中碳链脂肪酸甘油三酯的研究进展

中碳链脂肪酸甘油三酯作为一种高效消化吸收的结构脂质和控制脂肪吸收的低能油脂,不仅能够控制肥胖和降低血清胆固醇,还能够抑制或限制组织中的胆固醇沉积物.与普通植物油脂相比,中碳链脂肪酸甘油三酯独特的理化性质和代谢途径使其具有特殊的营养价值、药用价值和生理功能.本文对中碳链脂肪酸甘油三酯的理化性质、制备、代谢特征和生理功能等方面进行简要的概述,以期为中碳链脂肪酸甘油三酯在食品、医药和日用化工等领域的应用提供有益参考.     

母乳中长链甘油三酯研究进展

母乳中甘油三酯的结构对于婴幼儿的脂肪消化吸收具有重要影响。作者所在团队前期研究结果显示,母乳脂肪天然富含中长链甘油三酯（MLCT）,是母乳中含量最丰富的一类甘油三酯,其质量约占总甘油三酯的30%,主要结构是一个中链脂肪酸和两个长链脂肪酸构成的单中链型甘油三酯（MLL）。母乳中几乎不含中链甘油三酯（MCT）。作者综述了母乳脂肪中MLCT的含量、组成、影响因素以及母乳与婴幼儿配方奶粉中甘油三酯的差异,总结了MLCT的消化特性,以及MLCT型母乳替代脂的研究进展,为新型配方奶粉脂肪的开发提供理论依据。     

也谈中链甘油三酯及其应用

我们读了《陕西粮油科技》1992年第3期石金柱同志的《中链甘油三酯及其应用》一文后(以下简称《中》文),对该文另有一些见解与考证,特予专谈,以供广大读者讨论,如有不妥之处,敬请指正.1 MCT的有关概念在《中》文中,作者提及按组成饱和脂肪的脂肪酸碳链的长短,可将其分为三类,其中一类即中链甘油三酯(简称MCT,C_6～C_(12)).笔者以为,上述提法不妥.     

中碳链脂肪酸甘油三酯制备方法的研究进展

中碳链脂肪酸甘油三酯是一种天然油脂的改性产品,因其具有消化吸收快,能量易释放等优点被广泛用于营养、医药、化妆品等领域。对中碳链脂肪酸甘油三酯的理化性质和制备方法进行了综述,以期为进一步研究中碳链脂肪酸甘油三酯的高效合成及工业化生产提供参考。     

中链甘油三酯及其应用

脂肪(甘油酯)以多种形式存在于自然界中,它通常分为饱和和不饱和脂肪两类。在饱和脂肪中,又可按组成脂肪的脂肪酸碳链的长短,分为短链甘油三酯(简称SCT,C_8以下)、中链甘油三酯(简称MCT,C_6～C_(12))、和长链甘油三酯(简称LCT,C_(12)以上)。由于各种脂肪分子结构的不同,决定了它们对人类健康的不同影响。大量研究结果表明,MCT在体内的代谢与LCT有明显的不同(SCT与MCT的代谢相同,但在自然界中含量极少),它对人类的健康有特     

中链甘油三酯及其在食品工业中的应用

作为一种新型的功能性配料，中链甘油三酯具有广泛的工业用途。本文综述了国内外中链甘油三酯的研究进展，包括中链甘油三酯的理化性质、代谢特征和生理功能。最后还简要介绍了中链甘油三酯在食品工业中的应用。     

樟树籽仁油醇解工艺研究

以樟树籽仁油为原料,研究在合成中碳链甘油三酯过程中醇解的工艺条件,主要对樟树籽仁油醇解工艺参数,如醇油摩尔比、反应温度、反应时间、催化剂的用量等作了探讨,并从理论上加以分析,用正交法确定了醇解的最佳工艺参数,为樟树籽仁油生产中碳链甘油三酯提供关键技术.     

重构脂质研究与应用

<正>为能获得有特殊性能的油脂,现研究者和生产厂商都十分关注重构脂质,这是一类具有特定功能,含有混合长、中、短链脂肪酸的甘油三酯.目前主要应用于医药品领域,但在食品方面也有应用实例,如糖果食品等.     

中链甘油三酯的研究进展

中链甘油三酯独特的理化性质和代谢特点使其具有预防肥胖、改善机体糖脂代谢等多种功能,在食品、医药、化妆品、饲料等多种行业得到广泛应用。本文对中链甘油三酯的理化性质、代谢特点、功能性质及安全性进行综述。     

中链甘油三酯微胶囊的体外释放及对小鼠脂质代谢的影响

采用喷雾干燥技术制备中链甘油三酯微胶囊,将中链甘油三酯固态化,方便食品添加和储运;以人工胃液模拟体外释放,初步研究了中链甘油三酯微胶囊的缓释特性;并以基础合成饲料、长链甘油三酯微胶囊高脂饲料(长链甘油三酯供能占总能量30%左右)和中链甘油三酯微胶囊高脂饲料(中链甘油三酯供能占总能量30%左右)分别饲喂小鼠,并观察5周内小鼠健康状况和体质量、血清甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)含量、低密度脂蛋白胆固醇(LDL-C)含量、饲料消耗量的变化,研究中链甘油三酯对小鼠脂质代谢的影响。结果表明,中链甘油三酯微胶囊在人工胃液中可缓慢释放6h,能够缓解中链甘油三酯一次性摄入量超标引起的腹痛腹泻问题,膳食中添加中链甘油三酯微胶囊后,能降低体内TC和LDL-C的含量,中链甘油三酯微胶囊的高脂膳食具有预防肥胖、减少体质量增长和体脂累积、减轻肝脏脂肪沉积的作用,且其抑制体质量增长的机制与减少能量摄入量无关。     

中长链脂肪酸结构脂质及其制备工艺研究进展

中长链脂肪酸结构脂质(MLCT)是指甘油骨架上同时含有长链脂肪酸和中链脂肪酸的结构甘三酯,因其在人体中独特的代谢途径和在免疫系统中所起的积极作用等优势成为油脂领域研究的热点,在食品工业和医疗行业崭露头角.本文针对MLCT的发展历程、生理功效、制备工艺以及实际应用等研究现状进行了综述,以期为MLCT及其他相关功能性结构脂...     

Menhaden body lipids: Details of fatty acids in lipids from an untapped food resource

Menhaden are utilised almost exclusively for fish meal production. The depot fat is concentrated in the bodies. In anticipation of developments in deboned or minced fishery products menhaden body lipids have been recovered and separated into polar and triglyceride fractions for detailed fatty acid study. The original lipid contains about 30% long-chain polyunsaturated fatty acids and could be nutritionally beneficial if protected from autoxidation. A simple petroleum ether extraction removes essentially the same material as found in oil from reduction of whole fish but leaves half the original lipid in the fish.     

Optimization and Scale-Up of Enzymatic Synthesis of Structured Lipids Using RSM

Enzymatic synthesis of structured lipids by transesterification of ethyl caprylate (EC) and soybean oil and sunflower oil (90% oleic acid) in hexane was optimized using response surface methodology (RSM). Incubation time (IT), molar ratio of ethyl caprylate to total triglycerides (MR), percentage of soybean oil as source of long-chain triglycerides (PS), and long-chain triglyceride concentration (TC) were assumed the most important factors affecting nutritional attributes of structured lipids based on caprylic acid (C8:0) and linoleic acid (C18:2 n-6) content. Optimum conditions for synthesis of structured lipids were: IT = 26.4 hr; MR = 8; PS = 75%; TC = 0.58 M. The capryloyl acyl residues in triglyceride predicted by RSM was 67.6 (mol%) and linoleoyl 14.5%. Large scale synthesis was successful. The model was verified experimentally.     

Effects of energy balance on hepatic capacity for oleate and propionate metabolism and triglyceride secretion

The purpose of this study was to identify conditions that could decrease accumulation of triglyceride in liver, preferably by increasing hepatic secretion of triglyceride-rich lipoproteins. Hepatocytes isolated from lactating goats were incubated in vitro, and the fate of [1-14C]oleate was measured to determine hepatic capacity for various routes of long-chain fatty acid metabolism. The effect of in vivo energy balance and modifications of the nutrients present in the culture media were tested. Addition of linoleic acid, isovalerate, niacin, propionate, or propylene glycol did not affect triglyceride accumulation or secretion. Pyruvate decreased intracellular triglyceride accumulation. Changes in oxidation of oleate through manipulation of carnitine acyl transferase activity did not influence oleate esterification rate. Livers and hepatocytes isolated from goats in negative energy balance contained more lipid and triglyceride. Liver cells from goats in negative energy balance had decreased capacity for converting propionate to glucose with no change in ketogenic capacity as judged by acid soluble product formation from oleate. Hepatocytes from goats in negative energy balance retained less oleate as cell triglyceride with no change in triglyceride export, indicating a decreased net rate of esterification. Lactating goats, either in negative or positive energy balance, demonstrated the same low capacity for export of newly synthesized triglyceride as previously reported for fed wethers.     

Effects of fat and methionine hydroxy analog on prevention or alleviation of fatty liver induced by feed restriction

Two trials were conducted to examine the effects of supplemental methionine, provided as methionine hydroxy analog 13 g/d), or fat (454 g of calcium salts of long-chain fatty acids/d) on hepatic triglyceride concentration. In the first experiment, methionine hydroxy analog or fat was fed during feed restriction to determine if hepatic triglyceride accumulation is affected. The objective of the second experiment was to determine if feeding fat or methionine hydroxy analog influences the rate of triglyceride depletion from the liver of cows in positive energy balance following the induction of fatty liver by feed restriction. In experiment 1, feeding methionine hydroxy analog decreased plasma glucose, increased plasma nonesterified fatty acids, and had no effect on liver triglyceride. Feeding fat increased plasma nonesterified fatty acids and increased hepatic triglyceride during the 10-d feed restriction period. In experiment 2, feeding fat decreased the rate of triglyceride depletion from liver when cows were allowed to resume ad libitum consumption of feed; methionine hydroxy analog had no effect. Results of these studies indicate that feeding supplemental fat or methionine hydroxy analog at levels tested does not prevent or alleviate fatty liver induced by feed restriction.     

Ruminal fermentation in vivo as influenced by long-chain fatty acids

Responses of ruminal microbes to long-chain fatty acids in forms of free acids, calcium salts, or triglycerides were measured in trials with rumen cannulated heifers. Addition of fatty acids at 10% to a basal diet of 50% corn silage and 50% grain increased fat content 3 to 10 to 12%. Long-chain fatty acids with a high melting point (stearic acid) and calcium salts of long-chain fatty acids (vegetable fat and tallow) decreased acetate:propionate by about 20%. Long-chain fatty acids with a low melting point (oleic acid) and the triglyceride form of long-chain fatty acid (tallow) decreased acetate to propionate ratio by 50 to 60%. Even though they were not completely inert in the rumen, responses with the hard long-chain fatty acids (stearic acid) and with calcium salts of long-chain fatty acids confirm that these are efficacious for protecting ruminal microbes from adverse effects of fat. With calcium salts of long-chain fatty acids, dietary buffers may be needed to maintain ruminal pH so that dissociation of salts does not occur. Long-chain fatty acid supplementation at 10% of the diet is probably more than the amount needed to optimize productivity and health. With most diets, 6 to 8% supplemental long-chain fatty acid is probably sufficient.     

膳食脂肪的餐后代谢与脂蛋白脂肪酶研究进展

餐后膳食脂肪的代谢涉及到多个方面,主要包括消化道中的消化过程、细胞内乳糜微粒的形成和转运、血脂的消化和乳糜微粒残粒的清除。消化道中的多种酶将膳食脂肪消化成游离的长链脂肪酸,然后通过小肠细胞的多种蛋白将其进行跨膜转运吸收到细胞内,重新形成甘油三酯并和多种脂蛋白形成乳糜微粒。新组装的乳糜微粒携带膳食来源的甘油三酯转运到血液中,经毛细血管内皮表面附着的脂蛋白脂肪酶的催化形成脂肪酸,游离的脂肪酸被周围组织细胞吸收,残粒和多余的脂肪酸被肝细胞吸收。研究表明脂蛋白脂肪酶是血脂清除和组织摄入脂肪酸的限速酶,它的表达在转录和转译等多个不同水平上严格控制,以应对不同的生理信号刺激。如果膳食脂肪的代谢调控出现问题,将会导致高甘油三酯血症,诱发心血管疾病、胰岛素抵抗和肥胖等相关疾病。     

Lipid Modification Strategies in the Production of Nutritionally Functional Fats and Oils

Rapid improvements in the understanding of the nutritional requirements of both infants and adults has led to new developments in the modification of fats and oils. Specific targets include the improvement in growth and development of infants, treatment of disease in adults, and disease prevention. Efforts have been focussed on the production of structured lipids using medium-chain acids and long-chain polyunsaturated fatty acids (PUFAs), as well as the concentration of long-chain PUFAs from new and existing sources. Short- and medium-chain fatty acids are metabolized differently than long-chain fatty acids and have been used as a source of rapid energy for preterm infants and patients with fat malabsorption-related diseases. Long-chain PUFAs, specifically docosahexaenoic acid and arachidonic acid, are important both in the growth and development of infants, while n-3 PUFAs have been associated with reduced risk of cardiovascular disease in adults. Based on the requirements for individual fat components by different segments of the population, including infants, adults, and patients, ideal fats can be formulated to meet their needs. By using specific novel fat sources and lipid modification techniques, the concentrations of medium-chain, long-chain saturated, and long-chain polyunsaturated fatty acids as well as cholesterol can be varied to meet the individual needs of each of these groups. While genetic modification of oilseeds and other novel sources of specific lipid components are still being developed, chemical and lipase-catalyzed interesterification reactions have moved to the forefront of lipid modification technology. Fractionation of fats and oils to provide fractions with different nutritional properties has potential, but little work has been performed on the nutritional applications of this method. The choice of suitable lipid modification technologies will depend on the target lipid structure, production costs, and consumer demand. A combination of some or all of the present lipid modification techniques may be required for this purpose.     

Effect of beta-lactoglobulin on plasma retinol and triglyceride concentrations, and fatty acid composition in calves

Beta-lactoglobulin (beta-lg) is the main protein of ruminant milk whey. Although beta-lg can bind in vitro to a variety of hydrophobic substrates, mainly retinol and long-chain fatty acids, its physiological function is still unknown. In Exp. 1, we investigated the effect of beta-lg on the plasma retinol concentration in preruminant calves. Holstein male calves (n = 20) were fed Holstein whole milk at 40 g/kg body weight (BW) plus vitamin A acetate (500,000 i.u.) with or without beta-lg (0.4 g/kg BW). The plasma retinol concentration of 10-d-old calves was greater (P < 0.05) in the beta-lg-fed group) than in the control group during the period from 8 to 12 h and at 24 h after the feeding. The postprandial change of plasma retinol in 40-d-old calves fed milk with beta-lg was higher (P < 0.05) than that in the control calves only at 12 h after the feeding. In Exp. 2, Holstein male calves (n = 18) were used to investigate the effect of beta-lg on plasma triglyceride concentration and fatty acid composition. Calves were fed Holstein whole milk at 40 g/kg BW plus milk fat prepared from whole milk at 2 g/kg BW with or without beta-lg (0.4 g/kg BW). Plasma triglyceride concentration at age 10 d was higher (P < 0.05) in the beta-lg-fed group than in the controls during the periods from 1 to 2 h and from 7 to 11 h after the feeding. At age 40 d, plasma triglyceride in the beta-lg-fed group was higher (P < 0.05) than in the control group only at 9 h. Ratios of palmitic, stearic, and oleic acids to total plasma lipids were higher (P < 0.05) in the calves fed beta-lg milk than in the control calves at age 10 d. These results suggest that beta-lg enhances the intestinal uptake of retinol, triglyceride, and long-chain fatty acids in preruminant calves.