乳酸菌发酵生产共轭亚油酸

以盐生植物紫花苜蓿籽油为底物,用嗜酸乳酸杆菌(Lactobacillus acidophilus)1.1854催化紫花苜蓿籽油中的亚油酸转化为共轭亚油酸(CLA)。通过单因素实验,分析了发酵过程中pH、预培养、苜蓿籽油的浓度和乳酸菌菌液浓度对生产共轭亚油酸的影响。实验结果表明,预培养时加入一定量的苜蓿籽油可提高CLA转化率,发酵pH6.4,苜蓿籽油浓度0.05%,菌浓度2.5%时CLA转化率较高。     

海篷子籽油制备共轭亚油酸及其组分分析

研究海篷子籽油中亚油酸转化制备共轭亚油酸的工艺条件。以海篷子籽油为原料,KOH为催化剂,乙二醇为溶剂,碱异构法转化共轭亚油酸。采用Box-Behnken试验设计,优选海篷子籽油共轭亚油酸的最佳制备技术条件。结果表明海篷子籽油是制备共轭亚油酸的良好原料,所得产品中共轭亚油酸质量分数达87%以上,共轭亚油酸两种活性异构体9c,11t-CLA和10t,12c-CLA质量分数达68%以上。用海篷子籽油制备共轭亚油酸最适条件为:反应温度在180℃,反应时间3.9 h,溶剂用量为油质量的2倍,催化剂用量为籽油质量的25%。本研究所优选的工艺条件可使籽油中亚油酸转化率高达94.6%,所制得的海篷子共轭亚油酸产品的各项理化指标接近食用油标准,工艺条件实际可行,制备的共轭亚油酸产品安全无毒,有望开发成一种高附加值的保健食用油。     

响应面法优化黄秋葵籽油中亚油酸的共轭转化率

为了提高黄秋葵籽油中亚油酸的共轭转化率,在单因素实验的基础上,根据中心组合(Box-Benhnken)设计实验,以共轭亚油酸(CLA)的得率为响应值进行响应面分析,并建立了相应的回归模型。黄秋葵籽油中亚油酸共轭转化的最佳工艺条件为:反应时间4 h,反应温度162℃,籽油/KOH为1.9(m L/g),丙二醇/籽油为2.0(m L/m L),CLA转化率为74.20%,其中反应温度对转化率影响最大,反应时间与反应温度的交互作用显著。经验证,实测值(74.20%)与模型预测值(76.99%)基本一致,说明响应面法优化黄秋葵籽油中亚油酸的共轭转化工艺可行。     

盐地碱蓬共轭亚油酸的制备及结构分析

以丙三醇为溶剂体系，研究盐地碱蓬籽油合成共轭亚油酸(CLA)的工艺条件。并在该工艺中对丙三醇的可重复利用性进行了试验，由于油脂水解本身产生丙三醇，为此重复利用可以达到溶剂体系的循环适用。产物经分析表明，亚油酸异构化产物主要为共轭亚油酸结构，含有顺式和反式双键结构。试验结果表明，盐地碱蓬籽油是制备共轭亚油酸的好原料，所得产品中共轭亚油酸含量可以达到70％以上。用盐地碱蓬籽油制备共轭亚油酸的合适条件为：反应温度在185～190℃，时间在2～3h，催化剂用量为油重的20％，溶剂用量为油重的2～3倍。     

橡胶籽油碱催化异构化合成共轭亚油酸的制备工艺研究

以橡胶籽油为原料,碱异构化合成共轭亚油酸(CLA),采用单因素实验探讨了反应温度、反应时间、醇油比、催化剂KOH的用量等因素对CLA转化率的影响,同时采用响应曲面法进行优化,结果表明:橡胶籽油碱异构制备共轭亚油酸的最佳异构条件是:采用聚乙二醇-400为溶剂,KOH为催化剂,当反应温度148℃,反应时间2.6 h,醇油比:18∶1 m L/g,催化剂的用量6%,在此工艺条件下橡胶籽油共轭亚油酸的转化率为83.04%。     

海蓬子籽油亚油酸共轭化产物的抗肿瘤作用

目的:探讨海蓬子籽油亚油酸共轭化产物体外抗肿瘤活性。方法:以含有73.52%亚油酸的海蓬子籽油为原料,利用化学法转化制备共轭亚油酸(conjugated linoleic acid,CLA),采用国标法和小鼠急性毒性实验对共轭化油进行理化指标分析和急性毒性评价,MTT法检测共轭化油对人肿瘤细胞的生长抑制作用。结果:共轭化油中c9,t11-CLA和t10,c12-CLA含量为68.75%,理化指标符合相关产品要求。小鼠急性毒性LD50>20g/kg,属无毒级。共轭化油对食道癌EC109细胞和乳腺癌HTB-22细胞均有较强抑制作用,对宫颈癌HeLa细胞无抑制活性,对正常人胚肾细胞293T无毒性,对EC109细胞的IC50为111.9μg/mL。结论:利用海蓬子籽油转化的共轭亚油酸产物对人肿瘤细胞有较强的生长抑制作用,但其作用具有选择性。     

溶剂法提取紫花苜蓿籽油

以盐生植物紫花苜蓿籽为原料,采用两种有机溶剂—无水乙醚和正己烷对紫花苜蓿籽进行提油的工艺研究。通过正交试验确定了正己烷为最佳提取溶剂,最佳条件为提取温度90℃,提取时间4h,料液比1∶16,此条件下的出油率为11.68%。提出的籽油中含有亚油酸15.75%,油酸12.45%,亚麻酸12.20%,硬脂酸20.52%和棕榈酸10.83%。本研究又对苜蓿籽油的理化性质进行了研究,结果表明,溶剂法浸提紫花苜蓿籽油工艺可行,产品对人体具有较高的营养保健作用。     

酶法提取紫花苜蓿籽油的研究

以紫花苜蓿籽为原料,采用酶法提油,通过正交试验确定了复合酶配比及最佳提油工艺参数。结果表明:复合酶配比为AS1398中性蛋白酶添加量为0.4%,α-淀粉酶添加量为0.5%,果胶酶添加量为0.5%,料液比为1∶10,酶解温度为50℃,酶解时间为6 h,苜蓿籽的出油率最高为11.23%。提出的籽油中含有亚油酸15.38%,油酸14.45%,亚麻酸11.20%,硬脂酸23.25%和棕榈酸10.24%。并对苜蓿籽油的理化性质进行了研究,结果表明,酶法提取紫花苜蓿籽油工艺可行,产品对人体具有较高的营养保健作用。     

黄秋葵籽油的研究进展

参考了近5年研究文献,综述了黄秋葵籽油的制备工艺、脂肪酸组成、油用性能及应用情况。实验室提取黄秋葵籽油技术比较成熟,微波、超声波辅助提取可提高产率,不过黄秋葵籽油量产工艺有待加强。黄秋葵籽油中主要含有亚油酸、油酸、棕榈酸、硬脂酸等多种脂肪酸,饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸比例合适,接近1∶1∶1的理想模式。黄秋葵籽油中含有丰富的必需脂肪酸和抗氧化物质,具有清除自由基、保护肝脏、修复胃黏膜等功效,具有重要的保健功能和开发价值。黄秋葵籽油性能稳定,抗氧化性强,通过微胶囊化和共轭亚油酸的转化,可以提高其稳定性和抗氧化性。对黄秋葵籽油的研究方向提出了合理的建议。     

白藜芦醇共轭亚油酸酯凝胶油的制备及表征

以花生油为基料油,利用9c,11t-共轭亚油酸酯化改性白藜芦醇,并与蜂蜡复配制备白藜芦醇共轭亚油酸酯凝胶油,探讨蜂蜡与白藜芦醇共轭亚油酸酯添加量、蜂蜡与白藜芦醇共轭亚油酸酯质量比、加热温度、加热时间和冷却温度对白藜芦醇共轭亚油酸酯凝胶油持油性的影响,并对其基本理化性能、热性能、组成成分进行表征。结果表明：蜂蜡与白藜芦醇共轭亚油酸酯添加量12%、蜂蜡与白藜芦醇共轭亚油酸酯质量比7∶3、加热温度70 ℃、加热时间20 min、冷却温度4 ℃,白藜芦醇共轭亚油酸酯凝胶油的持油性最高可达98.6%;与蜂蜡凝胶油相比黏度降低30%、亮度降低、减少了α型晶体,并发现白藜芦醇共轭亚油酸酯凝胶油无反式脂肪酸生成。     

以葵花籽油为底物生物转化共轭亚油酸双歧杆菌的筛选

运用快速扫描法,筛选了10株可利用游离态亚油酸为底物高产共轭亚油酸的双歧杆菌菌株;然后以富含非游离态亚油酸的葵花籽油为底物,与初筛得到的高产菌株共培养后检测反应体系中共轭亚油酸的含量。结果表明,部分短双歧杆菌可将葵花籽油转化为共轭亚油酸,其中短双歧杆菌FFJND12M6的转化率最高,可达14.35%。     

ANTIOXIDANT EFFICACY OF EXTRACTS OF AN EDIBLE RED ALGA (GRATELOUPIA FILICINA) IN LINOLEIC ACID AND FISH OIL

The antioxidant activity of an extract of a marine red alga (Grateloupia filicina) was evaluated in linoleic acid and fish oil induct period oil at 65C. Oxidative stability of the oils was evaluated by employing peroxide value (PV), 2-thiobarbituric acid reactive substances (TBARS), conjugated diene (CD) and weight gain experiments. The algal extract was applied to linoleic acid and fish oil at 0.01, 0.03 and 0.05% and results were compared with those of commercial antioxidants such as butylated hydroxytoluene (BHT), butylated hydroxyanisol (BHA) and α-tocopherol at 0.01 %. Results indicated the ability of the alga extract to inhibit oxidation of linoleic acid and fish oil; at α 0.05%     

富含共轭亚油酸的食用油安全性毒理学试验研究

目的日本已经有富含共轭亚油酸的食用油商品。为了使共轭亚油酸在我国得到广泛的应用,进行富含纯度共轭亚油酸食用油的食品安全性毒理试验研究。方法依据GB15193—94《食品安全性毒理学评价程序和方法》进行急性毒性试验、三项遗传毒性试验和30天喂养试验。结果共轭亚油酸对两种性别的SPF级昆明种小鼠经口毒性,一次灌胃量达20g／kg·bw两周内动物未见明显中毒症状,无动物死亡,按急性毒性分级标准规定,该受试物属无毒级。三项遗传毒性试验（Ames、小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验）结果均为阴性。30天喂养试验结果表明：该受试物O．87、2．20、4.30g／kg.bw剂量（分别相对于推荐人群日摄影入量3．6g/kg.bw的20、50、100倍）对wistar大鼠的临床检查,血液学,生化学,脏器重量和系数以及病理组织多样指标无明显影响,未发现该受试物有明显的毒性作用。结论富含共轭亚油酸的食用油既无毒也无任何副作用。     

COMPARISON OF LINOLEIC AND CONJUGATED LINOLEIC ACIDS IN ENZYMATIC ACIDOLYSIS OF TRISTEARIN

The acyl incorporation and migration of linoleic and conjugated linoleic acids in enzymatic acidolysis were compared in a solvent-free system. Two systems were used in the Lipozyme RM IM-catalyzed acidolysis at 60C temperature and 5% by weight enzyme load (based on substrates). One included tristearin (SSS) and linoleic (L) or conjugated linoleic (cL) acids (1:6, mol/mol). The other was between tristearin and the mixture of linoleic and conjugated linoleic acids (1:3:3, mol/mol/mol). Acyl incorporation and migration together with triacylglycerol composition of the products were monitored with gas chromatography, pancreatic lipase hydrolysis, and high performance liquid chromatography. Both acyl incorporation and migration of linoleic acid were faster than those of conjugated linoleic acid. At 5 h reaction, there were 13.0% LLL, 46.5% LSL, 27.7% LSS, and 5.6% SSS in the product for a system between tristearin and linoleic acid; whereas there were 2.4% cLcLcL, 10.4% cLScL, 50.9% cLSS, and 36.2% SSS in the product for a system between tristearin and conjugated linoleic acid. The results suggest that linoleic acid was more reactive than conjugated linoleic acid in the enzymatic acidolysis probably because of the rigid structure of the latter.     

Composition and properties of milk and butter from cows fed fish oil

A control diet and a fish oil diet were fed to 12 multiparous Holstein cows to determine how the incorporation of Menhaden fish oil in the diet would influence the fatty acid composition, especially the conjugated linoleic acid and transvaccenic acid, contents of milk and butter. The control diet consisted of a 50:50 ratio of forage to concentrate, and the fish oil diet consisted of the control diet with 2% (on a dry matter basis) added fish oil. Milk from cows fed the control diet contained higher average concentrations of milk fat (3.37%) compared with milk from cows fed the fish oil diet (2.29%). Milk from cows fed fish oil contained higher concentrations of conjugated linoleic acid, transvaccenic acid, and total unsaturated fatty acids (0.68 and 2.51; 1.42 and 6.28; and 30.47 and 41.71 g/100 g of fat, respectively). Butter made from the fish oil diet milk also had higher concentrations of conjugated linoleic acid, transvaccenic acid, and unsaturated fatty acids. Penetrometer readings indicated fish oil diet butters were softer at 4 and 20 degrees C than the control diet butters. Acid degree values were similar in the fish oil butters compared with the control butters. No significant difference was found in the flavor characteristics of milk and butter from cows fed the control and fish oil diets. Production of milk and butter with increased amounts of conjugated linoleic acid, transvaccenic acid, and other beneficial fatty acids may have a desirable impact on the health of consumers and lead to increased sales.     

Quantitative determination of conjugated linoleic acids in hydrogenated vegetable oils using refractive index

Conjugated linoleic acid contents in hydrogenated vegetable oils were differentially determined using refractive indices when the iodine value could not be used. The refractive indices of soybean oil, cottonseed oil, and corn oil varied linearly with changes of linoleic acid contents of individual oils with determination coefficients of 0.91, 0.98, and 0.98, respectively. The refractive index can be used as a simple and fast method for control of the hydrogenation process of vegetable oils to obtain a desired conjugated linoleic acid content without fatty acid compositional analysis.     

共轭亚油酸生物合成的研究

共轭亚油酸是80年代末才被发现的一种具有多种生理功能的天然不饱和脂肪酸，具有抗癌、抗动脉粥样硬化、减肥、促进生长、缓和免疫反应副作用等许多重要生理功能，在医药、食品、保健品、化妆品等中具有广阔的应用前景。目前，工业化生产共轭亚油酸的方法是碱并构化法，但共轭亚油酸的生物合成法是未来的发展趋势。本文对近年来共轭亚油酸生物合成方面的研究进展进行了综述。     

新型功能性油脂-共轭亚油酸

共轭亚油酸是天然存在于食品中的亚油酸异构体,具有抑制癌症和肿瘤的形成、减肥、抗动脉粥样硬化、改善免疫功能、降低胆固醇、促进生长等多种功能,是一种新型功能性油脂。本文综述了共轭亚油酸的生理功能、来源、合成及纯化方面的研究进展。