Chemical Composition and Cholesterol Content in M. Longissimus Dorsi from Free-range Reared Swallow-belly Mangalitsa: The Effect of Gender

The objective of this study was to determine chemical composition and cholesterol content in M. longissimus dorsi (MLD) of Swallow-belly Mangalitsa, free-range reared, and to investigate possible effects of gender on these quality parameters of its meat. Average moisture and fat contents were significantly different in male and female pig muscles. The differences in average values of ash, protein and cholesterol contents between the two groups (genders) of meat samples were not significant. In MLD samples of female pigs, total fat had a significant influence on cholesterol content, while this influence was not established in MLD of male pigs.     

Fatty Acid and Cholesterol Changes in Pork Longissimus Muscle and Fat due to Ractopamine

Fatty acid (FA) composition and cholesterol (CHL) content from control and Ractopamine (Rac) treated pigs were evaluated. Lipids were extracted from the longissimus (LD) and subcutaneous fat (SC) and methyl esters of the FA were formed for gas chromatography. CHL content of the LD was determined using direct saponification. Pigs were fed 0, 5, 10 or 20 ppm Rac for about 40 kg of grain prior to slaughter. Rac had no consistent effect on the FA composition of SC or muscle (neutral or polar) lipids. CHL content in the LD of treated animals was about 9% lower (P < 0.01) than controls. Rac reduced the CHL content of the LD and had limited effect on the FA profile of muscle or SC fat.     

猪腿肉脂肪酸组成及脂肪氧化的研究

本文研究了不同性别英系大白腿肉中肌间脂肪和皮下脂肪含量,并对其脂肪酸组成进行了分析,同时研究了腿肉在(4±0.5)℃避光贮存条件下脂肪氧化程度的变化,结果表明,不同性别猪腿肉肌间和皮下脂肪酸组成及含量均没有显著性差异(p>0.05);在(4±0.5)℃避光贮存期间(0～5d),肌间脂肪氧化程度显著高于皮下脂肪氧化程度(p<0.05),尤其到第5d时,肌间脂肪氧化指标-TBA值接近0.5mg/kg,而皮下脂肪TBA值低于0.2mg/kg。一般来讲,当生肉的TBA值超过0.5mg/kg时,人就能感觉到有氧化异味。因此,控制肌间脂肪氧化保证冷却肉良好品质的关键。     

饲喂不同配比油脂饲料对肉鸡肉品质及肌肉中脂肪酸组成的影响

研究日粮中添加不同配比油脂对肉鸡肉品质、肌肉胆固醇含量及脂肪酸组成的影响。选取648只1日龄AA肉鸡,随机分成6组,CON为对照组(饲喂基础日粮),SO为正对照组(日粮中添加豆油),LO为负对照组(日粮中添加猪油),COP、COC、COV组分别在日粮中添加以棕榈油为主的配比油脂、以椰子油为主的配比油脂、多种植物油组成的配比油脂,实验期为42d。结果表明：COP组胸肌24h的滴水损失显著升高(P＜0.05);COC组腿肌烹饪损失显著降低(P＜0.05)。LO组胸肌不饱和脂肪酸/饱和脂肪酸得到提高(P＜0.05);SO、LO、COP、COC组n-3多不饱和脂肪酸含量均得到提高(P＜0.05);SO、COC组n-6多不饱和脂肪酸含量高于CON组(P＜0.05);除COV组外,各组n-6/n-3低于CON组(P＜0.05)。SO组胸肌胆固醇含量低于除LO组外的各组(P＜0.05)。结论：配比油脂组提高了肉鸡肌肉中多不饱和脂肪酸(PUFA)含量,对肉鸡肉品质没有产生不良的影响,豆油组改善了胸肌中脂肪酸比例并降低胆固醇含量,以椰子油为主的配比油脂次之。     

Lipid Classes, Fatty Acids, Flavor and Storage Stability of Washed Sheep Meat

Lamb was used for all experiments, except flavor evaluations for which mutton was used. Washing ground lamb 4 times with high-pH (8.2) tap water, at a meat-to-water ratio of 1:4 and with a 15 min extraction/washing cycle, sharply lowered total fat content (primarily by removing neutral lipids), lipid oxidation potential, and the volatile branched-chain fatty acids which reportedly contribute to undesirable species-related flavor of sheep meat. A trained sensory panel determined that washed-cooked mutton had "very weak" species-related flavor (<2 on a 9-point scale).     

植物甾醇对肉鸭生产性能、血液胆固醇含量和胴体品质的影响

选用15日龄健康商品代樱桃谷肉鸭2400只,随机分成6组,每组4个重复,日粮中分别添加植物甾醇0(对照组)、10、20、40、80、160mg/kg。研究植物甾醇对肉鸭生产性能和血液中胆固醇含量的影响。结果表明:与对照组相比,添加植物甾醇试验组肉鸭的平均日增重、料重比和平均体重差异不显著(P>0.05)。但添加植物甾醇均降低了肉鸭血浆中总胆固醇(TC)和低密度脂蛋白胆固醇(LDL-C)的含量,且添加量20mg/kg的组差异显著(P<0.05)。此外,各试验组肉鸭的肌间脂肪含量均有提高,其中10mg/kg的组与对照组相比有显著性差异(P<0.05),这提示植物甾醇可能具有重新分配动物体内脂肪的效果。     

Opportunities and Implications of Pasture‐Based Lamb Fattening to Enhance the Long‐Chain Fatty Acid Composition in Meat

Health‐conscious consumers following dietary fat recommendations require meat that is low in saturated fat with preferably high levels of long‐chain omega‐3 fatty acids. This review summarizes the influence of dietary lipids from red meat on human health and examines the potential to enhance lipid composition through pasture‐feeding. The role of fatty acids in plant and ruminant metabolism is discussed to highlight the complexity of ruminal digestion when trying to enhance fatty acids in meat. Generally, ruminants that consume pasture diets have been shown to produce a more desirable fatty acid composition than those fed grain and offer potential to be further enhanced by using specific plant species. Elevated polyunsaturated fat content in meat, however, tends to increase susceptibility to oxidation, which influences other meat quality characteristics including shelf‐life and color. The use of specific plant species may mitigate these negative effects due to vitamin E or other antioxidants in these plants, which protect polyunsaturated fats from oxidation. When assessing the potential of plants as a natural dietary fat source, consideration must be given to environmental influences on plant fatty acid composition to ensure consistent production of meat products with high nutritive value under a range of management practices. This review also explores the potential impact of climate change on plant fatty acid composition, and the potential implications of this for meat quality.     

Effect of Conjugated Linoleic Acids in Pig Nutrition on Quality of Meat

Relationships among conjugated linoleic acid (CLA) in pig nutrition and carcass quality parameters (hot carcass weight, carcass yield and meatiness) and meat quality parameters (initial and pH value after 24, 48 and 72 h, temperature, drip loss, sensory color and marbling) were determined in pigs (crossbreeds Yorkshire x Landrace). Commercial CLA preparation containing 60% CLA isomers was included in the diet. No significant differences in performance parameters were found between pigs fed with CLA and control group during 60 days period. CLA supplementation in feed significantly increased SFA and decreased MUFA and PUFA fraction in pig muscles.     

微生物酶与肉组织酶对干发酵香肠中游离脂肪酸的影响

以戊糖乳杆菌31-1和木糖葡萄球菌为发酵剂生产干发酵香肠,就发酵剂对干发酵香肠成熟过程中游离脂肪酸的影响进行了研究。研究结果表明,在灌肠后的1周内,脂肪的水解主要是由组织酶引起的,微生物对脂肪微弱的水解能力主要表现在干发酵香肠成熟的后期,并且发酵剂不能改变发酵香肠中游离脂肪酸的变化模式。     

脂肪酸与肉的品质

近年来,人们对肉中脂肪酸的组成及含量的问题越来越关注。其主要原因就是肉中含有大量的脂肪酸,尤其是饱和脂肪酸,它们与现代生活中的疾病紧紧相关,同时对肉的食用品质和产品货架期具有重要影响。本文综述了肉中的脂肪酸种类、含量及其对人体健康和肉品品质的影响,以期对肉品的生产与贮藏有一定的指导意义。     

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。     

反复冻融对兔肉氨基酸和脂肪酸的影响

以新鲜兔肉为原料,研究反复冻融对兔肉蛋白质、氨基酸和脂肪酸含量的影响。结果发现：与新鲜兔肉相比,随着反复冻融次数的增加,兔肉中蛋白质含量显著减少（p＜0.05）,第4次冻融后,兔里脊、后腿蛋白质含量较新鲜兔肉分别下降了5.91%、10.30%;呈味氨基酸总量没有显著变化（p＞0.05）,但必需氨基酸和氨基酸总量显著减少（p＜0.05）,第4次冻融后的兔肉里脊部位赖氨酸含量比新鲜兔肉下降了16.42%;后腿部位的赖氨酸含量比新鲜兔肉下降了14.69%;脂肪酸总量、饱和脂肪酸含量、单不饱和脂肪酸含量和多不饱和脂肪酸含量均显著减少（p＜0.05）。结果表明反复冻融破坏了兔肉的营养成分,严重影响了兔肉的食用品质。     

肌肉细胞膜脂肪酸组成和变化对猪肉风味的影响

脂肪酸在猪肉风味的形成中扮演重要的角色,脂肪酸的氧化是影响猪肉风味的主要原因之一。细胞膜上磷脂部分脂肪酸的氧化,是肌肉系统在细胞内膜水平上的磷脂组分变化,它决定了肉风味的形成。因此,猪肉肌肉细胞膜脂肪酸对猪肉风味的形成有着重要意义。本文主要综述猪肉肌肉细胞膜脂肪酸的组成、代谢及其氧化和挥发对于猪肉风味的影响及其调控。     

Yield, Lipid, Cholesterol and Fatty Acid Composition of Spent Hens Fed Full-Fat Oil Seeds and Fish Meal Diets

Yield, proximate and fatty acids composition of white and dark meats and whole carcasses were determined in spent hens fed flax or canola seeds, fish meal and a control diet. Live weights and percent carcass cut-up yield were not affected by the diets fed. However, hens fed flax seed diets contained significantly (P< 0.05) lower levels of cholesterol in the dark meat than the control group. The inclusion of oil seeds, in particular flax seeds in the hens diet, enriched the meats with omega-3 fatty acids (C18:3ω>3; C20:5ω3; C22:5ω3). Omega-3 fatty acids enriched poultry meats from spent hens could be useful in the development of “health oriented” further processed poultry products.     

青海牦牛肉与秦川牛肉氨基酸和脂肪酸的比较研究

通过青海牦牛肉与秦川牛肉的氨基酸和脂肪酸的比较研究,分析青海牦牛肉品质的特性及其潜在优势.选取秦川牛肉,青南、大通和环青海湖地区的成年牦牛肉以及大通犊牦牛肉进行氨基酸和脂肪酸的相关研究.结果表明:牦牛肉各组的蛋白质含量高于秦川牛肉,但差异不显著(P＞0.05);脂肪含量都低于秦川牛肉,差异极显著(P＜0.01).青南地区成年牦牛肉的必需氨基酸/非必需氨基酸(EAA/NAA)值、必需氨基酸/氨基酸总量(EAA/TAA)值、18∶2cis-12,15、α-亚麻酸、20∶0、多不饱和脂肪酸(PUFA)、必需脂肪酸(EFA)、多不饱和脂肪酸/脂肪酸总量(P∶S)值和n-3多不饱和脂肪酸都显著高于秦川牛肉(P＜0.05或P＜0.01);16∶0、二十碳五烯酸(EPA)和n-6/n-3值都显著低于秦川牛肉(P＜0.05或P＜0.01).大通成年牦牛肉的赖氨酸、组氨酸和15∶0都显著高于秦川牛肉(P＜0.05或P＜0.01);月桂酸、亚油酸、PUFA、EFA、n-6多不饱和脂肪酸和n-6/n-3值都显著低于秦川牛肉(P＜0.05或P＜0.01).环湖地区成年牦牛肉的脯氨酸、15∶0、16∶1cis-9、17∶0和18∶2cis-12,15都显著高于秦川牛肉(P＜0.05或P＜0.01);月桂酸和n-6/n-3值都显著低于秦川牛肉(P＜0.05或P＜0.01).大通犊牦牛肉的色氨酸、肉豆蔻酸、17∶1cis-9、18∶1cis-11、亚油酸、α-亚麻酸、20∶3cis-5,8,11、20∶3cis-7,10,13、花生四烯酸(AA)、EPA、PUFA、EFA、P∶S值、n-3多不饱和脂肪酸和n-6多不饱和脂肪酸都显著高于秦川牛肉(P＜0.05或P＜0.01);脯氨酸、14∶1cis-9、棕榈酸、17∶0、油酸、SFA、MUFA和n-6/n-3值都显著低于秦川牛肉(P＜0.05或P＜0.01).结论:青海成年牦牛肉的蛋白质和必需氨基酸含量稍高于秦川牛肉,组成与秦川牛相近,但犊牦牛肉的氨基酸含量稍差一些.牦牛肉的n-6/n-3多不饱和脂肪酸比秦川牛肉合理,都在4.0左右,其中犊牦牛肉的P∶S值为1.15,说明牦牛肉的脂肪酸品质优,尤其是犊牦牛肉.     

肉品中脂肪检测技术研究进展

脂肪是食品中重要的营养成分,可供给能量和必需脂肪酸,可作为脂溶性维生素载体.肉品中脂肪含量与脂肪酸种类及其组成直接影响肉品的质量和风味.本文介绍动物油脂的相关概念,重点论述肉品中脂肪的提取与检测方法,以及气相色谱法、高效液相色谱法、薄层色谱法和红外光谱法在脂肪酸分析检测中的应用现状.     

白牦牛肉脂肪酸分析及功能性评价

为分析白牦牛肉的脂肪酸组成及功能特性,采用气相色谱一质谱联用仪(GC-MS)对甘肃天祝白牦牛肉进行定性定量测定,并与当地黄牛肉进行比较.结果表明:白牦牛肉与黄牛肉中的脂肪酸均以饱和脂肪酸为主,在单不饱和脂肪酸和多不饱和脂肪酸尤其是功能性脂肪酸方面,两者有显著的差异(p<0.05或P<0.01),牦牛肉脂肪酸种类更丰富、营养价值更高.     

乌骨鸡与非药用鸡种鸡肉总脂质含量及脂肪酸组成的比较

分析比较了乌骨鸡与非药用鸡种鸡肉间的总脂质含量和脂肪酸组成的差异,为研究乌骨鸡总脂质的营养与补益功能提供基础。以相同条件养殖的非药用鸡种崇仁麻鸡、岭南黄鸡鸡肉为对照,测定3种鸡肉中的总脂质含量。采用GC-MS联用技术对3种鸡脂肪的脂肪酸组成进行定性、定量分析。结果发现：3种鸡肉中崇仁麻鸡的总脂质含量最高,乌骨鸡的含量最低。3种鸡的总饱和脂肪酸（SFA）和不饱和脂肪酸（UFA）差别不显著,乌骨鸡鸡肉中多不饱和脂肪酸（PUFA）、必需脂肪酸（EFA）和花生四烯酸质量分数分别为26.4%、23.38%、3.21%,显著高于其他两种鸡。乌骨鸡总脂质较非药用鸡种的总脂质有更好的营养价值。     

家庭烹调对鲟鱼中脂肪酸和胆固醇的影响

对杂交鲟鱼（Acipenser baerii×A. schrenckii）进行了清蒸、油煎、微波、微波烤、烤箱烤和压力锅煎6 种家庭烹调处理,测定其脂肪和胆固醇含量、脂肪氧化指标和各脂肪酸含量的变化。结果表明,所有烹调方法均降低了n-3/n-6多不饱和脂肪酸含量的比值,其中压力烹调比值最高（0.85）,清蒸次之（0.83）,而烤箱烤最低（0.73）。胆固醇保存率以清蒸和压力锅煎最高,两种处理间无显著差异。烹调后样品酸价和硫代巴比妥酸值上升而过氧化值下降,并与样品的胆固醇含量相关。清蒸和压力烹调中脂肪酸和胆固醇变化相对较少,可能与其密闭烹调条件造成氧化程度较低有关。