中碳链甘三酯的合成研究

以樟树籽仁油为原料,通过正交实验法研究了用醇解法合成和纯化中碳链甘三酯的生产工艺,得到了中碳链甘三酯生产工艺的最佳条件及产品的物性参数.结果表明,该法工艺简单、能耗小、副产物易于分离且环境污染小.通过对所得产品的物化参数与国外中碳链甘三酯产品标准对比,表明用醇解法合成和纯化中碳链甘三酯的生产工艺是切实可行.     

Enzymatic interesterification of palm stearin with Cinnamomum camphora seed oil to produce zero-trans medium-chain triacylglycerols-enriched plastic fat

It is known that Cinnamomum camphora seed oil (CCSO) is rich in medium-chain fatty acids (MCFAs) or medium-chain triacylglycerols (MCTs). The purpose of the present study was to produce zero-trans MCTs-enriched plastic fat from a lipid mixture (500 g) of palm stearin (PS) and CCSO at 3 weight ratios (PS:CCSO 60:40, 70:30, 80:20, wt/wt) by using lipase (Lipozyme TL IM, 10% of total substrate) as a catalyst at 65 °C for 8 h. The major fatty acids of the products were palmitic acid (C16:0, 42.68% to 53.42%), oleic acid (C18:1, 22.41% to 23.46%), and MCFAs (8.67% to 18.73%). Alpha-tocopherol (0.48 to 2.51 mg/100 g), γ-tocopherol (1.70 to 3.88 mg/100 g), and δ-tocopherol (2.08 to 3.95 mg/100 g) were detected in the interesterified products. The physical properties including solid fat content (SFC), slip melting point (SMP), and crystal polymorphism of the products were evaluated for possible application in shortening or margarine. Results showed that the SFCs of interesterified products at 25 °C were 9% (60:40, PS:CCSO), 18.50% (70:30, PS:CCSO), and 29.2% (80:20, PS:CCSO), respectively. The β' crystal form was found in most of the interesterified products. Furthermore, no trans fatty acids were detected in the products. Such zero-trans MCT-enriched fats may have a potential functionality for shortenings and margarines which may become a new type of nutritional plastic fat for daily diet.     

副干酪乳杆菌HCS17-040的筛选鉴定及其益生特性

目的：获得具有降甘油三酯功能的乳酸菌菌株。方法：从母乳及顺产的健康婴儿粪便中筛选分离乳酸菌菌株,采用单试剂法乳酸菌（GPO-PAP法）测定其甘油三酯去除能力。从中选择甘油三酯去除能力强的菌株进行形态学鉴定、生理生化及16S rDNA鉴定,并测定其耐受酸、胆盐和胃肠液的能力。结果：筛选分离出一株副干酪乳杆菌（Lactobacillus paracasei）,命名为HCS17-040（CGMCC No 19747）,其甘油三酯下降率达（42.80±1.79）%;该株菌在pH 3.0和pH 2.0的环境中培养17 h后存活率分别为89.39%和87.18%;在3 g/L和5 g/L的胆盐浓度环境中培养17 h后存活率分别为94.75%,92.97%;在人工胃液中作用3 h,存活率为93.93%;在人工肠液中作用4 h,存活率高达99.06%。结论：副干酪乳杆菌HCS17-040对甘油三酯具有一定的去除能力,且具有良好的耐酸、胆盐及人工胃肠液的能力。     

Enhanced cholesterol‐ and triglyceride‐ lowering effect of West African green tea

‘The Vert’ is a special type of green tea widely consumed in West Africa and locally associated with many health benefits. However, limited research has been conducted to evaluate its health benefits, such as its enhanced hypolipidemic potential. The objectives of this study were to (1) evaluate the cholesterol‐ and triglyceride‐lowering effects of West African green tea (WAGT) as affected by diet and tea intake, (2) determine the impact of WAGT consumption on the CHD risk ratio, and (3) explore possible mechanisms through which WAGT improves serum lipid profile. Forty‐five male Wistar rats were randomly assigned to one of nine treatment combinations, three diets (regular, high‐cholesterol, and trans‐fat diets) and three fluid sources (no tea, diluted tea, and concentrated tea). After 6 weeks of feeding, animal blood, liver, and feces were harvested. Total cholesterol, HDLc, LDLc, and triglycerides in serum, liver, and feces were determined. The concentrations of bile acids in feces were also measured. WAGT significantly lowered serum and liver cholesterol (30% and 15%, respectively) and increased serum HDL cholesterol (30%). It also reduced liver enlargement caused by storage of excess lipids in high‐cholesterol diet. Overall, the CHD risk ratio was cut by two‐thirds in rats fed high‐cholesterol diet and WAGT. A marked increase in fecal total lipids, cholesterol (60%), and bile acids (50%) was observed in rats that consumed WAGT compared to the control group. These beneficial effects could be attributed to the significantly high flavonoid content of WAGT. Copyright © 2007 Society of Chemical Industry     

高效体积排阻色谱测定油脂中氧化甘油三酯聚合物

为了分析甘油三酯氧化产物——氧化甘油三酯及其聚合物的组分分布,研究了高效体积排阻色谱检测高相对分子质量聚合物的方法,建立了采用正相硅胶制备色谱预分离油脂中极性组分,极性组分以高效体积排阻色谱-示差折光检测器测定,标准相对分子质量聚苯乙烯定性,峰面积归一化法定量的检测方法.油脂中极性组分的典型色谱峰构成是:氧化甘油三酯寡聚合体、氧化甘油三酯二聚体、氧化甘油三酯单体、甘油二酯、游离脂肪酸等.以氧化甘油三酯聚合物鉴别地沟油等深度氧化劣变食用油具有良好的应用前景.     

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。     

Hybrid <Emphasis Type="Italic">Hibiscus</Emphasis> seed oil compositions

The seeds of cultivated Hibiscus spp. were extracted with supercritical carbon dioxide, and the resulting extracts were analyzed to identify the major TG components as the corresponding FAME. The seed oils were composed predominantly of oleic and linoleic FA (69.6–83.4%) with lesser amounts of palmitic acid (14.8–27.0%). Minor amounts of C14, C18, and C20 saturated FA were also detected. The oil content of the seeds was determined to be between 11.8 and 22.1 wt% for hybrid varieties and between 8.9 and 29.5 wt% for the native species from which the hybrid varieties were developed. The protein content of the defatted seed meal averaged 20% for the hybrid varieties. The composition of the extracted hibiscus seed oils suggests potential edible applications.     

Lauric acid-containing triglycerides in seeds of umbellularia californica nutt. (Lauraceae)

A white crystalline material isolated from the seeds ofUmbellularia californica consisted mainly of the mixed triglyceride, dilaurocaprin, with smaller amounts of trilaurin and dicaprolaurin and a trace of tricaprin. The yield of crude oil from a tree growing at Royal Botanic Gardens, Kew, was considerably less than that reported previously for trees growing in California.     

Chemical composition and physical properties of soft (tub) margarines sold in Malaysia

Seven samples of domestic and imported Malaysian tub margarines were analyzed for their fatty acid and triglyceride (carbon number) composition, solid fat content, dropping and softening points, crystallization temperature, polymorphic form, color, and textural attributes. Domestic margarines were formulated from palm oil or palm olein and palm kernel oil with a liquid oil but no hydrogenated oils. Two imported products contained hydrogenated palm oil product, which resulted in a high level of β′ crystals, whereas the domestic nonhydrogenated products contained more β than β′ crystals. Crystal habit was related to the fatty acid and triglyceride composition of the high-melting glycerides. Domestic products were firmer in texture, probably because they were formulated to be sold in a tropical climate.