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The present study was accomplished to evaluate the intramuscular fatty acid (FA) composition of different muscles taken from Kundi steers (n = 15), which were approximately 24 months old, fed on a cottonseed cake supplement, and were made to graze on alfalfa pasture for 95 days prior to slaughter. The samples were taken from longissimus dorsi region (loin and ribeye portion) and distal region of semitendinosus muscle for intramuscular FA analysis. Saturated FA, comprising 49.48–52.09% of total FA composition, in all the muscles were studied. Ribeye portion of longissimus dorsi muscle contain relatively higher (P > 0.05) amount of trans FA (3.37%) as compared with loin portion of longissimus dorsi muscle (3.1%) and distal region of semitendinosus muscle (2.84%). The sum of monounsaturated FA in all the muscles studied was estimated in the range of 32.21–34.64%, while polyunsaturated FA contribute 11.39–12.39% of total FA. The mean conjugated linoleic acid was found to be 0.28, 0.35 and 0.41 in ribeye and loin portion of longissimus dorsi muscle and distal region of semitendinosus muscle, respectively.  相似文献   

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The ratio of n‐6 over n‐3 fatty acids (FA) in the Western diet is today on average between 10 and 15, while evidence suggests that humans would benefit substantially from a more balanced intake. Different strategies to reverse this trend can potentially be adopted. This paper explores the effect of n‐3 enrichment at the level of primary animal production on human FA intake. Consumption data from adolescents were linked to ‘currently available’ and to simulated ‘enriched’ FA profiles of foods from animal origin (by feeding α‐linolenic‐rich diets to pigs, dairy and beef cattle, and broiler and layer chickens). Under enriched conditions, population intakes for α‐linolenic acid and for all n‐3 FA shifted to recommended values. For long‐chain n‐3 polyunsaturated FA, the favourable trend in intake was not sufficient to meet recommendations. The effect on other FA was small. The n‐6/n‐3 ratio decreased considerably from an average value of 6.6 to 4.6. It is concluded that feasible and realistic n‐3 FA enrichments of foods from animal origin can add substantially to the overall efforts for reducing the n‐6/n‐3 intake ratio in the population. However, foods rich in long‐chain n‐3 FA remain essential in the human diet under such conditions. Copyright © 2006 Society of Chemical Industry  相似文献   

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Physicochemical properties and fatty acid profiles of meat from Bos indicus, Bos taurus and crossbred B. taurus × B. indicus bullocks (n = 216), finished on pasture or grain, were used to estimate the effects of heterosis. Meat quality and fatty acid profiles generally benefited with crossbreeding, but the advantages from heterosis differed among finishing systems. The Warner–Bratzler shear-force in fresh and aged meat was reduced due to heterosis in pasture-finishing, but the effect was minor under grain-finishing. With pasture-finishing, heterosis caused an increase of 5% in CLA concentration, but few other changes in fatty acid profiles. In grain-finishing, heterosis caused a reduction in intramuscular fat and cholesterol, increased amounts of PUFA, n− 6 fatty acids and PUFA/SFA ratio, and a decline in atherogenic index. The Δ9 desaturase estimated activity in crossbreds showed a behavior close to B. indicus, suggesting the existence of few loci and a dominance genetic effect on enzymes involved in fatty acid synthesis and metabolism.  相似文献   

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Seven sample lots of farmed Piaractus mesopotamicus , fed a set diet, collected at different times during the year were analysed. The total lipids (11 ± 3% fresh weight, muscle) consisted of 94% neutral lipids and 5% phospholipids. Sixty-seven fatty acids and dimethylacetals were detected in the total lipids, the principal acids being 18:1ω9±ω7 (41.0 ± 1.7%), 16:0 (24.2 ± 1.2%), 18.2ω6 (9.1 ω 0.5%), 16:1ω7 (8.9 ± 0.7%), 18:0 (7.7 ± 0.5%) and 14:0 (3.2 ± 0.5%). The neutral lipids exhibited a similar profile. The phospholipids had a higher proportion of polyunsaturated fatty acids, the major components being 18:1ω6 (9.1 ± 0.7%) (17.5 ± 1.8%), 16:0 (16.7 ± 2.0%), 20:4ω6 (11.6 ± 1.3%), 22:6ω3 (11.0 ± 1.3%), 18:2ω6 (9.1 ± 0.7%), 18:0 (8.9 ± 1.1%), 22:5ω (5.8 ± 0.7%). No definite trend was seen in relation to season (water temperature, 7–26°C). The fish samples analysed were poor in ω3 fatty acids, which appeared to reflect the low ω3 fatty acid content of the diet.  相似文献   

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The fatty acid composition of the seed oils of six pomegranate (Punica granatum L) cultivars was qualitatively and quantitatively determined by gas chromatography. The seeds contained oil in the range 51-152 mg kg?1 dry matter. Intervarietal differences in fatty acid composition were demonstrated (fatty acid esters as % (w/w) total fatty acid esters. Sour varieties had the highest while sour-sweet varieties had the lowest oil content. Eleven fatty acids were identified. In all varieties, the predominant fatty acids were linoleic (25.2-38.6%) and oleic acid (24.8-35.5%) followed by palmitic (18.2-22.6%), stearic (6.9-10.4%) and linolenic acid (0.6-9.9%). To a lesser extent arachidic (1.1-3.4%) and palmitoleic acid (0.2-2.7%) were also found in all varieties. Lauric, myristic, behenic and lignoceric acids were rarely detected. As far as we know linolenic (18:3), arachidic (20:0), behenic (22:0) or lignoceric (24:0) acids have not been previously reported in the seed oils of edible pomegranate varieties. Lignoceric acid has not previously been found in pomegranate seed oil.  相似文献   

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In this study, seasonal variations on total fatty acid composition of carp, Cyprinus carpio, and zander, Sander lucioperca, muscle lipids in Altinapa Dam Lake were determined. Fish samples in 2 seasons (summer and winter) were obtained from Altinapa Dam Lake in Konya, Turkey. Polyunsaturated fatty acids were found to be higher during the cold season than in the hot both in zander and carp. Whereas the Docosahexaenoic acid was high in zander both in summer and winter, in carp it was high only during wintertime. Zander contained more n-3 fatty acids during the cold season compared to carp. Especially, the n-3:n-6 ratios in zander were 3.89 and 3.84 in summer and winter, respectively. In conclusion, seasonal variations affected fatty acid composition of zander and carp in Altinapa Dam Lake.  相似文献   

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Chemical and mineral composition and the intramuscular fatty acid (IMF) profile of the Longissimus dorsi muscle (LM) of 60 purebred Hereford, 1/4 Braford and 3/8 Braford steers finished either in a feedlot or on improved pastures of the Pampa biome were evaluated. Pastures were improved with the introduction of Lolium multiflorum, Trifolium repens, and Lotus corniculatus. On average, beef from pasture-fed steers presented higher concentrations of the fatty acids C18:3n − 3 (P < 0.001), C20:3n − 3 (P = 0.035), total n − 3 (P < 0.001) and lower n − 6/n − 3 ratio (P < 0.001) in the IMF, and higher Mg and lower K content in muscle relative to those finished in the feedlot. C12:0 concentration in IMF was higher (P = 0.027) for 3/8 Braford than the purebred Hereford steers, whereas purebred Herefords presented lower C14:1 (P = 0.003) and higher C18:0 (P = 0.022) concentrations than the two Braford groups. The meat composition of purebred Hereford and Braford steers was not substantially different; however, beef produced exclusively on improved pastures presented higher concentration of components that are considered beneficial to human health, such as n − 3 fatty acids, and a lower n − 6/n − 3 ratio.  相似文献   

9.
Fresh eggs from hens fed diets supplemented with 4% linseed oil (LO) or sunflower oil (SO) were either directly submitted to pasteurisation, hard‐boiling or scrambling processing, or first submitted to refrigerated storage at 4 °C for 60 day and then to processing. Fresh LO eggs showed higher (P ≤ 0.05) proportions of monounsaturated fatty acids (MUFAs) and n‐3 polyunsaturated fatty acids (PUFAs), but lower (P ≤ 0.05) proportions of saturated fatty acids (SFAs), PUFAs and n‐6 PUFAs than the SO eggs. Storage decreased (P ≤ 0.05) the proportion of PUFAs and increased (P ≤ 0.05) that of MUFAs in egg yolks from both treatments. The pasteurisation process had no effect on the fatty acid composition of fresh eggs from both treatments, but increased (P ≤ 0.05) n‐6 PUFAs and decreased (P ≤ 0.05) n‐3 PUFAs in stored LO eggs. Hard‐boiling and scrambling modified the fatty acid composition of fresh and stored eggs from both treatments by decreasing (P ≤ 0.05) the proportion of PUFAs, particularly of the very long‐chain n‐3 eicosapentaenoic, docosapentaenoic and docosahexaenoic PUFAs. LO eggs showed a higher susceptibility to fatty acid modification upon processing as compared to the SO eggs.  相似文献   

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Proximate and fatty acid compositions and sensory acceptability of rib‐eye steaks (fresh and 6 months frozen‐stored) from three forage‐finished steers [S1 (bermudagrass + ryegrass, etc.); S2 (bermudagrass + ryegrass + berseem, etc.); S3 (bermudagrass+berseem+soybean+brown midrib sorghum, etc.)] and one commercial steak (C), cooked by one‐sided and/or two‐sided grilling, were evaluated. All forage‐finished steaks had lower [omega‐6/omega‐3] ratios than C. Sensory liking was assessed by Hispanic consumers. Raw C steak had higher fat and lower protein contents than others (S1, S2 and S3). Concerning raw steaks, S3 had higher liking scores for overall appearance and fat appearance than others. Two cooking methods did not cause significant differences in sensory liking. Juiciness and overall liking of cooked C and S3 (one‐sided grilling) steaks were not significantly different. Purchase intent (after knowing health benefits of forage‐finished steaks) increased from 62.0–73.8% to 69.8–85.7%. Forage‐finished steaks showed a potentially healthier lipid profile than grain‐finished steaks and had market potential towards Hispanic population.  相似文献   

12.
Quality aspects of marinated fish were examined over a 120 day period. Nutritional quality parameters (proximate composition, fatty acid profile and amino acid profile) were determined. Changes in amino acids and fatty acids were examined in the muscle of marinated fish during storage. Aspartic acid, threonine, proline, glycine, tyrosine and lysine concentrations in marinated anchovy and rainbow trout greatly influenced their quality. Polyunsaturated fatty acid concentrations decreased significantly (p < 0.05) in marinated anchovy but not (p > 0.05) in marinated rainbow trout, while total saturated fatty acid concentrations increased significantly (p < 0.05) in both marinated fish during storage. These changes in fatty acid and amino acid concentrations were found to be useful as an index of freshness and decomposition of marinated fish in storage. Copyright © 2005 Society of Chemical Industry  相似文献   

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This study compared carcass, meat quality and fatty acid profiles of longissimus thoracis (LT) from feedlot cattle fed barley grain with or without oilseed (OS). Six diets containing no oilseed (No-OS), 10% ground flaxseed (FS), 10% high oleate sunflower seeds (SS) with or without 30% triticale dried distiller's grain (DDGS) were prepared. Feeding DDGS increased chroma at 24 and 144 h post mortem. Feeding FS increased weight% of LT PUFA (P < 0.05) compared to No-OS or SS. An OS by DDGS interaction occurred for 18:3n − 3 (P < 0.05) where FS increased weight% of 18:3n − 3 (P < 0.05), a response accentuated (P < 0.05) by DDGS. Feeding DDGS increased weight% of LT 18:2n − 6 (P < 0.05), but neither OS nor DDGS affected conjugated linoleic acid (CLA, t7,c9 & c9,t11-18:2). Feeding FS increased weight% of n − 3 FA, and both FS and SS increased t10-18:1 with no effect on CLA or t11-18:1. Combination feeding of DDGS and FS further increased weight% of n − 3 FA and tempered increases in t10-18:1 with no effect on CLA or t11-18:1. The findings suggest a new strategy to increase beef omega-3 fatty acids efficiently through inclusion of a combination of DDGS and FS in feedlot diet.  相似文献   

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BACKGROUND: Two experiments were conducted to compare the effects of white and red clover on the fatty acid composition of milk fat from cows fed ryegrass‐based diets. In experiment 1, fresh ryegrass was mixed with white or red clover (60/40, on a dry matter (DM) basis). Experiment 2 involved similar mixed diets in ensiled form, and one ryegrass‐silage diet without the addition of clover. RESULTS: Total DM intake, milk yield and milk fat content were not affected by dietary treatments. Feeding freshly cut white versus red clover supplemented diets resulted in a higher proportion of n‐3 fatty acids, especially α‐linolenic acid, in milk fat. Addition of any clover silage to ryegrass silage increased the proportions of n‐3 fatty acids in milk fat, and reduced the proportions of conjugated linoleic acids (CLA), including C18:2 c9t11, and C18:1cis isomers. The n‐6/n‐3 ratio was elevated compared to the diet not supplemented with clover. CONCLUSION: White clover seemed to be slightly superior to red clover supplementation, but the effects of clover supplementation as such were generally larger than that of clover type. However, a higher concentration of n‐3 fatty acids with clover supplementation coincided with a lower concentration of CLA in the milk fat. Copyright © 2007 Society of Chemical Industry  相似文献   

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Conjugated linoleic acid (c9, t11 CLA) is a dietary fatty acid produced mainly by ruminant animals and exhibits promising health‐promoting biological effects. For lipid fatty acid composition analyses, including CLA, lipids must be pre‐treated so that the free and esterified fatty acids (triacylglycerols, phospholipids, etc) are available for determination. The most common treatments involve fatty acid methyl ester derivatives from relatively simple chemical reactions, but this becomes complicated when esterification of CLA is involved because of potential changes in its positional and geometrical isomers by reaction with certain reagents. In this review we explain concisely the advantages and disadvantages of the most popular methods (acid‐ and base‐catalysed methods) generally employed for total fatty acid derivatization and their determination on a gas chromatograph. Based on our experiences we put forward the (trimethylsilyl)diazomethane method as an alternative and successful approach for ruminant tissue lipid determinations. Copyright © 2005 Society of Chemical Industry  相似文献   

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The very long chain polyunsaturated fatty acids (PUFAs) (C18–C22) and n‐3 Omega PUFAs are apparently widely accepted as a part of modern nutrition because of their beneficial effects on metabolism. Most significantly, the reported protective effect of the n‐3 omega fatty acids in relation to cardiovascular inflammatory diseases and cancer has led people to consider these fatty acids more beneficial than other dietary supplements. Unfortunately, there is a lack of studies relating to the physical performance increasing effect in sports diets, cholesterol‐reducing effect in meat technology, effects on human serum profile, the application dose and the side effects with/without omega‐6 PUFAs, which has left us with several crucial unanswered questions. We still do not know the correct dose of n‐3 omega and the correct ratio of n‐3 omega to n‐6 omega or their possible contraindications when combined with drugs, other foods and herbal supplements. Another reported aspect of n‐3 omega PUFAs is that they protect and even enhance the effect in medical treatment of important diseases such as Alzheimer’s, multiple sclerosis and cancer. These reports led to PUFAs becoming one of the most accepted and consumed food supplements. Despite this weight of evidence and the considerable current use, there is still a need for studies, which will determine whether the n‐3 omega fatty acids are in fact important functional supplements with no adverse effects. This review will attempt to outline the current position of n‐3 omega fatty acids in the field of clinical nutrition and healthcare and outline the studies needed to determine whether there are significant advantages in taking them as food supplement without any adverse effects.  相似文献   

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The free fatty acid (FFA) effect on the oxidative stability of marine lipids was studied by fluorescence assessment. Under different reaction conditions, including time, temperature and FFA content and type (different chain lengths and unsaturation degrees), FFAs were made to interact in model systems with a commercial marine oil (cod liver oil) and two different fish (hake and pout) white muscles. Fluorescence assessment showed a pro‐oxidant effect of all types of FFA, which increased with time, temperature and FFA content in the reaction mixtures. At 30 °C a higher degree of oxidation was obtained in systems including the shorter‐chain‐length fatty acids (lauric and myristic) compared to systems including the longest ones (arachidic and stearic). At the same temperature an increasing pro‐oxidant effect was also observed with increasing degree of fatty acid unsaturation (stearic < oleic < linoleic < linolenic). When a lower temperature (−10 °C) was tested, a differential pro‐oxidant effect among fatty acids (chain length and unsaturation degree) was not observed. © 2001 Society of Chemical Industry  相似文献   

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