南极磷虾油、鱼油与花生四烯酸油对骨质疏松症小鼠脂质代谢的影响

目的：比较南极磷虾油、鱼油和花生四烯酸油对去卵巢骨质疏松小鼠脂质代谢的影响。方法：对8 周龄健康雌性C57BL/6J小鼠部分进行双侧去卵巢手术,建立绝经后骨质疏松症模型;部分不进行去卵巢手术,仅进行开腹腔与缝合的假手术,作为假手术组（生理盐水）。将造模成功的小鼠分为模型对照组（生理盐水）、南极磷虾油组（150 mg/kg mb）、鱼油组（80 mg/kg mb）和花生四烯酸油组（140 mg/kg mb）。连续灌胃12 周后取材,测定骨密度,血清和肝脏中的总胆固醇、甘油三酯水平,肝脏中脂质合成相关基因表达水平等相关指标。结果：两种n-3多不饱和脂肪酸（polyunsaturated fatty acids,PUFA）油脂南极磷虾油和鱼油能极显著降低骨质疏松小鼠体脂比（P＜0.01）,改善血脂及肝脏脂质水平,显著或极显著下调肝脏中脂质合成关键基因SREBP-1c、FAS、ACC、SCD1的mRNA表达（P＜0.05、P＜0.01）;而n-6 PUFA油脂花生四烯酸油会升高血脂水平并上调肝脏中脂质合成关键基因的表达。结论：两种n-3 PUFA均能够显著改善骨质疏松小鼠脂代谢紊乱,且南极磷虾油效果更好;而n-6 PUFA花生四烯酸油则加剧脂代谢紊乱。     

南极磷虾油提取工艺的研究进展

南极磷虾油是一种从南极磷虾中提取的功能性油脂,富含磷脂、虾青素、二十二碳六烯酸(Docosahexaenoic Acid,DHA)和二十碳五烯酸(Eicosapentaenoic acid,EPA)等活性物质,对人体有多种生理功能,如预防心脑血管疾病,促进大脑发育、抗氧化、缓解痛风和类风湿关节炎等。南极磷虾油提取工艺目前主要有有机溶剂提取法、超临界-CO₂萃取法、亚临界萃取法、酶解结合有机溶剂提取法及压榨法等。本文综述了南极磷虾油的提取工艺,以期为企业生产南极磷虾油提供参考。     

南极磷虾油制备技术及其生理功能的研究进展

南极磷虾油是一种从南极磷虾中提取出来的功能性油脂,富含磷脂、Omega-3多不饱和脂肪酸,特别是二十碳五烯酸（eicosapentaenoic acid,EPA）和二十二碳六烯酸（docosahexaenoic acid,DHA）以及虾青素等活性物质,对人体有多种生理功能,包括预防心脑血管疾病、抗癌、提升脑部机能以及促进运动健康等。目前南极磷虾油的提取工艺主要包括有机溶剂提取法、超临界CO2萃取法、亚临界萃取法、酶解结合有机溶剂提取法及压榨法等。该文综述南极磷虾油的提取工艺及南极磷虾油的生理功能,为南极磷虾油的开发利用提供参考。     

南极磷虾油提取工艺的优化

对从南极磷虾中提取磷虾油的工艺条件进行研究。探讨了在不同的料液比、处理温度、处理时间和超声波功率对磷虾油提取率的影响。在单因素试验的基础上,选择四因素三水平进行正交试验优化工艺参数。结果表明,磷虾油的最佳提取条件为:时间3 h,温度35℃,料液比1∶7(g/m L),功率130 W,磷虾油得率为16.3%。     

南极磷虾油提取方法及生理活性研究进展

南极磷虾是一类广泛分布于南极海域的多年生浮游甲壳动物,生物贮藏量大.南极磷虾油富含磷脂型n-3多不饱和脂肪酸,具有重要的生理功能,是一种可替代鱼油的新型功能性油脂.本文对南极磷虾油常用的提取方法(溶剂提取法、临界流体法和生物酶法)和生理活性(抗炎作用、保护心脑血管、神经保护和改善骨质疏松)进行论述,并对南极磷虾油的开发...     

南极磷虾油氧化稳定性研究进展北大核心CSCD

南极磷虾油是一种富含n-3多不饱和脂肪酸的功能性油脂。为提升南极磷虾油的氧化稳定性,首先简要介绍了影响南极磷虾油氧化稳定性的脂质组成要素,概括了不同加工方式对南极磷虾油氧化稳定性的影响,在此基础上详述以传统脂质氧化指标、微量成分含量变化、挥发性成分、脂质组学评估南极磷虾油氧化稳定性的现状。南极磷虾油的脂质劣变机制复杂,氧化状况评估困难,未来应筛选出合理化评估南极磷虾油氧化稳定性的方法,并系统研究其脂质组成与氧化稳定性之间的量效关系。     

南极磷虾油酶解法提取工艺研究

以复合蛋白酶为工具酶,研究采用酶解法从南极磷虾中提取油脂。采用单因素实验研究酶用量、酶解温度和酶解时间对南极磷虾油提取率的影响。在单因素实验基础上,采用响应面法进行工艺优化,得到最佳酶解条件为:中性环境,酶用量0.13%,酶解温度43.8℃,酶解时间4.9 h;在此条件下,南极磷虾油提取率为96.06%。所得南极磷虾油磷脂含量为28.7%,虾青素含量为150mg/kg,DHA含量为8.99%,EPA含量为16.90%。     

南极磷虾油磷脂富集工艺的优化

借鉴水化脱胶原理,对南极磷虾油磷脂富集工艺进行优化。通过单因素实验考察了反应溶液类型、质量分数、加入量,反应温度,反应时间及搅拌速度对南极磷虾油磷脂富集效果及富集后各功能成分的影响,得到南极磷虾油磷脂富集的最佳工艺条件为南极磷虾油中加入4倍南极磷虾油磷脂量的2%柠檬酸溶液、反应温度60 ℃、搅拌速度60 r/min、反应时间30 min。在最佳条件下磷脂富集效果明显,分离得到的磷脂溶液经冻干后磷脂含量可达70.78%,EPA和DHA含量分别为151.93 mg/g和113.70 mg/g;而分离得到的甘油三酯中虾青素含量最高可达780.49 mg/kg。     

酶解技术在南极磷虾油提取中的应用研究进展

南极磷虾油是提取自南极磷虾的重要产品,其作为一种新兴功能性海洋脂质,具有广阔的市场前景。首先概述了南极磷虾油的提取方法,在此基础上针对南极磷虾油酶解法提取工艺中涉及的蛋白酶种类、原料和酶解液脱脂方法进行综述,同时详述了酶解法处理过程中副产品的综合利用。酶解法提取南极磷虾油存在酶制剂价格较高、酶解后油相、水相存在乳化等问题,但该法不仅可以得到高品质的南极磷虾油,而且脱脂后的酶解副产品可进一步利用,最终实现南极磷虾的高值化利用。     

南极磷虾油改善大鼠学习记忆能力研究

目的：观察南极磷虾油对Wistar大鼠学习记忆能力的影响。方法：采用Morris水迷宫法及Y-型迷宫刺激法观察,比较南极磷虾油和深海鱼油对大鼠学习记忆能力的作用。结果：Morris水迷宫实验显示南极磷虾油能够显著减少大鼠寻找平台潜伏期时间并且增加垮台次数和目标区域游泳时间所占比例(P＜0.05或P＜0.01);Y-型迷宫刺激实验表明南极磷虾油能够显著减少大鼠达标所需次数,显著提高48h后的实验正确率(P＜0.05或P＜0.01)。结论：南极磷虾油可显著改善大鼠学习记忆能力,且效果优于深海鱼油。     

一种家庭用营养均衡型配方食用油的加热及烹饪稳定性北大核心CSCD

通过模拟加热(180℃加热15、30 min)及家庭烹饪(炒青菜)过程,研究了一种富含不饱和脂肪酸、n-6/n-3脂肪酸比例适宜且有益脂质伴随物含量丰富的配方食用油的加热及烹饪稳定性。结果表明:配方食用油在加热或烹饪青菜时其酸值、过氧化值略有上升,但均远低于GB 2716—2018的规定;加热和炒菜过程中不会造成反式脂肪酸含量的增加,且苯并(a)芘含量远低于国标限量,说明在加热和炒菜过程中该配方食用油能够保持安全稳定;此外,配方食用油脂肪酸组成在加热或烹饪前后变化不大,n-6/n-3脂肪酸比例稳定,生育酚和总酚含量在加热和烹饪后下降幅度在35%以内,植物甾醇含量下降约12%。由此可知,配方食用油能够在常规家庭烹饪过程中保持稳定,是一种日常补充n-3多不饱和脂肪酸和有益脂质伴随物的有效途径。     

Increasing dietary levels of docosahexaenoic acid-rich microalgae: Ruminal fermentation,animal performance,and milk fatty acid profile of mid-lactating dairy cows

This study aimed to evaluate the effects of increasing dietary levels of microalgae (ALG), rich in docosahexaenoic acid (DHA; All-G-Rich, Alltech, Nicholasville, KY), in isolipidic diets, on animal performance, nutrient digestibility, ruminal fermentation, milk fatty acid profile, energy balance, microbial protein synthesis, and blood serum metabolites in mid-lactating dairy cows. Twenty-four Holstein cows [130.3 ± 15.4 d in milk, and 30.8 ± 0.543 kg/d of milk yield (mean ± standard error)] were used in a 4 × 4 Latin square design experiment to evaluate the following treatments: control diet, without addition of ALG; and increasing levels of ALG [2, 4, and 6 g/kg of dry matter (DM)]. The ALG decreased DM intake and increased total-tract DM apparent digestibility. A tendency was observed for a quadratic effect on total-tract NDF digestibility by ALG inclusion, with peak value of the quadratic response at 4.13 g/kg of DM dose. Moreover, ALG increased ruminal pH and decreased acetate and total volatile fatty acid concentrations. Fat-corrected milk and energy-corrected milk were quadratically affected, and a tendency for a milk yield effect was observed when ALG levels increased, whereas maximal yields were observed with intermediate doses. Milk fat, protein, and lactose concentrations were diminished, whereas productive efficiency was improved by the increase of ALG levels. Saturated fatty acid proportions were decreased, whereas polyunsaturated fatty acid proportions were increased when ALG was fed. There was low DHA transfer into milk; however, ALG inclusion decreased C18:0, C18:1 cis-9, C18:2 cis-9,12, and C18:3 cis-9,12,15 proportions, and increased C18:2 cis-9,trans-11, C18:1 trans-9, and C18:1 trans-11 proportions. Gross energy intake was decreased, whereas no effect was observed on digestible, metabolizable, or net energy intake. The ALG inclusion quadratically affected the microbial protein synthesis, with maximal enhancement at 3.24 g/kg of DM dose, and also increased serum cholesterol concentration. Under the conditions of this experiment, the inclusion of ALG in diets for mid-lactating dairy cows decreased feed intake and increased nutrient digestibility, improving productive efficiency and modifying milk fatty acid profile. Estimated intermediate doses (1.22 to 2.90 g/kg of DM) of DHA-rich ALG may be beneficial to milk, fat-corrected milk, and energy-corrected milk yields, and is recommended for dairy cows.     

Endogenous production and elevated levels of long-chain n-3 fatty acids in the milk of transgenic mice

n-3 Polyunsaturated fatty acids (n-3 PUFA) are important for the normal development and functioning of all organisms. Mammals lack the n-3 fatty acid desaturase required for the synthesis of α-linolenic acid (18:3n-3), and are therefore dependent on dietary sources to obtain this essential fatty acid. Currently, the richest source of dietary long-chain n-3 PUFA, eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3), are triacylglycerides extracted from rapidly declining marine resources. The nematode Caenorhabditis elegans synthesizes a wide range of PUFA and possesses the only known example of an n-3 fatty acid desaturase enzyme in the animal kingdom. Transgenic mice expressing the C. elegans n-3 desaturase under the control of the lactation-induced goat β-casein mammary gland promoter were generated via pronuclear microinjection. Significant increases in n-3 PUFA, decreases in n-6 PUFA, and an overall decrease in the n-6:n-3 PUFA ratio were observed in the milk produced by transgenic mice. Neonate mice consuming milk from transgenic females accumulated increased levels of docosahexaenoic acid in their brains. This transgenic model may provide useful information to address some basic questions of neonatal nutrition, and demonstrates one of the steps that would be required to increase the n-3 PUFA content of milk and dairy products endogenously. Increasing the proportion of n-3 PUFA in milk fat would help to improve the nutritional composition of an important component of the North American diet.     

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.     

α-亚麻酸研究进展

α-亚麻酸属于n-3系列多不饱和脂肪酸,分子结构为△9,12,15-18:3,主要来源于陆地植物, 如杜仲、藿香、亚麻、紫苏等。在体内代谢过程中,它主要作为EPA和DHA前体物质,并具有降低胆固醇、血脂,预防心血管疾病、保护视力和抑制过敏反应等功能。该文主要介绍α-亚麻酸的来源、分离提取方法进展及生理功能,并对α-亚麻酸发展前景进行展望。     

南极磷虾脂质的亚临界提取及磷脂分析

研究了南极磷虾脂质的亚临界丁烷提取工艺。测定了南极磷虾脂质的酸值、过氧化值、氟含量、生育酚含量、虾青素含量、磷脂含量及磷脂种类组成、脂肪酸组成。结果表明,通过单因素试验确定了亚临界丁烷提取南极磷虾脂质的较佳工艺条件为:动态提取时间120 min(单次提取时间30min、提取4次)、提取压力1.0 MPa、提取温度40℃;在较佳工艺条件下南极磷虾脂质提取率为21.39%;提取的南极磷虾脂质的酸值(KOH)10.6 mg/g,过氧化值3.01 meq/kg,虾青素含量248.4mg/kg,生育酚含量67.7 mg/kg,磷脂含量28.68%,其中磷脂中磷脂酰胆碱占71.20%;磷脂酰胆碱中脂肪酸组成与甘三酯的基本一致,但磷脂酰胆碱中EPA和DHA含量明显高于甘三酯的。     

挤压对南极磷虾渣中脂质留存的影响

南极磷虾因其巨大的生物资源量,良好的营养和功能特性受到广泛关注。比较未经热处理南极磷虾和经热处理南极磷虾采用双螺杆挤压前后脂质含量和组成的变化,探索双螺杆挤压技术应用于南极磷虾单元加工的可行性。研究发现,两种处理方法的南极磷虾经过双螺杆挤压处理后,其饱和脂肪酸总含量减少,单不饱和脂肪酸总含量相对稳定,ω-3多不饱和脂肪酸总含量减少,ω-6多不饱和脂肪酸总含量增加。未经热处理的南极磷虾挤压前后脂质含量的变化1.74%小于经过热处理的南极磷虾挤压前后的脂质含量4.16%。试验结果表明,双螺杆挤压处理对南极磷虾固体部分脂质留存有较大的影响,其中经过热处理后的南极磷虾挤压后其固体部分的脂质改变较显著。     

南极大磷虾油脂的提取及其脂肪酸组成分析

通过单因素实验和正交实验对有机溶剂萃取南极大磷虾油脂的工艺参数进行了优化,并利用气相色谱分析了所提油脂的脂肪酸组成。研究结果表明无水乙醇为南极大磷虾油脂的最佳提取试剂,当提取温度为65℃,时间为3h,料液比为1:9(w:v)时,可获得最高提取率为19.60g/100g(干基)。气相分析发现南极大磷虾油脂中含有14种脂肪酸,其中不饱和脂肪酸占34.73%,饱和脂肪酸占65.26%;主要脂肪酸种类包括棕榈酸(29.3%)、二十二酸(20.1%)、油酸(13.7%)、十四酸(11.7%)、二十二碳六烯酸(10.2%)、十六烯酸(7.39%)、亚油酸(2.04%)。