海水养殖花鲈和淡水养殖花鲈肌肉脂肪酸组成和含量分析

采用Folch 液回流提取投喂相同配合饲料的海水养殖花鲈和淡水养殖花鲈背部肌肉脂质,脂质经氢氧化钾-三氟化硼法甲酯化后进行气相色谱分析。结果表明：海水养殖花鲈和淡水养殖花鲈肌肉脂肪酸组成存在一定差异。海水花鲈肌肉脂肪酸中单不饱和脂肪酸(MUFA)、n-3 系列多不饱和脂肪酸(PUFA)、EPA(C20:5 n-3)和DHA(C22:6 n-3)含量明显高于淡水花鲈,而饱和脂肪酸(SFA)、n-6 系列PUFA 和AA(C20:4 n-6)含量则低于淡水养殖花鲈。海水养殖花鲈和淡水养殖花鲈肌肉中n-6 和n-3 系列PUFA 比值分别为0.27 和0.42,均远低于HMSO(英国卫生部)推荐的最高安全限值(4.0)。     

沪浙地区不同泌乳期母乳脂肪酸组成及分布研究

研究了我国沪浙地区不同泌乳期(0～1,1～3,3～6和6～12月)母乳总脂肪酸、甘油三酯sn-2位脂肪酸和磷脂脂肪酸组成及分布。结果显示,随着泌乳期的延长,母乳脂肪中的中链饱和脂肪酸(MCSFA)、C_(12:0)和C_(14:0)含量逐渐升高,多不饱和脂肪酸(PUFA)、C_(18:2n-6)(LA)和C_(18:3n-3)(ALA)含量先升高后下降,C_(20:4n-6)(ARA)和C_(22:6n-3)(DHA)含量先显著下降而后趋于稳定,而饱和脂肪酸(SFA)、C_(16:0)和C_(18:0)含量几乎没有变化。母乳脂肪酸在甘油三酯结构中的位置分布具有独特性:MCSFA、SFA、C_(12:0)、C_(16:0)、ARA和DHA主要结合在sn-2位上,而MUFA、C_(18:1n-9)、PUFA、LA和ALA主要分布在sn-1,3位上,且这种独特的位置分布几乎不随泌乳期的变化而变化。母乳磷脂脂肪酸中的ARA和DHA含量尽管在不同泌乳期之间有所差异,但均显著高于其在母乳总脂肪酸中的含量。研究结果为我国婴儿配方乳粉的脂质母乳化特别是结构母乳化提供了重要的数据支撑。     

栉孔扇贝和海湾扇贝脂质及其脂肪酸组成分析

以栉孔扇贝和海湾扇贝为研究对象,采用Folch法提取两种扇贝肌肉和内脏中的总脂,并对其脂质和脂肪酸组成进行分析。结果表明:两种扇贝的肌肉总脂含量显著低于内脏,且肌肉总脂以磷脂为主,而内脏总脂以甘油三酯为主。两种扇贝的脂肪酸组成特征为多不饱和脂肪酸(PUFA)>饱和脂肪酸(SFA)>单不饱和脂肪酸(MUFA),其中,PUFA以n-3系列为主,主要为C20∶5n-3(16.58%~19.00%)和C22∶6n-3(11.49%~21.18%);肌肉中的n-3/n-6比值高于内脏,尤其C22∶6n-3含量显著高于内脏(P<0.01)。同时从两种扇贝中鉴定出6种脂肪醛二甲基缩醛(DMA),总量在7.77%~11.20%,并以C18∶0DMA(3.05%~6.89%)和C20∶1DMA(1.55%~4.25%)为主,且肌肉中DMA含量高于内脏,表明两种扇贝总脂中含有丰富的缩醛磷脂,肌肉总脂中的缩醛磷脂百分含量高于内脏。     

蒸煮对不同品质鸭肥肝营养特性及脂肪酸组成的影响

研究3种不同品质的鸭肥肝在蒸煮后常规养分、脂肪酸组成及脂质过氧化的变化。结果表明:1)熟化增加了鸭肥肝中C12:0、总脂和丙二醛(MDA)的含量,降低了水分、蛋白的含量,对鸭肥肝中糖原的含量无影响;2)鱼油组肥肝熟化后,其SFA、PUFA、n-6PUFA、n-3PUFA、EPA、DHA均显著高于大豆油组肥肝(P<0.05),极显著高于玉米组肥肝(P<0.01);3)玉米组肥肝熟化后SFA和MUFA显著降低(P<0.05),PUFA、n-6 PUFA、n-3 PUFA显著升高(P<0.05),大豆油组肥肝熟化对这几种脂肪酸的影响不大,而鱼油组肥肝熟化后这几种脂肪酸含量均升高,其中n-6PUFA达到显著水平(P<0.05);4)熟化具有降低3种肥肝中EPA和DHA的趋势,EPA降低幅度以玉米组肥肝最大,DHA降低幅度以大豆油组肥肝最大。以上结果提示,鱼油组肥肝的食用价值最高。     

牦牛肾脂氧化初期脂肪酸动态变化研究

以牦牛肾周脂为研究对象,研究了其在15±1℃下储藏期脂肪酸的动态变化。结果表明:牦牛肾脂肪氧化初期发生于储藏期第0～25d(15±1℃),在此期间,饱和脂肪酸(SFA)含量由49.68%提高至55.96%,多不饱和脂肪酸(PUFA)含量和单不饱和脂肪酸(MUFA)分别由10.73%和37.85%下降至6.95%和28.22%。第0～20d,n-6/n-3PUFA的比率低于4,但在第25d达到4.46,并且MUFA/SFA较PUFA/SFA下降幅度高11.24%。此外,除共轭亚油酸(CLA)和油酸(LA)外,功能性脂肪酸(ARA,EPA,DHA)在10d后下降显著(p<0.05)。     

中国老年人群膳食脂肪酸的摄入状况及食物来源分析

目的：分析中国老年人群膳食脂肪酸的摄入状况及食物来源。方法：利用中国成人慢性病与营养监测(2015)中3 d 24 h膳食调查数据,对18 116名年龄在60岁及以上人群的膳食脂肪酸摄入状况及食物来源进行分析。结果：中国老年人群膳食总脂肪(TFA)、饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)及多不饱和脂肪酸(PUFA)摄入量的中位数分别为53.4、13.4、22.9、14.1 g/d。城市居民SFA和PUFA的摄入量高于农村,而MUFA低于农村(P<0.001),3种脂肪酸的摄入量均表现为男性高于女性(P<0.001)。城乡居民的SFA、MUFA、PUFA之比均为1:1.5:1.1。城市和农村ω-6/ω-3 PUFA比例分别为8.5、7.9,城市高于农村(P<0.001)。膳食SFA、MUFA、PUFA的供能比分别为7.1%、12.1%、7.5%。城市居民SFA和PUFA的供能比高于农村(P<0.001),而MUFA的供能比低于农村(P=0.001)。植物油和动物性食物是膳食脂肪酸的主要来源,分别提供了47.7%和30.1%的TFA。农村居民膳食中ω-3 ...     

蒙古斑点马不同部位脂肪和肌肉组织中脂肪酸组成的比较研究

通过对蒙古斑点马不同部位脂肪和肌肉组织中脂肪酸组成进行分析比较,旨在明确蒙古斑点马体脂脂肪酸组成特点。选择3 匹成年蒙古斑点马,屠宰后采集肾周、肠周和皮下脂肪以及肩肌、背最长肌和臀肌样品,利用气相色谱法测定脂肪酸组成及含量。结果表明：蒙古斑点马不同脂肪组织中均检出19 种脂肪酸,其中饱和脂肪酸（saturated fatty acid,SFA）含量34.77%～37.38%,不饱和脂肪酸（unsaturated fatty acid,UFA）含量达60%以上,UFA中单不饱和脂肪酸（monounsaturated fatty acid,MUFA）含量33.04%～36.39%,多不饱和脂肪酸（polyunsaturated fatty acid,PUFA）含量26.47%～27.51%,其中皮下脂肪C10:0、C18:0、C20:0含量显著低于肾周和肠周脂肪（P＜0.05）;MUFA在皮下脂肪的沉积程度较其他2 个部位高,但均无统计学差异;PUFA中C18:3 n-3含量最高,其在各脂肪组织间无显著差异。3 个不同部位肌肉中均检出15 种脂肪酸,其中SFA含量占总脂肪酸含量的38.32%～40.04%,MUFA含量占35.70%～40.19%,PUFA含量占15.25%～20.33%;SFA中背最长肌和臀肌C12:0含量显著高于肩肌（P＜0.05）,其余SFA在不同部位肌肉间无显著差异;MUFA中背最长肌C16:1含量显著高于肩肌和臀肌（P＜0.05）;肩肌n-6/n-3 PUFA比值显著高于背最长肌和臀肌（P＜0.05）;皮下脂肪的C18:3 n-3和总PUFA含量显著高于背最长肌（P＜0.05）。综上所述,蒙古斑点马不同部位脂肪和肌肉组织脂肪酸组成各具特点,但UFA含量均较高。     

不同处理后的四川白兔肌内脂肪酸组成在冷藏过程中的变化

研究了用4种不同的处理方式(微波、烘烤、蒸煮、和超声波辅助腌制)对四川白兔的后腿肌(hind leg muscle,HL)进行处理后再用2种不同包装方式进行包装(非真空和真空包装),分析样品在冷藏过程中肌内总脂肪含量及脂肪酸组成的变化。结果表明,四川白兔肌内脂肪主要含20种脂肪酸,多数为不饱和脂肪酸。在0~12 d的冷藏过程中,4种方式处理后的四川白兔肌内脂肪含量显著下降(P0.05)。相对其他处理方式来说,微波处理对不饱和脂肪酸(UFA)尤其是多不饱和脂肪酸(PUFA)的影响较小,而蒸煮对PUFA破坏作用最大。随冷藏时间的延长,饱和脂肪酸(saturated fatty acid,SFA)的含量升高显著(P0.05),UFA、PUFA含量与P/S(PUFA/SFA)、n-6/n-3(n-6系列PUFA/n-3系列PUFA)的比值显著降低(P0.05),而单不饱和脂肪酸(MUFA)含量变化不显著。从脂肪氧化角度来看,处理后兔肉中丙二醛(MDA)的沉积量在0~10 d冷藏期间内不断升高,且耐贮性不断降低。真空包装的样品在饱和脂肪酸(saturated fatty acid,SFA)上升与UFA下降的趋势方面有减缓作用,同时将TBA值维持在较低的水平,延缓了加工肉品的腐败变质。     

鲟鱼籽酱(Huso dauricus × Acipenser schrenckii)冷藏期间脂肪酸组成的变化

实验通过气相色谱与质谱联用仪(GC-MS),研究了养殖鲟鱼籽酱在冷藏条件(0℃)下脂肪酸组成的变化。结果表明,鲟鱼籽酱脂肪总体组成为:23.03%饱和脂肪酸(SFA),33.68%单不饱和脂肪酸(MUFA)和33.03%多不饱和脂肪酸(PUFA),其富含n-3长链多不饱和脂肪酸,比如EPA(二十碳五烯酸,C20∶5(n-3))和DHA(二十二碳六烯酸,C22∶6(n-3)),营养价值非常高。随着冷藏时间的延长,饱和脂肪酸(SFA)含量显著升高,不饱和脂肪酸(UFA=MUFA+PUFA)含量显著降低,特别是多不饱和脂肪酸降低明显(p0.05),由此表明,仅低温冷藏不能保持鱼籽酱的脂肪酸营养品质。此外,在鲟鱼籽酱贮藏3月后,MUFA和PUFA出现显著性减少,且到贮藏5月时,分别从3月时的36.79、32.43降到34.83、31.86。由此可初步认定为3~5个月为鲟鱼籽酱冷藏时质量控制的关键时间段。     

褐点石斑鱼鱼肉及其副产物的脂肪酸分析

为了评估褐点石斑鱼的脂肪酸组成特点,采用固相萃取和气相色谱技术对鱼肉、头、皮和内脏的脂质含量、总脂及各脂类脂肪酸组成,甘油三酯(triacylglycerols, TAG)和磷脂(phospholipids, PL)中脂肪酸的位置分布进行了较全面的分析。石斑鱼鱼头和内脏中含有丰富的糖脂(saccharolipids, SL)和PL。在各组织总脂中,必需脂肪酸的含量占总脂肪酸的24.17%～24.51%,二十二碳六烯酸(docosahexaenoic acid, DHA)及二十碳五烯酸(eicosapentaenoic acid, EPA)的含量为12.42%～13.73%,动脉粥状硬化指数、血栓形成指数和n-6/n-3的比例处于较低水平。多不饱和脂肪酸(polyunsaturated fatty acids, PUFA),尤其是DHA+EPA(28.43%～37.37%)在PL中的比例要远高于在其它脂类中的占比。饱和脂肪酸主要分布在TAG和PL的sn-2位,单不饱和脂肪酸主要分布在TAG的sn-1,3位和PL的sn-2位,PUFA倾向于分布在TAG的sn-1,3位和PL的sn-1位;T...     

火麻油总脂肪酸及sn-2位脂肪酸组成分析

采用气相色谱法测定火麻油中总脂肪酸和sn-2位脂肪酸的组成和含量,并与其他9种常见植物油进行对比,旨在为火麻油的营养价值研究提供基础数据。结果表明,3种不同品牌火麻油主要由软脂酸（C16∶ 0）、硬脂酸（C18∶ 0）、油酸（C18∶ 1n9c）、亚油酸（C18∶ 2n6c）、α-亚麻酸（C18∶ 3n3）组成,其中多不饱和脂肪酸含量为70.57%~78.73%,sn-2位多不饱和脂肪酸含量为77.61%~83.74%,说明以亚油酸和α-亚麻酸为主的多不饱和脂肪酸更易连接在甘三酯结构的sn-2位上。另外,对比其他9种常见植物油,火麻油总脂肪酸和sn-2位脂肪酸中油酸含量均最低,亚油酸和亚麻酸含量较高;多不饱和脂肪酸含量均最高,分别为77.90%和83.74%;n-6系脂肪酸与n-3系脂肪酸比例分别为3.7∶ 1和4.2∶ 1。研究结果表明,火麻油是一种不饱和脂肪酸含量较高且易于被人体吸收代谢的植物油。     

反式脂肪酸危害与控制

通过对食品中反式脂肪酸含量强制标示,向广大消费者指出反式脂肪酸对人体健康危害;同时对油脂加工业而言,这也意味着一场旨在减少食品中反式脂肪酸变革开始。     

Effect of ruminal pulse dose of polyunsaturated fatty acids on ruminal microbial populations and duodenal flow and milk profiles of fatty acids

The objective of this study was to examine the effect of ruminal pulse dose of free linoleic acid (LA) and free docosahexaenoic acid (DHA) on microbial populations in the rumen, duodenal fatty acid (FA) flow, milk composition, and milk FA profiles of Chinese Holstein dairy cows. Four rumen- and duodenal-fistulated Chinese Holstein cows in mid lactation (138.5 ± 10 d in milk) were randomly assigned to 3 treatment groups and 1 control group in a 4 × 4 Latin square design over 4 periods (3 wk per period). Diets contained either no LA or 2.7% LA and either no DHA or 0.5% DHA in a 2 × 2 factorial arrangement of treatments. Ruminal pulse dose with DHA increased counts of Megasphaera elsdenii, decreased Fibrobacter succinogenes, but did not affect Butyrivibrio fibrisolvens or Ruminococcus flavefaciens. The pulse dose of LA at 2.7% dry matter had no effect on the population sizes of the 3 major cellulolytic bacterial species or M. elsdenii, and no interaction was observed between LA and DHA. The pulse dose of LA or DHA, either alone or in combination, increased the duodenal flow of vaccenic acid (VA). The milk VA and cis-9,trans-11 conjugated linoleic acid (CLA) contents also increased in response to the fatty acid pulse dose, and the pulse dose of both LA and DHA together had the most profound stimulatory effect. This study indicated that ruminal pulse dose of LA or DHA could be used to increase duodenal flow of VA and the milk contents of potentially health-promoting FA, such as VA and cis-9,trans-11 CLA. These results might be useful in formulating dietary interventions to improve milk cis-9,trans-11 CLA contents.     

脂肪酸乙酯的制备与纯化

介绍了合成脂肪酸乙酯的油脂乙醇解法和脂肪酸与乙醇酯化法的制备过程和优缺点,并分析了脂肪酸乙酯纯化方法及现状。     

Milk fatty acids as possible biomarkers to early diagnose elevated concentrations of blood plasma nonesterified fatty acids in dairy cows

Most cows encounter a state of negative energy balance during the periparturient period, which may lead to metabolic disorders and impaired fertility. The aim of this study was to assess the potential of milk fatty acids as diagnostic tools of detrimental levels of blood plasma nonesterified fatty acids (NEFA), defined as NEFA concentrations beyond 0.6 mmol/L, in a data set of 92 early lactating cows fed a glucogenic or lipogenic diet and subjected to 0-, 30-, or 60-d dry period before parturition. Milk was collected in wk 2, 3, 4, and 8 (n = 368) and blood was sampled weekly from wk 2 to 8 after parturition. Milk was analyzed for milk fatty acids and blood plasma for NEFA. Data were classified as “at risk of detrimental blood plasma NEFA” (NEFA ≥0.6 mmol/L) and “not at risk of detrimental blood plasma NEFA” (NEFA <0.6 mmol/L). Concentrations of 45 milk fatty acids and milk fat C18:1 cis-9-to-C15:0 ratio were subjected to a discriminant analysis. Milk fat C18:1 cis-9 revealed the most discriminating variable to identify detrimental blood plasma NEFA. A false positive rate of 10% allowed us to diagnose 46% of the detrimental blood plasma NEFA cases based on a milk fat C18:1 cis-9 concentration of at least 230 g/kg of milk fatty acids. Additionally, it was assessed whether the milk fat C18:1 cis-9 concentrations of wk 2 could be used as an early warning for detrimental blood plasma NEFA risk during the first 8 wk in lactation. Cows with at least 240 g/kg of C18:1 cis-9 in milk fat had about 50% chance to encounter blood plasma NEFA values of 0.6 mmol/L or more during the first 8 wk of lactation, with a false positive rate of 11.4%. Profit simulations were based on costs for cows suffering from detrimental blood plasma NEFA, and costs for preventive treatment based on daily dosing of propylene glycol for 3 wk. Given the relatively low incidence rate (8% of all observations), continuous monitoring of milk fatty acids during the first 8 wk of lactation to diagnose detrimental blood plasma NEFA does not seem cost effective. On the contrary, milk fat C18:1 cis-9 of the second lactation week could be an early warning of cows at risk of detrimental blood NEFA. In this case, selective treatment may be cost effective.     

坚果中脂肪含量及脂肪酸组成分析

目的分析16种市售坚果中脂肪含量及脂肪酸组成,比较不同品种坚果间脂肪含量、饱和脂肪酸和不饱和脂肪酸组成的差异。方法采用气相色谱分析法测定坚果中37种脂肪酸的含量,用最小显著性差异法(least-significant difference,LSD)法进行多重比较。结果坚果的平均脂肪含量为(55.6±0.86)g/100 g,变化范围为40.2~71.3 g/100 g,碧根果脂肪含量显著高于其他品种坚果脂肪含量(P0.05);坚果中的不饱和脂肪酸含量为72.77~95.47 g/100 g脂肪,平均值为(86.68±0.12)g/100 g脂肪,显著高于饱和脂肪酸4.53~22.19 g/100 g脂肪,平均值为(11.31±0.16)g/100 g脂肪(P0.05),东北榛子中单不饱和脂肪酸总含量最高,为84.34 g/100 g脂肪,而纸皮核桃中的多不饱和脂肪酸总含量最高,为74.17 g/100 g;坚果中不含短链脂肪酸和中链脂肪酸。结论坚果中不饱和脂肪酸含量较多,富含ω-6和ω-3脂肪酸,营养价值较高。     

Comparing the fatty acid composition of organic and conventional milk

During a 12-mo longitudinal study, bulk-tank milk was collected each month from organic (n = 17) and conventional (n = 19) dairy farms in the United Kingdom. All milk samples were analyzed for fatty acid (FA) content, with the farming system type, herd production level, and nutritional factors affecting the FA composition investigated by use of mixed model analyses. Models were constructed for saturated fatty acids, the ratio of polyunsaturated fatty acids (PUFA) to monounsaturated fatty acids, total n-3 FA, total n-6 FA, conjugated linoleic acid, and vaccenic acid. The ratio of n-6:n-3 FA in both organic and conventional milk was also compared. Organic milk had a higher proportion of PUFA to monounsaturated fatty acids and of n-3 FA than conventional milk, and contained a consistently lower n-6:n-3 FA ratio (which is considered beneficial) compared with conventional milk. There was no difference between organic and conventional milk with respect to the proportion of conjugated linoleic acid or vaccenic acid. A number of factors other than farming system were identified which affected milk FA content including month of year, herd average milk yield, breed type, use of a total mixed ration, and access to fresh grazing. Thus, organic dairy farms in the United Kingdom produce milk with a higher PUFA content, particularly n-3 FA, throughout the year. However, knowledge of the effects of season, access to fresh grazing, or use of specific silage types could be used by producers to enhance the content of beneficial FA in milk.     

反式脂肪酸与人体健康

油脂在加工过程中由于加氢、长时间高温等引起脂肪酸结构变化,顺式脂肪酸转变为反式脂肪酸.反式脂肪酸易导致肥胖、心血管疾病、糖尿病等疾病;长时间高温脱臭后油脂中反式脂肪酸含量将增加4%～6%,最高达8%～9%.建议从改进油脂生产的脱臭工艺与设备及日常生活中减少油炸食品、洋快餐食品摄入等入手,减少反式脂肪酸的摄入.     

支链脂肪酸的来源与功能研究进展

支链脂肪酸主要包括单支链脂肪酸和多支链脂肪酸,多存在于人体皮肤及其分泌物、微生物细胞膜、乳制品及肉制品中。近年来的研究表明,支链脂肪酸对乳腺癌细胞、前列腺癌细胞和膀胱癌细胞等具有潜在抑制作用,此外,支链脂肪酸还有抑制新生儿坏死性小肠结肠炎发病率等抗炎作用。进一步对各种食物以及人体各组织中的支链脂肪酸进行检测分析,并对支链脂肪酸结构功能与作用机理进行深入研究,是目前支链脂肪酸研究的重要方向。     

Acetyl CoA carboxylase shares control of fatty acid synthesis with fatty acid synthase in bovine mammary homogenate

The objectives of this research were to determine the flux control coefficients for acetyl CoA carboxylase and fatty acid synthase using an in vitro preparation of bovine mammary homogenate. For an enzyme to be considered rate limiting with the use of metabolic control analysis, its control coefficient would be equal to unity. The hypothesis for this experiment was that the control coefficient for acetyl CoA carboxylase was not equal to unity, and that this enzyme was not, therefore, the rate-limiting step. Mammary tissue was isolated from lactating Holstein cows at slaughter and frozen in liquid nitrogen. Tissue was ground, homogenized, and centrifuged to obtain a postmitochondrial supernatant for use in in vitro incubations containing labeled acetate. Specific inhibitors for acetyl CoA carboxylase and fatty acid synthase were used to fractionally inhibit de novo synthesis for the calculation of flux control coefficients. The composition of fatty acids synthesized in the absence of enzyme inhibitors was similar to the composition of fatty acids in the presence of inhibitors. Calculations following avidin inhibition of acetyl CoA carboxylase determined the flux control coefficient was 0.63 ± 0.15, which means that 63% of the control of fatty acid synthesis is exerted by acetyl CoA carboxylase. The remaining control (37%) was from fatty acid synthase, which indicates a significant degree of control over the flux of acetate in de novo synthesis resides with this enzyme. The rate-limiting status ascribed to acetyl CoA carboxylase was not supported, because the flux control coefficient was less than unity. Metabolic control analysis, through its use of pathway product measurements, allows for potential interactions in the pathway such as feedback inhibition contribution to the flux control coefficients, which would not otherwise be considered in studies measuring enzyme kinetics with purified enzymes.