高n-3多不饱和脂肪酸鸡蛋的开发研究进展

介绍了n-3多不饱和脂肪酸类别、营养功能及使用哪些饲料原料可以生产高n-3多不饱和脂肪酸鸡蛋,分析了鸡蛋中多不饱和脂肪酸的沉积规律和影响因素,并概述了高n-3多不饱和脂肪酸鸡蛋特点,以及存在的问题和解决途径,为开发高n-3多不饱和脂肪酸鸡蛋提供依据。     

n-3多不饱和脂肪酸分类、来源与疾病防治功能

n-3多不饱和脂肪酸包括ALA、EPA、DPA和DHA等。增加n-3多不饱和脂肪酸摄取量可以促进婴幼儿视网膜、大脑和神经系统发育；n-3多不饱和脂肪酸通过各种途径降低人体心血管疾病和炎症的发生，降低糖尿病患者血清LDL-C和TG水平，抑制体外培养的乳腺、前列腺和结肠癌细胞增生，促进细胞凋亡。     

n-3多不饱和脂肪酸功能性及其应用

<正> 研究表明n-3与n-6两个系列“多不饱和脂肪酸”(以下简称“PUFA”)是人体发育与生长必需脂肪酸,不仅有重要营养价值,而且具有独特生理功能。n-3 PUFA主要有以下三种:α-亚麻酸(α-C_(18:3)),二十碳五烯酸(EPA,C_(20:5)),二十二碳六烯酸(DHA,C_(22:6))。由于人类与其它哺乳类动物自身不能合成这些脂肪酸,必需由食物提供,所以称为必需脂肪酸。在最近30年,人们通过流行病学调查发现:n-3     

制备富含n-3多不饱和脂肪酸的磷脂

以Novozym435为工具酶，在正己烷体系里，使大豆粉末磷脂和n-3多不饱和脂肪酸EPA与DFIA发生酸解反应，制备了结构化磷脂。探讨了温度、时间、加酶量（基于磷脂质量）、底物浓度（磷脂／正己烷）、加水量（基于酶质量）、底物摩尔比（多不饱和脂肪酸／磷脂）对结构化磷脂制备的影响，得出较优条件为：温度50℃、时间60h、加酶量15％、底物浓度20％、加水量3％、底物摩尔比5：1。在此条件下接到磷脂上的EPA和DHA的含量之和可达21．56％。     

功能性n-3多不饱和脂肪酸的研究进展

脂肪酸是生命代谢活动中一种重要化合物,根据脂肪酸碳链数上的双键数将脂肪酸分为饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸三类。文章对n-3多不饱和脂肪酸来源、合成过程、n-3和n-6多不饱和脂肪酸的结构差异以及生物活性进行综述,为n-3多不饱和脂肪酸在功能保健食品、医学药用领域及基础研究进一步探索与全面开发提供理论依据。     

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。     

ω-3多不饱和脂肪酸的来源及生理功能研究进展

ω-3多不饱和脂肪酸主要包括α-亚麻酸、EPA和DHA,是重要的脂质营养素,广泛存在于植物、鱼类及藻类生物中,能有效促进人体生长发育,具有抗炎、抗癌、预防心脑血管疾病、防治糖尿病和降血脂等重要的生理功能。分别阐述α-亚麻酸、EPA和DHA的来源及生理功能,分析其各自的特点及优势,并对α-亚麻酸的应用前景进行展望。     

酶法纯化ω-6和ω-3多不饱和脂肪酸研究进展

多不饱和脂肪酸(PUFAs)具有重要的生理学活性,尤其是ω-6和ω-3系列与人体健康密切相关。因此,如何提取PUFAs非常重要,也是油脂领域的研究热点。利用酶法分离纯化PUFAs是一种环保、高效、具有广泛应用前景的方法。本文综述了酶法纯化ω-6和ω-3PUFAs的最新研究进展,并着重阐述了酶法催化水解、酶法选择性富集以及其它几种能和酶法有效结合、共同分离纯化PUFAs的物理化学方法,同时通过论述亚油酸、亚麻酸、花生四烯酸等PUFAs的纯化进展证明了酶法在该领域内具有很大发展前景。     

n-3多不饱和脂肪酸抑制骨骼肌蛋白异常分解的研究进展

胰岛素/Akt信号通路受阻所致的骨骼肌细胞蛋白异常分解,可能是骨骼肌萎缩发生的重要原因。不同n-3多不饱和脂肪酸在骨骼肌细胞内、外作用于胰岛素/Akt信号通路上的多个位点,均有助于维持通路的正常运作。其中,植物来源n-3多不饱和脂肪酸ALA能通过活化胰岛β细胞胞膜的GPR40直接促进胰岛素分泌;海鱼来源n-3多不饱和脂肪酸EPA与DHA能有效维持骨骼肌细胞内Akt活性并增加胰岛素敏感性。本文通过对相关文献的归纳总结,阐释n-3多不饱和脂肪酸基于胰岛素/Akt信号通路抑制骨骼肌细胞蛋白异常分解的机制,为通过膳食手段干预骨骼肌萎缩提供新的思路。     

超声辅助脂肪酶催化合成富含n-3多不饱和脂肪酸磷脂的研究

以脂肪酶Lipozyme TL IM为催化剂,研究了合成富含n-3多不饱和脂肪酸磷脂的最佳工艺条件,即以正庚烷:异辛烷:正已烷=8:1:1为超声介质,溶剂(mL)/底物(g)=2,酶用量为25%,超声介质中水分质量分数为2%,超声功率70 W,55℃下连续超声5.5 h,在此条件下酯交换到磷脂上的DHA和EPA总质量分数为22.99%。由此可见,通过超声辅助及酯交换条件的优化,不仅可以大大缩短反应所需的时间,而且也能充分激活Lipozyme TL IM的酶活力,从而提高酯化反应的效率。     

n-3多不饱和脂肪酸对疾病的预防与治疗作用

n-3多不饱和脂肪酸主要源于亚麻籽、胡桃仁、大豆以及海洋生物。增加n-3多不饱和脂肪酸摄取量可以促进视网膜、大脑和神经系统发育。n-3多不饱和脂肪酸通过各种途径降低人体心血管疾病和炎症的发生,降低糖尿病患者血清低密度脂蛋白胆固醇(LDL-C)和甘油三酯(TG)水平。膳食中增加n-3多不饱和脂肪酸的含量可以对心血管疾病、糖尿病、炎症等患者有辅助治疗效果;n-3多不饱和脂肪酸可以作用于神经细胞,对注意力不集中、抑郁症、精神分裂症有一定的疗效。n-3多不饱和脂肪酸可抑制体外培养的乳腺、前列腺和结肠癌细胞增生,促进细胞凋亡。     

酶法制备n-3多不饱和脂肪酸型磷脂的工艺

研究了无溶剂体系中固定化磷脂酶A1催化大豆磷脂与乙酯型鱼油进行酯交换反应,制备n-3多不饱和脂肪酸型磷脂的工艺。考察了反应温度、反应时间、底物比(乙酯型鱼油与磷脂的质量比)以及加水量的影响,得到了较优的反应条件。实验结果表明,加酶量(按大豆磷脂的质量计算)20%,底物比8∶1,底物总质量5.0g,加水量55μL,55℃反应12h时,所得产物中EPA和DHA的含量分别为8.0%和17.8%。     

鱼油提取、多不饱和脂肪酸富集及EPA和DHA的应用研究进展

文章对鱼油的提取工艺、多不饱和脂肪酸聚集方法、二十二碳六烯酸（DHA）和二十碳五烯酸（EPA）的保健功能进行了阐述,并对未来鱼油行业的发展进行了展望。     

Omega-3 fatty acids affected human perception of ground beef negatively

The objective was to determine the impact of increasing levels of Eicosapentaenoic acid (EPA; C20:5n3) and Docosahexaenoic acid (DHA; C22:6n3) on beef palatability. Two commercial supplements of EPA and DHA were added to 85% lean ground beef patties (176.2 ± 3.76 g) with different levels (0, 0.3, 0.4, 0.5, 0.6, 0.7, and 1% as-is). Olive oil was added so that all patties contained 1% added lipid. A control treatment was also prepared with no supplement or olive oil. Sensory evaluation and fatty acid analysis was conducted. Ground beef flavor decreased linearly (P<0.001) with increasing levels of EPA and DHA. Off-aroma and off-flavor increased linearly and then plateaued with increasing levels of EPA (P<0.0001). In conclusion, EPA had a greater negative impact on beef palatability than DHA. Also, the panelists were more sensitive to EPA in off-flavor perception than off-aroma.     

尿素包合法富集海狗油中的多不饱和脂肪酸

研究了尿素/脂肪酸的质量比、结晶时间和结晶温度三因素对尿素包合法富集多不饱和脂肪酸效果的影响。结果显示适宜的尿素包合条件为:尿素/脂肪酸的质量比4∶1;结晶时间20h;结晶温度4℃,在此条件下未包合脂肪酸中EPA、DPA和DHA的总含量可从21.1%提高至73.32%,富集得率为17.91%。     

淡水水产品EPA与DHA含量及富集方法研究进展

我国淡水水产品丰富,水产品中或多或少含有EPA和DHA。该文介绍几种淡水水产品EPA与DHA含量及其富集方法。     

不同类型n-3多不饱和脂肪酸对心血管疾病的防治作用及其机制研究进展

3种主要的食源性n-3多不饱和脂肪酸包括α-亚麻酸(ALA)、二十碳五烯酸(EPA)和二十二碳六烯酸(DHA)。综述了ALA、EPA和DHA降低甘油三酸酯水平和血小板凝集,改善炎症和氧化应激指标以及改善血管和心脏血液动力学的功能,从而对动脉粥样硬化等心血管疾病起到防治作用。此外,总结了联合使用ALA、EPA和DHA防治心血管疾病的作用,并进行了展望。     

Re-assembled casein micelles and casein nanoparticles as nano-vehicles for ω-3 polyunsaturated fatty acids

Food enrichment with nutraceuticals is an important goal, but its effectiveness in preventing diseases depends on preserving the functionality and bioavailability of the bioactive nutraceuticals. Omega-3 polyunsaturated fatty acids, such as docosahexaenoic acid (DHA), are important nutraceutical lipids, providing protection against cardiovascular and other diseases. Caseins are the major milk proteins whose biological function is to transport calcium, protein and phosphate from mother to the neonate. Our goal was to harness the natural self-assembly properties of caseins for protecting and delivering this important, but sensitive nutraceutical, DHA. Using spectrofluorescence we have shown, apparently for the first time, that casein can bind DHA with a relatively high affinity (K_b = (8.38 ± 3.12) × 10⁶ M⁻¹), and the binding ratio was 3–4 DHA molecules per protein molecule on average. Moreover, DLS particle characterization experiments have shown the formation of nanoparticles upon addition of DHA (predissolved in ethanol) to a casein solution. When calcium and phosphate were added (at 4 °C), DHA-loaded re-formed casein micelles (r-CM) with a size of 50–60 nm were obtained and there was no significant effect of the thermal treatment (74 °C, 20 s) on particle size. When casein nanoparticles (CNP) were prepared (at room temperature and without adding calcium and phosphate), DHA-loaded CNP with a diameter of 288.9 ± 9.6 nm were formed. Both the DHA-loaded r-CM and the DHA-loaded CNP systems showed a remarkable protective effect against DHA oxidation, demonstrating good colloidal stability and bioactive conservation throughout shelf life at 4 °C. These nanotechnologies may enable the enrichment of foods and beverages for promoting health of wide populations.     

Beta-lactoglobulin and its nanocomplexes with pectin as vehicles for ω-3 polyunsaturated fatty acids

The reduction of fat consumption calls for enrichment of non-fat foods and beverages with essential oil-soluble nutraceuticals, including ω-3 fatty acids. However, the low water-solubility and sensitivity to oxidation require new ways to solubilize and protect such sensitive compounds without compromising the desired sensory attributes of the enriched product. Beta-lactoglobulin (β-Lg), the major whey protein of cow milk, is a natural molecular nano-carrier for hydrophobic molecules. The present work provides apparently first evidence for the spontaneous binding (K_b = (6.75 ± 1.38) × 10⁵ M⁻¹) of docosahexaenoic acid (DHA) to β-Lg. Based on a recent study from our group [Ron, N. (2007). β-Lactoglobulin as a nano-capsular vehicle for hydrophobic nutraceuticals. M.Sc. thesis, Advisor: Dr. Yoav D. Livney, The Technion, Israel Institute of Technology, Haifa, Israel], we herein show the formation of colloidally stable nanocomplexes of DHA-loaded β-Lg and low methoxyl pectin below the isoelectric point of β-Lg (5.2), at pH = 4.5. By adding excess of pectin, negatively charged particles were formed containing ∼166 times higher DHA concentration than the surrounding serum. This enabled the formation of dilutable nanoparticle dispersions, which formed transparent solutions containing 0.05% β-Lg and DHA at a 1:2 (β-Lg:DHA) molar ratio, with a very good colloidal stability and average particle size of ∼100 nm. The entrapment by β-Lg, and moreover, the formation of nanocomplexes with the pectin provided good protection against degradation of DHA during an accelerated shelf-life stress test: only about 5–10% lost during 100 h at 40 °C, compared to about 80% lost when the unprotected DHA was monitored. This study presents a new way to nanoencapsulate long chain polyunsaturated fatty acids like DHA, useful for enrichment of clear acid drinks.     

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。