Levels Of Conjugated Linoleic Acid Research Articles

Diabetes Mellitus, Nonalcoholic Fatty Liver Disease, and Conjugated Linoleic Acid (Omega 6): What Is the Link?

Background and Objective Type 2 DM and obesity are the coming epidemics and their association with NAFLD is well established; essential fatty acids are vital for body health yet the body cannot make them; 2 essential fatty acids are especially important: linoleic (omega-6) and alpha-linoleic (omega-3) acids; they can be considered as “bioactive lipids” and serve as functional foods. Methods 50 type 2 Egyptian diabetic patients controlled on oral hypoglycemic drugs together with 20 age- and sex-matched healthy participants were enrolled in the study; all were subjected to complete history taking, BMI, fasting plasma glucose, HOMA-IR, ALT, AST, GGT, urea and creatinine, total lipid profile, hepatitis markers including hepatitis B surface antigen and hepatitis C virus antibodies, conjugated linoleic fatty acid “CLA,” and abdominal ultrasound for grading of NAFLD. Results Our study in Egyptian diabetics with NAFLD revealed a low level of serum CLA compared to healthy control; such deficiency was more marked with advanced grades of NAFLD; lowest levels were observed in those with severe steatosis (NASH) with definite association between CLA and obesity. Conclusion Insulin resistance is the main link between NAFLD, diabetes, and obesity. Conjugated linoleic acid (CLA) has a role in fat deposition in the liver and in development and improvement of insulin resistance. Fatty food had a documented role in the pathogenesis of obesity and diabetes but it can also be the cure.

Effects of Dietary Conjugated Linoleic Acid and Selected Vegetable Oils or Vitamin E on Fatty Acid Composition of Hen Egg Yolks

Abstract The objective of this study was to produce eggs enriched with conjugated linoleic acid (CLA) and ameliorate their fatty acid profile using the appropriate combination of dietary CLA with or without vegetable oils (olive oil or rapeseed oil) and vitamin E. In Experiment 1, 25-week-old laying hens were randomly distributed into eight groups of nine. Birds were fed with a standard diet with four different levels of CLA (0.0, 0.5, 0.75, 1.0%) and vegetable oils (olive oil or rapeseed oil, both in the amount of 1.46%). In Experiment 2, hens were randomly distributed into 12 groups of nine. The same four levels of CLA with three doses of vitamin E (0, 150, 300 mg/kg of diet) were applied. In both experiments, eggs were collected twice (at 4 and 8 weeks) for fatty acid profiling using GCMS. The differences between treatment means were considered significant at P<0.05. CLA treatments significantly increased the content of CLA, saturated fatty acids (SFA), and significantly decreased the content of monounsaturated fatty acids (MUFA) in the egg yolk, whereas levels of polyunsaturated fatty acids (PUFA) were unaffected. The vegetable oils used did not prevent the negative effects of CLA effectively. Only after eight weeks of experiment 1 SFA levels were significantly lower, but MUFA levels were significantly higher in groups fed with rapeseed oil compared to groups fed with olive oil. In experiment 2, the addition of vitamin E to the hen diet did not have an essential influence on the lipid profile of egg yolks.

IMPORTÂNCIA DO ÁCIDO LINOLEICO CONJUGADO (CLA) EM PRODUTOS DE ORIGEM ANIMAL

O termo CLA descreve um conjunto de isômeros geométricos do ácido linoleico com propriedades bioativas distintas, que têm duas duplas ligações separadas por apenas uma ligação simples. Assim, este trabalho trata-se de uma revisão bibliográfica baseada na literatura especializada, fundamentado através de consulta a artigos científicos selecionados em diferentes bases de dados com o objetivo de dar enfoque à importância do ácido linoleico conjugado (CLA) em produtos de origem animal e seus benefícios à saúde humana. Nesse contexto, em alimentos de origem animal é possível encontrar esse composto natural, principalmente na gordura do leite, carne e em alimentos naturalmente enriquecidos com este ácido e seus isômeros. O CLA tem propriedades bioativas distintas e é originário da biohidrogenação incompleta dos ácidos linoleico e linolênico realizada pelas bactérias ruminais ou da desaturação do trans-11 na glândula mamária e no intestino delgado. Os benefícios biológicos do CLA e dos isômeros cis-9 e trans-11, como um componente natural da gordura do leite, tem efeito anticarcinogênico, incluindo carcinomas na epiderme, tecido mamário e gastrintestinal. Dietas suplementadas com gorduras e a relação concentrado: volumoso, assim como a efetividade da fibra do volumoso podem aumentar a produção de leite, diminuir a produção de gordura e alterar seu perfil em ácidos graxos. Pesquisas avaliando os níveis de CLA nos produtos de origem animal e o seu efeito benéfico sobre a saúde e qualidade de vida do homem têm apresentado resultados satisfatórios, embora muitas vezes controversos, sendo necessários novos estudos para comprovar os resultados e a segurança na utilização desse composto, para que possa se determinar a sua real eficácia.

Does Maternal Synbiotic Supplementation Affect Conjugated Linoleic Acid Level in Breast Milk? A Randomized Placebo-Controlled Clinical Trial.

As conjugated linoleic acid (CLA)is a potential growth promotor in newborns, the present pilot study aimed at measuring the effect of synbiotic supplementation on breast milk CLA level. Sixty lactating mothers were randomly allocated to take either synbiotic (n = 31) or placebo (n = 29) for 30 days. Maternal anthropometric indices were measured at the onset and end of the study by standard methods and body mass index was calculated. Information on food intake was collected by using a 24 hours 24-hour recall method for 2 days and food record questionnaire for 1 day. Breast milk lipids were extracted and CLA level was quantified by gas chromatography. No significant differences were observed in the baseline mean breast milk concentrations of Fatty acids (FAs) between the synbiotic and placebo groups (p > 0.05). The CLA content of breast milk increased significantly by 58% (from 0.19 ± 0.15 to 0.30 ± 0.22 mmol/L) in the supplemented group, whereas it decrease decreased slightly but not significantly by 14% (from 0.22 ± 0.14 to 0.19 ± 0.10 mmol/L) in the placebo group. After adjustment for covariates, the CLA content of breast milk was significantly higher in the supplemented group compared with placebo group after the intervention (p = 0.03). The ratio of total n - 6:3 increased significantly over time in both groups, but was not different among groups (p < 0.05). This pilot study showed that supplementation of lactating women with synbiotic, resulted in increased breast milk CLA composition. Further research using different species of probiotic bacteria and analysis of maternal and infant plasma FAs would be beneficial.

Selection of Lactic Acid Bacteria for the Optimized Production of Sheep’s Milk Yogurt with a High Conjugated Linoleic Acid Content

Thirty-five different lactic acid bacteria (LAB) strains were screened for their conjugated linoleic acid (CLA) isomers (C18:2 cis-9, trans-11 and C18:2 trans-10, cis-12) producing ability from linoleic acid (LA) in sheep’s milk. Preliminary experiments revealed that Lactobacillus delbrüeckii ssp. bulgaricus 2230 and Streptococcus thermophilus St 360 among the screened strains had the highest CLA-producing ability. This two strains were assayed in an 11-run fractional factorial design to investigate the effect of four variables included glucose, powdered sheep milk, LA and inoculum ratio on CLA production in a sheep’s milk yogurt. The optimum conditions for producing the highest levels of CLA (42.86%) were obtained by adding 10.00 mg/mL of glucose, 30.00 mg/mL of powdered sheep milk, 0.90 mg/mL of LA and a 1:2 (St:Lb) ratio of bacterial strains in the inoculum. This CLA-rich sheep’s milk yogurt could be an important supplementary food source for increasing the CLA in the human diet.

Production of conjugated linoleic acid and gamma-aminobutyric acid by autochthonous lactic acid bacteria and detection of the genes involved

In this study, 85 strains of lactic acid bacteria isolated from artisanal cheeses were screened to determine their capacity to synthesise bioactive compounds.Four Lactobacillus plantarum and two Lactobacillus casei subsp. casei strains were capable of synthesizing conjugated linoleic acid (CLA). The highest level of CLA formed in MRS after 48h incubation was 19.26µg/mL. Six Lactobacillus brevis and four Lactococcus lactis subp. lactis strains produced gamma-aminobutyric acid (GABA) and the highest concentration (2524.05µg/mL) was found after 72h incubation.The detection of genes encoding linoleate isomerase or glutamate decarboxylase system could be suitable for use as screening method of CLA or GABA-producer strains, although this should be studied in a larger number of strains.Our findings suggest that the above strains are potential candidates for the design of starter cultures with the capacity to generate bioactive compounds, offering new possibilities for the manufacture of functional dairy products.

Strategies for Producing and Incorporating Conjugated Linoleic Acid-Rich Oils in Foods.

Conjugated linoleic acid (CLA) is in ruminant-derived foods and is known to combat obesity-related diseases. However, CLA levels in a healthy diet are too low to produce a clinical effect. Therefore, CLA has been produced by linoleic isomerization through fermentation and chemical catalysis. Many of these techniques are not practical for food production, but a recent development has enabled production of CLA-rich triglyceride vegetable oils from high linoleic acid oils by a minor modification of conventional food-oil processing techniques. These oils were used to produce common lipid-based food, such as margarine, shortenings, and salad dressings, whose quality was enhanced by the presence of CLA-rich oil and provided a significant CLA source. Meat and egg CLA content and subsequent food quality can also be increased by addition of dietary CLA. However, consumer awareness of CLA benefits needs to increase prior to commercial-scale production of CLA-rich oil.

Effect of conjugated linoleic acid supplementation on the microbial, physical, chemical and sensory properties of yoghurt

The aim of this study was to determine the effect of synthetic conjugated linoleic acid (CLA) supplementation on the quality of yoghurt. Yoghurt was prepared by adding CLA to create yoghurt with 0%, 25%, 50% and 100% w/w of the recommended dietary allowance for CLA. CLA inclusion had no effect on the viability of the yoghurt lactic acid bacteria. Physical properties such as viscosity and pH increased with increased CLA levels. CLA inclusion had a significant effect on the fatty acid composition of the yoghurt. Yoghurts from all four treatments were found acceptable by a consumer panel.

CONJUGATED LINOLEIC ACID IN MILK AND FERMENTED MILKS: VARIATION AND EFFECTS OF THE TECHNOLOGICAL PROCESSES

Background: Conjugated linoleic acid (CLA) is a generic term used to describe a group of geometric and positional isomers of linoleic acid with a conjugated double bond system. CLA-isomers have been widely studied because of their important biological activity and their protective effects against several diseases, such as obesity, atherosclerosis, chronic inflammatory diseases, and cancer. Consequently, these biomolecules have attracted much attention from the dairy industry, since they are naturally found in ruminants’ milk, and because the development of CLA-enriched dairy foods can be a good economic opportunity given the growth of the functional foods market, in which the dairy industry plays an important role. Objectives: This work presents a comprehensive review of the following aspects: (i) The synthesis and concentration of the CLA-isomers in milk, and the main strategies employed to increase their content in a natural manner; (ii) The influence of the main technological treatments applied to milk on the concentration of CLA-isomers; and (iii) The effects of milk fermentation on the content of CLA-isomers, and the challenges of this technological process, which has been though as a promissory alternative to naturally increase the content of CLA in fermented dairy products. Methods: Information available in various databases was reviewed. A total of 103 articles were selected on the basis of their relevance and scientific-technical quality. Results: The CLA concentration in cows’ milk normally ranges between 2 and 37 mg/g fat, and is mainly affected by the dietary regime offered to the animals. From the total CLA-isomers, rumenic acid represents between 75 and 90%. The technological processes normally applied to milk (thermal processing, high pressure processing, and fermentation) might cause slight changes on the CLA concentration, but the mechanisms causing these changes have not been still established. The increase in CLA concentration by milk fermentation is strain-dependent, because of the different linoleate isomerase activity of the species. . Conclusions: Although several studies have reported increases in the concentration of CLA in milk and fermented milks in a natural manner, they are fairly moderate, and the obtained levels of CLA are significantly lower than those recommended to achieve therapeutic effects.

Conjugated linoleic acid of dairy foods is affected by cows’ feeding system and processing of milk

The distribution of conjugated linoleic acid (CLA) in dairy products commercially available in Chile is poorly understood. This study aimed to assess the content of CLA in dairy cow products from Chile and the effect of processing fresh milk into dairy products. Samples of raw milk were categorized into two groups based on the animal feeding system utilized by the dairy farm: 1) grazing based systems (Los Lagos region); and 2) housing systems using total mixed ration (TMR) diets (Los Angeles region). Simultaneously, commercial samples of condensed milk, powdered milk, butter and Gouda cheese were analyzed. Furthermore, samples of raw milk and processed products (powdered and sweetened condensed milk) were also analyzed. Dairy farms based on grazing systems had higher levels of CLA in raw milk than TMR farms. In addition, average values of CLA were 1.72 g 100 g−1 of total fatty acids, in spring milk in the Los Lagos region, and 0.42 g 100 g−1 in summer milk, in the Los Angeles region. Similarly, the CLA content of dairy products was higher than that of raw milk. Milk processing affected the transferring of CLA from fresh milk into the final products. Sweetened condensed milk presented lower CLA values than raw and powdered milk. In conclusion, this study indicates the importance of the production systems to the CLA content as well as the effects of milk processing into dairy products. To sum up, more research is needed to elucidate the exact effect of the processing conditions of dairy products on the CLA content.

The In vitro Effects of Nano-encapsulated Conjugated Linoleic Acid on Stability of Conjugated Linoleic Acid and Fermentation Profiles in the Rumen.

This study was aimed to evaluate the stability of conjugated linoleic acids (CLAs) by nano-encapsulation against in vitro ruminal biohydrogenation by microbial enzymatic conversion. CLAs (free fatty acid form of CLA [CLA-FFA], nano-encapsulated CLA-FFA, triglyceride form of CLA [CLA-TG], and nano-encapsulated CLA-TG) were used in the in vitro fermentation experiments. When Butyrivibrio fibrisolvens (B. fibrisolvens) was incubated with CLA-FFAs, the concentrations of cis-9, trans-11 CLA and vaccenic acid (VA) slightly was decreased and increased by nano-encapsulation, respectively. When B. fibrisolvens was incubated with CLA-TG, the concentrations of cis-9, trans-11 CLA and VA decreased, but these were increased when B. fibrisolvens was incubated with nano-encapsulated CLA-TG. The nano-encapsulation was more effective against the in vitro biohydrogenation activity of B.fibrisolvens incubated with CLA-FFA than with CLA-TG. In the in vitro ruminal incubation test, the total gas production and concentration of total volatile fatty acids incubated with nano-encapsulated CLA-FFA and CLA-TG were increased significantly after 24 h incubation (p<0.05). Nano-encapsulated CLA-FFA might, thus, improve the ruminal fermentation characteristics without adverse effects on the incubation process. In addition, nano-encapsulated CLA-FFA increased the population of Fibrobacter succinogenes and decreased the population of B. fibrisolvens population. These results indicate that nano-encapsulation could be applied to enhance CLA levels in ruminants by increasing the stability of CLA without causing adverse effects on ruminal fermentation.

Effects of conjugated linoleic acid and lutein on the growth performance and immune response of broiler chickens

The effects of lutein and conjugated linoleic acid (CLA) on growth performance and immune response of broiler chickens were evaluated in the presence and absence of Salmonella lipopolysaccharide (LPS) immune challenge. Cobb chicks (360; 1 to 22 d of age) were used in a 3 × 2 factorial arrangement of CLA (0, 1, and 2%) and lutein (0 and 50 mg/kg) dietary levels. At d 8 and 15, birds were injected with BSA to assess IgY production. At d 20, birds were injected with LPS. Samples of liver, spleen, and duodenum were collected at 3 and 16 h post-LPS challenge for RT-qPCR analysis of RXRα, RXRγ, PPARα, PPARγ, TLR-4, IL-1β, IL-2, IL-10, and IL-12 gene expression. CLA decreased BW, BW gain (BWG), and G:F from d 1 to 20, but these effects were reversed when lutein was included in the 1% CLA diet (P < 0.001). The production of IgY anti-BSA increased following a 2% CLA supplementation (P < 0.01). LPS increased the liver:BW ratio at 3 h post-injection (P < 0.001) and decreased BWG at 3, 16, and 40 h (P < 0.001). Lutein decreased plasmatic nitric oxide levels (P < 0.01). LPS downregulated PPARα mRNA in the duodenum (P = 0.02) and liver (P = 0.04), and PPARγ (P = 0.01) and RXRα (P = 0.08) in the spleen; these effects were not reversed by CLA or lutein as initially hypothesized. Although LPS upregulated IL-1β (P = 0.02) and IL-12 (P = 0.07) expression, lutein downregulated these pro-inflammatory cytokines in the liver (P = 0.03 and P = 0.07, respectively). Lutein decreased splenic (P = 0.09) but increased hepatic (P = 0.06) TLR-4 mRNA. A dietary CLA supplementation of 2% increased hepatic RXRα (P = 0.10). In conclusion, CLA decreased broiler chicken growth performance, but lutein could prevent this negative effect (depending on CLA dose). Lutein had an anti-inflammatory effect, and a 2% CLA supplementation improved the humoral immune response.

Dietary CLA supplementation of pigs confers higher oxidative stability to Ciauscolo and Fabriano salami produced from their meat with no negative impact on the physico‐chemical, microbiological and sensorial characteristics

It has been reported that conjugated linoleic acid (CLA) isomers are considered particularly beneficial to human health and affect the technological properties of pork meat products such as salami. The objective of this study was to evaluate the effect of 0.5% CLA supplementation of heavy pig diets on the chemical composition, total fatty acids (FA), oxidative stability, sensory and microbial properties of Ciauscolo and Fabriano salami. The incorporation of CLA into the diet did not modify the chemical, microbial or sensory descriptive analysis of the salami. The CLA dietary supplementation changed the proportions of FA, in particular leading to an increase in the proportion of saturated fatty acids and CLA in both Ciauscolo and Fabriano salami. The results of consumer testing showed a higher degree of liking by consumers when the CLA sample was accompanied by product information, demonstrating the strong influence of the label on consumer perception. The interesting finding was the increase in the oxidative stability of the salami at the end of ripening. This confirms the hypothesis that CLA can affect the saturated and monounsaturated fatty acids/monounsaturated FA ratio in meat products and possesses antioxidative properties that can be transferred, through dietary supplementation, to salami.Practical applications: Feeding a 0.5% CLA diet to finisher pigs resulted in changes in the proportions of FA and enhanced the oxidative stability of salami but did not modify the sensory properties of the products. More research is needed to find the right inclusion level of CLA to be considered optimal from the point of view of producing a high quality product with superior organoleptical, technological and potential health‐related properties.Production of value‐added meat products, such as conjugated linoleic acids (CLA) enriched Ciauscolo and Fabriano salamis, by the inclusion of the c9 t11 and t10 c12 CLA isomers in the swine diet.

In-vitro microbial production of conjugated linoleic acid by probiotic L. plantarum strains: Utilization as a functional starter culture in sucuk fermentation

Twenty-three probiotic Lactobacillus plantarum strains were screened in-vitro to determine their ability to produce conjugated linoleic acid (CLA). L. plantarum AA1-2 and L. plantarum AB20-961 were identified as potential strains for CLA production. Optimum conditions for these strains to produce high levels of CLA were determined by evaluating the amount of added hydrolyzed sunflower oil (HSO) and initial pH levels in a nutrient medium. The highest CLA production was obtained in medium with pH6.0 and 2% HSO (P<0.05). Those strains were then used as starter culture in sucuk fermentation. Five sucuk treatments included a control (no starter culture), two sucuk groups with L. plantarum AA1-2 at the initial pH of 5.8 or 6.0 and two sucuk groups with L. plantarum AB20-961 at the initial pH of 5.8 or 6.0. Results indicate that L. plantarum AB20-961 produced higher amount of CLA in sucuk at initial pH of 5.8 and 6.0 levels during first 24h of fermentation compared with other groups. CLA isomer concentration decreased in all sucuk groups during the rest of the fermentation period (P<0.05) and remained quite stable during the storage. This study demonstrated that probiotic L. plantarum AB20-961 can be used in sucuk manufacturing without posing any quality problems.

Milk fatty acid composition and conjugated linoleic acid content of Jersey and Fleckvieh x Jersey cows in a pasture-based feeding system

A number of fatty acids (FAs), such as omega-3, omega-6 and conjugated linoleic acid (CLA), which are present in the milk from dairy cows are considered essential FAs and beneficial nutrients for humans. The aim of the study was to compare the milk FA content, particularly the CLA, omega-3 and omega-6 FA content of the milk fat of Jersey and Fleckvieh x Jersey (F x J) cows in a pasture-based feeding system. All cows were fed the same diet consisting of kikuyu-ryegrass pasture in a rotational grazing system supplemented with a standard commercial concentrate mixture at 7 kg per cow per day. Five milk samples were collected every five weeks from 10 days after calving, that is, days in milk (DIM) up to 175 DIM. In addition, two samples were collected every five weeks from 240 DIM to the end of the lactation period. Sampling was done at the evening and following morning’s milking session and pooled for each cow. Samples were kept frozen at −20 oC until laboratory analysis by gas chromatography. Thirty six FAs were detected and concentration levels determined. Higher levels of total CLA (0.74 ± 0.02 vs. 0.63 ± 0.02 g FA/100 g fat), linoleic acid (1.51 ± 0.03 vs. 1.36 ± 0.04 g FA/100 g fat) and total omega-6 FAs (1.74 ± 0.04 vs. 1.54 ± 0.05 g FA/100 g fat) were recorded in the milk fat of F x J cows in comparison with Jersey cows, respectively. Increases in total CLA and the c 9, t 11 CLA isomers in the milk of Jersey and F x J cows followed the same trend, showing an increase from the beginning to the end of the lactation period. Similarly, the CLA content of the milk fat showed an increase with lactation stage for both breeds. Keywords: Breed comparison, kikuyu-ryegrass, lactation stage, omega-3 fatty acid, omega-6 fatty acid

The effect of paternal bull on milk fat composition of dairy cows of different breeds

Intake of milk fat in human nutrition is important because of unsaturated and especially essential fatty acids (FAs), linoleic and α-linolenic acid, and conjugated linoleic acid (CLA), which is found only in meat and milk of ruminants. The objective of our study was to investigate the effect of paternal bulls on fatty acids composition in milk fat of dairy cows of different breeds. The milk samples were taken in total from 299 dairy cows from 11 dairy farms. In experiment Holstein (H, n = 105), Red Holstein (R, n = 120) and Pinzgau (P, n = 74) breeds originated from different bulls were used. Individual milk samples were analyzed for fatty acids in milk fat using gas chromatography (apparatus GC Varian 3800, Techtron, USA), using FID detector in capillary column Omegawax 530; 30 m. In the chromatography records there were identified 54 fatty acids inclusive of particular isomers. Their relative proportions were expressed in percent's (%). Among the studied breeds, the highest content of conjugated linoleic acid (CLA) - 0.67%, essential FAs (EFA) - 2.98%, monounsaturated FAs (MUFA) - 25.84% and the lowest atherogenic index (AI) - 3.10 was at breed P. Within this breed there was high variability and daughters of bull COS1 achieved significant above-average values of CLA content 1.07%, EFA 3.71%, MUFA 29.93% and under breed average AI = 2.40. The group of daughters of NOB3 was significant lower in CLA, 0.50% as compared with an average of P breed. . From the breed H bull MTY2 showed significantly higher value of 0.62% CLA, EFA 3.42%, 34.29% MUFA and lower value of AI, 1.9 as compared to H breed average. Statistically significantly lower levels of CLA 0.29% and 21.46% MUFA and higher AI 3.72 in milk fat of his daughters, bull STY3 may be considered as potential worser of these properties. At the breed R bull MOR506 showed in compar to the breed average significantly higher value of the EFA 3.80% and also the higher content of CLA 0.50% and MUFA 25.09%, resulting in statistically significant lower AI = 2.91. Bull MOR506 could be considered as potential improver of milk fat composition. The above described variability in the composition of milk fat of dairy cows and the subsequent relationships between these values suggest that the selection of the bull according to the fatty acid composition of milk fat may be considered.

Portable Infrared Spectrometer to Characterize and Differentiate Between Organic and Conventional Bovine Butter

AbstractThe performance of a portable infrared system combined with pattern recognition to discriminate between organically and conventionally produced bovine butter samples as well as to predict the levels of conjugated linoleic acid (CLA) were evaluated. Sixty butter (27 organic and 33 conventional) samples were used in this study. Bovine butter–fat were applied onto an attenuated total reflectance infrared (ATR‐IR) accessory equipped with a five‐bounce ZnSe crystal set at 65 °C for spectral collection. In addition, ATR‐IR spectra of bovine butter were directly collected at room temperature to avoid phase separation. The fatty acid profile and the levels of CLA were determined using reference FAME‐GC‐FID analysis. SIMCA models showed well separated clusters that discriminated between organic and conventional bovine butters due to C=C trans bending out of the plane vibration modes band at 967 cm−1. Additionally, strong PLSR models were developed to predict CLA levels using butter–fat and bovine butter spectra with SEP of 0.05 % and RPD of 4.7, indicating that the models are suitable for quality control applications. Portable IR technology offers the ability for “in situ” analysis of butters that is much less time consuming than current analytical practices for authentication and quality control efforts by the industry.

Butter naturally enriched in cis-9, trans-11 CLA prevents hyperinsulinemia and increases both serum HDL cholesterol and triacylglycerol levels in rats.

BackgroundEvidence from in vitro and animal studies indicates that conjugated linoleic acid (CLA) possesses anti-diabetic properties, which appear to be attributed to cis-9, trans-11 CLA, the major CLA isomer in ruminant fat. However, there is a shortage of studies addressing CLA from natural source. The present study aimed to evaluate the effects of butter naturally enriched in cis-9, trans-11 CLA on parameters related to glucose tolerance, insulin sensitivity and dyslipidemia in rats.MethodsForty male Wistar rats were randomly assigned to the following dietary treatments (n = 10/group), for 60 days: 1) Normal fat-Soybean oil (NF-So): diet containing 4.0% soybean oil (SO); 2) High Fat-Control Butter (HF-Cb): diet containing 21.7% control butter and 2.3% SO; 3) High Fat-CLA enriched Butter (HF-CLAb): diet containing 21.7% cis-9, trans-11 CLA-enriched butter and 2.3% SO; and 4) High fat-Soybean oil (HF-So): diet containing 24.0% SO. HF-Cb and HF-CLAb diets contained 0.075% and 0.235% of cis-9, trans-11 CLA, respectively.ResultsHF-CLAb-fed rats had lower serum insulin levels at fasting than those fed with the HF-Cb diet, while the PPARγ protein levels in adipose tissue was increased in HF-CLAb-fed rats compared to HF-Cb-fed rats. Furthermore, R-QUICK was lower in HF-Cb than in NF-So group, while no differences in R-QUICK were observed among NF-So, HF-CLAb and HF-So groups. Serum HDL cholesterol levels were higher in HF-CLAb-fed rats than in those fed NF-So, HF-Cb and HF-So diets, as well as higher in NF-So-fed rats than in HF-Cb and HF-So-fed rats. HF-CLAb, HF-Cb and HF-So diets reduced serum LDL cholesterol levels when compared to NF-So, whereas serum triacylglycerol levels were increased in HF-CLAb.ConclusionFeeding rats on a high-fat diet containing butter naturally enriched in cis-9, trans-11 CLA prevented hyperinsulinemia and increased HDL cholesterol, which could be associated with higher levels of cis-9, trans-11 CLA, vaccenic acid, oleic acid and lower levels of short and medium-chain saturated fatty acids from butter naturally modified compared to control butter. On the other hand CLA-enriched butter also increased serum triacylglycerol levels, which could be associated with concomitant increases in the content of trans-9 and trans-10 C18:1 isomers in the CLA-enriched butter.Electronic supplementary materialThe online version of this article (doi:10.1186/1476-511X-13-200) contains supplementary material, which is available to authorized users.

Conjugated linoleic acid alters growth performance, tissue lipid deposition, and fatty acid composition of darkbarbel catfish (Pelteobagrus vachelli).

Fatty liver syndrome is a prevalent problem of farmed fish. Conjugated linoleic acid (CLA) has received increased attention recently as a fat-reducing fatty acid to control fat deposition in mammals. Therefore, the aim of the present study was to determine whether dietary CLA can reduce tissue lipid content of darkbarbel catfish (Pelteobagrus vachelli) and whether decreased lipid content is partially due to alterations in lipid metabolism enzyme activities and fatty acid profiles. A 76-day feeding trial was conducted to investigate the effect of dietary CLA on the growth, tissue lipid deposition, and fatty acid composition of darkbarbel catfish. Five diets containing 0 % (control), 0.5 % (CLA0.5), 1 % (CLA1), 2 % (CLA2), and 3 % (CLA3) CLA levels were evaluated. Results showed that fish fed with 2-3 % CLA diets showed a significantly lower specific growth rate and feed conversion efficiency than those fed with the control diet. Dietary CLA decreased the lipid contents in the liver and intraperitoneal fat with the CLA levels from 1 to 3 %. Fish fed with 2-3 % CLA diets showed significantly higher lipoprotein lipase and hepatic triacylglycerol lipase activities in liver than those of fish fed with the control, and fish fed with 1-3 % CLA diets had significantly higher pancreatic triacylglycerol lipase activities in liver than those of fish fed with the control. Dietary CLA was incorporated into liver, intraperitoneal fat, and muscle lipids, with higher percentages observed in liver compared with other tissues. Liver CLA deposition was at the expense of monounsaturated fatty acids (MUFA). In contrast, CLA deposition appeared to be primarily at the expense of MUFA and n-3 polyunsaturated fatty acids (PUFA) in the intraperitoneal fat, whereas in muscle it was at the expense of n-3 PUFA. Our results suggested that CLA at a 1 % dose can reduce liver lipid content without eliciting any negative effect on growth rate in darkbarbel catfish. This lipid-lowering effect could be in part due to an increment in the activity of lipid metabolism enzymes and an extensive interconversion of fatty acids. Although CLA deposition in muscle (0.66-3.19 % of total fatty acids) are higher than presented in natural sources of CLA, EPA (C20:5n-3) in fish muscle appears simultaneously expendable, when the fish fed with 2-3 % CLA.

Conjugated linoleic acid in diets for lambari (Astyanax altiparanae ) (Garutti &amp; Britski, 2000)

This study aimed to evaluate the effect of different levels of conjugated linoleic acid (CLA) on growth performance, carcass chemical composition and fatty acid profile of lambari (Astyanax altiparanae). A completely randomized experimental design with six treatments, diets with graded levels of CLA (0.0, 5.0, 10.0, 15.0, 20.0 and 25.0 g kg−1) and five repetitions. Fish (n = 570; weight: 1.58 ± 0.23 g) were distributed into 30 (70-L) aquaria and fed the experimental diets during 90 days. No effects of dietary supplementation with CLA on fish performance and carcass chemical composition were observed. CLA influenced carcass fatty acid profile, a positive relationship was found for 16:1 n-9, 18:1 n-9, 18:2(cis-9, trans-11), 18:2(trans-10, cis-12) and 20:1 n-9, and a negative relationship was found for 15:1 n-7, 16:0, 16:1 n-5, 18:2 n-6, 18:3 n-3, 20:5 n-3 and 22:4 n-6. Total CLA and monounsaturated fatty acids (MUFA) linearly increased with the increase in dietary CLA, while saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) of n-6 and n-3 series linearly decreased. Dietary CLA can be incorporated into the lambari (A. altiparanae) muscle, and the fish can be used as functional foods, because CLA is related to the prevention of various diseases in humans.