Concentration of n‐3 polyunsaturated fatty acids in cholesterol‐reduced cod‐liver oil by lipases

This study was conducted to elucidate the effects of different lipases originated from Candida rugosa (CR), porcine pancreas (PP) and Aspergillus niger (AN) on the degree of hydrolysis (DH) in cholesterol‐reduced cod‐liver oil (87.5%) and evaluate the changes in n‐3 polyunsaturated fatty acid concentrations in the oil hydrolysed by the lipases. The lipase‐catalysed hydrolysis of cholesterol‐reduced cod‐liver oil was performed at 37 °C for 8 h. Among all the lipase samples studied, DH in the oil after lipase‐catalysed hydrolysis followed the decreasing order: CR lipase (70.01%) > PP lipase (26.18%) > AN lipase (18.57%). Triacylglycerol levels in the oil hydrolysed by all the lipases studied decreased, while mono‐ and diacylglycerol levels increased during lipase‐catalysed hydrolysis. The eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations in cholesterol‐reduced cod‐liver oil hydrolysed by the CR lipase were remarkably higher than those by the PP or AN lipase. Thus, it is suggested in this study that the CR lipase appears to be most suitable for producing and n‐3 polyunsaturated fatty acids including EPA and DHA concentrates from cholesterol‐reduced cod‐liver oil.     

Physico‐enzymatic production of monoacylglycerols enriched with very‐long‐chain polyunsaturated fatty acids

BACKGROUND: Monoacylglycerols (MAG) containing polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have interesting applications. The enzymatic processing of such MAG directly from fish oils is highly interesting, integrating the processing of MAG and concentration of EPA and DHA. The aim of this study was to develop an efficient enzymatic glycerolysis system together with physical fractionation for the production of PUFA‐MAG from tuna oil. RESULTS: Novozym 435 was eventually selected after evaluation together with immobilized lipase AK in a tertiary alcohol‐based system. A further evaluation of solvent mixtures involving tertiary alcohols was made, taking ease of operation into consideration. It turned out that a number of mixtures gave a similar performance to that of tert‐butanol (TB). Basic reaction parameters were thoroughly evaluated. In the batch reaction system with TB as solvent, the recommended conditions were: glycerol/tuna oil 4:1 (mol/mol), TB/tuna oil 2:1 (wt/wt), 15 wt% Novozym 435, and temperature 40 °C. Under these conditions, the yield of MAG was up to 90% after 3 h incubation. Crude MAG from the production was fractionated to produce MAG with higher EPA and DHA content. Using acetone as solvent at 0 °C led to ca 50% yield of MAG but contained EPA and DHA up to 71% in comparison with ca 30% in tuna oil. CONCLUSION: Potentially practical process steps have been developed for the production of MAG containing a high content of EPA and DHA from natural fish oils with high efficiency and simplicity. Copyright © 2007 Society of Chemical Industry     

Change in α‐tocopherol contents,lipid oxidation and fatty acid profile in eggs enriched with linolenic acid or very long‐chain ω3 polyunsaturated fatty acids after different processing methods

The influences of dietary supplementation with α‐tocopheryl acetate (α‐TA) and of processing (by hard‐boiling and scrambling) of eggs enriched with ω3 fatty acids, either very long‐chain ω3 polyunsaturated fatty acids (VLC ω3 PUFAs) or linolenic acid (LNA), on fatty acid composition, α‐tocopherol content and lipid oxidation (thiobarbituric acid (TBA) values) were studied. Four dietary treatments were formulated from a basal diet containing 40 g kg^?1 linseed oil (LO) or fish oil (FO) combined with either 0 or 100 mg α‐TA kg^?1 of feed. Eggs from LO treatments were enriched with LNA and those from FO treatments were rich in VLC ω3 PUFAs. Neither processing nor dietary supplementation with α‐TA modified greatly the fatty acid profile of eggs. Dietary supplementation with α‐TA increased the α‐tocopherol content of eggs (187.2 versus 407.9 µg g^?1 dry matter). Eggs from FO treatments showed lower α‐tocopherol content than those from LO treatments (273.5 versus 321.6 µg g^?1 dry matter), and processing of eggs enriched with VLC ω3 PUFA reduced the α‐tocopherol content by a significant 16%. Moreover, processing of eggs increased lipid oxidation two‐ to nine‐fold. Oxidation levels of hard‐boiled eggs were 30.4% higher than those of scrambled eggs. TBA values in hard‐boiled and scrambled eggs were significantly reduced when 100 mg α‐TA kg^?1 of feed supplemented the diet only in those eggs enriched with VLC ω3 PUFA (from FO treatments). Copyright © 2003 Society of Chemical Industry     

Enrichment of ω‐3 fatty acids in flax seed oil by alkaline lipase of Aspergillus fumigatus MTCC 9657

Flax seed oil obtained from the seeds of flax plant (Linum usitatissimum, L.) is an unexploited source which contains ω‐3 and ω‐6 fatty acids. Flax seed oil is hydrolysed with a novel alkaline lipase from Aspergillus fumigatus MTCC 9657 for the removal of unwanted fatty acids and enrichment of ω‐3 fatty acids. An appropriate balance of ω‐3 and ω‐6 polyunsaturated fatty acids and enzymatic enrichment of polyunsaturated fatty acids in diet promote nutrition and health. Fatty acid composition shows that flax seed oil contains about 26.80%, 13.5% and 25.45% of ω‐3 and ω‐6 fatty acids in triglyceride (TG), diglyceride (DG) and monoglyceride (MG), respectively. After 8 h of hydrolysis, ω‐3 content was increased to 39% in TG, showing that unwanted saturated fatty acids are removed. ω‐6 content of triglycerides in flax seed oil also showed 54.76% increase after 8 h of hydrolysis. An enzymatic method of hydrolysis by fungal lipase was developed by this study and achieved to concentrate the essential fatty acids linoleic acid (LA) and α‐linoleic acids (ALA).     

Importance of instrumental and sensory analysis in the assessment of oxidative deterioration of omega‐3 long‐chain polyunsaturated fatty acid‐rich foods

Omega‐3 long‐chain polyunsaturated fatty acids (LC PUFA) positively influence human health. Their main dietary source is fish, especially fish oil. Owing to low fish consumption in many Western countries the average intake of omega‐3 LC PUFA is below the recommended level. This raises interest in diet supplementation and food enrichment with fish oil. However, due to a high degree of unsaturation fish oil is extremely susceptible to oxidation. Oxidation of fish oil increases when added to food products, which may be enhanced by some antioxidants, under certain conditions. For quality control of omega‐3 LC PUFA‐containing foods adequate and combined methods of oxidation assessment should be used, beginning from the raw material and continuing during processing, storage and distribution. To achieve this goal correlation of instrumental and sensory methods with multivariate data analysis may give the best results. In this paper problems of oxidation of fish oil and fish oil‐containing foods, as well as methods for its assessment, are reviewed. Copyright © 2006 Society of Chemical Industry     

Effect of milk fat replacement by polyunsaturated fatty acids on the microbiological,rheological and sensorial properties of fermented milks

A modified milk (W3DD) where fat had been replaced by oils enriched in ω‐3 polyunsaturated fatty acids was used for the manufacture of a set‐type fermented product. In order to improve the organoleptic properties of the product, 30 g l^?1 whey protein concentrate (WPC) was added during the manufacturing process. Samples were fermented employing a commercial probiotic starter culture (ABT‐2), which contained Streptococcus thermophilus ST‐20Y, Lactobacillus acidophilus LA‐5 and Bifidobacterium lactis BB‐12. The acidification process was dependent on the WPC addition, which favoured the increase of viable counts, but fermentation was not influenced by the milk fat composition. The highest counts of the probiotic strains, L acidophilus LA‐5 (3.3 × 10⁵ cfu g^?1) and B lactis BB‐12 (5.5 × 10⁷ cfu g^?1), after 21 days of storage at 4 °C, were found in fermented products derived from W3DD supplemented with WPC. Addition of WPC also increased the firmness of the products and reduced syneresis. No apparent colour changes due to fat composition or WPC supplementation were observed in the products. Milk fat replacement by oils rich in ω‐3 polyunsaturated fatty acids had a negative influence on the product texture but did not affect the typical yoghurt flavour. These defects were overcome by the addition of 30 g l^?1 WPC, which improved the appearance, texture and general acceptability scores in the product. Copyright © 2004 Society of Chemical Industry     

Omega-3多不饱和脂肪酸在高脂血症中的作用机制研究进展

高脂血症是一种代谢紊乱疾病,直接引起或导致一些严重危害人体健康的疾病,如动脉粥样硬化、冠心病等。Omega-3多不饱和脂肪酸能够显著降低大鼠及人体血清中总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL)、极低密度脂蛋白(VLDL)的含量,同时增加高密度脂蛋白(HDL)的含量,其作用机制主要为增加外源性胆固醇代谢,减少内源性胆固醇合成,抑制肝脏胆固醇转运相关基因的表达,抑制肝脏载脂蛋白的产生,在高脂血症及其相关代谢性疾病的防治中发挥重要作用。基于国内外研究Omega-3多不饱和脂肪酸对血脂水平的调节作用,对Omega-3多不饱和脂肪酸在高脂血症中的作用机制进行综述,以期为深入研究Omega-3多不饱和脂肪酸对于血脂和脂质代谢调节的相关机制和后续相关药物的研发提供参考。     

ω‐3 in meat products: benefits and effects on lipid oxidative stability

Although ω‐3 intake has been associated with numerous health benefits, its addition to certain food matrices, and in particular meat products, may involve various technological barriers influencing the final quality of the products. Lipid oxidation must be highlighted due to the modification of both the sensory characteristics and the shelf‐life of meat products. In order to reduce the impact of chemical changes and promote oxidative stability, the use of natural antioxidants has gained ground owing to the health and safety advantages linked to its effectiveness at reducing lipid oxidation. Many natural compounds have also been successfully tested in animal feed, in order to protect the raw meat materials and reduce the risk of lipid oxidation in processed products. This review aims to address the challenges and advantages of the incorporation of ω‐3 fatty acids in raw meat materials and processed meat products, and to describe the use of different compounds to enhance lipid oxidative stability. © 2015 Society of Chemical Industry     

Hypolipidemic Activity of Peony Seed Oil Rich in α‐Linolenic,is Mediated Through Inhibition of Lipogenesis and Upregulation of Fatty Acid β‐Oxidation

Peony seed oil (PSO) is a new resource food rich in α‐Linolenic Acid(ALA) (38.66%). The objective of this study was to assess the modulatory effect of PSO on lipid metabolism. Lard oil, safflower oil (SFO), and PSO were fed to wistar rats with 1% cholesterol in the diet for 60 d. Serum and liver lipids showed significant decrease in total cholesterol (TC), triglyceride (TG), and low density lipoprotein‐cholesterol (LDL‐C) levels in PSO fed rats compared to lard oil and SFO fed rats. ALA, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), contents were significantly increased, whereas linoleic acid (LA), arachidonic acid (AA) levels decreased in serum and liver of PSO fed rats. Feeding PSO increased ALA level and decreased n‐6 to n‐3 polyunsaturated fatty acid (PUFA) ratio. The hypolipidemic result of PSO indicated that PSO participated in the regulation of plasma lipid concentration and cholesterol metabolism in liver. The decreased expression of sterol regulatory element‐binding proteins 1C (SREBP‐1c), acetyl‐CoA carboxylase (ACC), and fatty acid synthase (FAS)‐reduced lipid synthesis; Activation of peroxisome proliferator–activator receptor (PPARα) accompanied by increase of uncoupling protein2 (UP2) and acyl‐CoA oxidase (AOX) stimulated lipid metabolism and exerted an antiobesity effect via increasing energy expenditure for prevention of obesity.     

Plasma phospholipids n‐3 polyunsaturated fatty acid is associated with metabolic syndrome

The relationship between n‐3 PUFA and metabolic syndrome (MS) is not clear. The aim of this study was to examine relationships between plasma phospholipids (PL) n‐3 PUFA and MS in Chinese subjects. Nine hundred and twenty‐nine subjects were recruited in Hangzhou, China. Two hundred and ten (183 males, 27 females) with MS and 719 (545 males, 174 females) healthy subjects were identified in this cross‐sectional study. The prevalence of MS in females (24.56%) was significantly higher than that in males (10.04%) in this population. Total PUFA (p<0.001), n‐3 PUFA (p<0.001), and n‐3:n‐6 (p<0.001) were significantly lower in MS subjects compared to healthy subjects. Plasma phospholipid (PL), n‐3 PUFA was significantly inversely associated with MS (p=0.013). In addition, subjects with high levels of PL total fatty acids (FA) had a more than threefold higher likelihood of MS (OR=3.44, 95% CI=1.60–7.39) than the subjects with low levels of PL total FA. Our results suggest that plasma PL n‐3 PUFA was significantly inversely associated with MS, while high total FA were positively associated with MS in Chinese.     

Enrichment of food products with polyunsaturated fatty acids by fish oil addition

Fish oil remains the main dietary source of long chain polyunsaturated fatty acids omega-3, which desirably impact on human health. Increase of omega-3 fatty acids intake is currently recommended. Results of many studies showed that consumption of food products enriched with fish oil offers the potential health benefits, especially in protection against cardiovascular diseases (CVD), cancer and improvement of brain development and function. Health influence, methods, advantages and disadvantages of food enrichment with fish oil as well as characteristics of market of such products were presented.