超临界CO2萃取湘西月见草籽油的工艺研究

通过正交试验方案分析 ,得到采用超临界CO2 萃取月见草籽油的最佳工艺条件为 :萃取压力 35MPa、萃取温度 30℃、分离温度 35℃、萃取时间 6 0min ,萃取率 2 3 1%。同时对超临界萃取月见草籽油的理化参数以及脂肪酸含量进行了测定 ,结果表明 :其酸值低 ,不饱和度高 ,γ -亚麻酸含量高达 12 85 % ,具有较好的药用开发前景。     

四号溶剂萃取紫草籽油研究

北方硬紫草在90年代初期已开始人工栽培,紫草籽中含脂肪17％,其中γ-亚麻酸13.5％,α-亚麻酸31％,是迄今为止所发现γ-亚麻酸含量最高的油品之一。四号溶剂萃取技术提取紫草籽油,使其生理活性物质不受破坏,为紫草籽油开发利用提供保证。     

超临界C02萃取湘西月见草籽油的工艺研究

通过正交试验方案分析，得到采用超临界CO2萃取月见草籽油的最佳工艺条件为：萃取压力35MPa、萃取温度30℃、分离温度35℃、萃取时间60min，萃取率23.1％。同时对超临界萃取月见草籽油的理化参数以及脂肪酸含量进行了测定，结果表明：其酸值低，不饱和度高，γ-亚麻酸含量高达12.85％，具有较好的药用开发前景。     

微孔草籽油脂肪酸的HPLC-MS分析

采用柱前衍生-高效液相色谱荧光检测法(HPLC-FLD)分析了超临界CO2萃取得到的微孔草籽油的脂肪酸成分。用荧光衍生试剂1-[2-(对甲苯磺酸酯)乙基]-2-苯基咪唑[4,5-f]9,10-菲(TSPP)作为柱前衍生试剂,对39种饱和与不饱和脂肪酸标准品进行衍生,经梯度洗脱实现了39种脂肪酸衍生物完全分离,使用外标法定量,建立了同时测定17种脂肪酸绝对含量的方法。结果表明,微孔草籽油中油酸、亚油酸、亚麻酸相对含量分别是29.09%、23.85%、20.25%;不饱和脂肪酸占总脂肪酸的相对含量为73.19%。     

紫草籽油的开发研究

北方硬紫草在９０年代初期已经开始人工栽培,紫草籽中含脂肪１７％,其中γ－亚麻酸１３．５％,ａ－亚麻酸３１％,是迄今为止发现的γ－亚麻酸含量量最高的油品之一。低沸点溶剂萃取技术提取紫草籽油,使其生理活性物质不受破坏,为紫草籽油的开发利用提供了保证。     

猕猴桃籽油中α-亚麻酸富集纯化的研究

为获得较高纯度的α-亚麻酸,对猕猴桃籽油中的α-亚麻酸进行了富集纯化研究.采用超临界CO2萃取-精馏技术、超临界CO2萃取-精馏同尿素包合法、Ag 络合法分别结合的方式作为α-亚麻酸富集纯化的方法.结果表明在萃取压力20 Mpa、萃取温度35℃、精馏压力13 Mpa,精馏温度梯度40-55～70-85℃、CO2流量3 800g/h的条件下,精馏得到的α-亚麻酸含量为71.16%;采用15-17-19-21 Mpa程序升压的方式可使α-亚麻酸含量达到73.53%萃馏结合尿素包合法后的α-亚麻酸含量为72.30%;萃馏结合Ag 络合法的α-亚麻酸含量为75.59%.采用上述3种方法均实现了猕猴桃籽油中α-亚麻酸的富集纯化.     

狼紫草籽油中脂肪酸组成的研究

采用毛细管气相色谱法测定了狼紫草籽油中的脂肪酸组成及相对含量。鉴定了１５种脂肪酸，占脂肪酸总量的９９．３％。样品所含主要脂肪酸为棕榈酸、油酸、亚油酸、α—亚麻酸和γ—亚麻酸。不饱和脂肪酸为９０．６４％，其中α—亚麻酸２６．８８％，γ—亚麻酸６．７０％。     

响应面法优化超临界CO_2萃取栝楼籽油

通过响应面法(response surface methodology)优化超临界二氧化碳萃取栝楼籽油工艺,采用DesignExpert软件对试验数据进行分析,气相色谱-质谱(gas chromatography-mass spectrometry)对萃取栝楼籽油进行成分分析。结果表明,最佳工艺参数为萃取压力29.75 MPa,萃取温度45.1℃,萃取时间为175.8min,栝楼籽油萃取得率为32.82%,栝楼籽油主要成分为棕榈酸(7.90%)、α-亚麻酸(28.23%)、亚油酸(39.33%)和油酸(22.57%)为主,另外检出不饱和脂肪酸7-棕榈烯酸(0.40%)、γ-亚麻酸(0.22%)和11-二十碳烯酸(0.30%),同时检出不饱和烃类角鲨烯(0.33%)。萃取时间、萃取压力、萃取温度对栝楼籽油超临界CO_2萃取工艺有显著的影响,栝楼籽油不饱和脂肪酸质量分数达90.59%。     

响应面法优化月见草籽油中γ-亚麻酸的富集工艺参数

利用响应面法对月见草籽油中γ-亚麻酸的富集工艺参数进行优化.在单因素实验基础上选取实验因素与水平,根据中心组合(Box-Benhnken)实验设计原理采用四因素三水平的响应面分析法,依据回归分析确定各工艺条件的影响因素,以富集产物的γ-亚麻酸含量和γ-亚麻酸的回收率为响应值作响应面分析,得出最佳工艺条件为:包合温度为-10℃、尿素/混合脂肪酸(w/w)为3:1、95%乙醇/混合脂肪酸(v/w)为8:1,包合时间为15.6h,此工艺条件下产品中γ-亚麻酸含量可达53.60%,γ-亚麻酸回收率达94.48%.     

35个栽培牡丹品种油用特性的评价研究

对35个栽培牡丹品种的籽油超临界CO2萃取后,使用气质联用色谱法(GC-MS)分析其脂肪酸成分,采用内标法对其主要脂肪酸进行定量分析,以单株种子产量、种仁出油率、籽油α-亚麻酸含量为指标,对35个牡丹品种进行了聚类分析。结果表明,不同牡丹品种的单株种子产量、种仁出油率、籽油α-亚麻酸含量等存在明显差异。其中,长茎紫、鸦片紫、墨池金辉、蝴蝶报春、罗春刺、天香紫、冰凌子、胭红金波、层中笑可以作为油用兼观赏的牡丹品种。如花似玉、擎天粉、琉璃冠珠、满园春光可以作为培育高α-亚麻酸含量油用牡丹品种的重要亲本。     

Determination of ethanol,volatile fatty acids,lactic and succinic acids in fermentation liquids by gas chromatography

A rapid and simple quantitative method was developed to determine, by gas chromatography, the concentrations in fermentation liquids of ethanol, the C₂-C₆ volatile fatty acids, and lactic and succinic acids. Aqueous samples were acidified with 250μlml^?1 metaphosphoric acid (5:1 ratio), centrifuged, and injected directly on to a column containing a porous aromatic polymer (Chromosorb 101) maintained at 200°C in a gas chromatograph fitted with a flame ionisation detector. It was unnecessary to purify samples further before injection, although distillation and ion-exchange methods were examined. Derivatisation of lactic and succinic acids before injection was not necessary, but the lowest level of detection of these two relatively non-volatile acids was about four times greater than that for the volatile fatty acids. The method described was suitable for the analysis of rumen fluid, methane digester fluid, silage extracts and other anaerobic fermentation fluids. The relative retention times are given for 23 organic acids and six other fermentation end-products.     

Effects of abomasal infusions of fatty acids and 1-carbon donors on apparent fatty acid digestibility and incorporation into milk fat in cows

Our primary objective was to determine the effects of the abomasal infusion of 16-carbon (16C) and 22-carbon (22C) fatty acids (FA) on apparent FA digestibility, plasma FA concentrations, and their incorporation into milk fat in cows. Our secondary objective was to study the effects of 1-carbon donors choline and l-serine on these variables. Five rumen-cannulated Holstein cows (214 ± 4.9 d in milk; 3.2 ± 1.1 parity) were enrolled in a 5 × 5 Latin square experiment with experimental periods lasting 6 d. Abomasal infusates consisted of (1) palmitic acid (PA; 98% 16:0 of total fat), (2) PA + choline chloride (PA+CC; 50 g/d of choline chloride), (3) PA + l-serine (PA+S; 170 g/d of l-serine), (4) behenic acid (BA; 92% 22:0 of total fat), and (5) docosahexaenoic acid algal oil (DHA; 47.5% DHA of total fat). Emulsions were formulated to provide 301 g/d of total FA and were balanced to provide a minimum of 40 and 19 g/d of 16:0 and glycerol, respectively, to match the content found in the infused algal oil. Apparent digestibility of FA was highest in DHA, intermediate in PA, and lowest in BA. Digestibility of 16C FA was lowest in BA and highest in PA. The digestibility of 22C FA was highest in DHA relative to BA (99 vs. 58%), whereas 1-carbon donors had no effect on 22C FA digestibility. Plasma 16C FA concentrations were greatest with PA treatment, and 22C FA concentrations were ~3-fold greater in DHA-treated cows relative to all other treatments. Milk fat 16:0 content was highest in PA relative to BA and DHA (e.g., 37 vs. 27% in PA and DHA), whereas the milk yield of 16:0 was higher in PA relative to DHA (i.e., 454 vs. 235 g/d). Similarly, milk 22:0 content and yield were ~10-fold higher in BA relative to all other treatments, whereas DHA treatment resulted in higher content and yield of 22:6 in milk fat relative to all other treatments (41- and 38-fold higher, respectively). Consequently, the content of FA >16C (i.e., preformed) was higher in milk fat from cows infused with BA and DHA relative to PA. De novo FA content in milk did not differ between PA, PA+CC, and PA+S (~16% of milk fat) but was higher in BA and DHA treatments (19 and 21%, respectively). We conclude that FA carbon chain length and degree of saturation affected FA digestibility and availability for absorption as well as their incorporation into milk fat. The abomasal infusion of choline chloride and l-serine did not modify these variables relative to infusing palmitic acid alone.     

Short communication: Eicosatrienoic acid and docosatrienoic acid do not promote vaccenic acid accumulation in mixed ruminal cultures

Previous research found that docosahexaenoic acid (C22:6n-3) was a component of fish oil that promotes trans-C18:1 accumulation in ruminal cultures when incubated with linoleic acid. The objective of this study was to determine if eicosatrienoic acid (C20:3n-3) and docosatrienoic acid (C22:3n-3), n-3 fatty acids in fish oil, promote accumulation of trans-C18:1, vaccenic acid (VA) in particular, using cultures of mixed ruminal microorganisms. Treatments consisted of control, control plus 5 mg of C20:3n-3 (ETA), control plus 5 mg of C22:3n-3 (DTA), control plus 15 mg of linoleic acid (LA), control plus 5 mg of C20:3n-3 and 15 mg of linoleic acid (ETALA), and control plus 5 mg of C22:3n-3 and 15 mg of linoleic acid (DTALA). Treatments were incubated in triplicate in 125-mL flasks, and 5 mL of culture contents was taken at 0 and 24 h for fatty acid analysis by gas-liquid chromatography. After 24 h of incubation, the concentrations of trans-C18:1 (0.87, 0.88, and 0.99 mg/culture), and VA (0.52, 0.56, and 0.62 mg/culture) were similar for the control, ETA, and DTA cultures, respectively. The concentrations of trans-C18:1 (5.51, 5.41, and 5.36 mg/culture), and VA (4.78, 4.62, and 4.59 mg/culture) were also similar between LA, ETALA, and DTALA cultures, respectively. These data suggest that C20:3n-3 and C22:3n-3 are not the active components in fish oil that promote VA accumulation when incubated with linoleic acid.     

奶粉脂肪酸与乳制品风味关系研究

用气质（GC—MS）联用色谱分析了11个商业奶粉样品的脂肪酸组成以及含量,每个样品均检测到了28种脂肪酸,在表现奶粉风味的4个呈味脂肪酸,也即辛酸、己酸、壬酸和葵酸中只检测到了辛酸和葵酸。辛酸和葵酸含量在进口奶粉中普遍高于国产奶粉。国产奶粉中辛酸和葵酸的含量以2号最好,3号其次。亚油酸含量在国产奶粉中普遍高于进口奶粉。     

气相色谱法同时快速测定食品中丙酸、山梨酸、苯甲酸及脱氢乙酸

通过液液萃取净化样品研究,建立了食品中丙酸、山梨酸、苯甲酸、脱氢乙酸及其盐含量气相色谱同时快速测定方法,适用于固体非酯(脂)类食品的检测。结果表明:丙酸的回收率在85.1%~91.3%之间,其余3种防腐剂的回收率均在95.2%~99.4%之间;实验室内变异系数(CV,n=6)最大值≤4.7%,4种防腐剂检出限均在0.002 g/kg以下。4种目标物在有杂质干扰时,可用不同的极性毛细管柱做进一步的确认。本方法具有适用范围广、检测效率高、重现性好、准确度高、检出限低的特点,推广应用对我国食品安全的监督检验具有重要的意义。     

花生四烯酸、二十二碳六烯酸和二十碳五烯酸 在炎症中的作用概述

心脑血管疾病、肿瘤、糖尿病、神经系统疾病、自身免疫等疾病严重危害着人类的生命和健康,并消耗着大量医疗资源。事实上,很多疾病发生和发展的背后都伴随着炎症反应,炎症是众多疾病的病理基础,甚至是导致这些疾病的诱因。炎症本身是机体的防御性反应,但过度的炎症反应和长期慢性炎症会损害机体的稳态。炎症的调节和控制由炎症介质介导,花生四烯酸(arachidonic acid,AA)、二十二碳六烯酸(docosahexaenoic acid,DHA)和二十碳五烯酸(eicosapentaenoic acid,EPA)等长链多不饱和脂肪酸(10ng-chain polyunsaturated fatty acids,LC-PUFAs)的衍生物是一类重要的调控炎症的介质。炎性细胞间的交流和细胞内信号传递与LC-PUFAs有关。AA经环氧酶和脂氧合酶合成的类二十烷酸主要起促炎作用,但有的也有抗炎作用。DHA和EPA在体内起抗炎作用,由它们合成的消退素(resolvins,Rvs)和保护素(protectin,PD)是重要的抗炎活性物质。DHA和EPA还可以干扰炎性细胞内信号传导途径来抑制炎症反应。本文从炎症与疾病的关系、LC-PUFAs的衍生物及其促炎和抗炎机制等方面综述了AA、DHA和EPA在炎症中的作用。     

酸味酿造产品中三酸比例评析

酸味酿造产品中乳酸、醋酸、丁酸共存,但比例不同形成的酸味特征也不同。控制不同的环境条件,创造出不同的微生物区系,形成不同的三酸比例,才能形成不同的产品风格。该文对常见的酸味酿造产品中微生物区系的变化及三酸含量进行了分析。     

Growth of Aeromonas hydrophila K144 as Affected by Organic Acids

The influence of different acids on the aerobic growth kinetics of Aeromonas hydrophila was studied in BHI broth with 0.5 and 2.0% NaCl incubated at 5 and 19°C. Growth curve data were analyzed by the Gompertz equation and a nonlinear regression program; generation and lag times were calculated from the Gompertz parameters. Type of acid, pH, NaCl level and temperature influenced lag and generation times. The organic acids (acetic, lactic, citric and tartaric) inhibited growth at higher pH values than inorganic acids (HCl and H₂SO₄). The high NaCl level interacted with type of acid and pH to restrict growth of the organism at the lower temperature of incubation. Acetic and lactic acids were effective in controlling the growth of A. hydrophila and could readily be combined with low holding temperature to render foods free of the organism.     

杂多酸催化合成辛酸蔗糖酯

以蔗糖、辛酸为原料,杂多酸为催化剂合成辛酸蔗糖酯。用L16(45)正交设计优化实验,高效液相色谱法分析反应液组成。考察了催化剂种类和用量、反应温度、原料配比、反应时间等因素对辛酸蔗糖酯产率的影响,发现以二甲基亚砜为溶剂、蔗糖与辛酸摩尔比1∶9、磷钨酸用量为蔗糖质量的2.0%、110℃反应时间6h,蔗糖转化率达60%,产物产要是二酯。动力学研究发现,蔗糖反应级数为一级,反应表观速率常数为0.0059min-1(90℃)、0.0117min-1(110℃),反应表观活化能Ea=39.57kJ/mol。     

气相色谱法同时测定保健食品中的5种 不饱和脂肪酸

目的建立气相色谱法同时测定保健食品中亚油酸、α-亚麻酸、二十碳五烯酸(eicosapentaenoic acid,EPA)、二十二碳六烯酸(docosahexaenoic acid,DHA)和二十二碳五烯酸(docosapentaenoic acid,DPA)的含量。方法样品先采用氢氧化钾甲醇溶液进行皂化处理,再用三氟化硼甲醇溶液甲酯化,经HP-FFAP色谱柱(30m×0.53 mm,1.0μm)分离测定。结果 EPA甲酯、DHA甲酯、DPA甲酯、亚油酸甲酯、α-亚麻酸甲酯分别在0.03927~1.178、0.04200~1.260、0.03449~1.035、0.08368~1.255、0.08482~4.241 mg/mL的浓度范围内线性关系良好,相关系数r均大于0.999;检出限分别为0.0039、0.0042、0.0034、0.0042、0.0042 mg/mL;加标回收率在91.1%~109.3%之间,相对标准偏差均小于5%。结论该方法操作简单快捷,适用于保健食品中亚油酸、α-亚麻酸、EPA、DPA和DHA的测定。