Physico-Chemical Characterization of Oils Extracted from Noni,Spinach, Lady’s Finger,Bitter Gourd and Mustard Seeds,and Copra

The physico-chemical properties of solvent-extracted oil from the seeds of noni (Morinda citrifolia L.), spinach (Spinacia oleracea L.), lady’s finger (Abelmoschus esculentus (L.) Moench), bitter gourd (Momordica charantia L.), mustard (Brassica nigra (L.) Koch), and the dried kernel (copra) of coconut (Cocos nucifera L.) were characterized. Among these sources, spinach seed had the lowest oil content (4.5 ± 0.4%) while coconut kernel had the highest oil content (63.1 ± 2.8%). Palmitic, oleic, and linoleic acids were the major fatty acids for spinach, lady’s finger and noni seed oils, while erucic, eleostearic, and lauric acids were the major fatty acids for mustard seed oil, bitter gourd seed oil, and coconut kernel oil, respectively. All of the oils possessed at least three major peaks in their triacylglycerol profiles except for bitter gourd seed oil which had only one major peak (1-stearoyl, 2,3-dieleostearoyl). The last endothermic peaks were –12.4, –6.0, 6.8, 57.7, 2.7, and 24.3ºC for noni, spinach, lady’s finger, bitter gourd and mustard seed oils, and coconut oil, respectively. Initially, the solid fat content of bitter gourd seed oil decreased gradually, but became rapidly after 50 until 60ºC. Coconut oil had its solid fat content reduced rapidly around 14 to 28ºC.     

Enzymatic synthesis of medium‐ and long‐chain triacylglycerols–enriched structured lipid from Cinnamomum camphora seed oil and camellia oil by Lipozyme RM IM

Medium‐ and long‐chain triacylglycerols (MLCTs)–enriched structured lipid (SL) was synthesised through enzymatic interesterification from Cinnamomum camphora seed oil (CCSO) and camellia oil (CO) using Lipozyme RM IM from Rhizomucor miehei as a biocatalyst. Effects of different reaction conditions including substrate molar ratio, reaction time and reaction temperature were investigated. Results showed that 55.81% of total MLCT species (CCO/LaCL, LaCO/LCL, COO/OCO and LaOO/OLaO) was obtained in the interesterified product under the optimal conditions of substrate molar ratio of 1:1.5 (CCSO/CO) at 60 °C for 3 h. Thereafter, fatty acid profiles, tocopherol contents and physiochemical characteristics of the interesterified product and physical blend were comparatively investigated. The fatty acid composition of the interesterified product consisted of capric acid (26.33%), lauric acid (21.29%) and oleic acid (42.33%). It should be mentioned that the interesterified product contained predominantly oleic acid (88.69%) at Sn‐2 position, while MCFAs (68.05%) at Sn‐1,3 positions. Compared with physical blend, the reduction in tocopherol contents and changes of physiochemical characteristics occurred in SL. The smoke point of the interesterified product was much higher than that of the physical blend, which meant that such MLCTs‐enriched SL could be better for cooking purpose.     

超声波辅助溶剂法提取苦瓜籽油的工艺研究

以苦瓜籽为原料,无水乙醇为浸提溶剂,采用超声波辅助溶剂法提取苦瓜籽油。在单因素试验基础上进行正交试验,得出最佳提取工艺条件:颗粒粒径为212μm、液料比8∶1(mL/g)、超声时间60 min、超声温度50℃、超声功率160 W。在该工艺条件下,苦瓜籽油的平均提取率为84.32%。     

Valorization of Olive Pomace Oil with Enzymatic Synthesis of 2‐Monoacylglycerol

2‐Monoacylglycerols (2‐MAG) with a high content of oleic acid at sn‐2 position was synthesized by enzymatic ethanolysis of refined olive pomace oil, which is a byproduct of olive oil processing. Six lipases from different microbial sources were used in the synthesis of 2‐MAG. Immobilized lipase from Candida antarctica gave the highest product yield among the selected lipases. Response surface methodology was applied to optimize reaction conditions; time (4 to 10 h), temperature (45 to 60 °C), enzyme load (10 to 18 wt%), and ethanol:oil molar ratio (30:1 to 60:1). The predicted highest 2‐MAG yield (84.83%) was obtained at 45 °C using 10 (wt%) enzyme load and 50:1 ethanol:oil molar ratio for 5 h reaction time. Experiments to confirm the predicted results at optimum conditions presented a 2‐MAG yield of 82.54%. The purification yield (g 2‐MAG extracted/100 g of total product) was 80.10 and 69.00 for solvent extraction and low‐temperature crystallization, respectively. The purity of the synthesized 2‐MAG was found to be higher than 96%.     

Optimisation of enzymatic esterification of soybean oil deodoriser distillate

The enzymatic esterification of free fatty acids from soybean oil deodoriser distillate with ethanol, catalysed by immobilised fungal lipase, was studied. The extent of conversion of free fatty acids to ethyl esters was optimised using a response surface methodology obtained through a second‐order factorial experimental design. The variables studied were reaction temperature (30–70 °C), enzyme concentration (7–23%) and ethanol/free fatty acid molar ratio (0.3–3.7:1). The optimal reaction conditions achieved were temperature from 46.4 to 53.6 °C, enzyme concentration from 13.6 to 16.5% and ethanol/free fatty acid molar ratio from 1.7 to 2.3:1, with conversions above 88%. No significant tocopherol losses were observed during the process. In conclusion, enzymatic fatty acid esterification was shown to be a technically viable process. © 2001 Society of Chemical Industry     

Enzymatic production of low‐calorie structured lipid from Echium seed oil and lauric acid: optimisation by response surface methodology

Low‐calorie structured lipids (SLs) were produced from Echium seed oil and lauric acid by enzymatic acidolysis reactions. Lipozyme^® RM IM, commercially immobilised sn‐1,3 specific lipase derived from Rhizomucor miehei, was used in the reactions. The effects of substrate molar ratio and reaction time on incorporation of lauric acid were investigated and optimised by response surface technology (RSM) with five‐level, two‐factor central composite design. Good quadratic model was obtained for the response [lauric acid (%) incorporation]. Highest lauric acid incorporation into Echium oil was obtained at 5:1 lauric acid/Echium oil molar ratio and at 4‐h reaction time. The model was verified at these conditions and furthermore scale‐up synthesis of SLs was performed. At these conditions, SL contained predominantly lauric acid (42.8%), oleic acid (9.9%), linoleic acid (10.8%), α‐linolenic acid (15.1%), γ‐linolenic acid (7.5%) and stearidonic acid (8.5%) with% 64.4 of PUFA at sn‐2 position in gram‐scale synthesis.     

Production of reduced calorie structured lipid by acidolysis of tripalmitin with capric acid: optimisation by response surface methodology

BACKGROUND: Structured lipids (SLs) containing medium‐chain fatty acids (C8:0–C12:0) in the 1‐ and 3‐positions and long‐chain fatty acids in the 2‐position of triacylglycerols have interesting applications as reduced calorie fats. The aim of this study was to produce an SL by inserting capric acid (CA, C8:0) into tripalmitin (TP) and to optimise the reaction conditions by response surface methodology (RSM) with a three‐level, three‐factor face‐centred cubic design. RESULTS: Lipozyme TL IM from Thermomyces lanuginosa was used for the acidolysis of TP with CA in n‐hexane. The effects of three independent parameters, namely substrate molar ratio, enzyme amount and reaction time, on CA incorporation into TP were optimised. The range of each parameter was selected as follows: substrate molar ratio (CA/TP), 4–8; enzyme amount, 9–15 wt% of total substrate; reaction time, 6–10 h. Optimal conditions were determined to be a CA/TP molar ratio of 6.5, an enzyme amount of 11.6 wt% and a reaction time of 8.9 h. Experiments conducted under these optimised conditions yielded an SL containing 35.7 wt% (44.9 mol%) CA. A second‐order polynomial model was obtained for CA incorporation. CONCLUSION: The possibility of enriching CA in TP by enzymatic acidolysis has been established. The SL containing 44.9 mol% CA produced under optimal conditions may be considered a reduced calorie fat. Copyright © 2008 Society of Chemical Industry     

Enrichment of Rice Bran Oil with ��-Linolenic Acid by Enzymatic Acidolysis: Optimization of Parameters by Response Surface Methodology

Lipase-catalyzed enrichment of rice bran oil with n-3 fatty acid in order to obtain a structured lipid containing essential fatty acids has been optimized by response surface methodology. In this process, α-linolenic acid was used as an acyl donor using lipase-catalyzed acidolysis in hexane in presence of immobilized lipase from Rhizomucor miehei. The effect of incubation time and temperature, enzyme concentration and substrates mole ratio and their complex interaction on percentage incorporation of n-3 fatty acid, ratios of saturated fatty acid to polyunsaturated fatty acids, monounsaturated fatty acids to polyunsaturated fatty acids and n-6 to n-3 (18:2 to 18:3) fatty acids have been studied using a central composite rotatable design of experiments. The results showed that at the optimum conditions such as reaction time 4.5 h and reaction temperature 37. 5°C, substrate ratio ranging from 1.0 to 1.9, enzyme concentration varying from 1.0% to 2.0% are needed to fulfill the conditions such as percentage incorporation of n-3 fatty acid ≤18%, ratio of saturated fatty acid to poly unsaturated fatty acid ≥0.42, ratio of mono unsaturated fatty acid to poly unsaturated fatty acid ≥0.8, and ratio of n-6 to n-3 ≥1.30.     

Blending of corn oil with black cumin (Nigella sativa) and coriander (Coriandrum sativum) seed oils: Impact on functionality, stability and radical scavenging activity

Blends (10% and 20%, w/w) of black cumin seed oil (BCSO) and coriander seed oil (CSO) with corn oil (CO) were formulated. Oxidative stability (OS) and radical scavenging activity (RSA) of CO and blends stored under oxidative conditions (60 °C) for 15 days were studied. By increasing the proportion of BCSO and CSO in CO, levels of polyunsaturated fatty acids (PUFA) decreased, while monounsaturated fatty acids (MUFA) content increased. Progression of oxidation was followed by measuring peroxide value (PV), conjugated dienes (CD) and conjugated trienes (CT). Inverse relationships were noted between PV and OS at termination of storage. Levels of CD and CT in CO, and blends, increased with increase in time. CO:BCSO and CO:CSO blends gave 12-22% and 26-36% inhibition of DPPH radicals, respectively. Oxidative stability of oil blends were better than CO, most likely as a consequence of changes in fatty acids and tocopherols’ profile, and minor bioactive lipids (e.g., sterols and phenolics) found in coriander and black cumin oils.     

Optimisation of red pepper seed oil extraction using supercritical CO2 and analysis of the composition by reversed‐phase HPLC‐FLD‐MS/MS

Oil extractions from red pepper seed were performed by supercritical CO₂. Three‐level Box–Behnken factorial design (BBD) from response surface methodology (RSM) was applied to optimise the main extraction conditions including pressure, temperature and concentration of modifier (ethanol). The optimum conditions were as follows: extraction pressure, 27.17 MPa; extraction temperature, 47.67 °C; and the added concentration of modifier, 8.11 vol.%. Under the optimum conditions, the oil yield of 18.4% was obtained, which was well matched with the predicted yield. A simple, stable and sensitive method for the simultaneous determination of saturated and unsaturated free fatty acids in extracted oils using 2‐(11H‐benzo[a]carbazol‐11‐yl)‐ethyl‐4‐methylbenzenesulfonate (BCETS) as labelling reagent with fluorescence detection has been developed. All of free fatty acids (FFA) were found to give a linear response with correlation coefficients of >0.9991. The detection limits at a signal‐to‐noise ratio (S/N) of three are in the range of 19.06–41.19 fmol. This method should have powerful potential for the trace analysis of short‐ and long‐chain FFA from edible oils, foodstuff and other complex samples.     

Optimisation of Novozym‐435‐catalysed esterification of fatty acid mixture for the preparation of medium‐ and long‐chain triglycerides (MLCT) in solvent‐free medium

Novozym‐435‐catalysed esterification of caprylic acid, capric acid and oleic acid with glycerol for the synthesis of medium‐ and long‐chain triglycerides (MLCT) in vacuum and solvent‐free system was investigated in this study. Response surface methodology with a three‐level, four‐factorial design was applied to optimise the enzymatic esterification for the synthesis of MLCT. The optimum conditions were as follows: reaction temperature 90 °C, 4.80 wt% enzyme load (relative to the weight of total substrates) and substrate molar ratio (fatty acids/glycerol) of 3:1 and 12.37 h. Under above‐mentioned conditions, Triglycerides (TG) yield, MLCT and the residual free fatty acids (FFA) content in the product were 93.54%, 72.19% and 4.21%, respectively. The content of caprylic acid, capric acid and long‐chain fatty acids of TG was 24%, 10% and 66%, respectively. Novozym 435 in the study showed no selectivity for the different fatty acids and also could be used 14 times without obvious loss of enzyme activity.     

Enzyme-Catalyzed Production and Chemical Composition of Diacylglycerols from Corn Oil Deodorizer Distillate

Diacylglycerols (DAG) were enzymatically synthesized by lipase-catalyzed esterification of glycerol with fatty acids from corn oil deodorizer distillate (CrODD). Effects of reaction parameters such as reaction time, temperature, enzyme type, enzyme load, substrate mole ratio, and water content, as well as the effect of molecular sieves as a water adsorbent were investigated. Rhizomucor miehei lipase (Lipozyme RM IM) was found to be most effective among the lipases screened. The following conditions yielded 70.0% (w/w) DAG: 5 h reaction time, 65°C reaction temperature, 10% (w/w) Lipozyme RM IM, 2.5:1 fatty acid to glycerol molar ratio, and 30% (w/w) molecular sieves. DAG synthesis of 12.4% (w/w) was still observed at 10% (w/w) water content. 84.2% (w/w) of DAG was obtained after purification. The DAG oil comprised predominantly of 1-oleoyl-3-linoleoyl-glycerol (28.5%), 1,3-diolein (22.7%), 1-oleoyl-2-linoleoyl-glycerol (17.9%), and 1,2-diolein (10.9%). Fatty acid profile was similar to that of refined, bleached and deodorised (RBD) corn oil. The ratio of 1,3- to 1,2-positional isomers of DAG was at 1.82:1.     

Improvement of palm oil and sunflower oil blends by enzymatic interestrification

Palm oil (PO) and sunflower oil (SFO) blends with varying proportions were subjected to enzymatic interesterification (EIE) using a 1,3‐specific immobilised lipase. The interesterified blends were evaluated for their slip melting point (SMP), solid fat content (SFC) at 10–40 °C, p‐anisidine value, peroxide value, free fatty acids (FFA), induction period of oxidation at 110 °C (IP110) and composition of fatty acids by gas chromatography. Under EIE treatment, the blends of PO and SFO in different proportions (20:80, 40:60, 50:50, 60:40 and 80:20) had saturated and unsaturated fatty acid content in the range of 37.6–52.0% and 48.0–62.4%, respectively. The blends showed a considerable reduction in their SFC, SMP, peroxide value and oxidative stability at 110 °C, but presented increase in FFA and p‐anisidine value. The optimum condition for minimising the fatty acid in oil was obtained, at 64 °C, using 8.9% enzyme and 3 h reaction time.     

Physicochemical properties of Kalahari melon seed oil following extractions using solvent and aqueous enzymatic methods

The physico‐chemical properties of oil from Kalahari melon seed were determined following extraction with petroleum ether and aqueous‐enzymatic methods. Two different enzymes Flavourzyme 1000 L and Neutrase 0.8 L were separately used during aqueous‐enzymatic method. The free fatty acid, peroxide, iodine and the saponification values of the oils extracted using the methods were found to be significantly (P < 0.05) different. The melting point of the oils extracted was in the range of ?18.7 °C to ?17.5 °C and no significant (P > 0.05) difference between the oil obtained from solvent and aqueous‐enzymatic extractions was observed. Enzyme‐extracted oil tended to be light‐coloured and more yellow in colour compared with solvent‐extracted oil. The predominant fatty acids in the extracted oils were linoleic acid (62.2–63.1%), with some oleic (16.8–17.1%), palmitic (11.4–12.4%), stearic (7.5–8.1%), linolenic (0.7–1.2%) and eicosenoic (0.3%). Phenolic acids in enzyme‐extracted oils were comparable to the solvent‐extracted oil. The oils extracted with these two methods were differed in the composition of their phytosterol and tocopherol contents, but no significant (P > 0.05) difference between the two enzyme‐extracted oils was observed.     

Synthesis of high fatty acid starch esters with 1‐butyl‐3‐methylimidazolium chloride as a reaction medium

In this work, high fatty acid esters of corn starch were synthesized by reacting the starch with fatty acid methyl ester using 1‐butyl‐3‐methylimidazolium chloride (BMIMCl) ionic liquid (IL) as reaction media. The effect of reaction variables such as the catalyst amount, molar ratio of fatty acid methyl ester/anhydroglucose unit (AGU) in starch, pyridine/AGU molar ratio, reaction temperature, as well as reaction time on the degree of substitution (DS) of starch esters was investigated. The experimental results showed that the DS value of the obtained starch esters could be varied depending on the process conditions. In the optimum reaction condition, the achieved maximum DS of starch laurate and starch stearate was 0.37 and 0.28, respectively, at a reaction temperature of 110°C for starch laurate and 120°C for starch stearate for a reaction duration of 2 h. Furthermore, the starch esters were characterized by FTIR, SEM, and X‐ray diffractometry (XRD) techniques, respectively. Results from FT‐IR spectroscopy suggested that the hydroxyl groups in the starch molecules were converted into ester groups. SEM and XRD studies showed that the morphology and crystallinity of starch esters were disrupted largely in the IL medium under the reaction conditions.     

Supercritical CO2 oil extraction from Chinese star anise seed and simultaneous compositional analysis using HPLC by fluorescence detection and online atmospheric CI‐MS identification

BACKGROUND: Supercritical CO₂ was utilised to extract Chinese star anise seed oil (CSASO), and a three‐level Box–Behnken factorial design from response surface methodology was applied to optimise the extraction conditions, including pressure, temperature and amount of modifier (ethanol). The compositional analysis of fatty acids in CSASO was performed by HPLC with fluorescence detection using 2‐(11H‐benzo[a]carbazol‐11‐yl)‐ethyl‐4‐methylbenzenesulfonate (BCETS) as labelling reagent. Identification was carried out by online atmospheric chemical ionisation–mass spectrometry. RESULTS: The optimum extraction conditions were as follows: extraction pressure, 27.72 MPa, extraction temperature, 46.22 °C, and amount of modifier, 8.58 vol.%. The experimental result showed that the maximum extraction yield was 25.31 ± 0.22% (w/w) under the conditions proposed. The compositional analysis indicated that CSASO mainly contained C18:2, C18:1, C18:3, C20:4, C16, C18 and C20 fatty acids. CONCLUSION: In this study, a fast, simple and high‐efficiency supercritical technique for extracting oil from Chinese star anise seed was developed. Simultaneous determination of fatty acids in CSASO using BCETS as the labelling reagent with HPLC fluorescence detection and online mass spectroscopy identification has been successfully achieved. Copyright © 2010 Society of Chemical Industry     

响应面优化脂肪酶催化合成中长碳链甘三酯

采用响应面设计对脂肪酶Novozym 435在无溶剂体系中催化甘油和中长碳链脂肪酸(辛酸、癸酸和油酸混合物)酯化反应合成中长碳链甘三酯进行了研究.研究发现:反应温度、加酶量和反应时间对中长碳链甘三酯得率具有显著性影响(P＜0.05),而底物摩尔比(脂肪酸与甘油摩尔比)对中长碳链甘三酯得率不具有显著性影响.优化得到的最佳条件为:反应温度90℃,加酶量6.5％(以脂肪酸和甘油的总质量计),底物摩尔比3.5∶1,反应时间12.97 h.在此条件下,平均甘三酯得率为78.5％;产品中甘三酯、甘二酯、甘一酯和游离脂肪酸含量分别为85.6％、0.3％、0.1％和14.0％;产品甘三酯中辛酸、癸酸和长碳链脂肪酸含量分别为25.4％、10.7％和63.9％,与目标中长碳链甘三酯产品指标基本一致.     

紫云英籽油超声-微波协同提取及脂肪酸组成分析

采用超声-微波协同提取法提取紫云英籽油并测定其脂肪酸组成。在单因素实验的基础上,采用响应面(RSM)分析法,对紫云英籽油提取条件进行优化,并用气相色谱 ( GC) 分析了紫云英籽油脂肪酸组成。结果表明,对紫云英油的提取影响由大到小依次为提取时间、液料比、微波功率。超声-微波协同提取法提取紫云英籽油的优化工艺条件为：提取时间152 s、微波功率204 W和液料比10 mL.g^-1 ,紫云英籽油的出油率为31.52%。紫云英籽油达到食用植物油国家标准。紫云英籽油共检测到20种脂肪酸,主要成分为油酸(13.24%)、亚油酸(37.58%)、亚麻酸(30.03%)、硬脂酸(3.48%)、棕榈酸(10.56%)、芥酸(1.11%)。其中不饱和脂肪酸相对含量为82.83%。亚油酸与α-亚麻酸的比值为1.25。本研究为紫云英籽油的开发利用提供了科学依据和技术参考。     

超声波法提取西瓜籽油的最佳工艺研究

对超声波辅助提取西瓜籽油的最佳工艺进行了研究,利用正交试验探讨了影响提取率的主要因素。结果表明,影响西瓜籽油提取率的因素主次顺序依次为:料液比>超声温度>超声时间>超声功率;最佳提取条件为:石油醚为提取剂,料液比为1∶12(g∶mL),超声温度60℃,超声时间30 min,超声功率150 W,西瓜籽油提取率为50.8%,西瓜籽油的脂肪酸主要由棕榈酸和不饱和脂肪酸组成,不饱和脂肪酸占93.1%,特别是亚油酸的含量高达74.8%,具有较高的保健价值。     

共轭亚麻酸甲酯化方法的比较和优化

气相色谱分析油脂和生物样品的脂肪酸时样品需要进行甲酯化,本研究以富含共轭亚麻酸(CLNA)的栝楼籽油为材料,针对共轭亚麻酸三酰甘油和共轭亚麻酸自由脂肪酸两种脂质形式进行了甲酯化方法的优化和比较。结果表明直接以栝楼籽油(三酰甘油形式)采用酸性催化的方法进行甲酯化,在高温和长时间的反应条件下,石榴酸(栝楼籽油含有的主要CLNA)严重异构为其他形式的CLNA,而碱性催化的方法进行甲酯化,55℃反应20 min既能使甲酯化完全,且石榴酸等CLNA保持稳定,适宜作为自由脂肪酸含量低的脂质的甲酯化方法。而对自由脂肪酸含量高的脂质可以采用先以0.3 mol/L氢氧化钾90%乙醇溶液37℃皂化裂解2 h,再采用1 mol/L硫酸甲醇溶液50℃反应10 min进行甲酯化。