Biological activity of Boswellia serrata Roxb. oleo gum resin essential oil: effects of extraction by supercritical carbon dioxide and traditional methods

The findings of this study suggests that chemical composition, essential oil yield, antioxidant and antimicrobial activity of Boswellia serrata oleo gum resin essential oils extracted by hydro distillation, steam distillation and supercritical fluid carbon dioxide methods vary greatly from each other. The optimum essential oil yield was obtained using hydro distillation method (8.18 ± 0.15 %). The essential oils isolated through different extraction methods contained remarkable amounts of total phenolics and total flavonoids. Essential oil isolated through supercritical fluid carbon dioxide extraction exhibited better antioxidant activity with highest free radical scavenging potential (96.16 ± 1.57 %), inhibition of linoleic acid oxidation (94.18 ± 1.47 %) and hydrogen peroxide free radical scavenging potential (68.25 ± 1.02 %). Moreover, the antimicrobial activity of essential oils was performed through well diffusion, resazurin microtiter plate and micro dilution broth assay assays. The essential oil isolated through steam distillation method revealed highest antimicrobial activity with maximum inhibition zone (24.21 ± 0.34 to12.08 ± 0.30 mm) and least MIC values (35.18 ± 0.77 to 281.46 ± 7.03 µg/mL). The comparison of chemical composition of essential oils isolated at different extraction methods have shown that the concentration of α-thujene, camphene, β-pinene, myrcene, limonene, m-cymene and cis-verbenol was higher in steam distilled essential oil as compared to hydro and supercritical fluid carbon dioxide extracted essential oils. These compounds may be responsible for the higher antimicrobial activity of Boswellia serrata oleo gum resin steam distilled essential oil.     

Chemical composition and insecticidal properties of Origanum glandulosum (Desf.) essential oil from Algeria

BACKGROUND: To find natural compounds with insecticidal properties which could be an alternative to synthetic insecticides, oregano essential oil was tested against the insect Rhizopertha dominica devastating stored cereals. RESULTS: Oregano oils were isolated by steam distillation, analysed by gas chromatography and gas chromatography–mass spectrometry and investigated for their insecticidal activities against Rhizopertha dominica. Contact and fumigant toxicities of global oil and three of its fractions recovered respectively after 2 h and after 0–2.5, 2.5–5 and 5–10 min of extraction were tested using the filter paper method. Eighteen components, representing 92.6% of the oil, were identified. The major components were thymol (38.8%), carvacrol (32.9%), p‐cymene (7.9%) and γ‐terpinene (5.1%). Toxicity tests showed that insect mortality increases with the concentration used (0.39%, 0.78%, 1.56%, 3.12% and 6.24%V). For all concentrations, the contact effect of global oil and fraction F₂ was better than the fumigant effect. Whereas fractions F₁ and F₃ were more toxic by fumigation for concentrations lower or equal to 1.56%, their contact effect was more significant for concentrations higher than 1.56%. CONCLUSION: These results suggest that oregano oil has important insecticidal properties and may be useful as a natural grain protectant against Rhizopertha dominica to replace synthetic insecticides. Copyright © 2008 Society of Chemical Industry     

Comparison of isolation procedures for Mexican oregano oil

The influence of distillation time on the composition of Mexican oregano oil was investigated. It was observed that the order of recovery of the components was determined by their solubility when water is in contact with the plant material as in hydrodistillation and simultaneous distillation-solvent extraction, while in steam distillation the order was determined by their boiling points. The three methods produced the same composition. The oil obtained by extraction method had higher proportion of hydrocarbons and lower amount of p-cymene. As a result of this investigation it was shown that this compound was partly an artefact of distillation.     

不同方法提取的柚皮精油质量评价

利用水热法、超临界萃取法、有机溶剂萃取三种不同的方法从沙田柚皮中提取柚皮精油,比较了提取出的三种精油的理化指标、香气特征,并且对精油的主要官能团进行了鉴定。通过对柚皮精油进行综合评价,得出最佳的提取方法。结果表明用水热法提取的精油香气比较纯正,精油含量较高,而且生产成本投资较少,综合评价值最高。     

中药挥发油提取技术研究进展

综述了近年中药挥发油提取技术的研究进展,主要包括水蒸气蒸馏法、压榨法、溶剂提取法等传统的提取方法和微波提取法、超临界二氧化碳提取法、固相微提取法、超声波提取法、分子蒸馏、酶法提取、微胶囊双水相提取法等新提取方法及研究成果。     

超临界CO2-分子蒸馏纯化蒜油与水蒸气蒸馏法制取蒜油挥发性成分分析

采用分子蒸馏技术(MD)将超临界CO2(SFE)萃取的蒜油进行纯化,以顶空固相微萃取气质联用技术(HSSPME-GC-MS)分析蒜油中的挥发性成分,确定最佳工艺：进样速度1 滴/s,蒸馏温度60℃,刮膜转速250r/min。纯化的蒜油挥发性成分仅有4 种,二烯丙基二硫醚和二烯丙基三硫醚、2- 乙烯基-1,3- 二硫杂-4- 环己烯和3- 乙烯基-1,2- 二硫杂-5- 环己烯;与水蒸气蒸馏法制得的新鲜蒜油(F-GO)比较,SFE 法是一种理想的制取蒜油的方法;蒜油放置30d(S-GO)后有效成分含量下降,导致品质下降。     

Study on the pilot-scale extraction of onion oleoresin using supercritical CO2

Supercritical carbon dioxide (SC-CO₂) was used to produce oleoresin from dried onion by pilot-scale extraction. The results showed that the extraction pressure and temperature affected the yield and sulphur concentration of onion oleoresin. Increase of the temperature from 45 to 65°C at 300 bar resulted in an increase of the yield and the sulphur concentration of oleoresin. At the same temperature (45°C) the yield was also higher at 300 bar than 100 bar while sulphur concentration of oleoresin got smaller at 300 bar than at 100 bar. The volatile composition of oleoresin displayed practically no differences as a function of extraction parameters. Comparison of different extraction methods showed that the yield after SC-CO₂ extraction was 22 times higher than that after steam distillation, but it was 14 or 39 times less than that after alcohol extraction, shaking at 25°C or in Soxhlet apparatus, respectively. The concentration of sulphur was the highest in steam distilled onion oil while it was the lowest in the extract of hexane and alcohol (at 25°C). The results of sensory evaluation showed that oleoresin extracted by SC-CO₂ was the first in ranking (at level of significance 0·05), before steam distilled oil and alcoholic extract. There was no significant difference between steam distilled oil and alcoholic extract in ranking, but the alcoholic extract was the least desirable, since the intensity of its off odour attribute was the highest. © 1998 SCI.     

柑橘精油提取工艺的对比研究

采用水提法和加盐水蒸气蒸馏法从柑橘果皮中提取精油。通过单因素试验确定了水蒸气蒸馏法最佳提取条件:提取时间2.0 h、料液比1∶16(g/m L),提取率最高达1.969%。加盐水蒸汽蒸馏法在单因素试验的基础上,通过正交试验法对柑橘果皮中精油的提取进行了研究,结果表明:加盐后最佳工艺条件为Na Cl含量0.3 g,提取时间2.5 h,料液比1∶16(g/m L),提取率最高达3.838%。通过如上对比,建议工业上采用加盐水蒸气蒸馏法从柑橘果皮中提取精油。     

Isolation of volatile oil from thyme (Thymbra spicata) by steam distillation

The effects of steam flow rate (1.03 and 0.64 L/h), distillation time, and particle size (0.50, 1.00, 2.05 mm) of Thymbra spicata on essential oil yield and sequence of extraction of compounds were studied. A logarithmic model fitted well to experimental data. The composition of the essential oil obtained by steam distillation was investigated for whole leaves only since the grinding had an adverse effect on yield. The oil obtained was very rich with respect to its carvacrol content. For both steam flow rates, oxygenated monoterpenes were recovered the most rapidly. Using whole leaves (2.05 mm) and a higher steam flow rate (1.03 L/h) for 75 min of distillation was chosen as the optimum which gives the lowest amount of monoterpene hydrocarbons, the complete recovery of oxygenated compounds, and the highest yield in a shorter time. Yield was 1.57% at this optimum condition. The oil was composed of 53.1% oxygenated compounds, 25.7% monoterpene hydrocarbons, 4.4% sesquiterpenes, and 14.1% p-cymene.     

Antioxidant effect of oregano (Lippia berlandieri v. Shauer) essential oil and mother liquors

The conventional steam distillation process for oregano (Lippia berlandieri v. Shauer) essential oil extraction produces large volumes of mother liquor. This residual liquid represents a potential value because the soluble antioxidants it contains. Essential oil and ethyl acetate mother liquor extracts (MLEs) were evaluated for antioxidant activity. Total phenolic content and antioxidant activities by the 2-2′-diphenyl-1-picrylhydrazyl (DPPH) method, by the deoxyribose degradation assay, and by oxidation of low density lipoproteins (LDL) with CuSO₄ were evaluated. Oil yield was 4.34%. Total phenolic content was 151 ± 2.00 and 150.5 ± 0.98 mg of GAE (gallic acid equivalents)/mL for the essential oil and MLEs, respectively. DPPH assay showed a low radical scavenging activity (RSA) for oregano essential oil. Meanwhile MLEs exhibited no significant RSA at low concentrations, but at higher concentrations (100 μg/mL), it was superior to those exhibited by the controls ascorbic acid and butylated hydroxytoluene (BHT). Deoxy-d-ribose assay results for both essential oil and MLEs showed a good hydroxyl radical RSA at the concentrations tested. Essential oil and MLEs delayed induction time effectively. Solubility problems, chemical constituents, and their hydrophilic–lipophilic distribution are key factors that explain samples behavior for an eventual use of these natural products.     

牛至油、香芹酚、柠檬醛和肉桂醛抗真菌研究

采用纸片扩散法以及双倍稀释法研究牛至油、香芹酚、柠檬醛和肉桂醛对面包酵母和黑曲霉的抑菌效果、最小抑菌浓度(CMIC)和最小杀菌浓度(CMFC)。结果表明,牛至油、香芹酚、柠檬醛和肉桂醛对面包酵母和黑曲霉均有明显的抑制作用。抑菌效力相比较,对面包酵母的抑制效果:肉桂醛>香芹酚>牛至油>柠檬醛;对黑曲霉的抑制效果:香芹酚>牛至油>肉桂醛>柠檬醛。因此,牛至油、香芹酚、柠檬醛和肉桂醛可以作为天然抑菌剂应用于食品加工中。     

Antioxidant activity of essential oil of oregano species from Argentina in relation to their chemical composition

The purpose of this work was to determine chemical composition and antioxidant activity of essential oil of different oregano species from Argentina: ‘Cordobes’, ‘Criollo’, ‘Mendocino’ and ‘Compacto’. The essential oil composition was determined by gas–liquid chromatography and mass spectrometry. Scavenging activity was analysed by DPPH test. The antioxidant activity of the essential oils was determined by an accelerated oxidation test in canola oil. Thirty‐nine compounds were identified in the oregano essential oils. The oregano species showed differences in their chemical composition, radical scavenging activity and antioxidant activity. The main compounds in the studied oregano species were thymol and trans‐sabinene hydrate followed by γ‐terpinene, terpinen‐4‐ol and α‐terpinene. The oregano, ‘Criollo’, was rich in γ‐terpinene and had lower thymol and trans‐sabinene hydrate and higher α‐terpinene and carvacrol contents than the other oregano species. ‘Mendocino’ had higher trans‐sabinene hydrate and limonene than the other oregano species. ‘Cordobes’ and ‘Compacto’ had higher thymol content, radical scavenging activity and antioxidant activity in canola oil.     

Analysis of the essential oil of Mexican oregano (Lippia graveolens HBK)

The composition of the volatile oil of Mexican oregano (Lippia graveolens HBK) isolated by steam distillation was investigated by means of column chromatography, gas chromatography and mass spectrometry. A total of 33 components were identified including 22 hydrocarbons, 4 alcohols, 4 ethers, 2 phenols and 1 ketone. Of the 33 components observed in the present study 7 were identified in Mexican oregano for the first time.     

水蒸气蒸馏法提取化州橘叶精油技术研究

以化州橘叶为原料,采用水蒸气蒸馏法通过正交试验对化州橘红叶的精油提取工艺进行优选,以精油得率为指标,将加水量、浸泡时间、蒸馏时间、Na Cl的浓度(破乳剂)作为因素进行正交试验。结果表明:加水量是化州橘叶精油提取的关键因素,其次是浸泡时间和蒸馏时间,Na Cl浓度为最次要因素。化州橘叶精油的最佳提取工艺为加水10倍量(g/g),浸泡2h,蒸馏2h,添加1.00mg/m L的Na Cl。水蒸气蒸馏法提取化州橘叶的精油方法可行,其精油得率在0.5%左右。     

大蒜挥发油提取工艺的优化研究

采用L9(34)正交试验法,研究大蒜挥发油最优提取工艺。以挥发油得率为指标,以发酵温度、料液比、浸泡时间、蒸馏时间为研究因素,在单因素试验的基础上,进行正交试验。结果：影响大蒜挥发油提取的最主要因素为蒸馏时间,其次为加水量、发酵温度、浸泡时间。最佳提取工艺条件为：发酵温度35℃,料液比1:3.5(m/V),浸泡4h,提取2h。此提取工艺简便易行,在此最佳提取工艺条件下提取率为0.35%。     

芜菁子挥发油、多糖的组成及挥发油抗菌活性的研究

目的用3种方法提取芜菁子挥发油,对挥发油的抗菌作用进行定性和定量分析,并对芜菁子挥发油及多糖的组成进行分析。方法采用水蒸气蒸馏法、溶剂萃取法和同时蒸馏萃取法提取芜菁子挥发油,气相色谱-质谱联用法分析挥发油的组成。运用滤纸片扩散法和二倍稀释法检验芜菁子挥发油对大肠杆菌、金黄色葡萄球菌和绿脓杆菌的抑菌作用。利用水提醇沉法提取残渣中的多糖,酸水解后进行薄层分析。结果 3种方法提取的挥发油分别鉴别出21、7、14种成分。水蒸气蒸馏法提取挥发油中异硫氰酸酯类化合物占45.95%,同时蒸馏萃取法的为31.35%,溶剂萃取法提取挥发油无异硫氰酸酯类化合物。定性定量的抑菌实验结果显示,3种方法所得的挥发油对大肠杆菌、金黄色葡萄球菌和绿脓杆菌均有良好的抑制作用,水蒸气蒸馏法提取的挥发油的抑菌效果最好。在高效G板上,以乙酸乙酯:异丙醇:水=26:14:7(V:V:V)为展开剂,芜菁子多糖的分离效果较好,可鉴别出芜菁子多糖中的果糖和半乳糖。结论芜菁子挥发油对大肠杆菌、金黄色葡萄球菌、绿脓杆菌均有一定的抑制作用,可能与其中含有异硫氰酸酯类和腈类化合物有关。     

超临界CO2提取葛缕子精油及其成分分析

目的:优化葛缕子精油的提取工艺并对其成分进行分析。方法:以葛缕子籽粒为原料,采用超临界CO₂技术提取葛缕子精油,并通过气相色谱—质谱(GC-MS)对精油挥发性成分进行分析。结果:超临界CO₂提取葛缕子精油的最佳工艺条件为提取釜温度50℃,分离釜温度40℃,提取釜压力30 MPa,分离釜压力0.4 MPa,二氧化碳流速20 g/min,提取时间90 min,此条件下精油得率为4.79%。与同时蒸馏萃取(SDE)法相比,超临界CO₂流体能快速扩散到样品颗粒内部并充分溶解其中的精油成分,具有提取时间短、得率高、无溶剂残留的优点。超临界CO₂法制备的葛缕子精油中,主要成分为D-柠檬烯(50.96%)和香芹酮(46.65%),挥发性成分种类及含量均高于同时蒸馏萃取法的。结论:超临界CO₂法比同时蒸馏萃取法更适合葛缕子精油的提取。     

水蒸气蒸馏法提取八角精油工艺参数的研究

为研究水蒸气蒸馏法提取八角茴香油的最佳工艺参数。以八角茴香果实为原料,选取八角粉碎粒度、浸泡时间、料液比和蒸馏时间进行4因素3水平的正交试验,比较各因素各水平下八角茴香油的提取率,测定茴香油中反式茴香脑含量,计算提取量。研究结果表明影响八角茴香油提取率的主次因素为：蒸馏时间>粉碎粒度>料液比>浸泡时间,且不同粉碎粒度、料液比和蒸馏时间对八角茴香油提取率的影响差异显著（P < 0.05）。影响八角茴香油中反式茴香脑含量的主次因素为：蒸馏时间>粉碎粒度>料液比>浸泡时间,不同的蒸馏时间极显著（P < 0.01）影响八角茴香油中反式茴香脑含量。粉碎粒度和蒸馏时间对八角茴香油提取量的影响差异显著（P < 0.05）,不同的浸泡时间和料液比对八角茴香油提取量无显著影响（P > 0.05）。以提取率和提取量为参数,水蒸气蒸馏法提取八角茴香油的最佳提取条件为: 八角粉碎粒度40目,浸泡32 h,料液比1:10,蒸馏3 h。粉碎粒度、浸泡时间、料液比和蒸馏时间均不同程度地影响八角茴香油的提取率、反式茴香脑含量和提取量。     

Chemical constituents and antimicrobial and antioxidant potentials of essential oil and acetone extract of Nigella sativa seeds

The antifungal, antibacterial and antioxidant potentials of essential oil and acetone extract of black cumin were investigated by different techniques. In the inverted petriplate method, the essential oil showed complete zones of inhibition against Penicillium citrinum at a 6 µl dose. Essential oil showed complete growth inhibition against Bacillus cereus, Bacillus subtilis and Staphylococcus aureus, Pseudomonas aeruginosa at 2000 and 3000 ppm, respectively, by the agar well diffusion method. The antioxidant activity was evaluated by measuring peroxide, TBA and total carbonyl values of rapeseed oil at fixed time intervals. Both the extract and essential oil showed strong antioxidant activity in comparison with butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). In addition, their inhibitory action in the linoleic acid system was studied by monitoring the accumulation of peroxide concentration. Their radical scavenging capacity was carried out on 2,2′‐diphenyl‐1‐picrylhydrazyl (DPPH) radical and they showed excellent scavenging activity in comparison with synthetic antioxidants. Their reducing power was also determined, demonstrating strong antioxidant capacity of both the essential oil and extract. Gas chromatographic and gas chromatographic–mass spectrometric studies on the essential oil resulted in the identification of 38 components representing 84.65% of the total amount. The major component was p‐cymene (36.2%) followed by thymoquinone (11.27%), α‐thujene (10.03%), longifolene (6.32%), β‐pinene (3.78%), α‐pinene (3.33%) and carvacrol (2.12%), whereas extract showed the presence of 16 components representing 97.9% of the total amount. The major components were linoleic acid (53.6%), thymoquinone (11.8%), palmitic acid (10%), p‐cymene (8.6%), longifolene (5.8%) and carvacrol (3.7%). Copyright © 2005 Society of Chemical Industry     

Infrared Decontamination of Oregano: Effects on Bacillus cereus Spores,Water Activity,Color, and Volatile Compounds

Infrared (IR) heating, a novel technology for decontaminating oregano, was evaluated by investigating the reduction of inoculated Bacillus cereus spores and the effect on water activity (a_w), color, and headspace volatile compounds after exposure to IR treatment. Conditioned oregano (a_w 0.88) was IR‐treated in a closed heating unit at 90 and 100 °C for holding times of 2 and 10 min, respectively. The most successful reduction in B. cereus spore numbers (5.6 log units) was achieved after a holding time of 10 min at 90 °C, while treatment at 100 °C for the same time resulted in a lower reduction efficiency (4.7 log units). The lower reduction at 100 °C was probably due to a reduced a_w (a_w 0.76) during IR treatment or possibly to the alteration or loss of volatile compounds possessing antimicrobial properties. The green color of oregano was only slightly affected, while the composition of volatile compounds was clearly altered by IR heating. However, two of the key aroma compounds, carvacrol and thymol, were only slightly affected, compared to the effect on the other studied compounds, indicating that the typical oregano aroma can likely be preserved. In conclusion, IR heating shows potential for the successful decontamination of oregano without severe alteration of its color or the key aroma compounds, carvacrol and thymol.