Production and bioavailability of calcium and magnesium salts of omega-3 fatty acids

In order to provide an alternative to traditional liquid fish oil gelatin capsules, we developed a solid, powdered form of omega-3 fish oil concentrate by forming calcium- and magnesium-fatty acid salts. These salts were produced using a concentrated fish oil ethyl ester that contained in excess of 60% omega-3 fatty acids. The bioavailability of these omega-3 salts was compared with that of fish oil ethyl ester in mice. Animals were given 8 mg of omega-3 fatty acid ethyl ester concentrate (control), calcium- or magnesium-omega-3 salts daily for three weeks. The omega-3 salt products resulted in omega-3 fatty acid content in serum and red blood cell membranes comparable to that produced by the ethyl ester supplementation. In addition, fecal excretion of omega-3 fatty acids was not increased by the presence of calcium or magnesium. In fact, there was a tendency for less omega-3 fatty acids to be excreted.     

棕榈油酸功能的研究进展

omega-7脂肪酸是一组单不饱和脂肪酸,常见于深海鱼类(如凤尾鱼)和某些植物类食品(澳洲坚果油、沙棘果油、海藻等)中。近年来,omega-3、omega-6和omega-9脂肪酸的作用都为人所熟识,但omega-7脂肪酸的众多功效却少有人知道。omega-7脂肪酸不仅可以控制体重,改善皮肤状况,提高人体对胰岛素的敏感性,降低肝脂肪的蓄积和减少炎症,并且可以降低低密度脂蛋白胆固醇,增加高密度脂蛋白胆固醇,改善冠状动脉心脏疾病和高血压等。我国人口快速老龄化,患糖尿病、高脂血症等代谢综合征数量急剧增加,对以棕榈油酸为主的omega-7脂肪酸保健产品以及医药制剂有更大的需求。对棕榈油酸在控制体重、改善皮肤状况、预防动脉粥样硬化、改善代谢综合征与炎症、防止骨碎、改善干眼症等方面的功能研究现状及可能存在的消极作用进行综述,旨在为omega-7脂肪酸功能性产品开发提供参考。     

Evaluation of processed cheese fortified with fish oil emulsion

Processed cheese fortified with fish oil is an excellent food for the delivery of omega-3 long-chain polyunsaturated fatty acids (omega-3 LC PUFA). However, oxidation and the “fishy” flavour of fish oil limit the level of fortification. The physical properties, lipid oxidation, and sensory perception of model processed cheese slices fortified with a fish oil emulsion (encapsulated fish oil) were examined and were compared with those of samples fortified with straight fish oil. Peroxide values, the results of thiobarbituric acid reactive substances (TBARS) tests, and propanal values showed that cheese samples fortified with fish oil emulsion had lower levels of oxidation than cheese samples fortified with non-encapsulated fish oil. A sensory panel detected a “fishy” flavour at a higher level of fish oil addition in the samples fortified with fish oil emulsion. This suggests that a fish oil emulsion made with a milk protein complex is a useful carrier for elevating the fortification level of omega-3 LC PUFA in processed cheese products.     

Supercritical fluid extraction of fish oil from fish by-products: A comparison with other extraction methods

Fish and fish by-products are the main natural source of omega-3 polyunsaturated fatty acids, especially EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), both of them with a great importance in the food and pharmaceutical industries. Comparing to conventional fish oil extraction processes such as cold extraction, wet reduction or enzymatic extraction, supercritical fluid extraction with carbon dioxide under moderate conditions (25 MPa and 313 K) may be useful for reducing fish oil oxidation, especially when fish oil is rich in omega-3 such as salmon oil, and the amount of certain impurities, such as some species of arsenic. Furthermore, taking profit of the advantages of supercritical carbon dioxide as extractive solvent, a coupled extraction-fractionation process is proposed as a way to remove free fatty acids and improve fish oil quality, alternatively to physical and chemical refining procedures.     

Effect of Fish and Oil Nature on Frying Process and Nutritional Product Quality

ABSTRACT: The modifications on a lean fish (cod—Gadus morhua) and a fatty fish (farmed salmon—Salmo salar) after the application of pan-frying using 2 types of oil with different lipid profile (extra virgin olive oil and sunflower oil) was the aim of this study. Fat content and total energetic value increased significantly after the frying process only in the lean fish, without relevant changes in the fatty fish. Extra virgin olive oil led to a higher fat absorption rate than sunflower oil in both fish. Frying hardly affected the lipid profile of farmed salmon regardless the oil used, however it drastically changed in fried cod compared to raw cod. Omega-6/omega-3 ratio increased from 0.08 in raw cod to 1.01 and 6.63 in fried cod with olive oil and sunflower oil, respectively. In farmed salmon, the omega-6/omega-3 ratio was 0.38 (raw), and 0.39 to 0.58 in fried salmon. The amount of EPA + DHA slightly decreased with frying in salmon, and increased in cod. The type of oil has more influence in the nutritional fish quality for the lean fish compared to that of the fatty fish. The use of extra virgin olive oil was efficient to avoid a significant increase of the lipid oxidation intensity during frying in cod but not in salmon. Practical Application: Food modifies its composition and nutritional value with the application of cooking technologies. As most food table composition tables are based on raw food products, this article contributes with interesting data on pan-fried fish composition, which may improve the approach to achieve a real intake of healthy nutrients as omega 3 fatty acids.     

A review of the progress in enzymatic concentration and microencapsulation of omega-3 rich oil from fish and microbial sources

Technology continues to evolve for the concentration and stabilisation of omega-3 fatty acids for delivery into food and beverage products. The use of lipases for selective concentration of EPA and DHA, or for re-esterification reactions, is important in the production of omega-3 concentrates. Enzymatic strategies require robust enzymes that can be immobilised and multiply re-used. Novel and mild processing methods are particularly important for providing oils with good sensory properties, which are required for successful use as functional food ingredients. Although in some cases good quality oils can be used directly in some foods, such as margarine, many foods require that microencapsulated and stabilised omega-3 oils be used. This is particularly important when the oils are preconcentrated. There are a number of industrially used microencapsulation methods, but the most widely used are complex coacervates and spray dried emulsions. Fish oil is still the most widely used source of long-chain omega-3 fatty acids for addition to food, although algal oil is the primary source of DHA for infant formula use in North America. Algal oil is still significantly more expensive than fish oil for most applications, although many groups are improving both the cost and quality of omega-3 oil from algal sources. In particular, Thraustochytrid and Schizochytrid strains are a promising source of both DHA and EPA, and with further improvement could be used to provide varying ratios of these omega-3 fats. In this short review we will describe some of the current research in omega-3 fat concentration and microencapsulation, with particular emphasis on the use of lipases for concentration and complex coacervation for microencapsulation.     

DHA藻油的生理功能及在食品中复配协同应用的研究进展

二十二碳六烯酸（docosahexaenoic,DHA）是一种人体必需的多不饱和脂肪酸,属于omega-3家族,主要来源为鱼油和藻油。与鱼油相比,藻油因为含有较高的DHA纯度和更高的安全性而备受青睐,因此被大量应用在食品和保健品中,与食品中的成分相互影响、协同增效。本文综述了DHA藻油的生理功能,包括促进大脑和眼部神经发育、增强免疫力、抗氧化和抗癌等。总结了DHA藻油在牛奶、酸奶、奶粉中的应用,探讨了它与益生菌、益生元、磷脂酰丝氨酸、卵磷脂等食品成分相互作用的效果与机制,为食品、保健品行业更广泛、深入地使用DHA藻油提供理论依据。     

The effect of linseed oil on the fatty acid composition of blood plasma low- and very low-density lipoproteins and cholesterol in diabetics]

Twenty patients with compensated diabetes mellitus of 10-15-year duration took polyunsaturated fatty acids omega-3 (30 g of flax oil a day) in addition to their routine food. This led to an insignificant lowering in total cholesterol and elevation of cholesterol in high density lipoproteins. A significant rise in the level of omega-3 polyunsaturated fatty acids in lipoproteins occurred in 6 patients only. Minor effect of the diet oil may be due to low delta-6-desaturic activity in the majority of the examinees. The findings point to necessity to use other sources of omega-3 acids in diet therapy of diabetics, fish oil, in particular.     

Meat-based functional foods for dietary equilibrium omega-6/omega-3

Nutritionists encourage improving the diet by combining meat products with fish or other sea-related foods, in order to equilibrate the omega-6/omega-3 ratio. Strong scientific evidence supports the beneficial health effects of a balanced omega-6/omega-3 PUFA (poly unsaturated fatty acids) diets. In the present work, the scientific bases of new functional meat products with both a balanced omega-6/omega-3 ratio and a synergic combination of antioxidants are discussed. The aim is to contribute to the dietary equilibrium omega-6/omega-3 and to increase the antioxidant intake. Conventional meat products supplemented with a specific fatty acids and antioxidants combination led to functional foods with healthier nutritional parameters.     

Nutritional composition of fats in seafoods

Public interest in the health benefits of seafood lipids, or of fish oils, is a most unusual phenomenon because for once the recommendations of health authorities to "eat more fish" are in accord with newer and popular attitudes. Media exploitation of the more sensational health aspects is also generally in favor of more consumption of seafood. The public is however still confused by the multitude of species of fish and shellfish available, and in a quandary over whether fatty fish are risky in terms of calories or cholesterol, or of more benefit than lean fish in terms of omega-3 fatty acids. Most direct questions on how much omega-3 fatty acids are useful in the diet of an average individual may never be answerable until long term studies with humans are carried out. It does appear that marine fish can be broken down into four convenient categories: lean (including shellfish), low fat, medium fat and high fat; and in this review it is suggested that these could contribute, per 100 grams, respectively about 250, 750, 1000 and 2000 mg of total C20 + C22 omega-3 fatty acids. This intake can compare favorably with the alternative of commonly available fish oil capsules. Moreover this survey shows that at present the composite of total omega-3 fatty acids in fish and shellfish may contain roughly equal proportions of the functionally effective eicosapentaenoic acid, and of docosahexaenoic acid with its as yet unknown long-term biochemical effects, or be biased in favor of more of the latter. To assist the public, nutritionists, dietitians, and researchers this review discusses the distribution of fat in edible fish muscle, the classes of lipids encountered, and the major fatty acids of health interest. Included are limited numbers of analyses from parts of the world other than North America.     

Bioequivalence of encapsulated and microencapsulated fish-oil supplementation

Omega-3 oil from fish can be stabilised against oxidation using a variety of microencapsulation technologies. Complex coacervation has been used and found to be commercially useful for fortifying foods and beverages with long-chain omega-3 containing oils. Here we report a comparative human bioavailability study of microencapsulated omega-3 fish oil and standard fish-oil soft-gel capsules. Phospholipid levels of long-chain omega-3 fatty acids increased equivalently in both subjects groups. Also, triacylglycerol levels were reduced similarly in both groups. These results indicate that omega-3 fatty acids have equivalent bioavailability when delivered as microencapsulated complex coacervates or as soft-gel capsules.     

Feeding feedlot steers fish oil alters the fatty acid composition of adipose and muscle tissue

Sixteen steers (441±31.7kg initial body weight) consumed two high concentrate diets with either 0 or 3% fish oil to determine the impact of fish oil, an omega-3 fatty acid source, on the fatty acid composition of beef carcasses. Collected tissue samples included the Longissimus thoracis from the 6th to 7th rib section, ground 10th to 12th rib, liver, subcutaneous adipose tissue adjacent to the 12th rib, intramuscular adipose tissue in the 6th to 7th rib sections, perirenal adipose tissue, and brisket adipose tissue. Including fish oil in the diet increased most of the saturated fatty acids (P<0.01) and proportions of polyunsaturated fatty acids (P<0.06), and decreased (P<0.01) proportions of monounsaturated fatty acids. Dietary fish oil increased (P<0.01) levels of omega-3 fatty acids in sampled tissues, resulting in lower (P<0.01) omega-6:omega-3 ratios. The weight percentages of C20:5 and C22:6 in tissue may provide the recommended daily allowance for humans. Fish oil may have a role in beef niche marketing if there are no deleterious effects on consumer satisfaction.     

海洋鱼油的生产与应用

全面回顾了国内外海洋鱼油生产与应用的历史与现状,指出海洋鱼油作为二十碳五烯酸(EPA)、二十二碳六烯酸(DHA)等ω-3多不饱和脂肪酸的重要来源,正在饲料、食品以及药品等领域展示其良好的应用前景.     

Jumping on the omega-3 bandwagon: distinguishing the role of long-chain and short-chain omega-3 Fatty acids

Omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) are almost unanimously recognized for their health benefits, while only limited evidence of any health benefit is currently available specifically for the main precursor of these fatty acids, namely α-linolenic acid (ALA, 18:3n-3). However, both the n-3 LC-PUFA and the short-chain C(18) PUFA (i.e., ALA) are commonly referred to as "omega-3" fatty acids, and it is difficult for consumers to recognize this difference. A current gap of many food labelling legislations worldwide allow products containing only ALA and without n-3 LC-PUFA to be marketed as "omega-3 source" and this misleading information can negatively impact the ability of consumers to choose more healthy diets. Within the context of the documented nutritional and health promoting roles of omega-3 fatty acids, we briefly review the different metabolic fates of dietary ALA and n-3 LC-PUFA. We also review food sources rich in n-3 LC-PUFA, some characteristics of LC-PUFA and current industry and regulatory trends. A further objective is to present a case for regulatory bodies to clearly distinguish food products containing only ALA from foods containing n-3 LC-PUFA. Such information, when available, would then avoid misleading information and empower consumers to make a more informed choice in their food purchasing behavior.     

Benefits of fish oil replacement by plant originated oils in compounded fish feeds. A review

Fish oil constitutes a major dietary ingredient in compounded fish feeds for carnivorous marine fish due to its essential fatty acid content, in particular omega-3 polyunsaturated fatty acids (n-3 PUFA). The issue of fish oil substitution in fish feeds has come to the forefront only recently, due to the release of recent data which indicates that the aquaculture industry uses 40 and 75% of the global production of fish meal and fish oil, respectively. Within the next decade fish oil production may not meet the required quantities for aquaculture, meaning that food grade fisheries which provide fish oil and fish meal have reached their limit of sustainability. Over the past few years, significant breakthroughs have occurred in the replacement of fish oil with plant oils in compounded fish feeds in order to reduce dependence on fish oil as well as reduce costs. All recent data, focussing on the benefits of replacing fish oil with plant oils in compounded fish feeds, are presented in this review.     

Children's daily exposure to polychlorinated biphenyls from dietary supplements containing fish oils

In children, omega-3 polyunsaturated fatty acids (PUFAs) may elicit a suite of health benefits including enhancement of cognitive development. Subsequently, dietary supplements containing omega-3 PUFAs have become increasingly popular. Often, the largest source of beneficial PUFAs in these supplements is fish oil, which may contain significant levels of contaminants such as polychlorinated biphenyls (PCBs). The objectives of this study were to evaluate congener-specific PCB concentrations in 13 over-the-counter children's dietary supplements containing fish oils/powders and assess potential PCB exposures through ingestion of these products on a daily basis. Every supplement analysed contained PCBs, with a mean concentration of 9?±?8?ng PCBs/g supplement. When following serving size suggestions, mean daily exposure values ranged from 2.5 to 50.3?ng PCBs/day. Daily exposures for children's supplements were significantly lower than those previously reported for adult supplements and may be explained, in part, by the variability in the amount of fish oil (and PUFA content) in a serving size. Based on this study, factors such as fish oil purification methods (e.g., molecular distillation) and the trophic level of the fish species used to make the fish oil cannot be used as indicators of PCB levels within children's supplements. Fish supplements may decrease or increase daily PCB exposure compared with ingestion of fresh fish. However, eating fish high in omega-3 PUFAs and low in PCBs may reduce PCB exposure compared with daily supplementation with fish oils for some products studied.     

Omega-3 Fatty Acid Composition of Persian Gulf Fishes

The aim of this study was to investigate the content of omega-3 fatty acids in Persian Gulf fishes. The fishes were collected from Persian Gulf and the content of fatty acids in the head, muscle, and liver of fishes were determined. Quantitative analysis of fatty acids was performed by gas chromatography (GC) and methylmyristate was used as the reference material. GC and mass spectrometer (GC- mass) was applied for qualitative analysis and cod liver oil with all of omega-3 fatty acids was used as standard. Ghezel ala, Zamin kan-e-dom navari and Sorkhu mahi had maximum levels of omega-3 in total body. Halva Sefid, Gish-e-deraz baleh and Shamshiri were poor sources of omega-3. The liver of fish had the most content of omega-3 fatty acids followed by muscle and head, respectively.     

Yield, Lipid, Cholesterol and Fatty Acid Composition of Spent Hens Fed Full-Fat Oil Seeds and Fish Meal Diets

Yield, proximate and fatty acids composition of white and dark meats and whole carcasses were determined in spent hens fed flax or canola seeds, fish meal and a control diet. Live weights and percent carcass cut-up yield were not affected by the diets fed. However, hens fed flax seed diets contained significantly (P< 0.05) lower levels of cholesterol in the dark meat than the control group. The inclusion of oil seeds, in particular flax seeds in the hens diet, enriched the meats with omega-3 fatty acids (C18:3ω>3; C20:5ω3; C22:5ω3). Omega-3 fatty acids enriched poultry meats from spent hens could be useful in the development of “health oriented” further processed poultry products.