DOCSLIB.ORG

Download This Article in PDF Format

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Download This Article in PDF Format DOSSIER CLAs, nature, origin and some metabolic aspects Jean-Michel CHARDIGNY1 Abstract: CLA (conjugated linoleic acid) is a generic term for several isomers of linoleic acid with Corinne MALPUECH-BRUGÈRE2 conjugated double bonds. They have been reported since 1935 in butter fat, but the major natural Jean-Louis SÉBÉDIO2 isomer (9cis,11trans-18:2) was identified in 1977 and further named « rumenic acid ». This fatty acid is formed in the rumen as a product of biohydrogenation. Tissues may also produce rumenic acid from 1 Inra, Unité de nutrition lipidique, 17, rue Sully, vaccenic acid, which is a further intermediate of ruminal biohydrogenation. Interest for CLAs started with BP 86510, 21065 Dijon Cedex a report on beneficial effects of CLA from grilled beef on skin tumours. CLA was produced as mixtures of <[email protected]> isomers from chemically modified vegetable oil. As a metabolic point of view, it has been shown that 2 Inra-Université d’Auvergne, rumenic acid is bioconverted like linoleic acid and beta-oxidised. CLA isomers may also interfere with the metabolism of other fatty acids. Other targets than skin tumours have also been identified. These Unité du métabolisme protéino-énergétique, aspects will be developed in other sections of the present issue. Clermont-Ferrand Key words: CLA, rumen, milk, meat, metabolism Introduction Parodi [8] identified the major CLA isomer in produce rumenic acid from vaccenic acid by a dairy fat as 9cis,11trans-18:2. This fatty acid D9 desaturation. This pathway is now consid- For several years, conjugated linoleic acid (CLA) was then called “rumenic acid” by Kramer and ered as the major source of rumenic acid in isomers have been extensively studied, due to Parodi in 1998, instead of “bovinic acid” which milkfat, as its contribution may represent about their potential effects on various biological func- was considered as too restrictive [9]. 60% of the rumenic acid content of milk [10]. tions and disorders (cancer, cardiovascular dis- Consequently, dietary a-linolenic acid of rumi- eases, obesity, etc.) [1]. This interest is clearly nants is a precursor of milk rumenic acid by this illustrated by the increasing number of publi- Origin of CLA metabolic pathway. cations on CLA research since the mid’ 90s. The occurrence of rumenic acid in milk fat is One can have a look at the exhaustive list of now fully understood (figure 1). Dietary linoleic Starting interest for CLA papers dealing with CLA research which is acid is hydrogenated in the rumen. Rumenic available at the http://www.wisc.edu/fri/ (9cis,11trans), vaccenic (11trans) and stearic Biological effects of CLA have been discovered clarefs.htm web address. As an example, more (saturated) acids are formed as a result of when studying a lipid fraction from grilled beef, than 200 papers have been published per year hydrogenation, and vaccenic acid may also and not from milk and dairy products. At the in 2002 and 2003. result from the hydrogenation of dietary end of the 80’s, Ha and coworkers [11] studied This short paper will review the nature and a-linolenic acid (see the paper of Chilliard et al the effects of different lipid fractions from origin of different CLA isomers and will summa- in this issue for more details). These fatty acids grilled beef on chemo-induced skin tumours. rize CLA metabolism. are made available for peripheric tissues. They isolated a fraction containing CLA isomers Among them, the mammary gland is able to and this fraction was shown to be able to History of CLA The CLA story started as early as 1935 when Rumen Blood Tissues Booth reported that butterfat contained fatty acids which presented absorption at 230 nm 9cis,12cis-18:2 9cis,12cis-18:2 [2]. This characteristic was then associated with the occurrence of conjugated double bonds 9cis,11trans-18:2 9cis,11trans-18:2 associated with 18 carbon chains [3]. ≈60% Later, it was reported that biohydrogenation occurs in the rumen. Unsaturated fatty acids (mammary gland) were reported to be transformed in less unsat- urated fatty acids with trans double bonds [4, 11trans-18:1 11trans-18:1 5]. In 1967, Kepler [6] reported that a ruminal bacteria, Butyrivibrio fibrisolvens, was able to produce conjugated 18:2 from linoleic acid. 18:0 18:0 On the other hand, Kuzdal-Savoie and cowork- ers identified various cis,trans and trans,cis 18:2 Figure 1. Metabolic pathways involved in the biosynthesis of rumenic acid in ruminants (adapted from Griinari, Corl isomers by using AgNO3-TLC [7], and finally et al. 2000 [10]). 18 DOSSIER Article disponible sur le site http://www.ocl-journal.org ou http://dx.doi.org/10.1051/ocl.2005.0018 rumenic acid can be obtained by deshydrata- 12 tion of ricinoleic acid from castor oil [12]. 10 CLA in food Due to its biological origin, CLA is present in 8 food as rumenic acid as the major isomer (> 80% of total CLAs). The main dietary sources are ruminant fat, including milk, dairy 6 products, and meat. As an example, milkfat generally contains about 1% of total fatty acids Incidence (%) as rumenic acid. Consequently, rumenic acid 4 18:2 n-6 intake is estimated to be less than 500 mg per day in most countries. Acetone However, it is important to underline than the 2 CLA CLA content in food depends of various param- eters, including food intake of ruminants, sea- sons, etc. These aspects are developed in the 0 papers by Y. Chilliard et al. and N. Combe in 45678910 11 12 13 14 15 16 the present issue. Weeks post promotion CLA in human tissues Figure 2. Cumulative incidence of skin tumours after induction by DMBA in mice fed CLA from grilled beef, linoleic acid of vehicle (acetone) adapted from Ha, Grimm et al. 1987 [11]). Few studies reported the occurrence of CLA in human biopsies before any supplementation. Recently, we analysed abdominal adipose tis- R 12 10 9 11 9 sue from men and women in the surroundings 2 of Tours (France). The rumenic acid content ranged from 0.19 and 0.66 of total fatty acids R1 R2 R1 11 12 10 (mean 0.40) [13]. Similar data were obtained 9c-11t 9t-11t in mammary adipose tissue in French women (see the paper of P. Bougnoux et al. in this issue). In 10 human milk samples collected 4 days post partum, we found about 0.35% of total fatty acids as rumenic acid. We also found O-Linoleic 13 12 10 9 some 9cis,11cis- and 9trans,11trans-18:2, less acid water than 0.05 each), but some conjugated 20:3 FAO fatty acid was dtected, probably resulting from R2 R1 CAT 9c-12c bioconversion of rumenic acid (see below). OFA linoleic acid Similar data were obtained in human plasma samples (unpublished data). Metabolism of CLA isomers 13 12 10 13 11 R 1 Linoleic acid (9cis,12cis-18:2) is converted by successive desaturations and elongation in R2 11 R2 12 10 R1 arachidonic acid (figure 4). Rumenic acid is now 10t-12c 10t-12t known to be converted by similar metabolic pathways. Such bioconversion has been Figure 3. Formation of CLA isomers by radical oxidation of linoleic acid (adapted from Ha, Grimm et al. 1987 [11]). reported in rats and lambs, but the occurrence of conjugated 20:3 in human samples (see reduce the tumour incidence in skin, when were generally obtained by chemical isomeri- above), suggests that this pathways also occurs in men. The significance of the last step of chemically induced by DMBA (figure 2). It was sation of linoleic acid-rich oils (e.g. safflower conversion (conjugated 20:3 ⇒ conjugated suggested that CLA isomers were formed dur- oil). These mixtures may contain more than 10 ing heating by radical isomerization of linoleic 20:4) is less documented and occurs at a low geometrical and positional isomers. However, extent, as illustrated by the relative accretion of acid (figure 3), which produced several CLA most mixtures used in experiments mainly con- isomers. conjugated 20:3. Banni et al. studied the spe- tain rumenic acid and the 10trans,12cis isomer cific incorporation of these different conju- As a consequence, industrial production of (1:1 w/w), which together represent between gated metabolites in various lipid classes [14]. CLAs was initiated, and mixtures of isomers 60 and 95% of the fatty acid content of the They suggested that unlike linoleic acid and its were made available for various studies. These product. On the other hand, almost pure 18:3 (n-6) and 20:3 (n-6) metabolites which OCL VOL. 12 N° 1 JANVIER-FE´ VRIER 2005 19 1-[13C]-labelled CLA isomers given as TAG to 9cis,12cis-18:2 (Linoleic acid) 9cis,11trans-18:2 (Rumenic acid) overweight humans will be reported else- where. In conclusion, CLA are channelled as other fatty 6cis,9cis,12cis-18:3 6cis,9cis,11trans-18:3 acids between different metabolic pathways. Elongase However, they behave differently compared to 8cis,11cis,14cis-20:3 8cis,11cis,13trans-20:3 non conjugated fatty acids and may interfere with their metabolism. On the other hand, it has to be underlined that the major natural CLA 5cis,8cis,11cis,14cis-20:4 5cis,8cis,11cis,13trans-20 :4 isomer is rumenic acid. For a quantitative aspect, the second one is the cis7,trans9 iso- (arachidonic acid) mer, which has not yet been extensively stud- ied. Most studies consider the trans10,cis12 Figure 4. Desaturations and elongation of linoleic and rumenic acids. isomer together with rumenic acid in animals or humans. For the latter, the major endpoint is are mainly incorporated in phospholipids, previous results in rats [15].
Load more

Recommended publications
  • Nutrition Science Fact Sheet C Onnect to the World of Dairy
    Nutrition science Fact Sheet c onnect to the world of dairy Milk Fat MILK FATTY ACIDS › Dairy products are part of a healthy and balanced diet. The main characteristic of milk fat is the variety of fatty acids it contains: more than 400 different fatty acids! › Dairy products are much more than milk fat. Milk fat contains on average 65-70% saturated fatty acids › Dairy products are an important provider of and 30-35% unsaturated fatty acids (Figure). many minerals and vitamins and high quality protein. › Milk fat contains a wide variety of fatty acids. › Saturated fatty acids should be considered individually and not as a whole group due to their different physiological effects. › In the diet, saturated fatty acids come from different sources (animal and vegetable) and not just from dairy products. DAIRY IS MUCH MORE THAN MILK FAT Dairy products play an important role in the healthy, daily diet of the whole population. They are rich in many nutrients and key contributors of several minerals, vitamins and high-quality protein. Figure: General fatty acid composition of milk fat (data from Legrand P. Sciences des Aliments 2008. 28:34-43) In Western diets, dairy products are the primary source of calcium providing between 40-70% of daily needs. Cheese - independently from its fat content – provides many Saturated Fatty Acids minerals and vitamins such as fat-soluble vitamins A and Amongst saturated fatty acids in milk fat, there are around D, vitamins B2, B6, B12, as well as high-quality protein. 10-13% short- and medium-chain saturated fatty acids and Butter is a good source of fat-soluble vitamins such as 50-55% long-chain saturated fatty acids, including palmitic vitamin A (15% RDA in 15g) and provides essential fatty (27%), myristic (10-12%) and stearic acid (9%).
    [Show full text]
  • Effects of Dietary Conjugated Linoleic Acid on European Corn Borer Survival, Growth, Fatty Acid Composition, and Fecundity Lindsey Gereszek Iowa State University
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 2007 Effects of dietary conjugated linoleic acid on European corn borer survival, growth, fatty acid composition, and fecundity Lindsey Gereszek Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Biochemistry Commons Recommended Citation Gereszek, Lindsey, "Effects of dietary conjugated linoleic acid on European corn borer survival, growth, fatty acid composition, and fecundity" (2007). Retrospective Theses and Dissertations. 14527. https://lib.dr.iastate.edu/rtd/14527 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Effects of dietary conjugated linoleic acid on European corn borer survival, growth, fatty acid composition, and fecundity by Lindsey Gereszek A thesis submitted to the graduate faculty in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Co-majors: Biochemistry; Toxicology Program of Study Committee: Donald C. Beitz, Co-major Professor Joel R. Coats, Co-major Professor Jeffrey K. Beetham Robert W. Thornburg Iowa State University Ames, Iowa 2007 Copyright © Lindsey Gereszek, 2007. All rights reserved. UMI Number: 1443060 UMI Microform 1443060 Copyright 2007 by ProQuest Information and Learning Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O.
    [Show full text]
  • Kimberly Tippetts-Conjugated Linoleic Acid
    Frequency of Use, Information and Perceptions of Conjugated Linoleic Acid By: Kimberly Tippetts Abstract Extensive research has been conducted in both animal and human models, which demonstrate the efficacy of Conjugated Linoleic Acid (CLA) as both a weight loss and a lean body mass dietary supplement. Conversely, very little research has been conducted concerning the practical human application of CLA, (i.e. the frequency of supplementation, information individuals possess, perceptions about, and general experiences people have had with CLA). The purpose of this study was to gather a limited amount of applicable information to begin to fill the noticeable information void. A sixteen statement confidential online survey was provided for a number of participants to share their opinions and understanding of CLA. The survey results showed that while only a small population of survey participants had general information about CLA, a larger percentage of participants indicated that they would both use and/ or recommend the use CLA for lean body mass gain more than they would for weight loss. Based on this finding, it would be beneficial to conduct further product research amongst a narrower sample population such as bodybuilders. 1 Methods An invitation to participate in a study regarding the use of CLA was made to over 400 individuals. Sample size was derived from eight states, recruited by means of verbal request, promotional handout, text message, email invitation or Facebook request (see Appendix A). Of the 400+ people notified of the survey, over half were associated with the fitness industry. Of those notified, 131 healthy adults between the ages of 18-65 volunteered to take part.
    [Show full text]
  • Conjugated Linoleic Acid
    © CAB International 2000 Animal Health Research Reviews 1(1); 35–46 ISSN 1466-2523 Conjugated linoleic acid Patrick R. O’Quinn, James L. Nelssen, Robert D. Goodband* and Michael D. Tokach Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506, USA Received 4 November 1999; Accepted 15 June 2000 Introduction 1987). Naturally occurring CLA has since been identified in many different meat and dairy products (Chin et al., Conjugated linoleic acid (CLA), first positively identified 1991; Parodi, 1994; Lin et al., 1995). Conjugated linoleic in 1987 (Ha et al.), is a collective term describing the acid is a non-specific term that refers to any of the posi- positional and geometric conjugated dienoic isomers of tional and geometric isomers of a-linoleic acid linoleic acid. Linoleic acid (C18:2) has double bonds (c9,c12-octadecadienoic acid). The double bonds in CLA located on carbons 9 and 12, both in the cis (c) configu- occur predominantly at carbon positions 9 and 11 or 10 ration, whereas CLA has either the cis or trans (t) and 12. Thus, the original nomenclature for CLA gave configuration or both located along the carbon chain. rise to eight theoretically possible isomers (c9,c11; Sources of CLA have been shown to elicit many favor- c9,t11; t 9,c11; t 9,t 11; c10,c12; c10,t 12; t 10,c12; and able biological responses including: (i) increased rate t 10,t 12) of linoleic acid (Ip et al., 1991). However, as and (or) efficiency of gain in growing rats (Chin et al., the depth of research and analytical capabilities have 1994) and pigs (Dugan et al., 1997; Thiel et al., 1998; increased, more CLA isomers have been identified O’Quinn PR, Waylan AT, Nelssen JL et al., submitted for (Sehat et al., 1998; Yurawecz et al., 1998).
    [Show full text]
  • Trans Fatty Acids and Their Role in the Milk of Dairy Cows
    Cien. Inv. Agr. 40(3):449-473. 2013 www.rcia.uc.cl ANIMAL PRODUCTION LITERATURE REVIEW Trans fatty acids and their role in the milk of dairy cows Einar Vargas-Bello-Pérez1,2, and Phil C. Garnsworthy1 1The University of Nottingham, Sutton Bonington Campus. Loughborough, LE12 5RD, United Kingdom. 2Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile. Casilla 306, Santiago, Chile. Abstract E. Vargas-Bello-Pérez, and P.C. Garnsworthy. 2013. Trans fatty acids and their role in the milk of dairy cows. Cien. Inv. Agr. 40(3): 449-473. Lipids obtained from dairy products are an important part of the human diet in many countries. Approximately 75% of the total consumption of fat from ruminant animals comes from bovine milk fat. Trans fatty acids (tFA) are produced during biohydrogenation of mono- and poly-unsaturated FA in the rumen. They are mixtures of positional and geometrical isomers that are incorporated into the milk fat of lactating cows. The most important sources of tFA in the human diet are partially hydrogenated vegetable oils and ruminant milk and meat products. Ruminant-derived lipids often contain 1-8% of total fatty acids as tFA, which are predominantly 18:1 isomers. The most common FA in ruminant fat is vaccenic acid (18:1 trans-11) (VA), accounting for 60-80% of total tFA. Unlike other tFA, VA can be converted to rumenic acid (RA) through the action of stearoyl coenzyme-A desaturase. Today, consumers are becoming aware of the relationship between dietary fat, health maintenance, and disease prevention. These concerns have increased the need to investigate the metabolic fate and bioactivity of dietary FA.
    [Show full text]
  • Fatty Acid Composition of Summer and Winter Cows' Milk and Butter
    Journal of Food and Nutrition Research Vol. 49, 2010, No. 4, pp. 169–177 Fatty acid composition of summer and winter cows’ milk and butter JAROSLAV BLAŠKO – RÓBERT KUBINEC – RENÁTA GÓROVÁ – IGOR FÁBRY – WILHELM LORENZ – LADISLAV SOJÁK Summary Fatty acid (FA) composition of summer and winter cows’ milk and butter as well as pasture forage samples were ana- lysed by gas chromatography. The FA contents in butter fat were very similar to those in milk fat from which butters were produced. The higher average contents of FA in the summer milk compared with the winter milk (P < 0.001) were found for health-beneficial FA, e.g. cis-9, trans-11 conjugated linoleic acid 8.0 mg.g-1 vs 4.1 mg.g-1, trans vaccenic acid 17.8 mg.g-1 vs 8.5 mg.g-1, -linolenic acid 6.4 mg.g-1 vs 4.4 mg.g-1, linoleic acid 20.4 mg.g-1 vs 18.4 mg.g-1 (P < 0.01), oleic acid 218 mg.g-1 vs 194 mg.g-1, and for non-atherogenic stearic acid 102 mg.g-1 vs 90 mg.g-1 of total FA. On the other hand, the contents of health-risky palmitic acid and myristic acid were lower in the summer milk: 293 mg.g-1 vs 331 mg.g-1 (P < 0.001) and 102 mg.g-1 vs 112 mg.g-1 FA (P < 0.01), respectively. In comparison to the winter diet, the summer diet improved the rheological and nutritional properties of butter.
    [Show full text]
  • Conjugated Linoleic Acid: Cancer Fighter in Milk
    Conjugated Linoleic Acid: Cancer Fighter in Milk M.A. McGuire Department ofAnimal and Veterinary Science Uniµersity of Idaho, Moscow 83844-2330 Introduction lished40 concerning the effect of CLA on cancer used par­ tially purified extracts of CLA from grilled ground beef As an important source of nutrients, milk provides and demonstrated a reduction in the number of skin high-quality protein, energy, calcium and a variety of cancers, as well as the number of mice that had skin vitamins and minerals. Recent research has focused on cancers. Ip et al22 showed that dietary CLA is a potent altering the fat and protein content of milk and other inhibitor of mammary tumor development and growth dairy products in order to improve the nutrient content in rats (Figure 1). Further, Ip et al26 demonstrated that of these foods so that they more aptly reflect current CLA works as an anti-carcinogen regardless of dietary dietary recommendations and trends. For example, diet fat content or type of fat fed (corn oil vs lard). is a contributing factor to the onset or progression of Recent work demonstrated that CLA could inhibit some cancers, with epidemiological studies indicating the growth of human breast50 and prostate5 cancer cells diet composition may be related to 35 percent of human when implanted into immune-deficient mice. cancer deaths.11 A few substances in our diet have been Furthermore, consumption of CLA may play ben­ identified as anti-carcinogens, but most are of plant ori­ eficial roles in aspects of atherosclerosis, growth and dia­ gin and are only present in trace concentrations.
    [Show full text]
  • CLA-Producing Adjunct Cultures Improve the Nutritional Value of Sheep Cheese Fat ⁎ E
    Food Research International xxx (xxxx) xxx–xxx Contents lists available at ScienceDirect Food Research International journal homepage: www.elsevier.com/locate/foodres CLA-producing adjunct cultures improve the nutritional value of sheep cheese fat ⁎ E. Renesa, P. Gómez-Cortésb, M.A. de la Fuenteb, D.M. Linaresc, M.E. Tornadijoa, J.M. Fresnoa, a Department of Food Hygiene and Technology, Faculty of Veterinary Science, University of León, 24071 León, Spain b Institute of Food Science Research (CIAL, CSIC-UAM), Madrid, Spain c Teagasc Food Research Centre, Moorepark, Fermoy, Ireland ARTICLE INFO ABSTRACT Keywords: The influence of the autochthonous CLA-producing Lactobacillus plantarum TAUL 1588 and Lactobacillus casei Autochthonous cultures subsp. casei SS 1644 strains and the ripening time on the fatty acid (FA) content and sensory characteristics of Cheese sheep cheese were investigated. Three cheese types with different cultures and the control cheese were produced Conjugated linoleic acid in duplicate and ripened for 8 months. 86 individual FA were determined by gas chromatography. Ripening time Fatty acid (2, 90, 180 and 240 days) did not have a significant effect (P>.05) on the FA content. However, the presence of Sensory characteristics both Lactobacillus CLA-producing strains led to a decrease of the saturated FA content and to 1.30, 1.19 and 1.27 Sheep times higher levels of vaccenic acid, CLA and omega-3, respectively, when compared to the control cheese. This Chemical compounds studied in this article: combination allowed obtaining sheep milk cheeses with a healthier FA content, without appreciable changes on Linoleic acid (PubChem CID: 5280450) sensory characteristics.
    [Show full text]
  • Influence of Dietary Fat Sources and Conjugated Fatty Acid on Egg Quality, Yolk Cholesterol, and Yolk Fatty Acid Composition of Laying Hens
    Revista Brasileira de Zootecnia Full-length research article Brazilian Journal of Animal Science © 2018 Sociedade Brasileira de Zootecnia ISSN 1806-9290 R. Bras. Zootec., 47:e20170303, 2018 www.sbz.org.br https://doi.org/10.1590/rbz4720170303 Non-ruminants Influence of dietary fat sources and conjugated fatty acid on egg quality, yolk cholesterol, and yolk fatty acid composition of laying hens Moung-Cheul Keum1, Byoung-Ki An1, Kyoung-Hoon Shin1, Kyung-Woo Lee1* 1 Konkuk University, Department of Animal Science and Technology, Laboratory of Poultry Science, Seoul, Republic of Korea. ABSTRACT - This study was conducted to investigate the effects of dietary fats (tallow [TO] or linseed oil [LO]) or conjugated linoleic acid (CLA), singly or in combination, on laying performance, yolk lipids, and fatty acid composition of egg yolks. Three hundred 50-week-old laying hens were given one of five diets containing 2% TO; 1% TO + 1% CLA (TO/CLA); 2% LO; 1% LO + 1% CLA (LO/CLA); and 2% CLA (CLA). Laying performance, egg lipids, and serum parameters were not altered by dietary treatments. Alpha-linolenic acid or long-chain ω-3 fatty acids including eicosapentaenoic and docosahexaenoic acids were elevated in eggs of laying hens fed diets containing LO (i.e., LO or LO/CLA groups) compared with those of hens fed TO-added diets. Dietary CLA, alone or when mixed with different fat sources (i.e., TO or LO), increased the amounts of CLA in egg yolks, being the highest in the CLA-treated group. The supplementation of an equal portion of CLA and LO into the diet of laying hens (i.e., LO/CLA group) increase both CLA and ω-3 fatty acid contents in the chicken eggs.
    [Show full text]
  • Properties of Fatty Acids in Dispersions of Emulsified Lipid and Bile Salt and the Significance of These Properties in Fat Absorption in the Pig and the Sheep
    Downloaded from Br. y. Nutr. (1969), 23, 249 249 https://www.cambridge.org/core Properties of fatty acids in dispersions of emulsified lipid and bile salt and the significance of these properties in fat absorption in the pig and the sheep BY C. P. FREEMAN . IP address: Unilever Research Laboratory, Colworth House, Sharnbrook, Bedford (Received I July 1968-Accepted 25 October 1968) 170.106.35.76 I. The behaviour of fatty acids in dilute bile salt solution and in dispersions of triglyceride in bile salt solution was examined. The properties of fatty acids in bile salt solution were defined in terms of their saturation ratio, and of the critical micellar concentration of bile , on salt for each fatty acid as solute. The partition of fatty acids between the oil phase and the micellar phase of the dispersions was defined as the distribution coefficient K M/O. The 25 Sep 2021 at 20:48:57 phases were separated by ultracentrifugation. 2. Of the fatty acids examined, palmitic and stearic acids behaved in bile salt solution as typical non-polar solutes. Lauric, oleic and linoleic acids had properties similar to typical amphiphiles. The effectiveness of these and other amphiphiles was expressed in terms of an amphiphilic index. 3. The trans-fatty acids, vaccenic acid and linolelaidic acid possessed solubility properties similar to their &-isomers. The properties of elaidic acid were intermediate between those , subject to the Cambridge Core terms of use, available at of the non-polar and the amphiphilic solutes. 4. The distribution coefficients of fatty acids differed less significantly than their solubilities in bile salt solution, but were influenced to some extent by the composition of the oil phase.
    [Show full text]
  • JMBFS / Surname of Author Et Al. 20Xx X (X) X-Xx
    REVIEW CONJUGATED LINOLEIC ACID-ENRICHED DAIRY PRODUCTS: A REVIEW Mihaela Ivanova*1 Address: Mihaela Ivanova 1University of Food Technologies, Technological Faculty, Department of Milk and Dairy Products, 26, Maritsa Blvd., 4002 Plovdiv, Bulgaria, phone number: +35932603783 *Corresponding author: mihaela [email protected] ABSTRACT Conjugated linoleic acid (CLA) is a family of more than 28 isomers of linoleic acid wherein the isomers cis-9, trans-11 (rumenic acid) and trans-10, cis-12 are the most abundant. It is associated with a number of potential health benefits for human organism. Many foods are a good source of it but it is mosty found in meat and dairy products, derived from ruminants. Dairy products contain CLA in different amounts. The enrichment of these products with CLA is appropriate given the lower CLA content in these products in comparison with the recommended health intake. Modification of CLA concentration can be done by specific animal feeding and diet modification, by direct CLA supplementation in the form of oils or by addition of specific starter culture. The influence of technological treatments on the stability of the final product during storage and maturation is still not completely elucidated. There is a need for further studies on the physiological effects of CLA isomers on humans. The purpose of this review is to summarize the possibilities for increasing CLA content in milk and dairy products and to determine the possible effects of this enrichment on product stability – sensory, chemical, microbiological profile, shelf life and potential health effects of the obtained products. Keywords: conjugated linoleic acid, milk, dairy products, functional foods INTRODUCTION In recent years, there was an increased discussion about the role of milk fat and its components and their influence on human health.
    [Show full text]
  • Mechanisms of Action of Trans Fatty Acids Downloaded from by Bibliotheek Der User on 03 June 2020
    REVIEW Mechanisms of Action of trans Fatty Acids Downloaded from https://academic.oup.com/advances/article-abstract/11/3/697/5645621 by Bibliotheek der user on 03 June 2020 Antwi-Boasiako Oteng and Sander Kersten Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands ABSTRACT Human studies have established a positive association between the intake of industrial trans fatty acids and the development of cardiovascular diseases, leading several countries to enact laws that restrict the presence of industrial trans fatty acids in food products. However, trans fatty acids cannot be completely eliminated from the human diet since they are also naturally present in meat and dairy products of ruminant animals. Moreover, bans on industrial trans fatty acids have not yet been instituted in all countries. The epidemiological evidence against trans fatty acids by far overshadows mechanistic insights that may explain how trans fatty acids achieve their damaging effects. This review focuses on the mechanisms that underlie the deleterious effects of trans fatty acids by juxtaposing effects of trans fatty acids against those of cis-unsaturated fatty acids and saturated fatty acids (SFAs). This review also carefully explores the argument that ruminant trans fatty acids have differential effects from industrial trans fatty acids. Overall, in vivo and in vitro studies demonstrate that industrial trans fatty acids promote inflammation and endoplasmic reticulum (ER) stress, although to a lesser degree than SFAs, whereas cis-unsaturated fatty acids are protective against ER stress and inflammation. Additionally, industrial trans fatty acids promote fat storage in the liver at the expense of adipose tissue compared with cis-unsaturated fatty acids and SFAs.
    [Show full text]