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1.
Optimization of Selective Lipase-Catalyzed Feruloylated Monoacylglycerols by Response Surface Methodology 总被引:1,自引:0,他引:1
Yan Zheng Jing Quan Li-Min Zhu Bo Jiang Hua-Li Nie 《Journal of the American Oil Chemists' Society》2008,85(7):635-639
The use of solvent engineering to achieve selective enzymatic synthesis of feruloylated acylglycerols during the transesterification
of ethyl ferulate with TAG was investigated. Novozym 435 catalyzed transesterification of ethyl ferulate and TAG resulted
in a mixture of feruloylated monoacylglycerols (FMAG) and feruloylated diacylglycerols (FDAG). These feruloylated acylglycerols
have recently received much attention because of their health benefits, antioxidant properties and UV absorption. However,
FMAG in a pure form is more advantageous than the FMAG–FDAG mixture in exhibiting stabilizing, emulsifying and conditioning
properties. Thus, it is significant to perform efficient selectivity in the synthetic process. In this present study, the
effect of various solvent mixtures, including unitary, binary and ternary organic media selective enzymatic synthesis of feruloylated
acylglycerols was investigated by response surface methodology. Selectivity towards FMAG substantially increased from 14.5%
in the unitary solvent n-hexane to 94.2% in the binary mixtures of 2-methyl-2-butanol (2M2B) and toluene (1:1, v/v). The maximum conversion achieved
was 75.4% in this binary mixture medium. Analysis of variance (ANOVA) showed that 99.6% of the observed variation was explained
by the polynomial model. Lack of fit analysis indicated that the regress equation was adequate for predicting the degree of
the selectivity. 相似文献
2.
The biosynthesis of structured lipids (SL) in organic solvent media was carried out by the interesterification of flaxseed oil (FO) and tricaprylin (TC), using Novozym 435. The bioconversion yield (BY, %) of medium-long-medium type SL, including C-caprylic and Ln-linolenic acids (CLnC), La-linoleic acid (CLaC) and O-oleic acid (COC), was monitored. Response surface methodology was used to obtain significant models for the responses, on the basis of a five level, five variable central composite rotatable design. In the experimental preliminary trials significant reaction parameters, including reaction temperature (T r), TC/FO molar ratio (M r), enzyme concentration (E c), reaction time (R t) and initial water activity (a w), were considered for optimization. Significant models for CLnC, CLaC and COC were determined after regression analysis with backward elimination. The optimal conditions, generated for a maximum CLnC, CLaC and COC, were found to be 54.50–56.25 °C for T r, 6.23–6.25 mol/mol for M r, 2.68–3.13 % for E c, 36.58–37.50 h for R t and 0.15–0.33 for a w. Under these optimum conditions, the BY of CLnC, CLaC and COC was predicted to be 32.48–36.67, 3.26–3.38 and 5.79–6.16 %, respectively. 相似文献
3.
Leslie Kleiner Luis Vázquez Casimir C. Akoh 《Journal of the American Oil Chemists' Society》2012,89(11):1999-2010
Stearidonic acid (SDA, 18:4 ω-3) content of modified soybean oil (MSO) containing?~25?% SDA, was increased by lipase-catalyzed hydrolysis. Four non-immobilized powdered lipases, Lipase AY 30 (Candida rugosa), Lipase G 50 (Penicillium camembertii), Lipomod? 34P-L034P (Candida cylindracea [rugosa]), Lipomod? 36P-L036P (Rhizopus oryzae), and an immobilized lipase, Lipozyme RM IM (Rhizomucor miehei) were assessed, at various incubation times, for their ability to hydrolyze MSO and specificity toward SDA. The SDA enriched products contained triacylglycerols (TAG), diacylglycerols (DAG) and monoacylglycerols (MAG). Lipase 34P-L034P exhibited specificity towards SDA, while Lipase AY was able to discriminate against it. The highest total SDA content (40.9?mol%) was obtained with Amano AY lipase at 4?h incubation (66.2?% hydrolysis). Unhydrolyzed TAG, 1,3-DAG, 2,3(1)-DAG, and MAG contained 37.7 (56.4 at the sn-2 position), 41.6, 51.5 (54.9 at the sn-2 position), and 49.9?% SDA, respectively. Amano AY lipase was also used to hydrolyze previously SDA-enriched TAG (48.7?% SDA) obtained from low temperature crystallization of MSO. The highest total SDA content (62.7?mol%) was obtained at 12?h incubation (85.9?% hydrolysis). The SDA contents of unhydrolyzed TAG, 1,3-DAG, 2,3(1)-DAG, and MAG were 58.7 (65.7 at the sn-2 position), 71.2, 70.2 (52.9 at the sn-2 position), and 59.4?%, respectively. 相似文献
4.
Leslie Kleiner Luis Vázquez Casimir C. Akoh 《Journal of the American Oil Chemists' Society》2012,89(7):1267-1275
The objective of this work was to synthesize a structured lipid (SL) enriched in stearidonic acid (SDA, C18:4 ω-3), from modified soybean oil (MSO) originally containing ~25% SDA. Low temperature crystallization (LTC) of MSO triacylglycerols (TAG) and free fatty acids (FFA) was performed. The TAG and FFA crystallization products (LTC-TAG and LTC-FFA, respectively) had SDA contents of 48.72 and 60.78%, respectively. Enzymatic acidolysis between MSO and LTC-FFA was studied utilizing Novozym 435 and Lipozyme TL IM as biocatalysts. Substrate molar ratio, incubation time, solvent, and enzyme load were explored. Equilibrium was reached at 96 and 48 h for Novozym 435 and Lipozyme TL IM-catalyzed reactions, respectively. The best conditions from these studies were also applied to the acidolysis of LTC-TAG and LTC-FFA. Utilizing Lipozyme TL IM and solvent free conditions, SLs with SDA contents of 37.61 ± 1.00% (20.86 ± 6.48% at sn-2 position) and 53.46 ± 1.85% SDA (36.37 ± 3.14% at sn-2 position) were obtained from the acidolysis reaction between MSO and LTC-FFA, and LTC-TAG and LTC-FFA, respectively. Compared to the original SDA content of MSO, this process leads to a 52 and 116% increase in SDA content, respectively. 相似文献
5.
《分离科学与技术》2012,47(7):1164-1171
In this study a suitable alcohol/salt aqueous two-phase (ATP) system was selected for the recovery of lactic acid from an aqueous solution. From the different ATP systems studied, the ethanol/dipotassium hydrogen phosphate ATP system appeared to be favorable. To examine the potential of this ATP system, the extraction yield of lactic acid in aqueous solutions was optimized with the response surface methodology. The parameters studied were concentrations of ethanol (22.00–38.80%, w/w), dipotassium hydrogen phosphate (15.00–31.80%, w/w) and lactic acid (26.36–93.64 g/L). The optimum conditions were found to be 30.23% w/w ethanol, 18.40% w/w dipotassium hydrogen phosphate, and 80 g/L lactic acid. Under these conditions, a favorable extraction yield of lactic acid was obtained. The maximum partition coefficient of lactic acid and extraction yield was determined as 2.26 and 87%, respectively. The optimum extraction conditions were then used to guide the recovery of lactic acid from a real fermentation broth. As a result, the partition coefficient and extraction yield of lactic acid reached 2.06–80%, respectively. 相似文献
6.
Hongjie Ren Yang Li Wei Du Dehua Liu 《Journal of the American Oil Chemists' Society》2013,90(1):73-79
Free lipase-mediated alcoholysis for biodiesel production has drawn increasing attention in recent years due to its advantages of lower cost and faster reaction rate compared to immobilized lipase. Ethanol, derived from renewable biomass, has a great potential for biodiesel production. A previous study showed that free lipase NS81006 could effectively catalyze the ethanolysis of triglycerides for biodiesel preparation. Since most crude plant oils always contain an amount of free fatty acids, oleic acid was used as the model substrate for this study on lipase-mediated esterification for biodiesel production. The central composite design of the response surface methodology was adopted for process optimization. A biodiesel yield of over 90 % was achieved under optimal reaction conditions and the repeated use of the free lipase was easily realized through phase separation either by natural gravity force or centrifugation. 相似文献
7.
以迷迭香为原料,以m(水)∶m(迷迭香)、浸润时间、提取时间为影响因子,迷迭香挥发油提取率为响应值,应用Box-Behnken响应面法设计试验对水蒸气蒸馏法提取迷迭香挥发油工艺参数进行优化。优化后的最佳提取条件为m(水)∶m(迷迭香)=1,浸润时间1h,提取时间142min,迷迭香挥发油最佳提取率达到了2.36%。由响应面分析可知,m(水)∶m(迷迭香)和提取时间对挥发油提取率影响显著。优化后的提取工艺条件,大大减少了水的用量,缩短了整个提取时间,挥发油的提取率得到了较大的提高。 相似文献
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《精细化工》2017,(11)
利用响应面法优化款冬花中绿原酸的微波提取工艺。以绿原酸得率为响应值,在单因素实验的基础上,采用Box-Behnken中心组合设计响应面优化法,对乙醇体积分数、微波功率、微波时间、液固比4个因素进行考察,模拟得到二次多项式回归方程的预测模型。通过响应面模型确定微波辅助提取款冬花绿原酸的最佳提取工艺为:微波功率200 W,微波时间7 min,乙醇体积分数60%,液固比80∶1(m L/g),在该条件下款冬花绿原酸的得率为11.19%,与模型预测值11.10%非常接近,高于传统浸提法和超声法提取的绿原酸得率。响应面法优化款冬花绿原酸的微波提取工艺与传统浸提法、超声法相比,具有能耗低、时间短、得率高等优点,可为工业生产提取天然绿原酸工艺提供参考。 相似文献
12.
Response surface methodology (RSM) was applied to study the effects of types of wall materials (modified starch + maltodextrin and whey protein concentrate + maltodextrin), feed concentration, oil concentration, and outlet air temperature on oil retention and surface oil content of the encapsulated powder. The results revealed that the oil retention was significantly (P < 0.05) affected by the constant term of types of wall materials and the linear term of feed concentration but seemed to be almost independent (P > 0.05) of experimental range of oil concentration and outlet air temperature. The types of wall materials, oil load, and outlet air temperature showed a significant (P < 0.05) influence on surface oil content. The types of wall materials (Hi-Cap and WPC) also influenced significantly the oil retention and surface oil content. Based on the limited range of experimental conditions used in this work, it was not possible to choose the wall materials that can give both high oil retention and low surface oil content. Disregarding the effect of wall material, an optimum response was obtained at 40% of feed concentration (w/w), 18% of oil concentration, and 65°C of outlet air temperature. 相似文献
13.
Response surface methodology was employed to optimize the conditions of supercritical CO2 extraction of the oil from freeze‐dried onion powder. The effects of pressure, temperature and extraction time on the yield of oil were investigated. The maximum extraction yield of 4.69 ± 0.04 g/kg dry basis was achieved at a pressure of 20.6 MPa, a temperature of 40.6 °C, a time of 260 min, a CO2 flow rate of 22 L h–1, and an entrainer ratio of 0.1 mL absolute ethanol per gram dry basis. The chemical composition of the oil was analyzed by gas chromatography‐mass spectrometry. The most representative compounds of the essential oil were organosulfur‐containing compounds and, among these, the main constituents were methyl 5‐methylfuryl sulfide (18.30 %), methyl 3,4‐dimethyl‐2‐thienyl disulfide (11.75 %) and 1‐propenyl propyl disulfide (9.72 %). 相似文献
14.
Enzyme-Assisted Aqueous Extraction of Kalahari Melon Seed Oil: Optimization Using Response Surface Methodology 总被引:2,自引:0,他引:2
Kar Lin Nyam Chin Ping Tan Oi Ming Lai Kamariah Long Yaakob B. Che Man 《Journal of the American Oil Chemists' Society》2009,86(12):1235-1240
Enzymatic extraction of oil from Kalahari melon seeds was investigated and evaluated by response surface methodology (RSM). Two commercial protease enzyme products were used separately: Neutrase® 0.8 L and Flavourzyme® 1000 L from Novozymes (Bagsvaerd, Denmark). RSM was applied to model and optimize the reaction conditions namely concentration of enzyme (20–50 g kg?1 of seed mass), initial pH of mixture (pH 5–9), incubation temperature (40–60 °C), and incubation time (12–36 h). Well fitting models were successfully established for both enzymes: Neutrase 0.8 L (R 2 = 0.9410) and Flavourzyme 1000 L (R 2 = 0.9574) through multiple linear regressions with backward elimination. Incubation time was the most significant reaction factor on oil yield for both enzymes. The optimal conditions for Neutrase 0.8 L were: an enzyme concentration of 25 g kg?1, an initial pH of 7, a temperature at 58 °C and an incubation time of 31 h with constant shaking at 100 rpm. Centrifuging the mixture at 8,000g for 20 min separated the oil with a recovery of 68.58 ± 3.39%. The optimal conditions for Flavourzyme 1000 L were enzyme concentration of 21 g kg?1, initial pH of 6, temperature at 50 °C and incubation time of 36 h. These optimum conditions yielded a 71.55 ± 1.28% oil recovery. 相似文献
15.
采用单因素试验及响应面法对超临界CO2萃取丁香精油进行工艺优化.选取萃取温度、萃取压力及萃取时间作为考察因素,以丁香精油收率为考察指标进行单因素试验.依据单因素试验结果确定最佳萃取温度、萃取压力及萃取时间,采用响应面法进行3因素3水平试验,考察3因素及其交互作用对丁香精油收率的影响.结果表明:超临界CO2萃取丁香精油的最优工艺为萃取温度49℃、萃取压力36 MPa、萃取时间105 min、CO2流量为10 kg·h-1,最优工艺下丁香精油平均收率为20.1%.通过试验验证,此法可靠,可以用于超临界CO2萃取丁香精油工艺的初步分析及优化. 相似文献
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Tuyen C. Kha Minh H. Nguyen Paul D. Roach Costas E. Stathopoulos 《Drying Technology》2014,32(4):385-397
The objective of this study was to optimize the wall material concentration and the oil load on the encapsulation of Gac oil using spray drying by response surface methodology. Results showed that the quadratic polynomial model was sufficient to describe and predict encapsulation efficiencies in terms of oil, β-carotene, lycopene, peroxide value (PV), moisture content (MC), and total color difference (Δ E) with R 2 values of 0.96, 0.95, 0.86, 0.89, 0.88, and 0.87, respectively. Under optimum conditions (wall concentration of 29.5 % and oil load of 0.2), the encapsulation efficiencies for oil, β-carotene, lycopene, PV, MC, and Δ E were predicted and confirmed as 92 %, 80 %, 74 %, 3.91 meq/kg, 4.14 % and 12.38, respectively. The physical properties of the encapsulated oil powders obtained by different formulations were also determined. It was concluded that the protein-polysaccharide matrix as the wall material was effectively used for spray-drying encapsulation of Gac oil. 相似文献
18.
ABSTRACTIn this study, an ozonation process was used to increase biodegradability of textile wastewater by considering chemical oxygen demand (COD) and color removal. Response surface methodology was applied in order to determine the significance of independent variables which are initial pH, reaction time and ozone dose. While a biological oxygen demand (BOD)/COD rate of 0.315 was obtained at optimum conditions, which are pH 9, 75 min of reaction time and 26 mg/L ozone dose, color and COD removal was obtained at 74% and 39%, respectively. BOD/COD ratio value increased from 0.18 to 0.32 by ozonation process. In addition, k coefficient for BOD also increased from 0.21 to 0.30 d?1. 相似文献
19.
Functional Ionic Liquids Catalyzed the Esterification of Ricinoleic Acid with Methanol to Prepare Biodiesel: Optimization by Response Surface Methodology 下载免费PDF全文
An efficient route to preparing biodiesel by the esterification of ricinoleic acid (RA) with methanol was investigated in the work. Six kinds of functional ionic liquids (IL) were selected as catalysts. The effects of reaction variables (reaction time, temperature, IL load, and the ratio of reaction substrates) were also evaluated and optimized using response surface methodology (RSM). Among IL tested, 1‐butylsulfonic‐3‐methylimidazolium trifluoromethanesulfonate showed the highest catalytic efficiency for the esterification. Reaction variables were optimized using RSM as follows: IL load 4 % (relative to the weight of RA), molar ratio of methanol to RA 9.2:1, 67 °C, and 28 min. Under the optimized conditions, the esterification degree of RA was 92.3 ± 1.7 %. 相似文献
20.
Optimization of Epoxidized Methyl Acetoricinoleate Synthesis by Response Surface Methodology 下载免费PDF全文
Epoxidized methyl acetoricinoleate (EMAR) was generated by epoxidation of methyl acetoricinoleate (MAR) in the presence of formic acid and hydrogen peroxide by using ionic liquids as catalysts, and the product was characterized by means of infrared spectroscopy and mass spectrometry. The efficiencies of four different catalysts, 1‐methylimidazole hydrogen sulfate salt ([Hmim]HSO4), 1‐methylpyrrolidone hydrogen sulfate salt ([Hnmp]HSO4), phosphoric acid, and sulfuric acid, were compared. The effects of the formic acid/MAR molar ratio, hydrogen peroxide/MAR molar ratio, reaction temperature, reaction time, and catalyst dosage on the epoxy value of EMAR were investigated by single‐factor experiments. 相似文献