor for consumers' health. Feeding n-3 PUFA to pigs, using linseed, improves pork nutritional quality. A meta-analysis involving 1006 pigs reported in 24 publications was carried out to assess the effects of dietary linseed on alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) content in muscle and adipose tissue. Data showed positive effects of n-3 PUFA on muscle fatty acid composition: ALA + 137%, EPA + 188%, DPA + 51% and DHA + 12%. Same results were observed in adipose tissue: ALA + 297%, EPA + 149%, DPA + 88% and DHA + 18%. A positive correlation between dietary treatment and ALA and EPA content in muscle (P < 0.001) and adipose tissue (P = 0.036) was observed. A significant association between DPA (P = 0.04) and DHA (P = 0.011) and live weight in muscle was observed. Feeding linseed to pig improves the nutritional pork quality, raising the n-3 PUFA content in muscle and adipose tissue.     

Restoration of EPA and DHA in rainbow trout (Oncorhynchus mykiss) using a finishing fish oil diet at two different water temperatures

Feeding fish a fish oil finishing diet (FOFD) after grow-out on vegetable oil diet is one strategy to restore eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels. We investigated restoration of EPA and DHA in rainbow trout fed a FOFD preceded by a grow-out period on 50% or 75% palm fatty acid distillate (PFAD) diets at optimal (15 °C) or elevated (20 °C) water temperatures. Using the FOFD restored EPA and DHA in fillet and whole carcass of fish previously fed either 50% PFAD diet from 85% to 98% or 75% PFAD from 66% to 93% of values obtained for fish fed FO diet throughout. Water temperature did not influence EPA and DHA restoration. Growing rainbow trout with diets where FO was replaced by either 50% or 75% PFAD followed by a FOFD reduced FO usage by around 30% and 44% at 15 °C, respectively, and 32% and 48% at 20 °C, respectively.     

Effect of cooking method on the fatty acid profile of New Zealand King Salmon (Oncorhynchus tshawytscha)

Farmed New Zealand King Salmon (Oncorhynchus tshawytscha) was prepared according to common consumer techniques; raw, poached, steamed, microwaved, pan fried (no added oil), oven baked (no added oil) and deep fried (in sunflower oil). The fatty acid profile was investigated to determine the optimal preparation techniques to achieve both optimal sensory and nutritional qualities, in particular the levels of long chain polyunsaturated omega-3 fatty acids. The modified Bligh and Dyer method was used for lipid extraction and the Hartman and Lago method for FAMES preparation. Fatty acid composition was determined by gas chromatography. There were moisture and lipid losses during cooking amongst the different methods. The fatty acid profile showed only minor differences between the methods apart from an increase in PUFA in the deep fried salmon due to linoleic acid uptake from the frying oil. In all the cooking methods the omega-3 fatty acids were well preserved. However, deep fried showed the lowest amounts of omega-3 fatty acids. As the results showed good preservation of omega-3 fatty acids regardless of cooking method, there may be possible “internal protection” of omega-3 fatty acids in King Salmon that warrants future research.     

Triacylglycerols and their fatty acid composition in edible Mediterranean molluscs and crustacean

The triacylglycerol (TAG) composition of edible Mediterranean molluscs (Eledone moschata, Sepia officinalis, Todarodes sagittatus) and crustacean (Penaeus kerathurus) was studied using a combination of preparative RP–HPLC and GC/MS. In S. officinalis and T. sagittatus mantle TAG, the main fatty acids were C16:0 and C18:0 while in E. moschata they were C18:1ω-9, C16:0, C20:5ω-3 and C22:6ω-3. In P. kerathurus muscle and cephalothorax TAG, the main fatty acids were C16:0, C18:0, C18:1ω-9, C20:4ω-6, C20:5ω-3, C22:6ω-3 and C16:0, C18:1ω-9, C20:4ω-6, C20:5ω-3, C22:6ω-3, respectively.     

Effect of a supplementation of Euphorbia heterophylla on nutritional meat quality of Guinea pig (Cavia porcellus L.)

The aim of the present work was to study the effect of dietary supplementation of Euphorbia heterophylla on the quality of the Guinea pig meat. Forty guinea pigs were divided into two groups fed ad libitum during 46 days a Panicum maximum diet (Panicum diet) or a mixed diet (75% Panicum maximum + 25% Euphorbia heterophylla) (Paneuphorbia diet) to compare their effects on performances and on the composition of guinea pig tissues and carcass. Daily weight gain, liver weight, carcass yield, and the lipid content of both the carcass and the perirenal fat were significantly increased by the Paneuphorbia diet. Feeding Paneuphorbia diet increased (P < 0.05) the n-3 PUFA content in perirenal fat, muscle, liver and in the carcass and decreased (P < 0.05) the n-6/n-3 ratios in all these tissues and the carcass. In conclusion, this study shows that Euphorbia heterophylla is a source of n-3 fatty acids which can improve significantly the n-3 PUFA content of Guinea pig meat and carcass.     

Seasonal Variation in Proximate Composition and Fatty Acid Profile of Grey Triggerfish (Balistes capriscus) Captured Along the Coast of Portugal

Proximate composition (ash, moisture, total protein, and fat contents) and fatty acid profile of Balistes capriscus (grey triggerfish) were assessed over a 6‐months period (April to September, 2011) in animals captured along the coast of Peniche (Portugal). High protein (18.9% to 21.4%) and low lipid (0.5% to 0.8%) contents were determined. The highest lipid level was found in June‐captured animals. High proportions of n‐3 polyunsaturated fatty acids (n‐3 PUFA) were observed (53.87 ± 2.00%) together with substantial quantities of oleic acid (27.58 ± 1.09%) and palmitic acid (16.52 ± 0.93%). Docosahexaenoic acid accounted for 77% of the total PUFA and was 7 times more abundant than eicosapentaenoic acid, and the n‐3/n‐6 ratio was 7.2. Gender did not influence lipid levels and the fatty acid profile, but seasonal variations were observed for PUFA and monounsaturated fatty acid contents. Overall, the nutritional properties of this underexploited species may be comparable to those of other lean fish species with higher economic value.     

Effect of cooking methods on fatty acids,conjugated isomers of linoleic acid and nutritional quality of beef intramuscular fat

The effect of boiling, microwaving and grilling on the composition and nutritional quality of beef intramuscular fat from cattle fed with two diets was investigated. Longissimus lumborum muscle from 15 Alentejano young bulls fed on concentrate or pasture was analyzed. Cooking losses and, consequently, total lipids, increased directly with the cooking time and internal temperature reached by meat (microwaving > boiling > grilling). The major changes in fatty acid composition, which implicated 16 out of 34 fatty acids, resulted in higher percentages in cooked beef of SFA and MUFA and lower proportions of PUFA, relative to raw meat, while conjugated linoleic acid (CLA) isomers revealed a great stability to thermal processes. Heating decreased the PUFA/SFA ratio of meat but did not change its n−6/n−3 index. Thermal procedures induced only slight oxidative changes in meat immediately after treatment but hardly affected the true retention values of its individual fatty acids (72–168%), including CLA isomers (81–128%).     

The labile lipid fraction of meat: from perceived disease and waste to health and opportunity

The fatty acid composition of beef and pork has been stigmatized due to their relationships with several diseases from cardiovascular disease to cancer. Meat lipids are, however, one of the few components of meat that can be modified in content and composition, and can present opportunities for value added production and health promotion. Until regulations and policies are in place to define requirements for fatty acid enrichment, however, the process remains relatively academic. Once practical goals are in place for fatty acid enrichment in meat, both theory and practice need to converge for successful production of fatty acid enriched meat. The present review covers aspects of policy in Canada, and requirements for research networks to respond to theoretical and practical challenges associated with production of fatty acid enriched meat. Finally, needs for education and marketing are outlined which must be in place to truly realize a transition of meat lipids from perceived disease and waste to health and opportunity.     

Effect of the feeding system on intramuscular fatty acids and conjugated linoleic acid isomers of beef cattle,with emphasis on their nutritional value and discriminatory ability

Thirty two Alentejano purebred bulls were used to investigate the effect of four feeding systems (pasture only, pasture feeding followed by 2 or 4 months of finishing on concentrate, and concentrate only) on meat fatty acid composition (GC-FID), including conjugated linoleic acid (CLA) isomeric distribution (Ag[+]–HPLC–DAD). In addition, meat fatty acids and CLA isomers were used to elucidate the impact of the different feeding regimens on the nutritional value of intramuscular fat and their usefulness as chemical discriminators of meat origin. The diet had a major impact on the fatty acid composition of beef (affected 27 of 36 fatty acids and 10 of 14 CLA isomers), which was independent of the fatty acid concentration. Beef fat from pasture-fed animals had a higher nutritional quality relative to that from concentrate-fed bulls. Finally, meat fatty acid composition was an effective parameter to discriminate between ruminant feeding systems, including different finishing periods on concentrate.     

Seasonal changes and muscle type effect on the nutritional quality of intramuscular fat in Mirandesa-PDO veal

The influence of slaughter season and muscle type on the detailed fatty acid composition, including conjugated linoleic acid isomers, and contents of total cholesterol and lipid-soluble antioxidant vitamins (α-tocopherol and β-carotene) in Mirandesa-PDO veal was assessed. Mirandesa purebred calves (n = 29) were raised in a traditional production semi-extensive system, slaughtered in late spring (June) or early autumn (October) and the longissimus lumborum and semitendinosus muscles were sampled for analysis. Although the lipid composition of PDO veal was only slightly affected by the slaughter season, it was markedly changed by the muscle type. However, PDO veal had values of pasture-fed cattle for lipid grass intake indicators, in both seasons and muscles. From a human health standpoint, intramuscular fat in Mirandesa-PDO veal has a high nutritional value throughout the year, with favorable ratios of n− 6/n− 3 and contents of n− 3 PUFA and α-tocopherol, as a result of the beneficial effects of grass feeding.     

Nutritional composition of blubber and meat of hooded seal (Cystophora cristata) and harp seal (Phagophilus groenlandicus) from Greenland

Seal blubber and skin are widely used, but the utilisation of blubber and meat for human consumption is limited. The aim of this study was to evaluate the nutritional composition of seal blubber and meat. The fatty acid composition, selected minerals and trace-elements, vitamins, amino acids and proximal composition of blubber and meat from hooded seal (Cystophora cristata) and harp seal (Phagophilus groenlandicus) from the “West Ice” near Greenland were analysed. The results showed that seal blubber is an excellent source of long- and very long-chain (VLC) n − 3 polyunsaturated fatty acids (PUFAs), in addition to long- and VLC monounsaturated fatty acids (MUFAs). Eicosapentaenoic acid (EPA) content contributed to a clear separation between blubber and meat from the two species. The blubber of harp seal showed the highest EPA (9.2%), whereas the muscle of harp seal showed the lowest EPA (3%) content. Seal meat is lean with less than 2% total fat, mainly composed of MUFAs, long- and VLC n − 3 PUFAs. In addition, the meat contains a high amount of proteins with a well-balanced amino acid composition. The trace-element content of seal meat is very high, particularly iron (379 μg/g muscle in hooded seal) and zinc (30 μg/g muscle in harp seal), as also is the vitamin content, especially vitamins A, D₃ and B₁₂. The seals included in this study varied greatly in age and size, which in turn may be the principal reason for the great individual variation observed in nutritional composition. On average, however, consumption of only 40 g seal meat covers the recommended daily intakes of iron and vitamin B₁₂ for young women. In conclusion, as long as the products fulfil the amending legislations regarding contaminants, both seal blubber and meat, from the present species, represent high quality food regarding nutrients and bioactive components beneficial for human health.     

Ability of methanolic seed extracts of pawpaw (Asiminatriloba) to inhibit n-3 fatty acid oxidation initiated by peroxyl radicals and reactive oxygen,nitrogen, and sulfur

Methanolic extracts from underripe, ripe, and ripe then dried pawpaw seeds (PPSE) were tested for antioxidative effectiveness. Underripe seeds contained more total phenolic compounds than ripe seeds, but ripe seeds showed the highest reducing potential. PPSE samples effectively scavenged DPPH (>86%). PPSE (0–26.8 μM gallic acid) effectively inhibited lipid oxidation biomarkers in 22:6 phosphatidylcholine (PC) liposome suspensions over 7 day’s incubation at room temperature. PPSE inhibited TBARS in 22:6 PC liposome suspensions induced by peroxyl radical generators, free radical generators that produce reactive oxygen, reactive nitrogen, and reactive sulfur species. After 120 min of storage TBARS inhibition by PPSE was in the order of H₂O₂ ? SIN-1 = DSSO = AAPH ? Sulfite > ONOO = MMb > iron/ascorbate. PPSE inhibited lipid oxidation biomarkers in skeletal muscle homogenates induced by iron/ascorbate. The development of value added products from pawpaw seeds may lead to successful commercialisation of this underutilised fruit.     

Long-chain n-3 fatty acids and classical cardiovascular disease risk factors among the Catalan population

The protective cardiovascular effect of long-chain n-3 fatty acids has been firmly established in populations with high fish consumption, like those from Mediterranean countries. The current fish consumption in a representative sample from Catalonia, a Mediterranean region, and its relationship with plasma concentrations of eicosapentaenoic (EPA) and docosahexaenoic (DHA) and some classical cardiovascular disease risk factors was evaluated. Mean fish and seafood intake was 78.5 ± 51.4 g/day. Mean plasma concentrations of EPA and DHA were respectively 0.48% and 1.99% of total fatty acids. Consumption of marine foods among the Catalan population, the main source of n-3 fatty acids, appears to beneficially affect some cardiovascular disease risk factors. Our results show that both EPA and DHA are negatively associated with triacylglycerol (TG) concentrations and the ratio of total cholesterol (TC) to HDL-cholesterol. Furthermore, EPA but not DHA has a beneficial effect on plasma HDL-cholesterol among the Catalan population. There were no significant associations between long-chain n-3 fatty acids and LDL-cholesterol, TC, glucose, insulin or blood pressure. Oily fish intake, which is richest in EPA and DHA, is currently at an order of only 1 serving per week in the Catalan population and its increase should therefore be promoted.     

Effect of nutritional and environmental conditions on the production of exo-polysaccharide of Agaricus brasiliensis by submerged fermentation and its antitumor activity

Mushrooms have become attractive as a functional food and as a source for the development of drugs and nutraceuticals. A. brasiliensis is considered as the best among them. There are several published works on the fruiting bodies of this mushroom, showing high antitumor activity. The mycelium polysaccharide and exo-polysaccharide (EPS) of this mushroom also demonstrated a strong antitumor action. However, there is little information available in the literature about the optimization of physical and chemical conditions for production of EPS by submerged fermentation (SmF). After initial screening from the five strains available in the LPB Culture Collection, A. brasiliensis LPB 03 was selected for EPS production in SmF. Studies on supplementation of a carbon source to the medium revealed that sucrose was most effective for EPS production. Yeast extract was the best for EPS among the inorganic and organic nitrogen sources tested. The factorial experiment demonstrated that a temperature of 30 °C and a pH of 6.1 were the best for the EPS production. Glucose 10 g/l, yeast extract 3 g/l, K₂HPO₄ 0.6 g/l and MgSO₄ 0.3 g/l were most suitable for the EPS production. Maximum EPS production was obtained in the static condition with manual agitation two times per day after a 1-week culture (382 mg/l), increasing by 78.62% more than that before optimization. In the bioreactor with aeration and agitation, the maximum EPS was produced at 321.2 mg/l. The EPS of A. brasiliensis produced in SmF showed strong inhibition against Sarcoma 180 in mice, reaching 72.19% inhibition compared with the control group. Furthermore, 50% of mice in the test group demonstrated total tumor regression.     

Fatty acid composition of several wild microalgae and cyanobacteria, with a focus on eicosapentaenoic, docosahexaenoic and α-linolenic acids for eventual dietary uses

A total of 13 species of microalgae and 14 strains of cyanobacteria, collected directly in the Portuguese coast and lagoons, were characterized for their fatty acid contents, focusing on two with a market potential — i.e. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); and another already with alternative (yet somehow more expensive) natural sources — i.e. α-linolenic (ALA) acid. The purpose of this work was their eventual inclusion as additives in food or feed. ALA was the most abundant PUFA in Nannochloropsis sp. (0.616 ± 0.081 mg_FA.L_culture^{− 1}.d^{− 1}), and EPA in Phaeodactylum tricornutum (0.148 ± 0.013 mg_FA.L_culture^{− 1}.d^{− 1}); Pavlova lutheri was particularly rich in EPA (0.290 ± 0.005 mg_FA.L_culture^{− 1}.d^{− 1}) and DHA (0.140 ± 0.037 mg_FA.L_culture^{− 1}.d^{− 1}). Despite several previous reports on similar topics and encompassing some of our microalgal species, the wild nature of our strains accounts for the novelty of this work — in addition to the characterization of a few wild cyanobacteria. Eustigmatophyceae class was the best producer of ALA, while Prymnesiophyceae was the best for EPA and ALA. Nodularia harveyana exhibited the highest ALA level (0.611 ± 0.022 mg_FA.L_culture^{− 1}.d^{− 1}) and Gloeothece sp. was highest in EPA (0.030 ± 0.004 mg_FA.L_culture^{− 1}.d^{− 1}).     

The effects of fish oil-enriched diets on growth,feed conversion and fatty acid content of red hybrid tilapia, Oreochromis sp.

Juvenile, red hybrid tilapia were fed diets containing cod liver oil (0%, 4%, 8%, 12% of total diet) substituted against corn oil. After 10 weeks, no significant differences between treatments were seen in weight gain, specific growth rate, feed conversion ratio, whole body or dorsal muscle (fillet) proximate composition. Gas chromatography revealed significant differences in the total n-3 content and fatty acid profiles of dorsal muscle. The total n-3 content of dorsal muscle increased from 7.6% to 18.6%, total n-6 content fell from 37.5% to 12.9% and docosahexanaenoic acid increased from 5.8–16.1% of total fatty acids, in fish fed 0% and 12% fish oil, respectively. The retention of eicosapentaenoic acid was low in all dietary groups, possibly indicating selective use as a substrate for β-oxidation. The results demonstrate the potential to enhance the total n-3 fatty acids and docosahexaenoic acid in tilapia fillets by increasing dietary fish oil.