Effect of dietary replacement of sunflower oil with linseed oil on intramuscular fatty acids of lamb meat

The effect of stepwise replacement of dietary sunflower oil (SO) with linseed oil (LO) on carcass composition, meat colour and fatty acid (FA) composition of intramuscular lipids of lamb meat was investigated. Thirty-six lambs were fed one of four diets consisting of pellets of lucerne with oil (60 g/kg): the diet varied in the composition of oil added and were: 100% SO; 66.6% SO plus 33.3% LO; 33.3% SO plus 66.6% LO and 100% LO. The experimental period was 7 weeks. Live slaughter weight, hot carcass weight and intermuscular fat percentage of chump and shoulder increased linearly with replacement of SO by LO.     

低反式脂肪酸含量大豆油脱色条件的优化

对大豆油脱色过程中反式脂肪酸含量进行研究,通过单因素试验与响应面分析,对影响脱色的主要工艺参数进行了优化.得到低反式脂肪酸大豆油脱色的最佳工艺参数为:脱色温度97℃,脱色时间30 min,脱色剂用量3.8%.在真空度0.095 MPa、搅拌速度220 r/min条件下,按最佳工艺参数脱色,得到大豆油反式亚油酸含量为1.18%,脱色率达到96.57%.     

毛细管气相色谱法测定精炼和氢化大豆油中的反式脂肪酸

采用CP—Sil88强极性毛细管柱气相色谱法对精炼和氢化大豆油中的顺、反异构和位置异构的脂肪酸进行定性、定量分析。结果表明，精炼和氢化大豆油中主要顺、反式脂肪酸实现了很好地分离，各种位置异构的反式脂肪酸也实现了较好地分离。采用归一化法对各种脂肪酸进行定量分析，结果表明，精炼大豆油中反式脂肪酸为总脂肪酸含量的3．45％，以△9c，12t—C18：2、△9t，12c—C18：2和△9c，12c，15t—C18：3、△9t，12c，15c—C18：3 4种形式为主；氢化大豆油中反式脂肪酸为总脂肪酸含量的38．73％，以△9t—C18：1、△10t—C18：1、△11t—C18：1 3种形式为主的反式十八碳单烯酸（t—C18：1）占反式脂肪酸总量的90．81％。     

降低大豆油精炼过程反式脂肪酸含量研究

研究精炼过程对大豆油反式脂肪酸含量变化,发现在碱炼、脱色工段反式脂肪酸含量没明显变化,而在脱臭工段反式脂肪酸含量发生显著变化,表明精炼时脱臭是产生反式脂肪酸主要阶段;同时比较脱臭温度,脱臭塔结构,脱臭时间对大豆油反式脂肪酸形成影响,并根据研究结果,提出工业化降低大豆油反式脂肪酸可行性工艺。     

肉类脂肪酸的营养与免疫调节作用

综述了肉类脂肪中饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸及共轭多不饱和脂肪酸构成特性及其对人体的营养与健康功能,以及肉类脂肪中三酰甘油、磷脂、固醇类等的免疫调节作用与疾病的关系。     

Effect of dietary conjugated linoleic acid in combination with monounsaturated fatty acids on the meat composition and quality traits of dry-cured loin

Three levels (0%, 1% and 2%) of an enriched conjugated linoleic acid oil (CLA) were combined with two levels of monounsaturated fatty acids (MUFA) (low −19% average and high −39% average) for pig feeding. Composition, weight losses, lipid oxidation (thiobarbituric acid test, TBARs), change in the fatty acid content of the lipid fractions and sensory analysis of dry-cured loin as affected by dietary CLA, MUFA and CLA × MUFA interaction were studied. CLA and CLA × MUFA did not affect moisture and intramuscular fat content of dry-cured loin, weight losses during the processing, changes in the content of most fatty acids from lipid fractions and sensory traits. CLA and MUFA supplementation led to lower TBARs values (1.3 mg MDA/kg sample for 0% CLA and 0.9 mg MDA/kg sample for 2% CLA; 1.2 mg MDA/kg sample for low MUFA diets and 0.9 mg MDA/kg sample for high MUFA diets), the highest TBARs values being detected for 0% CLA-low MUFA diets [1.5 mg MDA/kg sample]. The combination of dietary CLA with different MUFA levels in pig diets did not affect most composition and quality traits of dry-cured loin. Dietary CLA and MUFA seemed to lead to lower lipid oxidation in this product.     

不同类型膳食脂肪酸对肥胖小鼠肝脏及其血液中脂肪酸组成和代谢相关基因影响

目的探讨不同类型膳食脂肪酸对肥胖小鼠肝脏及其血液中脂肪酸组成及代谢相关基因的影响。方法 8周龄雄性C57BL/6小鼠随机分为7组,即对照组(喂基础饲料)、长链饱和脂肪酸(LCSFA)组(喂猪油高脂饲料)、中链饱和脂肪酸(MCSFA)组(喂椰子油高脂饲料)、n-3多不饱和脂肪酸(n-3 PUFA)组(喂亚麻籽油高脂饲料)、n-6多不饱和脂肪酸(n-6 PUFA)组(喂大豆油高脂饲料)、单不饱和脂肪酸(MUFA)组(喂橄榄油高脂饲料)和反式脂肪酸(TFA)组(喂8%氢化大豆油高脂饲料),每组10只,共干预16周,所有种类饲料总能量均相同,基础饲料脂肪供能比为10%,各高脂饲料脂肪供能比均为45%,喂养周期结束后,禁食12 h,麻醉后立刻解剖取出肝脏。采用气相色谱法分析肝脏及其血液中脂肪酸组成的变化,实时荧光定量聚合酶链式反应(PCR)检测肝脏脂肪酸代谢相关基因的表达,肝脏脂质沉积采用油红O染色法检测。结果与对照组比较,LCSFA组、MCSFA组、n-6 PUFA组、MUFA组和TFA组小鼠肝脏中均出现明显的脂质沉积,n-3 PUFA组小鼠肝脏未出现明显的脂质沉积。与对照组比较,LCSFA组小鼠肝脏及血液中总n-6 PUFA和总PUFA含量升高; n-3 PUFA组小鼠肝脏及血液中总n-3 PUFA和总PUFA含量增加,但总MUFA含量减少; n-6 PUFA组小鼠肝脏及血液中总n-6PUFA、总n-3 PUFA和总PUFA含量升高,但总饱和脂肪酸(SFA)和总MUFA含量降低; MUFA组小鼠肝脏及血液中总SFA含量减少; TFA组小鼠肝脏及血液中C18∶1 n-9t(TFA)含量升高;以上差异均有统计学意义(P0. 05)。LCSFA组和MCSFA组小鼠肝脏脂肪酸代谢基因固醇调节元件结合蛋白1(SREBP-1c) mRNA水平高于对照组和n-6 PUFA组,差异均有统计学意义(P0. 05)。结论小鼠肝脏及其血液中脂肪酸构成与其对应的膳食脂肪酸模式一致。不同类型脂肪酸高脂饲料可通过对相关基因的表达影响肥胖状态下肝脏的脂质代谢及脂质沉积。     

Effects of previous diet and duration of soybean oil supplementation on light lambs carcass composition, meat quality and fatty acid composition

Forty Merino Branco ram lambs were used to study the effects of initial diet and duration of supplementation with a conjugated linoleic acid (CLA) promoting diet, on carcass composition, meat quality and fatty acid composition of intramuscular fat. The experimental period was 6 weeks. The experimental design involved 2 initial diets (commercial concentrate (C); dehydrated lucerne (L)), and 2 finishing periods (2 and 4 weeks) on dehydrated lucerne plus 10% soybean oil (O). Data were analysed as a 2 × 2 factorial arrangement with initial diet and time on finishing (CLA promoting) diet as the main factors. The lambs were randomly assigned to four groups: CCO; COO; LLO; LOO according to the lamb’s diet fed in each period.Lambs initially fed with concentrate showed higher hot carcass weights (11.2 vs 9.6 kg) than lambs fed initially with lucerne. The increase of the duration of finishing period reduced the carcass muscle percentage (57.4% vs 55.5%) and increased the subcutaneous fat percentage (5.67% vs 7.03%). Meat colour was affected by initial diet. Lambs initially fed with concentrate showed a lower proportion of CLA (18:2cis-9, trans-11 isomer) (0.98% vs 1.38% of total fatty acids) and most of n−3 polyunsaturated fatty acids than lambs initially fed with lucerne. Initial diet did not compromise the response to the CLA-promoting diet and the proportion of 18:2cis-9, trans-11 in intramuscular fat increased with the duration of time on the CLA-promoting diet (1.02% vs 1.34% of total fatty acids).     

伊拉兔肉肌内脂肪酸组成及温度对其脂肪氧化的研究

研究了伊拉肉兔后腿肉的肌内脂肪含量,并分析测定了其脂肪酸组成,同时研究了兔腿肉在常温(15±0.5)℃和低温(4±0.5)℃贮藏条件下的脂肪氧化稳定性。结果表明,兔腿肉肌内脂肪主要含有19种脂肪酸,其中棕榈酸(16∶0)、硬脂酸(18∶0)、油酸(18∶1)、亚油酸(18∶2)的总含量占脂类总脂肪酸含量的71.06%左右。伊拉兔肉肌内脂肪中主要是不饱和脂肪酸,尤以多不饱和脂肪酸居多。在常温(15±0.5)℃和低温(4±0.5)℃贮藏条件下,兔腿肉POV、TBA值的差异极显著(p<0.01)。常温条件下,第5d兔肉出现异味并逐渐变成臭味,而低温条件下,第7d才开始出现轻微异味,低温冷藏对保证肉品质量有重要意义。      

Changes in the composition of the fatty acids and aldehydes of meat lipids after heating

The effects of heating at 132°C on the fatty acids and fatty aldehydes of neutral lipids and phospholipids of lean beef, veal, lamb, pork and chicken were studied. Heating caused hydrolysis of the plasmalogens in the phospholipids, and varying amounts of the liberated fatty aldehydes were recovered in the neutral lipid fractions. Beef phosphatidyl choline lost more polyunsaturated fatty acids than that of the other meats. Beef and veal phosphatidyl ethanolamine lost more polyunsaturated fatty acid than that of lamb, pork or chicken, but the effect was obscured by the influx of fatty acids from elsewhere into this fraction after heating.     

固体超强酸催化大豆油和大豆油脂肪酸酯化与酯交换制备单甘酯的研究

采用固体超强酸催化大豆油和大豆油脂肪酸与甘油酯化和酯交换制备单甘酯,通过二级分子蒸馏纯化单甘酯。通过响应面优化得到的最佳条件为：大豆油30.0 g,大豆油脂肪酸20.0 g,反应温度200℃,固体超强酸催化剂添加量0.26%（占大豆油和大豆油脂肪酸质量）,甘油添加量12.66 g和反应时间4.81 h。在最佳条件下,反应得到的甘油酯混合物中,单甘酯含量达到69.82%。甘油酯混合物在Ⅰ级135℃分子蒸馏除去游离脂肪酸和甘油,在Ⅱ级185℃分子蒸馏蒸出单甘酯,得到产品中单甘酯含量为96.54%。     

反胶束萃取豆油对脂肪酸成分的影响

用AOT/异辛烷反胶束体系从全脂豆粉中同时分离大豆蛋白和油脂;考察了预处理、加酶、温度、WO值对脂肪酸(FA)组分的影响。结果表明,反胶束萃取时对FA组分影响不大,除WO外,各因素几无影响,WO对FA影响较大,可能与AOT残留有关。     

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.     

黑豆油理化指标及脂肪酸组成分析

黑豆系为食药两用植物种籽,为更好开发和利用黑豆资源,分别对南北黑豆油理化指标、脂肪酸组成及甘油三酯组成进行测定。结果表明,黑豆含油量为17%左右,粗蛋白含量达46%左右,粗纤维含量为4.5%左右;黑豆油富含油酸和亚油酸,不饱和脂肪酸含量高达80%以上。     

Frying oils with lower levels of saturated fatty acids induce less heterocyclic amine formation in meat floss (boiled,shredded and fried pork)

Heterocyclic amines (HAs) as potent mutagens are formed in meat floss which is a boiled, shredded and fried traditional meat product. In this study, effects of frying oils (lard, soybean oil and palm oil) on the formation of HAs in meat floss during frying have been investigated. The results showed that the contents of Norharman, Harman, AαC and MeAαC in meat floss that treated with lard and palm oil were higher than soybean oil which contained less saturated fatty acids (P < 0.05). The contents of total HAs in meat floss that treated with palm oil at 150 °C and 180 °C were significantly higher than that treated with soybean oil and lard (P < 0.05). In conclusion, meat floss treated with soybean oil at 120 °C, 150 °C and 180 °C contained lowest levels of HAs and soybean oil could be used as lard substitution to produce healthy meat floss.     

气相色谱-质谱法测定腌制肉类食品中的多种脂肪酸

建立了腌制肉类食品中多种脂肪酸的气相色谱-质谱检测方法。样品采用ASE快速溶剂萃取仪提取、1%硫酸-甲醇溶液甲酯化,采用气相色谱质谱测定。样品添加回收率为80.2%⁹6.2%,RSD为2.4%⁶.8%;32种脂肪酸甲酯在0.010⁰.10mg/mL质量浓度范围内良好的线性关系,相关系数为0.9915⁰.9990;检出限为0.02⁰.14μg/kg,定量限为0.06⁰.46μg/kg;方法具有快速、准确、灵敏度高的特点,适用于腌制肉类食品中多种脂肪酸的检测分析。      

毛霉型豆豉和黄豆脂肪酸检测前处理方法比较研究

选取毛霉型豆豉和原料黄豆为材料,采用索氏抽提结合氢氧化钾-甲醇（KOH-CH3OH）、豆粉甲醇钠（CH3ONa）和豆粉KOH-CH3OH 3种甲酯化方法前处理样品,利用气相色谱-质谱联用技术（GC-MS）分析豆豉和黄豆的脂肪酸组分含量,并对3种样品前处理方法进行比较分析。结果显示,豆粉KOH-CH3OH甲酯化法前处理检测得到10种脂肪酸,其他两种方法预处理均只检测到5种脂肪酸。豆粉KOH-CH3OH甲酯化法前处理简便快捷,适合大量样品的快速检测,可以避免长时间加热对脂肪酸组分的影响,测定结果相对准确,对应用气相色谱法测定黄豆发酵前后脂肪酸种类及含量具有实际指导意义。     

从油脂加工控制反式脂肪酸

随着氢化油的大量使用,反式脂肪酸的危害逐渐显现。过量摄入反式脂肪酸会增加心血管疾病的危险性、诱导血栓形成,还能干扰脂肪酸代谢,影响青少年儿童的生长和智力发育。近年来,公众对反式脂肪酸的担忧越来越强。本文综述了反式脂肪酸的产生、来源及对人体的危害。反式脂肪酸有两个来源,天然存在和油脂加工过程中产生,其危害主要来自油脂氢化、精炼及煎炸过程产生的反式脂肪酸。因此,本文提出主要从以下3个方面控制反式脂肪酸:(1)寻找氢化油的替代品:酯交换油脂、酯化产品、油凝胶、棕榈油分提物等;(2)采用油脂提取新技术:水酶法提油、冷榨提油、超临界萃取提油等;(3)减少煎炸。旨在从源头把关,从根本上消除反式脂肪酸可能引起的健康隐患。     

Effects of vitamin E and fish oil inclusion in broiler diets on meat fatty acid composition and on the flavour of a composite sample of breast meat

BACKGROUND: Enriching poultry meat with long‐chain n‐3 polyunsaturated fatty acids (LC n‐3 PUFA) can increase low population intakes of LC n‐3 PUFA, but fishy taints can spoil reheated meat. This experiment determined the effect of different amounts of LC n‐3 PUFA and vitamin E in the broiler diet on the fatty acid composition and sensory characteristics of the breast meat. Ross 308 broilers (120) were randomly allocated to one of five treatments from 21 to 42 days of age. Diets contained (g kg^?1) 0, 9 or 18 LC n‐3 PUFA (0LC, 9LC, 18LC), and 100, 150 or 200 mg LD ‐α‐tocopherol acetate kg^?1 (E). The five diets were 0LC100E, 9LC100E, 18LC100E, 18LC150E, 18LC200E, with four pens per diet, except 18LC100E (eight pens). Breast meat was analysed for fatty acids (uncooked) and sensory analysis by R‐index (reheated). RESULTS: LC n‐3 PUFA content (mg kg^?1 meat) was 514 (0LC100E) and 2236 (9LC and 18LC). Compared with 0LC100E, meat from 18LC100E and 18LC150E tasted significantly different, while 23% of panellists detected fishy taints in 9LC100E and 18LC200E. CONCLUSION: Chicken meat can be enriched with nutritionally meaningful amounts of LC n‐3 PUFA, but > 100 mg dl‐α‐tocopherol acetate kg^?1 broiler diet is needed to protect reheated meat from oxidative deterioration. Copyright © 2010 Society of Chemical Industry     

Hypolipidemic effect of blends of coconut oil with soybean oil or sunflower oil in experimental rats

Blended oils, consisting of coconut oil with sunflower oil or soybean oil, were prepared (22–24% linoleic acid) to provide higher amounts of PUFA to coconut oil consumers. Animal experiments were carried out to find the effects of coconut oil blends, using weanling rats, by feeding native and blends of oils at 10% level in the diet for 60 days. Serum cholesterol levels were reduced by 5% and 21%, respectively, in rats given blended oils containing CNO/SFO and CNO/SBO while liver cholesterol did not show a significant change when rats were given blends in comparison with rats given CNO. Serum and liver lipid analyses also showed significant change in TG concentration in rats fed blended oils compared with rats given CNO. These studies indicated that the atherogenic potentials of a saturated fatty acid-rich CNO can be significantly decreased by blending with an oil rich in unsaturated lipids in appropriate amounts.