芹菜素对3T3-L1前脂肪细胞增殖及分化作用研究

目的：研究芹菜素(apigenin,AP)对3T3-L1 前脂肪细胞增殖及分化的影响。方法：采用3T3-L1 前脂肪细胞,利用MTT 比色分析法检测不同质量浓度芹菜素对3T3-L1 前脂肪细胞增殖的影响;采用传统的鸡尾酒诱导剂诱导分化3T3-L1 前脂肪细胞,利用油红O 染色检测,通过比色分析法检测不同质量浓度芹菜素对3T3-L1 前脂肪细胞分化的影响。结果：30、50μg/mL 芹菜素相对于空白组和阳性对照组能够显著抑制3T3-L1 前脂肪细胞增殖和分化,提示其可能具有预防肥胖的作用。     

染料木黄酮抑制3T3-L1细胞成脂分化机制

目的：研究染料木黄酮是否通过雌激素受体介导影响3T3-L1前脂肪细胞成脂分化,并探讨其可能的机制。方法：以不同浓度染料木黄酮处理3T3-L1细胞,四甲基偶氮唑蓝（methyl thiazolyl tetrazolium,MTT）法测定细胞存活率;在3T3-L1前脂肪细胞成脂分化过程中分别加入不同浓度染料木黄酮、染料木黄酮和ICI182780（一种雌激素受体抑制剂）混合物及不同浓度雌二醇,油红染色观察分化结果,测定细胞甘油三酯（triglyceride,TG）含量;染料木黄酮、染料木黄酮和ICI182780混合物及不同浓度雌二醇处理诱导成熟后的脂肪细胞,测定培养液甘油含量;分别用染料木黄酮（30 μmol/L）、染料木黄酮（30 μmol/L）和ICI182780混合物干预细胞成脂分化,Western blotting法检测细胞外信号调节激酶（extracellular signal-regulated kinase,ERK）、p-ERK、腺苷酸活化蛋白激酶（adenosine monophosphate activated protein kinase,AMPK）、p-AMPK、激素敏感性脂肪酶（hormone sensitive lipase,HSL）、脂肪酸合成酶（fatty acid synthetase,FAS）蛋白表达量。结果：3T3-L1细胞存活率随染料木黄酮浓度的升高而降低,50～200 μmol/L染料木黄酮能抑制细胞生长（P＜0.01）;染料木黄酮能负向调节成脂分化后细胞胞浆内TG含量,在0～50 μmol/L浓度范围内呈剂量依赖关系,高剂量雌二醇（100 nmol/L）能下调TG含量;染料木黄酮能促进成熟脂肪细胞脂解,提高细胞培养液甘油浓度;染料木黄酮（30 μmol/L）能上调p-AMPK、HSL蛋白表达,下调FAS蛋白表达（P＜0.01）,对ERK、p-ERK、AMPK表达量无明显影响（P＞0.05）。ICI182780（1 μmol/L）能部分阻断染料木黄酮（30 μmol/L）对p-AMPK的调节作用（P＜0.05）。结论：染料木黄酮能抑制3T3-L1细胞成脂分化,其机制可能是染料木黄酮一方面下调FAS蛋白表达,抑制脂肪合成,另一方面激活AMPK-HSL途径促进脂肪分解;染料木黄酮还可能通过非雌激素受体途径抑制3T3-L1细胞成脂分化。     

叶瓜参鞘脂抑制3T3-L1前脂肪细胞分化及构效关系研究

目的:探究叶瓜参脑苷脂、神经酰胺、长链碱等鞘脂对3T3-L1前脂肪细胞增殖分化的影响。方法:由叶瓜参制备脑苷脂、神经酰胺和长链碱,以相同浓度的3种物质或含有等量长链碱的3种物质孵育3T3-L1细胞,采用MTT法检测叶瓜参鞘脂对3T3-L1细胞增殖的影响。利用0.5 mmol/L IBMX,1μmol/L DEX及10μg/m L胰岛素诱导3T3-L1细胞分化为成熟脂肪细胞,采用油红O染色法检测叶瓜参鞘脂对脂肪细胞分化的影响。结果:叶瓜参脑苷脂、神经酰胺、长链碱均能显著抑制3T3-L1细胞的增殖及分化。海参脑苷脂由亲脂性神经酰胺及亲水性糖基两部分组成,而神经酰胺由长链脂肪酸和长链碱以酰胺键相连而成。当3种物质浓度相同时,对3T3-L1细胞增殖分化的抑制率:长链碱神经酰胺脑苷脂;而当3种物质含有等量的长链碱时,其作用效果相当。结论:叶瓜参脑苷脂、神经酰胺、长链碱等鞘脂抑制脂肪细胞的增殖分化,其活性成分为长链碱。     

中长链脂肪酸对3T3-L1脂肪细胞凋亡和脂肪生成的作用

为了探究不同种类、不同浓度脂肪酸对3T3-L1脂肪细胞凋亡和脂肪生成的影响,以3T3-L1脂肪细胞为研究对象,用不同种类、不同浓度的中长链脂肪酸处理细胞,观察细胞凋亡和脂肪生成情况。结果发现:中长链脂肪酸可以抑制3T3-L1脂肪细胞增殖,并且存在剂量依赖性,C16∶0、C18∶0、C18∶3c6,9,12、EPA处理组与对照组相比,具有显著性差异,而DHA处理组与对照组相比具有极显著性差异;C18∶3c6,9,12和EPA处理后,剪切形式PARP增加,说明C18∶3c6,9,12和EPA能诱导细胞凋亡;油红O染色结果表明两种浓度(150μmol/L和180μmol/L)的EPA和DHA均能显著促进脂肪细胞的脂肪生成。综上可知,不同脂肪酸对细胞生长、增殖和凋亡有不同作用,特别是EPA能诱导细胞凋亡,EPA和DHA可显著促进细胞的脂肪生成。     

绿茶成分对3T3-L1细胞的细胞增殖及脂肪代谢的影响

目的:研究绿茶成分——儿茶素、咖啡碱和茶氨酸对3T3-L1前脂肪细胞的细胞增殖及脂肪代谢的影响。方法:测定不同浓度儿茶素、咖啡碱和茶氨酸对3T3-L1细胞增殖的影响,确定无毒性浓度。在分化诱导液中添加各绿茶成分后对3T3-L1细胞进行96h诱导分化,分化后第6天测定脂肪细胞中甘油三酯(TG)含量。细胞分化后第9天,单独添加绿茶成分或同时添加去甲肾上腺素(NA)24h,分析对细胞中脂肪分解的影响。结果:添加20μg/mL以上质量浓度的儿茶素能显著抑制3T3-L1细胞增殖,但质量浓度40,80μg/mL的儿茶素对3T3-L1细胞有毒性作用,而160μg/mL咖啡碱和茶氨酸对细胞增殖无明显影响。20μg/mL儿茶素能显著抑制3T3-L1细胞中TG的合成,而咖啡碱和茶氨酸对细胞脂肪沉积无明显影响。与单独添加NA相比,同时添加咖啡碱能显著促进NA诱导细胞中脂肪分解的能力。结论:儿茶素抑制脂肪细胞的增殖和脂肪沉积,咖啡碱促进激素诱导脂肪分解。绿茶成分中儿茶素和咖啡碱对脂肪细胞内的脂肪代谢有调节作用。     

紫马铃薯花色苷对3T3-L1前脂肪细胞增殖分化的影响

目的:研究紫马铃薯花色苷提取物对3T3-L1前脂肪细胞增殖分化的影响及其机理。方法:采用MTT法检测紫马铃薯花色苷提取物(PPAE)对细胞生长的抑制效果,确定半抑制浓度(IC50);采用流式细胞仪测定细胞周期及凋亡情况;对3T3-L1前脂肪细胞进行诱导分化,油红O染色比色分析紫马铃薯花色苷提取物(PPAE)对其分化程度的影响。结果:紫马铃薯花色苷提取物(PPAE)能显著地抑制3T3-L1前脂肪细胞的增殖且呈剂量时间依赖性;能有效诱导细胞凋亡,同时在G2/M期产生阻滞;紫马铃薯花色苷提取物能显著地抑制3T3-L1前脂肪细胞分化,减少细胞中脂质的沉积。结论:紫马铃薯花色苷提取物能有效抑制3T3-L1前脂肪细胞的增殖与分化,提示其可能具有预防肥胖的功效。     

不同比例LA/ALA对HepG2细胞炎症因子的影响

选取植物油中典型的多不饱和脂肪酸亚油酸(LA)和α-亚麻酸(ALA)为原料,分为7个不同摩尔浓度配比实验组(组1,LA;组2,10∶1 LA/ALA;组3,5∶1 LA/ALA;组4,1∶1 LA/ALA;组5,1∶5 LA/ALA;组6,1∶10 LA/ALA;组7,ALA)体外评估不同比例n-6/n-3 PUFAs对HepG2细胞炎症因子的影响。结果表明:60μmol/L各实验组均可降低HepG2细胞产生的促炎因子TNF-α和IL-6水平,提高抗炎因子IL-10和抗炎介质LXA4水平,其中组4(1∶1 LA/ALA)作用最显著。     

双酚S影响3T3-L1前脂肪细胞分化及其作用机制的研究

双酚A(BPA)的内分泌干扰作用以及对人体产生的不良影响,使双酚S(BPS)作为替代品在食品包装材料中应用更加广泛。BPS在大规模应用之前,并没有对其安全性进行充分研究。本文以3T3-L1前脂肪细胞为体外模型,探究BPS对3T3-L1前细胞分化的影响及作用途径,评价BPS安全性的同时,也为肥胖等慢性代谢疾病的预防提供参考。研究结果表明:BPS能促进3T3-L1前脂肪细胞生长,当浓度超过400μmol/L时,才能显著抑制细胞的增殖;BPS能显著诱导分化的3T3-L1细胞内脂质的积累,并呈现非剂量依赖关系;与模型组相比,BPA上调PPARγ、C/EBR和aP2基因的表达,而BPS只作用PPARγ基因的过表达,BPS和BPA都能使GLUT4基因的表达显著下降(p0.01)。总之BPS和BPA作用脂肪细胞分化的途径不完全一样,可能是在多种转录因子的共同作用下完成的。     

异甘草素对3T3-L1前脂肪细胞分化的抑制作用

目的：考察异甘草素对3T3-L1前脂肪细胞分化的影响,探究其作用机制。方法：采用3T3-L1前脂肪细胞,利用磺酰罗丹明B（sulforhodamine B,SRB）法检测异甘草素对3T3-L1前脂肪细胞增殖的影响,采用传统的鸡尾酒法诱导3T3-L1细胞分化为脂肪细胞,利用油红O染色法检测分化细胞脂滴形成;采用实时荧光定量逆转录聚合酶链式反应方法,检测细胞CCAAT增强子结合蛋白（CCAAT-enhancer-binding proteins,C/EBP）亚型C/EBPα、C/EBPβ、脂肪酸合成酶（fatty acid synthetase,FAS）、脂肪分化相关蛋白adipophilin、过氧化物酶体增殖物激活受体γ（peroxisome proliferators activated receptor γ,PPARγ）、腺苷酸活化蛋白激酶（adenosine monophosphateactivated protein kinase,AMPK）的mRNA表达水平,Western blotting法检测AMPK蛋白磷酸化水平。结果：异甘草素可浓度依赖性地抑制3T3-L1细胞增殖,并明显抑制分化细胞内脂滴形成,同时抑制了细胞分化相关基因C/EBPα、C/EBPβ、FAS、adipophilin、PPARγ mRNA的表达,AMPK mRNA的表达未受影响,但异甘草素处理明显上调了AMPK蛋白的磷酸化水平。结论：异甘草素可抑制3T3-L1前脂肪细胞向脂肪细胞分化,其机制可能与活化AMPK信号通路相关。     

代代花总黄酮对3T3-L1细胞增殖活性的影响

本文研究了代代花总黄酮抑制3T3-L1细胞增殖及诱导其凋亡的作用。不同浓度的代代花总黄酮作用于3T3-L1细胞24 h之后,采用MTT法检测代代花总黄酮对细胞增殖的抑制作用;使用倒置显微镜观察细胞形态学的变化;Annexin V-EGFP/PI标记检测细胞凋亡率;PI标记法检测了代代花总黄酮对细胞周期的影响;活性氧(ROS)试剂盒检测细胞内ROS水平;荧光定量PCR检测了凋亡相关基因的m RNA水平表达。结果表明,高浓度(300μg/m L和400μg/m L)的代代花总黄酮可显著抑制3T3-L1细胞增殖,细胞的抑制率分别为38%和63%,且细胞形态发生了明显变化,并显著升高了细胞内ROS浓度。细胞凋亡实验结果显示,代代花总黄酮可诱导3T3-L1细胞早期凋亡和晚期凋亡,100μg/m L、200μg/m L和300μg/m L代代花总黄酮处理组的细胞早期凋亡率分别为4.6%、15.7%和22.5%;晚期凋亡率分别为14.4%、8.3%和32.2%。而细胞周期实验则表明,处理后3T3-L1细胞G0/G1期细胞数比例从58.9%下降到51.4%,而相应的S期细胞数比例呈小幅度增加,G2/M期细胞数比例变化不明显。凋亡相关基因p21及p53的m RNA表达明显升高及促凋亡基因bax与抗凋亡基因bcl-2比例的升高使3T3-L1进入细胞凋亡程序。     

Endogenous production of n-3 and n-6 fatty acids in mammalian cells

Polyunsaturated fatty acids (PUFA) are important components of mammalian diets, and the beneficial effects of n-3 PUFA on human development and cardiovascular health have been well documented. Caenorhabditis elegans is one of the few animals known to be able to produce linoleic (LA, 18:2n-6) and alpha-linolenic (ALA, 18:3n-3) essential fatty acids. These essential PUFA are generated by the action of desaturases that successively direct the conversion of monounsaturated fatty acids (MUFA) to PUFA. The cDNA coding sequences of the C. elegans Delta(12) and n-3 fatty acid desaturases were each placed under the control of separate constitutive eukaryotic promoters and simultaneously introduced into HC11 mouse mammary epithelial cells by adenoviral transduction. Phospholipids from transduced cells showed a significant decrease in the ratios of both MUFA:PUFA and n-6:n-3 fatty acids relative to control cultures. The fatty acid profile of transduced cellular phospholipids revealed significant decreases in MUFA and arachidonic acid (20:4n-6), and increases in LA, ALA, and eicosapentaenoic acid (20:5n-3). The fatty acid composition of triacylglycerols derived from transduced cells was similarly, but less dramatically, affected. These results demonstrate the functionality of C. elegans fatty acid desaturase enzymes in mammalian cells. Expression of these desaturases in livestock might act to counterbalance the saturating effect that rumen microbial biohydrogenation has on the fatty acid profile of ruminant products, and allow for the development of novel, land-based dietary sources of n-3 PUFA.     

n-3脂肪酸鸡蛋营养价值分析

n-3类脂肪酸健康功效明确,其中EPA和DHA对降低心血管疾病风险等方面有较强作用,但人群摄入量往往不足.研究表明,通过对母鸡饲料进行n-3脂肪酸强化能有效地增加蛋黄内EPA和DHA的含量,其中DHA强化鸡蛋比未强化鸡蛋含量高2.4～10倍.每人每天食用1～2个n-3脂肪酸鸡蛋可使得机体每日摄入的EPA和DHA达到膳食推荐量.而由于n-3脂肪酸的引入,相应的安全性评估也应加强,包括需从n-3脂肪酸的摄入量、n-3脂肪酸鸡蛋里的深海鱼污染物和胆固醇含量等几个方面进行评价.     

Production response of multiparous Holstein cows treated with bovine somatotropin and fed diets enriched with n-3 or n-6 fatty acids

Multiparous cows (n = 59) were blocked by expected calving date and previous milk yield and assigned randomly to treatments to determine the effects of bovine somatotropin (bST; Posilac, Monsanto Animal Agricultural Group, St. Louis, MO) and source of dietary fat on production responses. Diets were provided from calving and included whole, high-oil sunflower seeds [SS; 10% of dietary dry matter (DM); n-6:n-3 ratio of 4.6] as a source of linoleic acid (18:2) or a mixture of Alifet-High Energy and Alifet-Repro (AF; Alifet USA, Cincinnati, OH; 3.5 and 1.5% of dietary DM, respectively; n-6/n-3 ratio of 2.6) as a source of protected n-3 fatty acids. Diets contained 181 versus 188 g of crude protein and 183 versus 186 g of acid detergent fiber/kg of DM and 1.54 versus 1.66 Mcal of net energy for lactation at the actual DM intake for SS versus AF, respectively. Cows received 0 or 500 mg of bST every 10 d from 12 to 70 d in milk (DIM) and at 14-d intervals through 280 DIM. The 2 × 2 factorial combination of diet (SS or AF) with or without bST administration resulted in treatments designated as SSY, SSN, AFY, and AFN, respectively. Data were analyzed as repeated measures using mixed model procedures to determine the effects of diet, bST, and their interactions. Yield of 3.5% fat-corrected milk was not altered by diet, but was increased by 4.0 ± 1.9 kg/d from 12 to 70 DIM and by 5.1 ± 1.2 kg/d from 12 to 280 DIM by bST. Treatment did not affect DM intake or energy balance (EB) nadir. There was an interaction of bST and diet on EB because AF decreased the impact of bST on overall EB and allowed AFY cows to reach a positive EB earlier than SSY cows. Gross feed efficiency adjusted for body weight change was greater for bST-treated cows (1.03 vs. 1.15 ± 0.03 kg of fat-corrected milk/Mcal of net energy for lactation). Circulating insulin-like growth factor-I concentrations were increased by bST (85 vs. 125 ± 8 ng/mL). Body weight, body condition score, and backfat thickness were reduced by bST, but differences between treated and nontreated cows did not differ by 280 DIM. Results indicate cows responded to bST administration in early lactation, but the magnitude of the response was greater after 70 DIM. Source of dietary fat had a minimal effect on most production measurements, but relative to SS, AF decreased the impact of bST on overall EB. Results support the premise that bST administration prolongs the delay in postpartum tissue replenishment.     

甘油酯型n-3多不饱和脂肪酸富集方法研究进展北大核心CSCD

n-3多不饱和脂肪酸(n-3 PUFA)具有多种生理活性,其主要有3种存在形式,其中甘油酯型n-3 PUFA因其生物利用度高和不易被氧化而优于游离型和乙酯型。然而,目前鲜有对甘油酯型n-3 PUFA进行高纯度富集的方法。为了对甘油酯型n-3 PUFA的高值化更加深入的研究提供参考,综述了富集甘油酯型n-3 PUFA的3种常见方法(物理一步法、两步法和酶一步法)及优缺点。物理一步法可以避免产物氧化,但得率较低;两步法工艺复杂,并有可能产生环境污染;而酶一步法具有简单、高效等优点,成为学者们关注的焦点。现有脂肪酶对甘油酯型n-3 PUFA的富集能力有限,还需进一步发掘富集能力更强的选择性脂肪酶。     

高脂日粮中n-6、n-3脂肪酸配比对小鼠机体抗氧化能力及血脂的影响

为了了解不同n-6、n-3系多不饱和脂肪酸配比对小鼠机体抗氧化能力和血脂的影响,通过测定饲喂6周不同饲料C57小鼠血浆中总抗氧化能力(T-AOC)、超氧化物岐化酶(SOD)、丙二醛(MDA)、总胆固醇(TC)、甘油三酯(TC)、高密度脂蛋白胆固醇(HDL)、低密度脂蛋白胆固醇(LDL)和致动脉粥样硬化指数(A11并进行统计分析.实验结果表明,从改善血脂、提高机体抗氧化能力来看,n-6、n-3不饱和脂肪酸比例10:1组效果好于5:1组,若添加抗氧化剂LA,有利于改善机体脂质过氧化产生的不良影响,对预防动脉粥样硬化会起到积极的作用.     

Significance of Increasing n-3 PUFA Content in Pork on Human Health

Evidence for the health-promoting effects of food rich in n-3 polyunsaturated fatty acids (n-3 PUFA) is reviewed. Pork is an important meat source for humans. According to a report by the US Department of Agriculture (http://www.ers.usda.gov/topics), the pork consumption worldwide in 2011 was about 79.3 million tons, much higher than that of beef (48.2 million tons). Pork also contains high levels of unsaturated fatty acids relative to ruminant meats (Enser, M., Hallett, K., Hewett, B., Fursey, G. A. J. and Wood, J. D. (1996) Enser, M., Hallett, K., Hewett, B., Fursey, G. A. J. and Wood, J. D. (1996). Fatty acid content and composition of English beef, lamb and pork at retail. Meat Sci. 44:443–458.[Crossref], [Web of Science ®] , [Google Scholar]. Fatty acid content and composition of English beef, lamb, and pork at retail. Meat Sci. 44:443–458). The available literature indicates that the levels of eicosatetraenoic and docosahexaenoic in pork may be increased by fish-derived or linseed products, the extent of which being dependent on the nature of the supplementation. Transgenic pigs and plants show promise with high content of n-3 PUFA and low ratio of n-6/n-3 fatty acids in their tissues. The approaches mentioned for decreasing n-6/n-3 ratios have both advantages and disadvantages. Selected articles are critically reviewed and summarized.     

Enhanced n-3 phospholipid content reduces inflammatory responses in bovine endothelial cells

Uncontrolled inflammation contributes to the increased incidence and severity of infectious diseases in periparturient dairy cattle. The objective of this study was to determine if increasing n-3 fatty acid (FA) content and altering the profile of vasoactive eicosanoids could attenuate endothelial cell inflammatory responses. Bovine aortic endothelial cells (BAEC) were cultured with free FA mixtures that mimic the plasma NEFA composition during the first week of lactation of dairy cows or with a free FA mixture supplemented with a higher proportion of n-3 FA, including eicosapentaenoic and docosahexaenoic acids. The effects of increasing the docosahexaenoic and eicosapentaenoic acid content of BAEC on the expression of proinflammatory mediators and eicosanoid biosynthesis was assessed. Culturing BAEC with enriched concentrations of n-3 FA decreased the expression of proinflammatory cytokines, adhesion molecules, and reactive oxygen species with a concomitant increase in the biosynthesis of proresolving eicosanoids, including resolvins, protectins, and lipoxins. This study showed for the first time that increasing the n-3 FA content of endothelial cell phospholipids could alter the expression of eicosanoids and control the magnitude of inflammatory responses. Future studies are necessary to elucidate the mechanisms by which resolvins, protectins, and lipoxins may modify endothelial inflammatory pathways necessary to reduce the severity and duration of disease in periparturient cows.     

Stability and consumer acceptance of long-chain omega-3 fatty acids (eicosapentaenoic acid, 20:5, n-3 and docosahexaenoic acid, 22:6, n-3) in cream-filled sandwich cookies

ABSTRACT:  We formulated a filling for sandwich cookies containing 400 mg of eicosapentaenoic acid, 20:5, n-3 (EPA) + docosahexaenoic acid, 22:6, n-3 (DHA) encapsulated in a matrix of starch and gelatin. Cookies were stored at 2 different temperatures (18 °C and 35 °C) and under 2 different packaging conditions (atmospheric and vacuum packed) for 28 d. At regular intervals, cookies were analyzed for moisture, water activity, and concentrations of EPA, DHA, and dienes. Results showed that there were no significant losses of EPA and DHA during storage under the conditions of study. A maximum loss of 5% was observed after 28 d of storage. The concentration of dienes obtained under different conditions were low (< 25 mmol/kg) as compared to a salmon oil sample with appreciable signs of oxidation (600 mmol/kg). Sensory evaluation of cookies by an untrained panel of healthy consumers and ulcerative colitis patients revealed no aftertaste and high acceptability of the cookies. Our results demonstrated that it is possible to make shelf-stable fortified foods with high levels of long-chain ω3FA.     

n-3多不饱和脂肪酸饮食对小鼠肥胖及相关细胞因子的影响

目的：研究n-3 多不饱和脂肪酸(polyunsaturated fat acids,PUFAs)饮食对小鼠肥胖程度及相关细胞因子血清水平的影响,探讨其作用机理。 方法：将健康小鼠分为高饱和脂肪酸饮食组、n-3 多不饱和脂肪酸饮食组和对照组,记录每周小鼠进食量和体质量,实验结束时用ELISA 法检测小鼠血清增食因子A(orexin-A)、抵抗素(resistin)、脂联素(adiponectin)水平。 结果：n-3 多不饱和脂肪酸饮食组小鼠与高饱和脂肪酸饮食组小鼠相比,肥胖程度明显降低 (P ＜ 0.05),血清的增食因子A 水平明显降低(P ＜ 0.05),血清的抵抗素水平明显升高(P ＜ 0.05),血清的脂联素水平升高但无统计学差异;n-3 多不饱和脂肪酸饮食组小鼠的各项指标和对照组相比均无统计学差异。结论：n-3 多不饱和脂肪酸饮食与饱和脂肪酸饮食相比,可抑制肥胖的发生和发展。     

Production of n-3 polyunsaturated fatty acid concentrate from sardine oil by immobilized Candida rugosa lipase

ABSTRACT:  This study was conducted to develop an immobilized-enzyme system to entrap lipase in chitosan-alginate-CaCl₂ beads for the purpose of concentrating n-3 polyunsaturated fatty acids (n-3 PUFAs) from sardine oil. Lipase was immobilized by an ionotropic gelatin method analyzed for characteristics. Optimum pH of immobilized lipase shifted from pH 7.0 to 6.0 and immobilized lipase showed higher stability against pH and temperature changes. Original sardine oil contained 38.1% n-3 PUFAs (25.2% 20:5n3 and 7.20% 22:6n3), and the concentration was significantly increased to 65.3% (40.2% 20:5n3 and 15.5% 22:6n3) with free lipase and to 64.8% (39.6% 20:5n3 and 15.3% 22:6n3) with immobilized lipase after 90 min of repeated hydrolysis. Fatty acid content of the free fatty acid (FFA) fraction of hydrolyzed oil showed that lipase preferably hydrolyzed 16:0, 16:1n7 and 18:0 accounting for 76.6% and 69.5% of total FFAs (after 1st and 2nd hydrolysis, respectively). This study shows that use of immobilized lipase systems for increasing n-3 PUFA concentration in sardine oil provides new processing opportunities for the industry.