Production of conjugated linoleic acid-rich potato chips

ABSTRACT:  Conjugated linoleic acid (CLA) is found primarily in diary and beef products, but the health benefits of CLA can only be realized if they are consumed at much greater levels than a normal healthy dietary intake. We have recently shown that a CLA-rich soy oil can be produced by simple isomerization of linoleic acid in soy oil by photoirradiation. This oil may allow greatly increased dietary CLA without significantly elevating fat intake. The objective of this study was to prepare CLA-rich potato chips by frying in CLA-rich soy oil. Soy oil was photoisomerized in the presence of iodine catalyst with UV/visible light. The irradiated oil was clay processed to remove the residual iodine and this oil was then used to fry potato chips. Oil was extracted from fried chips and analyzed for its CLA content with gas chromatography. A 1-oz serving of CLA-rich potato chips contained approximately 2.4 g CLA as compared to 0.1 g CLA in 3-oz serving of steak fillet and 0.06 g CLA in 8-oz serving of whole milk. The peroxide value of the oil extracted from potato chips was found to be 1 meq/1000 g sample, which was within the acceptable commercial standards. This study may lead to the commercialization of CLA-rich food products.     

海带内生真菌Galactomyces geotrichum次生代谢产物改善小鼠的学习记忆能力

报道了海带内生真菌白地霉Galactomyces geotrichum次生代谢产物的乙酸乙酯萃取物具有改善小鼠学习、记忆能力的作用。以D-半乳糖所致的阿尔兹海默病(AD)小鼠为模型,采用Morris水迷宫实验测定了不同剂量组的上述萃取物对小鼠血清、肝脏和脑部组织中的超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活性和丙二醛(MDA)的含量及脑组织中乙酰胆碱转移酶(Ch AT)和乙酰胆碱酯酶(Ach E)的活性的影响。Morris水迷宫结果显示,试验各剂量组的逃避潜伏期的时间均显著缩短(p0.05),而空间探索能力也有所改善;与模型组相比,低、中、高剂量组血清、肝脏与脑部组织的SOD、GSH-Px、CAT活力升高,而MDA含量降低,脑部组织中Ach E活力下降、Ch AT活力上升。上述发现说明,该次代谢产物的乙酸乙酯萃取物对AD模型小鼠具有明显改善学习记忆能力的作用。     

Pilot-scale production of conjugated linoleic acid-rich soy oil by photoirradiation

ABSTRACT:  Conjugated linoleic acid (CLA) is found naturally in dairy and beef products at levels of 0.2% to 2% of the total fat. A more concentrated source of dietary CLA, low in saturated fat, would be highly desirable to obtain optimum CLA levels of about 3 g/d. We recently reported photoisomerization of soy oil with iodine catalysis to be a simple way of producing CLA in laboratory without high-energy input or expensive enzymes and microorganisms. However, a long irradiation time of 144 h has been a limitation for this technique to be of practical value. The objectives of this study were to build a pilot plant unit to rapidly produce high-CLA soy oil by photoirradiation and optimize the processing parameters to obtain high-CLA soy oil. Degassed oil with dissolved-iodine catalyst was irradiated by UV lamps in an illuminated laminar flow unit (ILFU). The ILFU consists of 2 borosilicate glass plates in a silicone lined stainless steel frame. The static mode of operation yielded 5.7% of total CLA isomers and performed twice as well than the continuous mode with 2.5% of total CLA. Irradiating oil in a static mode with reflective surfaces increased the CLA yields 3-fold to 16.4%. About 22% of total CLA isomers can be rapidly produced from soy oil linoleic acid with 0.35% iodine catalyst in a 0.5-cm-thick oil layer maintained at 48 °C for 12 h. The peroxide value and GC-MS analysis did not identify any volatile compounds characteristic of lipid oxidation. This study is a definitive step toward the commercialization of large-scale production of CLA-rich soy oil.     

红酵母发酵废糖蜜产类胡萝卜素的研究

对红酵母利用糖蜜发酵产类胡萝卜素进行了研究,结果表明:对糖蜜的预处理的最佳酸为硫酸;利用经过酸处理后的糖蜜发酵,菌株的生物量为30.75g/L,单细胞色素含量为104μg/g,色素产量为26mg/L;最佳发酵时间为168h。使用糖蜜代替葡萄糖做廉价碳源对红酵母进行发酵,确定添加量为170g/L,色素产量最大值为葡萄糖发酵的0.97倍,生物量为1.04倍。      

红酵母发酵废糖蜜产类胡萝卜素的研究

对红酵母利用糖蜜发酵产类胡萝卜素进行了研究,结果表明:对糖蜜的预处理的最佳酸为硫酸;利用经过酸处理后的糖蜜发酵,菌株的生物量为30.75g/L,单细胞色素含量为104μg/g,色素产量为26mg/L;最佳发酵时间为168h.使用糖蜜代替葡萄糖做廉价碳源对红酵母进行发酵,确定添加量为170g/L,色素产量最大值为葡萄糖发酵的0.97倍,生物量为1.04倍.     

产油丝状真菌高山被孢霉中蝶呤类化合物的提取及检测

建立了高效液相色谱-荧光检测法同时测定高山被孢霉体内新蝶呤、蝶呤和生物蝶呤的方法。高山被孢霉在液氮破壁、酸性条件下经碘-碘化钾溶液氧化1h、滴加抗坏血酸还原液后,体内的四氢生物蝶呤及其前体二氢蝶呤三磷酸盐和6-丙酮酰四氢生物蝶呤分别被氧化成相应的氧化产物新蝶呤、蝶呤、生物蝶呤。经离子交换树脂纯化后,利用高效液相色谱进一步分离得到了氧化产物蝶呤、新蝶呤和生物蝶呤,并采用电喷雾质谱对定性结果进行确认。色谱柱为Inertsil ODS-3C₁₈（5μm,150mm×4.6mm）,用10mmol/L的磷酸氢二钠（pH6.0）作为流动相,流速为1.2mL/min,荧光检测器激发波长为350nm,吸收波长为450nm。检测出的新蝶呤、生物蝶呤和蝶呤的检出限依次是:0.003、0.002、0.005μg/mL。本方法能快速并准确的检测各类蝶呤类化合物,为利用高山被孢霉发酵生产四氢生物蝶呤奠定一定基础。      

北虫草培养基黄酒发酵工艺

试验利用北冬虫夏草大米培养基为原料,设计该原料发酵黄酒的工艺流程,并找到合适的技术参数.工艺流程将传统发酵工艺与现代酿造方法相结合,先利用单因素试验选取了适宜的灭菌时间、发酵温度与时间,并分析糖化酶、酵母、酸度的量等因子的最适范围,再用正交设计方法进一步探索最佳发酵条件.结果表明,每1kg干原料捣碎,120℃蒸煮1h,摊冷.添加100mL酵母、糖化酶、醋酸预混液.预混液中,冰醋酸含量为3％(体积分数),酵母10g,糖化酶15g.30.℃恒温前酵15d后4层纱布粗过滤,滤液4℃后酵30d,取上清,微孔滤膜除菌,密封,低温贮存.可得到品质较好的黄酒,其酒精度数在15％vol左右,含糖量低于10％.     

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。     

Production of conjugated linoleic acid by Propionibacterium freudenreichii

Two strains each of Propionibacterium freudenreichii ssp. shermanii and P. freudenreichii ssp. freudenreichii were tested for their ability to produce conjugated linoleic acid (CLA) in sodium lactate medium (SLM), De Man-Rogosa-Sharpe (MRS) medium and skim-milk. Data showed that both strains were able to produce CLA in three media supplemented with different concentrations of sunflower oil. Maximum production of CLA (78.8 μg/ml) was observed after 36 h of incubation in MRS containing 12 mg/ml of sunflower oil by P. freudenreichii ssp. shermanii. Moreover, the growths of both strains were inhibited by sunflower oil and a positive relationship between CLA production and ability to tolerate sunflower oil was observed. At the same time, it was also observed that the inhibitory effects on P. freudenreichii ssp. shermanii and P. freudenreichii ssp. freudenreichii in three media follow the order SLM > skim-milk > MRS and SLM > MRS > skim-milk, respectively. Micro aerobic conditions were in favour of increasing the amounts of CLA. The amounts of CLA increased from 0 to 36 h under micro aerobic conditions and no significant (p > 0.05) increases in total CLA levels were observed after 80 h of incubation. Results showed that P. freudenreichii may have potential for producing CLA.     

Production of lipase-catalyzed structured lipids from safflower oil with conjugated linoleic acid and oxidation studies with rosemary extracts

Structured lipid (SL-safflower) was produced by lipase-catalyzed esterification (acidolysis) from safflower oil and conjugated linoleic acid (CLA). SL-safflower was then isolated by alkaline de-acidification, and its chemical characteristics were studied. Also, the change of fatty acid composition and tocopherol content was monitored during the reaction. After 2 h reaction, 18.5 mol% CLA was incorporated into SL-safflower, which further increased to 22.5 mol% after 24 h reaction. The content of -tocopherol was gradually reduced to more than 85% after 24 h. Besides, the oxidative stabilities of SL-safflower and safflower oil were studied. SL-safflower showed higher peroxide value (POV), ρ-anisidine value (AV), and 2-thiobarbituric acid reactive substances (TBARS) value than safflower oil, indicating that SL-safflower containing CLA is more susceptible to oxidation than safflower oil. Rosemary extracts with different amount (100, 200 or 300 ppm) could effectively reduce the oxidation, showing the most effective at 300 ppm.     

白腐菌Trametes hirsuta BYBF在三相流化床生物反应器产漆酶的研究

应用三相流化床生物反应器对Trametes hirsuta BYBF进行了产漆酶的研究,结果表明,菌丝球在流化床内稳定,能达到较好的流化状态,其最佳的条件为接种量10%,通气量0.3L/min,发酵5d后酶活即可达到3.36U/mL。并对白腐菌进行了重复分批培养,与摇床发酵相比,不仅提高了漆酶活力,而且也大大缩短了产酶周期,提高了生产效率。     

响应面法优化假单胞菌TS1138的产酶条件(英文)

以假单胞菌(Pseudomonas sp.)TS1138为供试菌株,运用响应面法对酶法合成L-半胱氨酸所用酶的生产条件进行优化。首先利用Plackett-Burman设计从影响TS1138菌株产酶的众多因素中筛选出影响较大的四个因素:DL-ATC 、玉米浆、转速和装液量。在此基础上再利用二次响应面分析法进行优化,得出了最佳的实验条件。最佳产酶培养基配方为(g/L):葡萄糖 30、DL-ATC·3H2O 3.0、玉米浆 3.1、尿素 3、MnSO4·H2O 1、K2HPO4·3H2O 3、FeSO4·7H2O 0.01、MgSO4·7H2O 0.5、NaCl 3;最佳产酶培养条件为:摇床转速 190r/min、500ml摇瓶装液量 42ml、接种量 10%、产酶培养基初始 pH7.5、培养温度 29℃。在优化条件下进行产酶培养,细胞酶活力达 2255U/ml,比未优化前的 2053U/ml 提高了 9.8%。     

溶氧对假单胞菌TS1138生产L-半胱氨酸合成酶系的影响

假单胞菌(Pseudomonas sp.)TS1138在含有DL-2-氨基-Δ2-噻唑啉-4-羧酸(DL-2-amino-Δ2-thiazoline-4-carboxylic acid,DL-ATC)的环境中能够转化DL-ATC生成L-半胱氨酸的酶系。通过固定不同溶氧浓度,探索溶氧对假单胞菌TS1138发酵产酶的影响。摇瓶实验结果表明：溶氧浓度过低,菌体生长缓慢,细胞产酶能力较低;溶氧浓度过高,菌体生长速度快,但不利于细胞产酶。7L罐发酵实验结果表明：在产酶中后期,应根据溶氧浓度变化来调节搅拌转速或空气流量,使溶氧浓度控制在30%以上。     

Production of conjugated linoleic acid by lactic acid bacteria in milk without any additional substrate

This study was undertaken to evaluate the production and isomeric distribution of conjugated linoleic acid (CLA) in milk fermented with lactic acid bacteria (LAB. A total of 155 cultures of LAB were analysed. Control milk samples had an average CLA content of 0.41 g/100 g of fatty acids (FA), while the lactic cultures produced CLA in the range of 0.43–1.12 g. No major changes in free fatty acids profiles were observed in milk samples fermented with CLA‐producing LAB. The present study demonstrated that LAB can increase levels of CLA in nonsupplemented milk fermented for a short period of 4 h.     

Topical clindamycin 1% vs. linoleic acid-rich phosphatidylcholine and nicotinamide 4% in the treatment of acne: a multicentre-randomized trial

It has been shown that topical linoleic acid rich-phosphatidylcholine seems to be effective in normalization of follicular hyperkeratinization, whereas nicotinamide has an interesting anti-inflammatory effect. However, little is known about their combined effect on acne. A multicentre, double-blind, 12-week randomized vehicle and parallel-active control study was conducted by clinical and biophysical non-invasive measurements to evaluate the efficacy, tolerability and safety of a 4% nicotinamide-phospholipidic (N-PHCL) emulsion vs. 1% topical clindamycin phosphate applied once daily. Four percentage N-PHCL cosmetic treatment resulted slightly superior to topical clindamycin with all the parameters studied for its better compliance and the global clinical improvement.     

Lipozyme RM IM脂肪酶催化酸解制备MLM型结构脂质

采用脂肪酶Lipozyme RM IM催化辛酸、癸酸与大豆油进行酸解反应以制备MLM型结构脂质。通过单因素实验研究底物摩尔比、辛癸酸摩尔比、酶添加量、反应时间、反应温度和初始水分含量对酸解反应的影响。得到适合的反应条件为:底物摩尔比3∶1(总脂肪酸/大豆油),辛酸与癸酸摩尔比(辛酸/癸酸)2.5∶1,酶添加量7.5 wt%(基于底物总重),反应时间5 h,反应温度65℃,加水量1.0 wt%(基于底物总重),得到MLM结构脂脂肪酸组成中辛酸含量为20.0 wt%,癸酸含量为10.5 wt%,两者质量比为1.92。     

Production of conjugated linoleic acid by food‐grade bacteria: A review

Conjugated linoleic acid (CLA) is a group of isomers of linoleic acid (LA) with several potential health benefits which justifies the efforts to obtain foods with enhanced CLA contents. A possible way to obtain CLA‐enriched products is via fermentation as several micro‐organisms, many of which are employed in the manufacture of foods, are known to convert free LA into CLA. However, due to several constraints, the use of CLA‐producing bacteria still remains challenging and continuous efforts are required. This review summarises the current knowledge on microbial CLA production by food‐grade micro‐organisms, its technical issues and limitations, potential applications and bioactivities.     

Derivatization of fatty acids and its application for conjugated linoleic acid studies in ruminant meat lipids

Conjugated linoleic acid (c9, t11 CLA) is a dietary fatty acid produced mainly by ruminant animals and exhibits promising health‐promoting biological effects. For lipid fatty acid composition analyses, including CLA, lipids must be pre‐treated so that the free and esterified fatty acids (triacylglycerols, phospholipids, etc) are available for determination. The most common treatments involve fatty acid methyl ester derivatives from relatively simple chemical reactions, but this becomes complicated when esterification of CLA is involved because of potential changes in its positional and geometrical isomers by reaction with certain reagents. In this review we explain concisely the advantages and disadvantages of the most popular methods (acid‐ and base‐catalysed methods) generally employed for total fatty acid derivatization and their determination on a gas chromatograph. Based on our experiences we put forward the (trimethylsilyl)diazomethane method as an alternative and successful approach for ruminant tissue lipid determinations. Copyright © 2005 Society of Chemical Industry