Lipid and fatty acid composition of rabbit meat: Part 2.-Phospholipids

The phospholipid contents (and their fatty acid composition) of the meat of two rabbit breeds (New Zealand white and the commercial hybrid HYLA) fed with two commercial diets of different protein and fibre contents, have been determined. The phospholipid contents in the meat of both rabbit breeds ranged from 9% to 19% total lipid. In this fraction seven different phospholipid classes were detected but phosphatidylcholine (PC) and phosphatididylethanolamine (PE) had average percentages of 50 and 20 of the total phospholipids. The major fatty acids of both phosphatidylcholine and phosphatidylethanolamine were C-16:0, C-18:0, C-18:1 and C-18:2, these together representing more than 70% of the total fatty acids. In general, the PC had an higher saturated fatty acid content than PE, which had a lower percentage of C-16:0 but higher C-20:4. Although differences in the fatty acid composition of the phospholipid fractions of the rabbit meat were observed, the only clear influences of age, sex, breed, and/or feeding were found with the C-16:0, C-18:0 and C-18:2 fatty acids.     

Seasonal variations in lipid composition of spanish wild rabbit (Oryctolagus cuniculus) meat

Four batches of wild rabbit (Oryctolagus cuniculus: winter, spring, summer and autumn) were caught at the end of the respective season of the year. A study of the meat chemical composition of these animals was carried out. The classes and amounts of total, apolar and polar lipid fractions, and their fatty acids, have been extensively studied. The total, apolar and polar lipid contents from the muscle of the four batches ranged from 37 to 14, 30-1 to 8–4 and 9–0 to 4–8 g kg^?1 FW respectively. Triglycerides accounted for more than 59% of the apolar lipids, and phosphatidylcholine and phosphatidyl-ethanolamine were the major phospholipids (>44% and >35% of total phospholipids, respectively). Almost always, 16:0, 18:0, 18:1 and 18:2 were the more abundant fatty acids of the total lipid fraction. Many seasonal differences may be observed in the fatty acid composition of total and apolar lipid fractions which are obviously related to the kinds of feed available in each season. One of the most significant differences is in 18:1 concentration. This fatty acid accounted for more than 50% in the apolar lipids from rabbits caught in autumn whereas the same fatty acid never reached 30% in other seasons. On the contrary, 18:2 and 20:0 showed a lower concentration in the autumn batch by comparison with those of the other seasons.     

Effect of fat-enriched diets on rabbit meat fatty acid composition

The effects of beef tallow-, soya and sunflower olein- and soya bean oil-enriched (3%) diets on the chemical and fatty acid composition of total, a polar and polar lipids of rabbit meat have been studied. No significant differences (P > 0.05) in the meat chemical composition were observed between groups. However, a large effect of the diet on the total and apolar lipid fatty acids was found, with C18:1 and C18:2 the most affected fatty acids. The influence of the diets on the fatty acids of the polar fraction was less marked. It is concluded that the enrichment of the rabbit diet with either soya and sunflower oleins or soya bean oil allows the production of rabbit meat with a higher unsaturation degree than is obtained by using conventional diets, which constitutes an important nutritional benefit to the human being.     

Changes in fatty acids of frog legs during frozen storage

The changes in the fatty acids of frog leg meat during frozen storage were studied with column and gas-liquid chromatography. The major component of the lipids, the phospholipids constituted 90% of total lipids. 16:0, 18:0, 22:0 and 18:2 polyunsaturated fatty acid were the major fatty acids of the frog legs meat lipids. Short chain fatty acids were noticed to the extent of 10%. During frozen storage the proportion of phospholipids decreased, while that of neutral lipids increased. Since the total lipid content was constant, phospholipases were presumably responsible for this change. Alterations in the fatty acid composition of the neutral lipids during storage were consistent with such a hypothesis.     

Effects of different levels of trans fatty acids and oxidised lipids in diet on cholesterol and cholesterol oxidation products formation in rabbit

The objective was to assess the effects of trans fatty acids and oxidised lipids, present in dietary fat by-products used in feeds, on cholesterol and oxycholesterols in meat, liver and plasma of rabbits. A palm fatty acid distillate, before and after hydrogenation (trans fatty acid trial), and a sunflower–olive oil blend (70/30, v/v), before and after use in a commercial frying process (oxidised lipid trial), were used in experimental feeds (at 3%, w/w). High trans fatty acid and oxidised lipid diets caused significantly higher cholesterol and oxycholesterol levels in all tissues of rabbit (0.01 < p ? 0.05). The content of oxycholesterols in rabbit meat, liver and plasma obtained from trans fatty acid experiments varied from 9 to 34 μg/100 g, 24 to 61 μg/100 g and 60 to 138 μg/dl, respectively, from low to high levels. In the oxidised lipid experiments, content of oxycholesterols varied from 16 to 52 μg/100 g, 14 to 108 μg/100 g and 52 to 269 μg/dl in meat, liver and plasma, respectively. As a consequence, meat products from rabbits fed a diet containing higher levels of trans fatty acids or oxidised lipids may result in higher intakes of cholesterol and oxycholesterols by humans.     

Sugar-beet pulp as an alternative ingredient of barley in rabbit diets and its effect on rabbit meat

The effects of rabbit diets with four different levels of barley and sugar-beet pulp on the dressing percentage, chemical and fatty acid composition of meat from rabbits slaughtered at a liveweight of 2000 and 2500 g have been studied. Results revealed detectable (P < 0·05) effects of the total substitution of barley by sugar-beet pulp for carcass weight, dressing percentage and dry matter from animals slaughtered at a liveweight of 2000 g. No significant differences (P > 0·05) among batches were observed when slaughter weight was 2500 g. No influence of the diet on the total lipid fatty acids was found. In general, similar results were found when rabbit diets were formulated with 50% barley and 0% sugar-beet pulp, 30% barley and 0% sugar-beet pulp or 15% barley and 15% sugar-beet pulp.     

Comparative lipid composition of porcine muscles at different anatomical locations

The influence of anatomical location on the intramuscular lipids was studied in Large White pigs. The amount of total, neutral and polar lipids and the composition of fatty acids of the above three fractions were determined for Longissimus dorsi (LD) at two points and Transversus abdominis (TA) and Biceps femoris (BF) taken from the two half carcasses of an animal. The symmetrical samples from the same animal had identical intramuscular lipid characteristics. The three muscles did not show significant differences in their total (2·8 to 2·4g/100g) and neutral (2·1 to 1·4g/100g) lipid contents. The amount of polar lipids was characteristic of every muscle (0·65 g, 0·84 g and 0·97 g per 100 g, respectively, in LD, BF and TA). The fatty acid composition of neutral lipids was influenced by the type of muscle. Polar lipid had similar fatty acid composition in the three muscles. The intramuscular lipids contained appreciable amounts of essential fatty acids of the family n-6; interestingly, a part of which (25% of EFA) was the long chain fatty acid (C20 and C22) located in the polar lipids.     

Fatty acid profiles of the total lipids and lipid oxidation in pork muscles as affected by canola oil in the animal diet and muscle location

Twelve pigs at about 35 days of age were fed a control diet or test diets containing either 10% or 20% canola oil (CO) for 100 days. Four different muscles were excised from each carcass at 24 h post-mortem for analyses. Inclusion of 10% and 20% CO in the animal diet increased (P < 0·05) the relative amount (weight per cent) of unsaturated fatty acids in the total lipids (lipids extracted by 2:1 chloroform-methanol) by 6·7 and 15·8 percentage points, respectively, from 57·8% for the control and also increased (P < 0·05) that of polyunsaturated fatty acids by 5·5 and 9·7 percentage points, respectively, from 19·4% for the control. The 20% CO treatment increased (P < 0·05) the relative amount of monounsaturated fatty acids (primarily C18:1) by 6·1 percentage points from 38·4% for the control, while the 10% CO treatment had no significant effect. The 10% or 20% CO treatment had no significant effect on microsomal enzymic lipid peroxidation activity, heme pigment content, nonheme iron content and total lipid concentration. Overall lipid oxidation in ground muscle samples stored at 4°C tended to be higher for the 10% and 20% CO treatment groups than for the control. The tendency of increased lipid oxidation by the CO treatments apparently resulted from the increased percentages of polyunsaturated fatty acids, rather than from changes in catalytic constituents.     

Fatty acid composition of the meat and fat of the one-humped camel (camelus dromedarius)

The fatty acid composition of lean raw meat taken from the hind leg of seven young (1-3 years of age) male one-humped camels (Camelus dromedarius) has been determined by capillary gas-liquid chromatography; fat samples taken from the hump of these seven camels were also analysed. The saturated fatty acids in the meat account for 51·5% of the total fatty acids, while the monosaturated and polyunsaturated chains constitute 29·9 and 18·6%, respectively. The major fatty acids in camel meat are palmitic (26·0%), oleic (18·9%) and linoleic (12·1%), with smaller amounts of other fatty acids, both normal and branched, that range in chain lengths from C(14) to C(22). The fatty acids of dromedary fat are dominated by saturated even-numbered chains with smaller amounts (5·4%) of odd-numbered normal and branched chains. The main fatty acid of the hump fat is palmitic (34·4%) followed by oleic (28·2%), myristic (10·3%) and stearic (10·0%).     

烹饪方式对凡纳滨对虾（Penaeus vannamei）脂质及挥发性物质的影响

为探究风味差异的形成机制,以凡纳滨对虾为研究对象,研究蒸制和微波加热2种烹饪方式对脂质组成、脂质氧化水解程度及挥发性物质的影响。结果表明,凡纳滨对虾在烹饪后总脂和脂质组成(磷脂、甘油三脂及游离脂肪酸)含量均显著降低(P<0.05)。蒸制和微波加热的对虾,其脂质组成也有所差别,与蒸制相比,微波加热虾肉中的磷脂含量偏高,而游离脂肪酸含量偏低。鲜虾烹饪后饱和脂肪酸含量显著下降,不饱和脂肪酸含量显著上升(P<0.05),可能与磷脂的水解有关。蒸制和微波加热加速了脂质的氧化水解,酸价和硫代巴比妥酸反应物值均显著升高(P<0.05)。电子鼻分析结果显示鲜虾、蒸制和微波加热虾肉的气味特征有明显不同,且微波加热气味变化更大。采用气相色谱-离子迁移谱从虾肉中分离鉴定出25种挥发性物质,其中2,3-戊二酮、2-丁酮、2-甲基丁醛、己醛、1-辛烯-3-酮和戊醛等是熟虾肉主要的风味物质,且在微波加热的样品中含量更高。Pearson相关性分析结果表明,脂质的氧化水解对风味形成有重要贡献,游离脂肪酸中的C_14:0、C_15:0、C_16:1     

Lipid content and fatty acid composition of green algae Scenedesmus obliquus grown in a constant cell density apparatus

The lipids of alga Scenedesmus obliquus grown under controlled conditions were separated and fractionated by column and thin-layer chromatography, and fatty acid composition of each lipid component was studied by gas-liquid chromatography (GLC). Total lipids were 11.17%, and neutral lipid, glycolipid and phospholipid fractions were 7.24%, 2.45% and 1.48% on a dry weight basis, respectively. The major neutral lipids were diglycerides, triglycerides, free sterols, hydrocarbons and sterol esters. The glycolipids were: monogalactosyl diglyceride, digalactosyl diglyceride, esterified sterol glycoside, and sterol glycoside. The phospholipids included: phosphatidyl choline, phosphatidyl glycerol and phosphatidyl ethanolamine. Fourteen fatty acids were identified in the four lipid fractions by GLC. The main fatty acids were C18:2, C16:0, C18:3(alpha), C18:1, C16:3, C16:1, and C16:4. Total unsaturated fatty acid and essential fatty acid compositions of the total algal lipids were 80% and 38%, respectively.     

热风干制前后凡纳滨对虾中脂质及其脂肪酸组成变化

为了研究凡纳滨对虾在热风干制前后脂质及其脂肪酸组成变化,通过硅胶柱层析法分离对虾脂质中的各个组分,采用气相色谱-质谱联用分析总脂、甘油三酯、脑磷脂与卵磷脂中脂肪酸组成在干制前后的变化.结果表明:干制后对虾总脂含量发生极显著下降(P<0.01),由6.46 g/100 g(以干基计)下降至4.28 g/100 g,甘油三...     

Changes in lipid composition and fatty acid profile of Nham,a Thai fermented pork sausage,during fermentation

Changes in lipid composition and fatty acid profile of Nham during fermentation were investigated. Total lipids of Nham were in the range 2–3%. The extracted lipid of initial Nham mix consisted mainly of triglycerides (TG), accounting for more than 75% of the total lipid, followed by phospholipids (PL) and a trace amount of diglycerides (DG) and free fatty acid (FFA). During fermentation, TG, DG and PL decreased with a concomitant increase in FFA, indicating lipolysis of Nham lipids during fermentation. Changes in fatty acids of the total lipids, non-polar and polar lipid fractions were observed during fermentation. In both total and non-polar lipid fractions, the major fatty acids found in a descending order were oleic (C18:1), linoleic (C18:2) and palmitic (C16:0) acids, which together accounted for 90% of the total fatty acids. Increases in fatty acid contents in both total and non-polar lipid fractions, were observed with a corresponding decrease in the quantity of fatty acids of phospholipids. As the fermentation proceeded, peroxide value generally increased while TBARS values decreased. Overall, lipid oxidation in Nham occurred during fermentation but did not cause the objectionable odour and taste in any Nham tested.     

NaCl对腌制兔肉食用品质的影响

本文分别以质量分数0%、3%、6%、9%、12%、15%的NaCl将兔肉腌制处理48 h后,探讨不同添加量的NaCl对腌制兔肉加工品质和脂质氧化的影响。结果显示,随着NaCl添加量增加,腌制后兔肉pH、蒸煮损失率、亮度值（L*）、红度值（a*）、黄度值（b*）均有所降低,而兔肉的硬度、内聚性、胶着性和咀嚼性依次升高,弹性呈现先增大后降低的趋势,在3%的NaCl添加量时兔肉弹性最大。NaCl对兔肉中脂质氧化也有较大的影响,兔肉过氧化值（POV）和硫代巴比妥酸反应物值（TBARS）都随着NaCl添加量的增大呈现上升的趋势,且在添加量为9%达到最大值,之后随着添加量增大会略微降低;兔肉在腌制后脂肪酸营养价值会有所降低,其中饱和脂肪酸（SFA）含量总体上升,多不饱和脂肪酸（PUFA）含量降低,而单不饱和脂肪酸（MUFA）含量变化不大,n-6/n-3比值和PUFA/SFA比值下降。总体而言,NaCl的适量添加（0%~6%）会改善兔肉质构特性,增强保水能力,但会加速脂质氧化。     

LIPID CHARACTERISTICS OF EMU MEAT AND TISSUES

Twenty four (24) samples of emu meat (drumstick) and fat (abdominal fat (AF) and back fat (BF)), liver and heart tissue were collected from three (3) farms, and twelve (12) samples of chicken (drumstick) and beef (steak) were collected from supermarkets. The AF and BF of emu contained over 99% triacylglycerols. Monounsaturatedfatty acids (MUFA) constituted to 56% in AF and BF, saturated fatty acids (SAFA) at 31% and polyunsaturated fatty acids (PUFA) constituted to 13%. Oleic acid (C18:1n-9) was the predominant MUFA at 48%. The emu leg meat total lipids were up to 3%. Phospholipid constituted the major lipid class in emu and chicken meat at 64%, higher (P<0.05) than beef meat (47%). The emu drumstick contained higher (P<0.05) linoleic (C18:2n-6), arachidonic (C20:4 n-6), linolenic (C18:3 n-3) and docosahexaenoic (C22:6 n-3) acids than chicken drumstick and beef steak. The ratio of polyunsaturated fatty acids to saturated fatty acids in emu meat was 0.72, higher (P<0.0001) than chicken meat, 0.57 and beef meat, 0.3. The ratio of n-6 to n-3 fatty acids did not differ (P>0.05) among the three sources of meat.     

苏尼特羊和小尾寒羊的屠宰性能、肉品质、脂肪酸和挥发性风味物质比较

选择5月龄苏尼特羊、小尾寒羊各10?只,测定其屠宰性能,再分别取背最长肌测肉品质、脂肪酸含量以及挥发性成分并进行比较。结果表明：苏尼特羊的净肉率和肉骨比显著大于小尾寒羊（P＜0.05）。苏尼特羊的色泽（a*、b*）、嫩度优于小尾寒羊（P＜0.05）,熟肉率和pH值没有显著差异;从脂肪酸含量分析发现,苏尼特羊肉中饱和脂肪酸与多不饱和脂肪酸含量均高于小尾寒羊,其中C16:0和C18:0含量显著高于小尾寒羊（P＜0.05）,但含量比较丰富的不饱和脂肪酸（C18:1、C18:2n6c和C20:4n6）在2?种羊之间没有显著差异（P＞0.05）。羊肉的挥发性成分主要由羰基化合物和醇类化合物组成,不同品种对挥发性成分的相对含量和构成影响很大,苏尼特羊的醛类和酮类化合物含量高于小尾寒羊,但醇类化合物含量低于小尾寒羊,筛选主要风味化合物为己醛、辛醛、壬醛、1-辛烯-3-醇和2,3-辛二酮。     

反复冻融对缠丝兔加工过程中脂肪酸含量变化的影响

以反复冻融兔肉为原料,分析缠丝兔加工过程中的脂肪酸含量变化。结果表明：与新鲜原料兔肉对照,随着冻融次数增加,反复冻融原料兔肉及其腌制后和烘烤后的脂肪含量显著降低,硫代巴比妥酸值显著增加（P＜0.05）;原料兔肉检测出棕榈酸（C16∶0）、亚油酸（C18∶2）等脂肪酸,在缠丝兔加工过程中,脂肪降解产生了油酸（C18∶1）;反复冻融兔肉在腌制和烘烤后的脂肪酸也呈显著性变化（P＜0.05）;5 次冻融原料的缠丝兔脂肪含量最低（0.023 8%）、硫代巴比妥酸值最高（0.216 8 mg/kg）。表明兔肉反复冻融对缠丝兔的脂肪酸含量影响显著。     

不同部位伊拉兔肉脂肪酸组成的对比分析

研究不同部位兔肉的脂肪含量和脂肪酸组成的差异,以伊拉肉兔的肩胛肌、背腰肌、后腿肌和肝脏为原料,对比分析4 者脂肪含量和肌内总脂、甘油三酯、磷脂、游离脂肪的脂肪酸组成。测定结果表明：4 部位肌内总脂、甘油三酯、磷脂和游离脂肪酸含量均有显著差异（p＜0.05）,但甘油三酯和磷脂的脂肪酸组成在不同部位间的差异不显著（p＞0.05）,只有少数脂肪酸在肝脏中的含量与其他3 部位差异显著（p＜0.05）,而总脂肪酸、游离脂肪酸的组成在各部位间差异显著（p＜0.05）。由于游离脂肪酸在肌内脂肪中含量较少,不足以对总脂肪酸组成产生显著影响,因此不同部位伊拉兔肉肌内脂肪含量和脂肪酸组成的显著差异主要是由肌内甘油三酯含量的显著差异引起的。     

Fatty acid profile and mineral content of the wild snail (Helix pomatia) from the region of the south of the Turkey

AbstractThe fatty acid and mineral compositions in the flesh of wild snail (Helix pomatia) collected in the region of Cukurova in Turkey were evaluated. Proximate analysis of snails showed that they are rich in protein (18%) and low in lipid (0.49%). The main fatty acids detected were C16:0 (12%) C18:0 (19%), C22:0 (7%), C18:1 n–9 (17%), C18:2 n–6 (16%) and C20:2 n–11.14c (10%). The total SFA, MUFA and PUFA content of lipids were 37.87, 19.65 and 25.83% of total fatty acids, respectively. The major minerals found were Ca, P, K, Mg and Na. However, Fe, Mn and Zn contents of snail meat are less than 2 mg/100 g. The results of this study have showed that snails are good sources of protein and minerals.