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1.
Cardiovascular disease (CVD) and insulin resistance are directly linked to overweight and obesity. Thus, any dietary strategy capable of causing weight reduction will lower CVD and diabetes risk. Oils rich in medium‐chain saturated fatty acids (MCFA) are among several dietary components that may have potential in the treatment of obesity. MCFA are less energy dense and highly ketogenic compared to long‐chain saturated and unsaturated fatty acids (LCFA). MCFA also differ from LCFA in their digestive and metabolic pathways, since they are easily oxidized and utilized as energy, with little tendency to deposit as body fat. The dietary intake of short (SCFA) and medium‐chain saturated fatty acids from natural food sources is approximately 2.4 g/day and accounts for about 9% of the total saturated fatty acid (SFA) intake. Although early clinical studies with high levels of MCFA resulted in increased levels of plasma triacylglycerols (TAG) and low‐density lipoprotein cholesterol (LDL‐C), and reduced levels of high‐density lipoprotein cholesterol (HDL‐C) compared to diets enriched in unsaturated LCFA, these adverse effects have not been observed in more recent studies with smaller more realistic amounts of MCFA. The lower caloric value of SCFA and MCFA and their unique metabolic features form the basis for their clinical use in enteral and parenteral nutrition and for novel reduced calorie lipids for use in conventional food products.  相似文献   

2.
We observed earlier that phytanic acid activated subtype α of the peroxisome proliferator‐activated receptor (PPAR) via the cytosolic liver‐type fatty acid‐binding protein (L‐FABP). In a further search for minor lipid nutrients that interact with genes, we explored here the potential of branched‐chain fatty acids to serve as agonists for the PPAR subtypes α, β and γ in rodent and human molecular test systems. Beyond chlorophyll‐derived pristanic and phytanic acids, bacteria‐derived iso‐ and anteiso‐fatty acids and avian‐derived ‘uropygial’ fatty acids were tested by transactivation assay. In addition, we studied binding of these fatty acids to recombinantly expressed PPAR ligand binding domains (LBDs) and to L‐FABP by competition with fluorescent parinaric acid. In contrast to single methyl‐branched agonists, multi methyl‐branched fatty acids had high transactivation potentials in either test system; in addition, some agonists of the latter were highly subtype selective. Multi methyl‐branched chain fatty acids were superior activators of human PPARγ, a preference not seen in the murine test system. High‐affinity binding of isoprenoid‐derived pristanic and phytanic acids to PPARγ‐LBD and to L‐FABP was observed, and also of pristanic acid to PPARα‐LBD. Polyketidic uropygial fatty acids bound to PPARγ‐LBD only, though weakly. As both isoprenoid and polyketidic fatty acids showed high activation potentials, it became clear that binding data determined in vitro cannot predict biological activity as determined by transactivation assay. For pristanic acid, however, a signalling path similar to that found for phytanic acid can be concluded. Taken together, multi methyl‐branched fatty acids of the human food chain can affect cellular metabolism through regulating gene expression.  相似文献   

3.
The catabolic rates of individual fatty acids in mice were compared using stable isotope (13C)‐labeled fatty acids and isotope‐ratio mass spectrometry (IRMS). The catabolic rates were evaluated from the ratio of 13C and 12C in carbon dioxide expired by mice. The results showed that the catabolic rate of octanoic acid is three times faster than that of palmitic acid. This result is consistent with previous reports using radioisotope 14C showing that medium‐chain fatty acids are more easily beta‐oxidized than long‐chain fatty acids. The catabolic rates of odd‐numbered fatty acids such as pentadecanoic acid and heptadecanoic acid were significantly lower compared to those of even‐numbered fatty acids such as palmitic acid. These findings support previous reports that show odd‐numbered fatty acids easily accumulating in body fat. The high accumulation of odd‐numbered fatty acids in body fat thus directly reflects a low degree of beta‐oxidization. The combination of stable isotope‐labeled compounds and IRMS serves as a powerful tool in lipid analysis.  相似文献   

4.
Glass  Robert L.  Krick  Thomas P.  Olson  Daniel L.  Thorson  Roxanne L. 《Lipids》1977,12(10):828-836
Furan fatty acids (F acids) have been found in the livers and/or testes of 20 species, representing 9 families of male freshwater fish. In 9 species they are major components of the lipids while in the remaining 11 species they occur to a much lesser extent. The F acids in some species reach a maximum concentration in the testes lipids, and minimum liver lipid concentration, at spawning. In all species in the testes, the F acids are confined almost exclusively to the triglyceride fraction while, in the liver lipids, they are found, in order of decreasing concentration, in the cholesteryl esters, the triglycerides, and the phospholipids. In the lipids of many individuals F6 12,15-epoxy-13,14-dimethyleicosa-12,14-dienoic acid, is the major fatty acid present. It is presumed that these acids perform some as yet unidentified metabolic function. Isolation technology and identification of F acids by a specific thin layer chromatographic spray reagent are discussed. Scientific Journal Series 9910, Agricultural Experiment Station, University of Minnesota, St. Paul, MN 55108.  相似文献   

5.
Highly unsaturated fatty acids derived from fish or algal oils, particularly EPA and DHA, are in high demand as healthy food ingredients in fortified foods. Due to their oxidative instability most food products incorporate stabilized microencapsulated EPA and DHA oils to avoid negative sensory impact associated with oxidation of these fatty acids. Complex coacervation has been particularly successful in stabilizing fish oil and providing an ingredient with a sensory shelf‐life consistent with that of the food product. Overcoming the technical challenges associated with the instability of these oils will help drive growth of the omega‐3 fortified healthy food ingredient market.  相似文献   

6.
‘Omega‐6 vegetable oils’ are a small but important group of vegetable oils used widely in the food, neutraceutical, cosmetic and pharmaceutical industries for their linoleic acid (18:2 n‐6) and more importantly gamma linolenic acid (18:3 n‐6) content. These omega‐6 fatty acids have numerous health benefits recognized worldwide. With linoleic acid being readily available from many dietary sources, one wonders why there is a need to extract the oil from speciality oilseeds, however those that suffer with many of the conditions that omega‐6 fatty acids are said to be beneficial for are frequently advised to take extra supplements of these fatty acids. Due to their wide use as a nutraceutical, omega‐6 fatty acids are in high demand, causing a niche market for extraction of these oils from speciality seeds.  相似文献   

7.
Alkyl‐branched fatty compounds are of interest for industrial products in the cosmetics and lubricant areas. In this review, clay‐ and zeolite‐catalyzed isomerizations of unsaturated fatty compounds, especially of oleic acid, are discussed. While clay‐catalyzed reactions give most complex mixtures of dimeric fatty acids and of monomeric so‐called “isostearic acid”, the zeolite‐catalyzed process yields preferentially an isomeric mixture of isostearic acids having the methyl branch on the 8–14 positions of the alkyl chain. Synthetically useful additions of alkyl radicals can only be performed on ω‐unsaturated fatty compounds, whereas perfluoroalkyl iodides were added to fatty compounds with terminal as well as internal double bonds using electron transfer‐initiated radical addition reactions. Electrophilic additions of alkyl carbenium ions generated by decomposition of alkyl chloroformates by ethylaluminum sesquichloride give well‐defined alkyl‐branched oleochemicals with good yields.  相似文献   

8.
Estimations of the fat content of food are generally based on the weight of the fraction extracted by a solvent. Unfortunately these solvents extract varying amounts of substances which are nonlipids, and they fail to extract all of the fatty acids, especially those present in complex forms. Though current procedures are simple, they are unreliable. Calories contributed by food fats can be calculated accurately only from data on the total fatty acid content of these foods. An improved method for the complete extraction of food fatty acids is described. This method involves an extraction of food samples with chloroform: methanol (2∶1) both before and after treatment with 2 N hydrochloric acid in methanol, removal of the solvent from the combined extracts, and then extraction with chloroform. This method was compared with the AOAC method in the analysis of 18 foods for fatty acid content. The values obtained by the new method were higher in every case, and significantly higher in most cases, due primarily to a more complete extraction of the bound fatty acids. The usefulness of the new method in the routine analysis of foods was demonstrated in 58 additional food samples.  相似文献   

9.
Currently the most common microalgae used for commercial production of omega‐3 fatty acids are marine derived, particularly from family members of Thraustochytriaceae and Crypthecodiniaceae. Thraustochytrids are marine heterotrophic fungi like microorganisms known to produce several commercially interesting biotechnological compounds including omega‐3 fatty acids such as docosahexaenoic acid (DHA), docosapentaenoic acid (DPA) and eicosapentaenoic acid (EPA), carotenoids, sterols, exopolysaccharides and enzymes. Therefore, exploring the potential of thraustochytrids has much to offer to the commercial production of bioactive compounds. In response to growing demand for omega‐3 fatty acids, various isolation, fermentation and lipid recovery strategies have been developed in recent years.  相似文献   

10.
The catabolism rates of a medium chain fatty acid (octanoic acid), an even‐numbered fatty acid (palmitic acid), and odd‐numbered fatty acids (pentadecanoic acid and heptadecanoic acid) in mice were compared using stable isotope (13C) labeled fatty acids and isotope‐ratio MS (IRMS). The catabolism rates of respective fatty acids were evaluated by the ratio of 13C and 12C in carbon dioxide expired from mice. The results show that the catabolism rate of octanoic acid is three times faster than that of palmitic acid. This result is in agreement with previous knowledge that medium chain fatty acids are easily beta‐oxidized as compared to long chain fatty acids. The catabolism rates of odd‐numbered fatty acids such as pentadecanoic acid and heptadecanoic acid were significantly lower as compared to those of even‐numbered fatty acids such as palmitic acid. This finding supports our previous report that odd‐numbered fatty acids are easily accumulated into body fat. The high accumulation of odd‐numbered fatty acids in body fat would be a direct result of their low beta‐oxidizability. Practical applications: 13C‐labeled fatty acids were administered to mice and the rates of 13CO2 formation were compared among medium chain, even‐numbered, and odd‐numbered fatty acids using IRMS. We found that the catabolism rates of odd‐numbered fatty acids such as pentadecanoic acid and heptadecanoic acid were significantly lower in comparison to those of even‐numbered fatty acids such as palmitic acid. These findings could be valuable for the development of the lipid metabolism field.  相似文献   

11.
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are polyunsaturated fatty acids (PUFA) of the n‐3 series. Fish oil is a classical source of n‐3 PUFA, where they occur in the form of triacylglycerols (TAG). However, new sources of n‐3 PUFA esterified in phospholipids (PL) are emerging. We prepared liposomes from a natural marine lipid extract and examined their behaviour under conditions mimicking that of the gastrointestinal tract. This physicochemical approach proved that liposomes could be used as an effective oral PUFA delivery system. In vivo studies in rats were performed to examine the metabolic fate of EPA (20:5 n‐3) and DHA (22:6 n‐3) delivered either in PL from liposomes or in TAG from oil. Liposome ingestion increased PUFA bioavailability in lymph compared with fish oil. The proportion of n‐3 PUFA esterified in the sn‐2 position of chylomicron TAG depended on the dietary lipid source. Complex time‐course profiles were observed for plasma lipids with liposome supplementation over a 2‐week period, suggesting time‐dependent regulations. Taken together, the type of PUFA, EPA or DHA, as well as its intramolecular distribution in chylomicron TAG seemed to influence the metabolic fate of the fatty acids and their physiological activities.  相似文献   

12.
Codakia orbicularis may obtain nutrients from chemoautolithotrophic bacteria. The chemical composition of theC. orbicularis was investigated because of this unusual source of nutrition, and because it is a human food source in the Caribbean. The lipid fraction of these molluscs is discussed in detail. Polyunsaturated fatty acids account for only 11–15% of the total fatty acids, and non-methylene interrupted dienes are present as high as 9.5%. Cholesterol represents about 45% of the total sterols present. Mention of a commercial company or product does not constitute an endorsement by NOAA, National Marine Fisheries Service.  相似文献   

13.
Lipid soluble fluorescent pigments from human testis were fractionated by silicic acid column chromatography and silica gel thin layer chromatography. Fluorescence analyses revealed a family of at least 3 compounds with similar fluorescence properties, including excitation and emission maxima, reversible fluorescence quenching by alkaline pH, and fluorescence quenching by heavy metal chelation. These fluorescence characteristics strongly indicated the presence of the conjugated Schiff base fluorophore-N=C-C=C-N-. The chromatographic separations employed enabled a more definitive fluorescence characterization of the lipid soluble pigments known to accumulate late in tissues with age and as a result of lipid peroxidation. Total lipids and fatty acid composition of the total lipids were determined. Polyenoic acids constituted about 40% of the total fatty acids. Histological examination of the tissues revealed some degeneration and edema, but significant spermatogenesis and normal complement of Leydig cells.  相似文献   

14.
Medium‐chain fatty acids, which are saturated fatty acids composed of 8–10 carbons, have unique nutritional characteristics different from those of long‐chain fatty acids. Medium‐chain triacylglycerol (MCT) is more readily digested and absorbed than long‐chain triacylglycerol (LCT), and easily utilized as energy. The use of MCT as an edible oil is limited because it has a low smoking point and easily foams during deep‐frying like lauric acid does. Medium‐ and long‐chain triacylglycerol (MLCT) prepared by transesterification between MCT and LCT has a higher smoking point and reduced foaming property. MLCT oil has been shown to result in less body fat accumulation in animal and human studies. It has been approved as a food for specified health use (FOSHU) and widely sold in Japan as a cooking oil less likely to lead to body fat accumulation.  相似文献   

15.
A set of 46 different trademarks of margarines produced in Brazil by eight different companies was investigated in terms of the national labeling requirements for trans fatty acids (TFA). Experimental measurements of the content of total saturated fatty acids, cis‐monounsaturated fatty acids, cis‐polyunsaturated fatty acids and total TFA by gas chromatography showed the reliability of the data listed on the nutrition facts panel, which were used as reference for this analysis. The results revealed that 50% of the manufacturers and 13% of all the investigated trademarks of margarines violated the current Brazilian labeling regulations. A group of 200 consumers categorized by age, sex and years of formal education was also questioned about the importance of nutrition labeling information and TFA. Approximately 33% of the consumers interviewed were not informed about the possible detrimental effects of TFA on human health. Individuals with longer years of formal education and those affected by coronary heart diseases attributed to the intake of TFA were most interested in reading the nutrition labeling.  相似文献   

16.
17.
The effects of seasons on the lipid content and fatty acid compositions of five different shrimp and prawn species (green tiger prawn – Penaeus semisulcatus, kuruma prawn – Marsupenaeus japonicus, caramote prawn – Melicertus kerathurus, deepwater pink shrimp – Parapenaeus longirostris, speckled shrimp – Metapenaeus monoceros) were evaluated. Results showed that lipid content ranged from 0.89 to 1.55% in muscle, showing that all species were considered as lean. There were significant differences (p<0.05) in the levels of saturated fatty acids (SFA), monounsaturated fatty acids and polyunsaturated fatty acids (PUFA) in terms of season and species. They were rich in n‐3 fatty acids, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The highest proportions of EPA were obtained from kuruma prawn (180.9 mg/100 g) in spring and deepwater pink shrimp (173.2 mg/100 g) and caramote prawn (146.3 mg/100 g) in summer. Kuruma prawn had the highest DHA in spring (140.8 mg/100 g) followed by deepwater pink shrimp (132.2 mg/100 g) and caramote prawn (129.6 mg/100 g) in summer. The results also showed that the seasons affected lipid content and the fatty acid composition of shrimp and prawn species. Practical Application: The beneficial effect of seafood consumption on human health has been related to the high content of n‐3 fatty acids, especially EPA (20:5n‐3) and DHA (22:6n‐3). The ratios of n‐6/n‐3, PUFA/SFA and EPA + DHA are considered as useful criteria for comparing relative nutritional and oxidation values of marine oils. In the current study, the influence of seasonality on the lipid content and the fatty acid compositions of shrimp and prawn were investigated in order to find the best source of n‐3 fatty acids during the year.  相似文献   

18.
Long‐chain internal olefins were prepared by silver(II)‐catalyzed oxidative decarboxylation of unsaturated fatty acids by sodium peroxydisulfate. Similar to saturated carboxylic acids, 1‐alkenes were the major decarboxylation product in the additional presence of copper(II), whereas in the absence of copper(II) alkanes were predominantly formed. In both cases, the internal unsaturation of the fatty acids remained largely intact, although the moderate yields indicated that side reactions occurred to a significant extent. The simple procedure makes this multistep one‐pot reaction useful for the synthesis of a variety of internally unsaturated hydrocarbons. The purified products, almost all of which are prepared for the first time, may serve as reference compounds for studies on the heterogeneously catalyzed decarboxylation of triglycerides and fatty acids in the absence of hydrogen. Practical applications: The products of the chemistry described in this contribution, i.e., unsaturated long‐chain hydrocarbons, provide bio‐based building blocks for further chemical modification toward products which may be applied as (bio)fuels, lubricants, solvents, and polymeric materials.  相似文献   

19.
Three surveys of the content of trans fatty acids (TFA) in foods on the Danish market were carried out before and after the Danish regulation was introduced in January 2004 restricting the use of industrially produced (IP)‐TFA to a maximum of 2 g per 100 g fat in any food product. For this purpose, food samples were collected in 2002–3, 2004–5, and 2006–7. Of these, 60 paired samples (defined as samples included in two of the three investigations and with higher levels of IP‐TFA in the first determination than in the second) were identified. Comparisons of the fatty acid profiles showed that, in 68% of the products (e.g. sweets, cakes and cookies as well as fast food such as pie and tortilla), IP‐TFA were mainly substituted with saturated fatty acids (SFA). In some cases, the SFA source was coconut fat, whereas in other products, palm oil was added instead of partially hydrogenated oils. However, in important cases like frying fats, healthier fat substitutes with monounsaturated fatty acids were used. The surveys showed that the IP‐TFA content has been reduced or removed from most products with originally high IP‐TFA content, like French fries, microwave oven popcorn and various bakery products, so that IP‐TFA are now insignificant for the intake of TFA in Denmark.  相似文献   

20.
反式脂肪酸测定方法的研究   总被引:2,自引:0,他引:2  
简要介绍了反式脂肪酸(TFA)的生成途径及主要的食物来源,反式脂肪酸对人体健康的主要危害和影响,综述了反式脂肪酸的分析检测方法如气相色谱法、红外光谱法、Ag离子色谱技术、毛细管电泳法等,并比较了各种方法的优缺点。  相似文献   

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