Amino acids,fatty acids and sterols profile of some marine organisms from Portuguese waters

Marine organisms have been increasingly regarded as good sources of new drugs for human therapeutics and also as nutrients for human diet. The amino acids, fatty acids and sterols profiles of the widely consumed echinoderms Paracentrotus lividus Lamarck (sea urchin), Holothuria forskali Chiaje (sea cucumber), the gastropod molluscs Aplysia fasciata Poiret and Aplysia punctata Cuvier (sea hares), from Portuguese waters, were established by GC–MS analysis. Overall, 10 amino acids, 14 fatty acids and 4 sterols were determined. In general, all species presented the 10 amino acids identified, with the exceptions of H. forskali, in which no glycine, proline, trans-4-hydroxy-proline or phenylalanine were found, and of A. fasciata which did not contain proline. Unsaturated fatty acids were predominant compounds, with those from the ω-6 series, being in higher amounts than their ω-3 homologues, and cholesterol being the main sterol. The amino acids, fatty acids and sterols qualitative and quantitative composition of A. fasciata, A. punctata and H. forskali is reported here for the first time.     

Effect of cooking methods on fatty acids,conjugated isomers of linoleic acid and nutritional quality of beef intramuscular fat

The effect of boiling, microwaving and grilling on the composition and nutritional quality of beef intramuscular fat from cattle fed with two diets was investigated. Longissimus lumborum muscle from 15 Alentejano young bulls fed on concentrate or pasture was analyzed. Cooking losses and, consequently, total lipids, increased directly with the cooking time and internal temperature reached by meat (microwaving > boiling > grilling). The major changes in fatty acid composition, which implicated 16 out of 34 fatty acids, resulted in higher percentages in cooked beef of SFA and MUFA and lower proportions of PUFA, relative to raw meat, while conjugated linoleic acid (CLA) isomers revealed a great stability to thermal processes. Heating decreased the PUFA/SFA ratio of meat but did not change its n−6/n−3 index. Thermal procedures induced only slight oxidative changes in meat immediately after treatment but hardly affected the true retention values of its individual fatty acids (72–168%), including CLA isomers (81–128%).     

Effect of the feeding system on intramuscular fatty acids and conjugated linoleic acid isomers of beef cattle,with emphasis on their nutritional value and discriminatory ability

Thirty two Alentejano purebred bulls were used to investigate the effect of four feeding systems (pasture only, pasture feeding followed by 2 or 4 months of finishing on concentrate, and concentrate only) on meat fatty acid composition (GC-FID), including conjugated linoleic acid (CLA) isomeric distribution (Ag[+]–HPLC–DAD). In addition, meat fatty acids and CLA isomers were used to elucidate the impact of the different feeding regimens on the nutritional value of intramuscular fat and their usefulness as chemical discriminators of meat origin. The diet had a major impact on the fatty acid composition of beef (affected 27 of 36 fatty acids and 10 of 14 CLA isomers), which was independent of the fatty acid concentration. Beef fat from pasture-fed animals had a higher nutritional quality relative to that from concentrate-fed bulls. Finally, meat fatty acid composition was an effective parameter to discriminate between ruminant feeding systems, including different finishing periods on concentrate.     

Synthesis of cyclopropane fatty acids in Lactobacillus helveticus and Lactobacillus sanfranciscensis and their cellular fatty acids changes following short term acid and cold stresses

An implemented GC method to separate and quantify the cell cyclopropane fatty acids lactobacillic (C19cyc11) and dehydrosterculic (C19cyc9) was used to study the adaptive response to sublethal acid and cold stresses in Lactobacillus helveticus and Lactobacillus sanfranciscensis. The comparison of the composition of cellular fatty acids of the two strains and their changes after 2 h of stress exposure under micro-aerobic and anaerobic conditions indicated that the aerobic biosynthetic pathway for unsaturated fatty acids is prevalent in L. sanfranciscensis, while the anaerobic pathway is prevalent in L. helveticus. Indeed in the latter strain, in the presence of a source of oleic acid and under micro-aerobic conditions, C18:1n11 and its post-synthetic derivative C19cyc11 accounted for overall proportion ranging from 52 to 28% of the total FAs. On the other hand L. sanfranciscensis synthesizes by aerobic pathway C18:1n9 and transforms it to C19cyc9. However in this species the cumulative level of these two FAs did not exceed 30%. The relevant proportion of dodecanoic acid in the latter species suggests that carbon chain shortening is the principal strategy of L. sanfranciscensis to modulate fluidity or chemico-physical properties of the membranes.     

Purification and identification of bovine cheese whey fatty acids exhibiting in vitro antifungal activity

Milk lipids contain several bioactive factors exhibiting antimicrobial activity against bacteria, viruses, and fungi. In the present study, we demonstrate that free fatty acids (FFA) derived from the saponification of bovine whey cream lipids are active in vitro at inhibiting the germination of Candida albicans, a morphological transition associated with pathogenicity. This activity was found to be significantly increased when bovine FFA were enriched in non-straight-chain FFA. At low cell density, this non-straight-chain FFA-enriched fraction was also found to inhibit in a dose-dependant manner the growth of both developmental forms of C. albicans as well as the growth of Aspergillus fumigatus. Using an assay-guided fractionation, the main components responsible for these activities were isolated. On the basis of mass spectroscopic and gas chromatographic analysis, antifungal compounds were identified as capric acid (C10:0), lauroleic acid (C12:1), 11-methyldodecanoic acid (iso-C13:0), myristoleic acid (C14:1n-5), and γ-linolenic acid (C18:3n-6). The most potent compound was γ-linolenic acid, with minimal inhibitory concentration values of 5.4 mg/L for C. albicans and 1.3 mg/L for A. fumigatus, in standardized conditions. The results of this study indicate that bovine whey contains bioactive fatty acids exhibiting antifungal activity in vitro against 2 important human fungal pathogens.     

Factors influencing proportion and composition of CLA in beef

Bovine meat is criticised for the bad nutritional image of its lipids and fatty acids. However, with dairy products, beef is the major source of conjugated linoleic acid (CLA) which could have several human health benefits. The present study compared, from data of five nutritional experiments on bovine animals performed by the laboratory, the impact of factors linked to the animals (breed, age, sex, type of muscle) and to feeding conditions (basal diet, lipid supplements) on the CLA proportion and composition in muscles. Among these factors, linseed supplementation was an efficient way to increase CLA proportion in beef (+22% to +36%) but was highly modulated by the nature of the basal diet, and by intrinsic factors (breed, age/sex, type of muscle) since these ones could modulate CLA proportion in beef from 24% to 47%. Moreover, these factors modified also the proportion of cis,trans-CLA, related to cis,cis- and trans,trans-isomers. Specific biological properties of these latter isomers should be determine to understand the consequences of intramuscular CLA isomer variations for the health of consumers.     

Biohydrogenation, duodenal flow, and intestinal digestibility of trans fatty acids and conjugated linoleic acids in response to dietary forage:concentrate ratio and linseed oil in dairy cows

Duodenal flows of hydrogenation intermediates in response to changes in dietary forage:concentrate ratio (F:C) and linseed oil were evaluated using 4 lactating Holstein cows fed a low (65:35 forage to concentrate) or high (35:65) concentrate diet without (LC, HC) added oil or with linseed oil (LCO, HCO) at 3% of DM. A 4 x 4 Latin square design was implemented for 5 wk. Lower hydrogenation of 18:2n-6 and 18:3n-3 was observed with HC, but it increased with LCO or HCO. Duodenal flow of total conjugated linoleic acids (CLA) increased by 1.40 (LCO) to 3.01 (HCO) g/d with linseed oil. This response was associated with greater flows of cis9,trans11- (+0.21 to +0.55 g/d), trans11,cis13- (+0.33 to +0.36), trans11,trans13- (+1.01 to +1.15 g/d), and trans,trans-CLA (+0.12 to +0.72 g/d). Trans10,cis12-CLA flow averaged 0.08 g/d and was not affected by F:C or oil. trans11,cis15-18:2 flow increased by 8.5 (LCO) to 62 (HCO) g/d in response to linseed oil. Total trans-18:1 flow was 37 g/d in cows fed LC and increased to 81 g/d with HC. Feeding oil increased total trans-18:1 to the greatest extent with HCO. Flow of trans10-18:1 was lower with LC than with HC (1.46 vs. 20 g/d). Linseed oil increased trans11-18:1 flow by 40 (LCO) to 113 g/d (HCO). Feeding LCO and HCO also increased flows of trans6+7+8-, trans13+14-, trans15-, and trans16-18:1. Apparent intestinal digestibility of trans-18:1 isomers was largely unaffected by concentrate level and ranged between 67 and 95%. Linseed oil increased digestibility of nearly all isomers by 3 to 16 percentage units. Digestibility of cis9,trans11-CLA was greater in cows fed HC (55%) compared with cows fed LC (32%) and was not affected by linseed oil. Data suggest that high concentrate diets enhanced ruminal outflow of trans10-18:1. We provide initial in vivo evidence that supplemental 18:3n-3 is hydrogenated to trans11,cis15-18:2, trans11-18:1, trans13+14-18:1, trans15-18:1, trans6+7+8-18:1, and trans16-18:1 primarily.     

Changes in milk fat in response to dietary supplementation with calcium salts of trans-18:1 or conjugated linoleic fatty acids in lactating dairy cows

Milk fat was investigated in lactating dairy cows fed diets supplemented with Ca salts of trans fatty acids (Ca-tFA) or Ca salts of conjugated linoleic acids (Ca-CLA). Forty-five Holstein cows (115 days in milk) were fed a control diet (51% forage; dry matter basis) supplemented with 400 g of EnerG II (Ca salts of palm oil fatty acids) for 2 wk; subsequently, 5 groups of 9 cows each were assigned for 4 wk to the control diet or diets containing 100 g of Ca-CLA or 100, 200, or 400 g of Ca-tFA in a randomized block design. Treatments had no effect on dry matter intake, milk production, protein, lactose, or somatic cell count. Milk fat percentage was reduced from 3.39% in controls to 3.30, 3.04, and 2.98%, respectively, by the Ca-tFA diets and to 2.54% by the Ca-CLA diet. Milk fat yield (1.24 kg/d in controls) was decreased by 60, 130, and 190 g/d with increasing dose of Ca-tFA and by 290 g/d with the Ca-CLA supplement. Consistent with increased endogenous synthesis of cis-9-containing CLA from precursors provided by the Ca-tFA diets, total CLA were similar in milk of cows fed Ca-CLA or Ca-tFA. Compared with controls, the Ca-CLA diet increased trans-10, cis-12-18:2 yield in milk, without altering levels of trans-18:1 isomers. In contrast, yields of most trans-18:1 isomers were elevated in milk of cows fed Ca-tFA diets, whereas yields of trans-10, cis-12-18:2 remained similar to control values. We conclude that milk fat depression can occur without an increase in trans-10, cis-12-18:2 in milk and that other components, perhaps the trans-10-18:1 isomer, may be involved.     

储藏条件对花生的氨基酸和脂肪酸组成及风味的变化影响

花生在储藏过程中易走油霉变,分析花生在贮藏过程中的氨基酸和脂肪酸含量变化是研究花生品质的重要内容。将花生在低温常湿、常温低湿和常温常湿环境下储藏12个月,利用高效液相色谱和气相质谱联用仪测定不同储藏条件下花生的氨基酸与脂肪酸随储藏时间的变化情况,结合电子鼻和傅里叶变换红外吸收光谱对花生品质进行分析。研究结果显示:低温冷藏环境下花生中氨基酸总量由233.42 mg/g降至215.41 mg/g,常温常湿的条件下降至197.85 mg/g;脂肪酸变化最明显的是油酸和亚油酸的含量,低温冷藏12个月后O/L值从0.94上升至0.96,而常温低湿条件下达到1.54,亚油酸遭到严重破坏;红外谱图中蛋白质和脂肪酸的特征峰1653 cm^-1和1744 cm^-1均减弱,常温常湿条件下最明显。低温冷藏是最佳贮藏条件。      

Comparison of free amino acid,carbohydrates concentrations in Korean edible and medicinal mushrooms

Ten popular species of both edible and medicinal Korean mushrooms were analysed for their free amino acids and disaccharides. The average total free amino acid concentration was 120.79 mg g⁻¹ in edible mushrooms and 61.47 mg g⁻¹ in medicinal mushrooms, respectively. The average total of free amino acids for all mushrooms, edible mushrooms and medicinal mushrooms was 91.13 mg g⁻¹. Agaricus blazei (227.00 mg g⁻¹) showed the highest concentration of total free amino acids; on the other hand, Inonotus obliquus (2.00 mg g⁻¹) showed the lowest concentration among the 10 species of mushrooms. The average total carbohydrates concentration was 46.67 mg g⁻¹ in the 10 species of mushrooms, where the edible mushrooms contained 66.68 mg g⁻¹ and the medicinal mushrooms contained 26.65 mg g⁻¹. The carbohydrates constituents of the 10 mushroom species were mainly mannose (36.23%), glucose (34.70%), and xylose (16.83%).     

Characterization of wax esters,free fatty alcohols and free fatty acids of crude wax from sunflower seed oil refineries

The sunflower seed wax (10–12%) from oil refineries was purified through two steps, namely, extraction using solvents and precipitation with chilled acetone. Fatty esters, free fatty alcohols and free fatty acids were separated by thin-layer chromatography (TLC). The fractions of fatty esters and free fatty alcohols were separated and identified by gas chromatography (GC) using a Dexil-300 column and OV-101 column, respectively, at temperatures from 150–290 °C and were further confirmed by Gas chromatography–mass spectrometry (GC–MS), using a capillary silica column SPB™-1 coated with polydimethyl siloxane. Among the long chain fatty esters (C₃₈–C₅₄), comprised of one unit of fatty alcohol and one unit of fatty acid through an ester linkage, the major esters were C₄₀–C_44, of which C₄₂ was predominant. These fatty esters, upon hydrolysis, followed by methylation and subsequent GC–MS analysis, showed the presence of C₁₆–C₃₀ fatty acids in the bound form, whereas methylation of native wax indicated the presence of C₁₈–C₃₀ fatty acids in the free form. Acetylation of hydrolysis product showed the presence of C₁₈–C₃₀ fatty alcohols in the bound form, where as acetylation of native wax indicated that the C₁₈–C₃₂ fatty alcohols were in the free form. n-Triacontanol (C₃₀), a plant growth regulator, was found in both free and bound forms.     

Trans fatty acids in a range of UK processed foods

A survey to determine the trans fatty acid content of a range of processed foods was carried out in response to recent reformulation work by the food industry to lower the artificial trans fatty acid content of processed products. Sixty two composite samples, made up of between 5 and 12 sub-samples, were collected in 2010 and were analysed for fatty acids, and a range of nutrients. The foods analysed included pizza, garlic bread, breakfast cereals, quiche, fat spreads, a range of fish and meat products, chips, savoury snacks, confectionery and ice cream. Levels of trans fatty acids were reduced considerably compared with previous UK analyses of similar foods where comparisons are possible. Concentrations of trans elaidic acid (t9-C18:1) from hydrogenated oils in all samples were <0.2 g/100 g food. These results confirm information provided by the food industry in 2007 on the levels of trans fats in key processed food sectors.     

Muscle lipids and fatty acid profiles of three edible fish from the Mauritanian coast: Epinephelus aeneus, Cephalopholis taeniops and Serranus scriba

Muscle lipids and fatty acids (FA) of three largely consumed seawater species of Serranidae (Epinephelus aeneus, Cephalopholis taeniops, and Serranus scriba) from the Mauritanian coast, were determined through 1 year. The lipid contents were relatively poor, ranging from 0.8% to 2.3% showing a significant seasonal dependency. Amongst the 35 FA identified, 35–51% were saturated FA (SFA), 21–33% monounsaturated FA (MUFA), and 18–34% polyunsaturated FA (PUFA). Palmitic acid was found to be the main SFA, and was seasonal dependent, with a mean value of 30.5% for E. aeneus, 27.9% for C. taeniops, and 20.9% for S. scriba. Amongst MUFA, oleic acid, with 11–16%, was the main acid in all three species. The n6 PUFA level was low, in particular for C. taeniops (1.3–1.6%), and a little higher for S. scriba (3.6–4.2%). The three species were characterised by high amounts of n3 PUFA. Amongst them, docosa-4,7,10,13,16,19-hexaenoic acid (DHA, 22:6n3) was the highest with 5–9% for C. taeniops, 13–17% for S. scriba, and 10–16% for E. aeneus. Eicosa-5,8,11,14,17-pentaenoic acid (EPA, 20:5n3), was the second highest n3 PUFA, with 4–13%.     

Stability of fatty acid composition after thermal,high pressure,and microwave processing of cow milk as affected by polyunsaturated fatty acid concentration

Interest has been increasing to enhance the contents of healthy polyunsaturated fatty acid (PUFA) in milk. However, trans fatty acids and conjugated linoleic acid (CLA) can be altered after thermal processing and high pressures disrupt the milk fat globule membrane, exposing the lipid core and helping its oxidation. The objective of the present research was to study whether processing can alter the fatty acid composition of milk and if these changes are affected by PUFA concentration as previous studies suggest. Two cow milk batches (500 L each), one naturally enriched in PUFA, were processed to obtain pasteurized; high temperature, short time; UHT; high pressure; and microwave pasteurized samples. The detailed fatty acid composition was analyzed with special attention to trans fatty acids and CLA isomers. Results showed that after high temperature, short time processing, total CLA content increased in both milk batches, whereas sterilization resulted in a sigmatropic rearrangement of C18:2 cis-9,trans-11 to C18:2 trans-9,trans-11. The extent of these effects was greater in milks naturally enriched in PUFA.     

A marine unicellular alga in diets of pregnant and lactating rats as a source of ω3 fatty acids for the developing brain of their progeny

The period of brain development in rats occurs during the late pregnancy and early lactation periods. During that time a large quantity of omega-3 (ω3) long-chain polyunsaturated fatty acids, mostly decosahexaenoic acid, is deposited in the brain lipids of the developing and growing pup. A dietary source of ω3 fatty acid should be provided during this period to the dams' diet to assure sufficient of ω3 fatty acids to the developing progeny. Although a wide variety of lipids from plants and marine animals was examined in this respect, we provide herein for the first time, experimental data that indicate that the marine unicellular alga Nannochloropsis can be efficiently used as a dietary source of the ω3 fatty acid eicosapentaenoic acid for pregnant and lactating dams. Furthermore, the dietary ω3 lipids of the alga are efficiently transferred to the developing foetus and pups to support the requirements for normal brain development.     

Organic acids,antioxidant capacity,phenolic content and lipid characterisation of Georgia-grown underutilized fruit crops

Four underutilized Georgia-grown fruit crops, namely loquat (Eriobotrya japonica), mayhaw (Crataegus sp.), fig (Ficus carica), and pawpaw (Asimina triloba), and their leaves were analysed for total polyphenols by Folin–Ciocalteau method, and antioxidant capacity by ferric-reducing antioxidant power (FRAP) and Trolox-equivalent antioxidant capacity (TEAC) assays. Organic acids and phenolic compounds were identified by RP-HPLC. For lipid profile, fruits were separated into two fractions – seed and fruit (i.e., without seed); lipid was extracted using the Folch method and analysed for fatty acids, phytosterols, tocopherols, and phospholipids. The major organic acid identified in all samples was malic acid (177–1918 mg/100 g FW). The predominant phenolic acids in all the fruits were gallic (1.5–6.4 mg/100 g FW) and ellagic (0.2–33.8 mg/100 g FW), and the most abundant flavonoid was catechin (12.2–37.8 mg/100 g FW). Total lipid content varied from 0.1% in mayhaw fruit to 21.5% in pawpaw seed. Linoleic acid was the predominant fatty acid in all of the samples (28.2–55.7%).     

Effects of feeding flaxseed or sunflower-seed in high-forage diets on beef production,quality and fatty acid composition

Yearling steers were fed 70:30 forage:concentrate diets for 205 d, with either grass hay (GH) or red clover silage (RC) as the forage source, and concentrates containing either sunflower-seed (SS) or flaxseed (FS), each providing 5.4% oil to diets. Feeding diets containing SS versus FS significantly improved growth and carcass attributes (P < 0.05), significantly reduced meat off-flavor intensity (P < 0.05), and significantly increased intramuscular proportions of vaccenic (t11-18:1), rumenic (c9,t11-CLA) and n − 6 fatty acids (FA, P < 0.05). Feeding diets containing FS versus SS produced significantly darker and redder meat with greater proportions of atypical dienes (P < 0.05). A significant forage × oilseed type interaction (P < 0.05) was found for n − 3 FA, α-linolenic acid, and conjugated linolenic acid, with their greatest intramuscular proportions found when feeding the RC-FS diet. Feeding GH versus RC also significantly improved growth and carcass attributes, sensory tenderness (P < 0.05) and significantly influenced intramuscular FA composition (P < 0.05), but overall, forage effects on FA profiles were limited compared to effects of oilseed.     

Seasonal changes and muscle type effect on the nutritional quality of intramuscular fat in Mirandesa-PDO veal

The influence of slaughter season and muscle type on the detailed fatty acid composition, including conjugated linoleic acid isomers, and contents of total cholesterol and lipid-soluble antioxidant vitamins (α-tocopherol and β-carotene) in Mirandesa-PDO veal was assessed. Mirandesa purebred calves (n = 29) were raised in a traditional production semi-extensive system, slaughtered in late spring (June) or early autumn (October) and the longissimus lumborum and semitendinosus muscles were sampled for analysis. Although the lipid composition of PDO veal was only slightly affected by the slaughter season, it was markedly changed by the muscle type. However, PDO veal had values of pasture-fed cattle for lipid grass intake indicators, in both seasons and muscles. From a human health standpoint, intramuscular fat in Mirandesa-PDO veal has a high nutritional value throughout the year, with favorable ratios of n− 6/n− 3 and contents of n− 3 PUFA and α-tocopherol, as a result of the beneficial effects of grass feeding.