Dietary C18:1 trans fatty acids increase conjugated linoleic acid in adipose tissue of pigs

The effect of dietary C18:1 trans fatty acids on back fat composition in pigs was investigated with special emphasis on conjugated linoleic acids (CLA). A total of 12 × 4 siblings of Large White and Swiss Landrace breed were housed in groups and fattened from 22 to 103 kg live weight. Pigs were fed a control diet (barley, wheat, soybean meal) or experimental diets which consisted of the control diet with a 5% replacement of olein or stearin fractions of pork fat, or partially hydrogenated fat. The hydrogenated fat was rich in C18:1 trans fatty acids but contained only negligible amounts of CLA. In contrast olein and stearin fractions contained far less C18:1 trans fatty acids but some CLA. In the control diet no C18:1 trans fatty acids and only traces of CLA were detected. The partially hydrogenated fat led to the highest CLA content in back fat (0.44%). Intermediate amounts of CLA were measured in pigs fed the fractionated pork fat (0.22/0.23%). In pigs fed the control diet, also small amounts of CLA were detected. The results indicate that CLA may be produced by endogenous Δ9‐desaturation out of dietary trans vaccenic acid in pigs.     

Seasonal study of the lipid composition in different tissues of the common octopus (Octopus vulgaris)

Seasonal variation of octopus (Octopus vulgaris) lipid composition was investigated in four tissues: arm, mantle, ovary and digestive gland. A non‐homogeneous fat distribution was observed, with the digestive gland exhibiting a higher (p <0.05) lipid content than the other tissues. The ovary showed a higher (p <0.05) fat content than both muscle tissues, reaching its highest (p <0.05) value in winter. Neutral lipids – free fatty acids (FFA), triacylglycerols, and sterols (ST) – exhibited their highest (p <0.05) concentrations in the digestive gland and their lowest (p <0.05) values in muscle tissues. The phospholipid (PL) content of the ovary was the highest (p <0.05) of all tissues analysed, with the PL content also being significantly (p <0.05) higher in the digestive gland than in arm and mantle. The concentrations of most lipid classes (FFA, PL and ST) exhibited a seasonal variation. The fatty acid composition showed a remarkable difference between the digestive gland and all other tissues analysed. Thus, the digestive gland exhibited higher (p <0.05) contents in monounsaturated fatty acids and also lower (p <0.05) contents in both saturated (SFA) and polyunsaturated (PUFA) fatty acids. The highest mean values in SFA and PUFA were observed in ovary and muscle tissues, respectively. A seasonal effect was observed for SFA and PUFA.     

The fatty acid composition of lipids from muscle and adipose tissues of pigs fed various oil mixtures differing in their ratio between oleic acid and linoleic acid

High concentrations of polyunsaturated fatty acids (PUFA) in meat have detrimental effects on its technical properties. The present study was carried out to investigate whether PUFA levels in pork can be reduced by increasing the concentrations of oleic acid in pig diets. To this end a bifactorial experiment was carried out with 48 female growing finishing pigs. Six different diets were used with two different concentrations of linoleic acid (12 vs. 24 g/kg) and three different concentrations of oleic acid (12 vs. 18 vs. 24 g/kg). The experiment started at a body weight (BW) of 58 kg and continued until 115 kg BW. The fatty acid composition of total lipids of backfat, perirenal fat and musculus (m.) longissimus dorsi was analysed. Concentrations of linoleic acid and total PUFA in backfat and perirenal fat were affected only by the dietary linoleic acid content but not at all by the dietary oleic acid content. Increasing the dietary concentration of oleic acid raised the level of oleic acid in those tissues at the expense of saturated fatty acids, suggesting competition between monounsaturated fatty acids and saturated fatty acids for incorporation into triglycerides. At the low dietary linoleic acid concentration, the percentages of linoleic acid and total PUFA in total lipids of m. longissimus dorsi were also unaffected by the dietary oleic acid content. In contrast, at the high dietary linoleic acid concentration, percentages of linoleic acid and total PUFA of the m. longissimus dorsi were reduced by increasing the dietary concentration of oleic acid, suggesting that oleic acid and linoleic acid compete for incorporation into muscle lipids. Thus, at high dietary linoleic acid levels the fatty acid composition of the m. longissimus dorsi was favourably affected by high dietary oleic acid concentrations; in backfat and perirenal fat, however, no beneficial effect of high dietary oleic acid levels was seen.     

The impact of fatty acid profile on the physicochemical properties of commercial margarines in Brazil

This study aimed to evaluate how lipid profiles affect the physicochemical properties, fatty acid profiles, and nutritional qualities of Brazilian margarines. We analyzed the texture profiles of 13 margarine samples and characterized their fatty acid composition, solid fat content, crystallization kinetics by NMR and thermal behavior by differential scanning calorimetry. The samples had total fat content ranging from 20% to 82% and low trans fatty acid (TFA) levels, except for two samples (5–7% elaidic acid). The fatty acid compositions of all samples showed a predominance of linoleic (23%–46%), oleic (20%–46%), and palmitic acids (7%–14%), indicating that they were formulated with soybean and palm oils. Saturated fat content ranged from 23% to 31%. Compared to the other evaluated samples, those with higher content of lipid and saturated fatty acids (SFAs) exhibited increased hardness and stickiness but reduced spreadability and adhesiveness. The presence of TFAs resulted in increased plasticity of the samples. Reformulation resulted in products with greater SFA levels, which had a negative impact as it increased the atherogenic index (AI: 0.22–0.48). The HF55 sample contained canola oil-based fat and presented the best nutritional and physical properties. This study is the first to report a complete evaluation of representative margarines, with essential information in reformulating to achieve lower SFA.     

甜菜碱对聚异戊二烯橡胶性能的影响简

探讨甜菜碱(三甲铵乙内酯,天然橡胶非胶组分)对聚异戊二烯橡胶(IR)硫化特性、强伸性能和热稳定性能的影响。结果表明:与未加甜菜碱的IR相比,添加甜菜碱的IR硫化速度显著提高,交联密度增大,强伸性能改善,热稳定性能略有提高;当甜菜碱用量为0.5份时,IR的综合性能最佳。     

多功能两性表面活性剂椰油酰胺丙基甜菜碱

概述了国内外多功能两性表面活性剂椰油酰胺丙基甜菜碱的制备与性能。详细分析了椰油酰胺丙基甜菜碱的结构特性,系统地介绍了其反应原理和制备工艺。提出了提高产品质量和收率的可行性方案,对其水溶、去污、发泡、增稠、调理以及温和等突出性能作了介绍,并举例进行应用方面的讨论。     

Gut microbial fatty acid metabolites (KetoA and KetoC) affect the progression of nonalcoholic steatohepatitis and reverse cholesterol transport metabolism in mouse model

Nonalcoholic steatohepatitis (NASH) is a common liver disease that occurs in both alcoholics and nonalcoholics. Oxidative stress is a possible causative factor for liver diseases including NASH. Gut microorganisms, especially lactic acid bacteria, can produce unique fatty acids, including hydroxy, oxo, conjugated, and partially saturated fatty acids. The oxo fatty acid 10-oxo-11(E)-octadecenoic acid (KetoC) provides potent cytoprotective effects against oxidative stress through activation of Nrf2-ARE pathway. The aim of this study was to explore the preventive and therapeutic effects of gut microbial fatty acid metabolites in a NASH mouse model. The mice were divided into 3 experimental groups and fed as follows: (1) high-fat diet (HFD) (2) HFD mixed with 0.1% KetoA (10-oxo-12(Z)-octadecenoic acid), and (3) HFD mixed with 0.1% KetoC. After 3 weeks of feeding, plasma parameters, liver histology, and mRNA expression of multiple genes were assessed. There was hardly any difference in fat accumulation in the histological study; however, no ballooning occurred in 2/5 mice of KetoC group. Bridging fibrosis was not observed in the KetoA group, although KetoA administration did not significantly suppress fibrosis score (p = 0.10). In addition, KetoC increased the expression level of HDL related genes and HDL cholesterol levels in the plasma. These results indicated that KetoA and KetoC may partly affect the progression of NASH in mice models.     

Fatty acid composition of French infant formulas with emphasis on the content and detailed profile oftrans fatty acids

The aim of the present study was to identify and quantitatetrans isomers of C18 fatty acids in some French infant formulas. Twenty powdered infant formulas were purchased in pharmacies and supermarkets in order to assess theirtrans mono- and poly-unsaturated fatty acids content. The fatty acid profiles were examined using methyl and isopropyl ester derivatives. The combination of gas-liquid chromatography, high-performance liquid chromatography, and silver nitrate thin-layer chromatography was needed to describe the detailed fatty acid compositions of the samples, includingtrans isomers of unsaturated C18 fatty acids. All the samples containedtrans isomers of C18∶1 acid (mean level 1.97±0.28% of total fatty acids), with vaccenic acid being generally the major isomer (15 out of 20 samples), thus indicating the origin from bovine milk. All the formulas also contained various isomers of linoleic and α-linolenic acids, but at lower levels.Trans PUFA isomers are the same as those present in deodorized oils. In conclusion, all the infant formulas analyzed in this study contained sometrans fatty acids, including isomers of essential fatty acids. This should be taken into account in the dietary intake of the newborn.     

Effect of temperature on fatty acid composition in the Nile tilapia (Oreochromis niloticus): A temperature dependent nutritive lipid profile

In this study, the effects of temperature on the fatty acids profile and the effects of temperature on the degree of unsaturation of fatty acids of Oreochromis niloticus were investigated. The analysis was performed by gas chromatography. The study showed that there were large temperature variations (10.0–32.0°C) during the study period (January–December). The highest crude fat content was found in January (3380 mg/100 g) and the lowest in June (2050 mg/100 g). The fatty acids profile showed significantly different diversity (p < 0.05). Total saturated fatty acid (∑SFA) content ranged from 409.54 to 1297.61 mg/100 g, monounsaturated fatty acid (∑MUFA) from 207.68 to 665.81 mg/100 g, and polyunsaturated fatty acid (∑PUFA) from 175.12 to 972.23 mg/100 g. The ∑MUFA and ∑PUFA concentrations were highest in January and lowest in June, and the ∑SFA concentration was lowest in January and highest in June. EPA and DHA contents were highest in January (198.96 mg/100 g) and lowest in June (48.76 mg/100 g). The contents of omega-3 (653.17 mg/100 g) and omega-6 fatty acids (252.54 mg/100 g) were highest in January and lowest in June (ω-3; 106.43 and ω-6; 60.91 mg/100 g). It concluded that the degree of unsaturation of fatty acids increases with decreasing temperature. In this study, the nutritional quality of the FAs profile was assessed using lipid quality indices. The indices indicating dietary quality of lipids by their values: Atherogenic index (0.47), thrombogenic index (0.38), hypocholesterolemic to hypercholesterolemic (3.00), meat fat quality (6.78), ω6/ω3 ratio (0.39), PUFA/SFA (2.37), MUFA/SFA (1.62), PUFA/MUFA (1.46), and PUFA + MUFA/SFA (3.99). These values are within the recommended range, indicating that the lipid profile of O. niloticus has high nutritional quality, which can be further improved by harvesting the fish during the winter season. Due to the nutritional importance of O. niloticus, the culture of this species could have significant interest to the people of Karachi, especially the coastal communities. To promote the nutritional diet in local population, the government should support the aquaculture of Nile tilapia.     

Effect of grass vs. concentrate feeding on the fatty acid profile of different fat depots in lambs

The aim of this study was to produce high‐quality meat from lambs under different feeding conditions, as measured by the accumulation of n‐3 fatty acids and conjugated linoleic acids (CLA) in muscle and subcutaneous fat. In total, 13 male crossbred lambs (Black Head×Gotland), each at 24 kg live weight, were divided into two feeding groups. Lambs were kept either on pasture (pasture grazing, n = 6) or in the stable (concentrate feeding, n = 7). The linolenic acid (C18:3n‐3) contained in the grass was absorbed and deposited into the different lipid classes of muscle and subcutaneous fat. The proportion of total n‐3 fatty acids in the different lipids of grazing lambs was significantly (p = 0.05) higher compared to that in concentrate‐fed lambs. The n‐6/n‐3 ratio (mean ± SEM) in muscle of grazing lambs was 1.2 ± 0.09 in contrast to 2.3 ± 0.09 (p = 0.05) of the animals kept in the stable. In subcutaneous fat, this ratio was 0.9 ± 0.2 in lambs kept on pasture versus 3.5 ± 0.2 (p = 0.05) after indoor keeping. The relative concentration of C18:1trans‐11 in total muscle lipids, phospholipids, triacylglycerols and subcutaneous fat was significantly increased by grass feeding compared to concentrate feeding. Significant influences of feeding were shown for saturated fatty acids. In concentrate‐fed lambs, a lower content of saturated fatty acids was detected. The proportion of CLAcis‐9,trans‐11 (1.9 ± 0.2% vs. 1.1 ± 0.1% in muscle, 2.5 ± 0.2% vs. 1.4 ± 0.2% in subcutaneous fat, 0.7 ± 0.04% vs. 0.4 ± 0.04% in phospholipids) in lambs was significantly (p = 0.05) higher after grazing than after concentrate feeding, respectively.     

Fatty acid profile and aroma compounds of lipoxygenase-modified chicken oil

Adipose fat tissue, which contributes 1.6–5.8% of total chicken carcass weight, has been underutilized by chicken processors because of its “chickenish odor.” The objective of this study was to prepare a chicken oil from which the undesirable odor notes were eliminated and in which the desirable volatile compounds were enhanced. Chicken adipose fat was dry-rendered at 140°C for 30 min and yielded 78.5% oil. Monoenoic FA constituted 55.8% of the chicken oil, and of that oleic acid constituted 92.8%. Treatment of chicken oil with an algal lipoxygenase extracted from Ulva spp. at 33°C for 30 min resulted in an increase of 0.40% in total monoenoic acids, a decrease of 33.3% in total polyenoic acids, and a decrease in total FA of 0.8%. A noticeable improvement in the odor of chicken oil after lipoxygenase treatment was observed by sensory evaluation and a GC-sniffing technique. The modified chicken oil contained more desirable volatile compounds—ethyl acetate, pentanal, 2-pentyl furan, E-2-heptenal, and nonanal—than the original chicken oil, provided fruity and tea-leaf aromas, and had reduced levels of the undesirable volatile compounds heptanal, 2,4-heptadienal, 2,4-nonadienal, and dodecanal. These modifications reduced the chickenish and oxidized odor notes.     

Effect of Exogenous Glycine Betaine on the Germination of Tomato Seeds under Cold Stress

Cold stress is known to influence tomato growth, development, and yield. In this study, we analyzed the germination of tomato seeds treated with exogenous glycine betaine (GB) at a low temperature (14 °C). The results showed that cold stress inhibited tomato seed germination, and pretreatment with exogenous GB reduced this inhibition and enhanced the germination rate (GR), germination index (GI), and viability of tomato seeds at low temperatures. Analysis of gene expression and metabolism revealed that GB positively regulated endogenous hormone gibberellin (GA) content and negatively regulated abscisic acid (ABA) content, while GB reduced the starch content in the seeds by up-regulating the amylase gene expression. Gene expression analysis showed that the key genes (SlSOD, SlPOD, and SlchlAPX) involved in reactive oxygen species (ROS) scavenging systems were up-regulated in GB-pretreated tomato seeds compared with the control. At the same time, levels of malondialdehyde and hydrogen peroxide were significantly lower, while the proline content and peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) levels were elevated compared with those in the control. These results demonstrate that exogenous GB as a positive regulator effectively alleviated the inhibition of tomato seed germination under cold stress by different signal pathways.     

Fatty Acids of Microbial Origin in the Perirenal Fat of Rats (Rattus norvegicus domestica) and Guinea Pigs (Cavia porcellus) Fed Various Diets

Guinea pigs are assumed to practice caecotrophy to a higher degree than rats. Studies from leporids suggest that through the practice of caecotrophy, hindgut fermenting species could build up microbial fatty acids (FA) in body tissues. We hypothesized that microbial FA would be detectable in the body tissue of guinea pigs and rats, and this to a higher degree in guinea pigs. Twenty-four rats and guinea pigs were fed with four different pelleted diets (lucerne-, meat-, meat-bone-, insect-based) in groups of six animals for 8 weeks. Perirenal adipose tissue differed in FA composition between the species in spite of the common diets. FA typically associated with microbial activity (saturated FA (SFA; typically 18:0), monounsaturated FA (MUFA; typically trans-fatty acids TFA), and odd- and branched-chain FA (Iso-FA)), were all detected. Guinea pigs had higher SFA levels than rats except on the lucerne diet. Concentrations of 18:0 were higher for guinea pigs on the meat and bone diet. Iso-FA concentrations in guinea pigs exceeded those of rats on all diets. FA profiles with a microbial fingerprint appear—although in low proportions—in the body tissue of both species, and this seemingly to a higher extent in guinea pigs. With respect to whether consumption of rodent meat rich in microbial FA has particular effects on human health as shown for ruminant products, microbial FA concentrations are probably too low to cause any distinct effects.     

Sex and Depot Differences in Palmitoleic Acid Content of Human Blood and Fat

Palmitoleic acid has been classified as an insulin-sensitizing lipokine, but evidence for this from human studies has been inconsistent. We hypothesized that this is related to either the types of samples or conditions under which samples are collected. We measured plasma palmitoleic acid and total free fatty acids (FFA) using ultra-performance liquid chromatography in blood samples collected from 34 adults under a variety of conditions. We collected duplicate samples of adipose (n = 10), FFA (n = 9), and very low density lipoprotein triacylglycerol (VLDL-TAG) (n = 7) to measure the palmitoleic acid as a percentage of total fatty acids. We tested whether the percentage of palmitoleic acid was correlated with insulin resistance, as measured by homeostatic model of insulin resistance (HOMA-IR). Adipose stearoyl-coenzyme A desaturase 1 (SCD-1) protein was measured by capillary Western blotting. FFA-palmitoleic acid percentage increased as a function of total FFA and was greater (p < 0.005) in females than males. Adipose palmitoleic acid percentage was greater in females than males (p < 0.001), as was adipose SCD-1. Palmitoleic acid was greater in femoral fat than in abdominal fat in both females and males (p < 0.001), and correlated positively with HOMA-IR only in females. The test–retest reliability values for percentage palmitoleic acid were 7 ± 10% for adipose, 24 ± 26% for VLDL, and 53 ± 31% for FFA. Because FFA-palmitoleic acid percentage varies as a function of total FFA, investigators should re-evaluate how palmitoleic acid data is presented. The positive relationship between adipose palmitoleic acid and HOMA-IR in females suggests that it is not a potent insulin-sensitizing lipokine in humans.     

Exploring the Role of Skeletal Muscle in Insulin Resistance: Lessons from Cultured Cells to Animal Models

Skeletal muscle is essential to maintain vital functions such as movement, breathing, and thermogenesis, and it is now recognized as an endocrine organ. Muscles release factors named myokines, which can regulate several physiological processes. Moreover, skeletal muscle is particularly important in maintaining body homeostasis, since it is responsible for more than 75% of all insulin-mediated glucose disposal. Alterations of skeletal muscle differentiation and function, with subsequent dysfunctional expression and secretion of myokines, play a key role in the pathogenesis of obesity, type 2 diabetes, and other metabolic diseases, finally leading to cardiometabolic complications. Hence, a deeper understanding of the molecular mechanisms regulating skeletal muscle function related to energy metabolism is critical for novel strategies to treat and prevent insulin resistance and its cardiometabolic complications. This review will be focused on both cellular and animal models currently available for exploring skeletal muscle metabolism and endocrine function.     

Effect of PUFA at sn‐2 position in dietary triacylglycerols on the fatty acid composition of adipose tissues in non‐ruminant farm animals

The influence of the distribution of polyunsaturated fatty acids on the glycerol backbone of dietary triacylglycerols on the fatty acid profile of adipose tissue and muscle phospholipids was investigated in growing‐finishing pigs (48) and broiler chicken (84). The animals were fattened on barley/soybean meal diets supplemented with a blend of soybean oil and beef tallow, either in the ratio 3:1 w/w (high‐PUFA) or 1:3 w/w (low‐ PUFA). Part of the high‐ and low‐PUFA blends was chemically interesterified to randomly distribute all fatty acids over the three positions of the glycerol. Thus, two sets of diets of identical overall fatty acid composition, but differing in the distribution of fatty acids in the triacylglycerols, were fed. Growth performance and carcass composition were neither affected by fatty acid composition nor by randomisation of dietary fats in either animal species. Apparent digestibility of energy was slightly lower in pigs fed the low‐PUFA blends. Fatty acid profile of subcutaneous fat of pigs and broilers as well as of internal body fat (lamina subserosa) and muscle phospholipids of pigs varied according to the dietary fatty acid composition but was not affected by randomisation of dietary fats. These findings are explained in terms of the hydrolysis of TAG during transport of lipids from enterocytes to adipose tissue cells and the continuous lipolysis and re‐esterification of fatty acids that take place in adipose tissue cells.     

“Click Chemistry” for the Simple Determination of Fatty‐Acid Uptake and Degradation: Revising the Role of Fatty‐Acid Transporters

Fatty acids (FAs) have numerous functions in all living organisms, ranging from structural roles and energy production to the biosynthesis of secondary metabolites. Because of the high energy content of exogenous FAs, their acquisition is central of metabolism, and several biological systems are known, although their precise roles are not yet entirely clear. We investigated the roles of FadD (CoA ligase) and FadL (FA transporter) in different bacterial strains by using an improved version of click‐chemistry‐assisted labelling of azido‐FAs. The high sensitivity of this method allows a direct and precise assessment of FA metabolism, and is thus far better suited than growth experiments. Our results show that although FA activation is indeed essential for FA degradation, their transport can be independent of transporters like FadL.     

Assessment of the effects of sex and harvesting season on lipid and fatty acid composition of Sparidae species

In the present study, the lipid amount and fatty acid profile of different Sparidae species, including gilthead seabream, juvenile gilthead seabream, annular seabream, white seabream, common two-banded seabream were evaluated. Fish were seasonally collected from Köyceğiz Lagoon (Muğla, South Western Turkey) from June 2018 to June 2019 and after collection, the sex of each specimen was recorded. According to the results of the study, the highest lipid amount was found in female annular seabream individuals as 8.09 ± 0.78% in November and the lowest lipid amount was found in male juvenile gilthead seabream as 0.98 ± 0.12% in March. Palmitic acid and oleic acid were determined as the most abundant SFA and MUFA for all species, respectively. The highest value of DHA, which was the predominant PUFA was assessed as 15.33 ± 0.26% in female white seabream in November whereas the lowest value (3.83 ± 0.36%) was found in gilthead seabream in December. The n-6/n-3 ratio was determined between 0.27 ± 0.00 (for male common two-banded seabream in July)-1.20 ± 0.03 (for male gilthead seabream in December) and it followed within the range of healthy values for all species. As a conclusion, it was found that values of lipid and fatty acid profiles among the examined Sparidae species vary among the season of collection. The results of the study gave the seasonal nutritional values of four economically-important Sparidae species that being rich in healthy polyunsaturated fatty acids such as DHA, have beneficial in human nutrition.