Extraction yield of isoflavones from soybean cake as affected by solvent and supercritical carbon dioxide

Soybean cake has been shown to be a rich source of isoflavone and can be produced during processing of soybean oil as byproduct. The objectives of this study were to compare the extraction yield of isoflavone from soybean cake by solvent and supercritical carbon dioxide, and study the conversion of isoflavone glucosides to the biologically active aglycone by employing β-glucosidase. Results showed that with supercritical carbon dioxide extraction, a maximum yield of malonylglucoside and glucoside was generated at 60 °C and 350 bar, while a high level of acetylglucoside and aglycone was produced at 80 °C and 350 bar. Supercritical carbon dioxide extraction resulted in a lower yield of total isoflavone than solvent extraction, but the former was more applicable to extraction of acetylglucoside and aglycone, and the latter to malonylglucoside and glucoside. A peak level of aglycone was attained from conversion of isoflavone glucoside by β-glucosidase at 55 °C, pH 5, concentration 50 U/ml and incubation time of 2 h.     

超临界CO2萃取燕麦油的技术研究及其脂肪酸分析

利用正交实验设计,研究超临界CO2从燕麦麸皮中萃取燕麦油的工艺参数,且用GC-MS分析了燕麦油的脂肪酸组成,为开发功能性油脂提供一定的理论参数.实验结果表明,最佳工艺参数是压力15MPa、温度35℃、时间3h.所得燕麦油澄清透明,呈现金黄色,具有特殊的麦香味.其脂肪酸主要有棕榈酸、硬酯酸、反-9-十八碳烯酸、亚油酸、亚麻酸、顺-9-十八碳烯酸,相对含量分别为15.30%、2.24%、44.84%、33.81%、1.69%和2.12%,而且不饱和脂肪酸占82.26%.     

Purification and characterisation of antibacterial peptide-containing compound derived from palm kernel cake

Palm kernel cake (PKC), the most useful by-product resulted from palm kernel oil production. In this study, PKC-derived protein product was found suitable for use as an antimicrobial agent with potent antibacterial activity, particularly against Bacillus species, after enzymatic hydrolysis with alcalase. The hydrolysate was further purified by gel filtration chromatography. The purified fraction was found to have 14.63 ± 0.70% (w/w) protein, a molecular mass of 2.4 kDa and low hemolytic activity (<50% hemolysis of human erythrocytes at concentration of 1000 μg/ml). The presence of lysine and the major component lauric acid derivative, as indicated by electrospray ionisation-mass spectrometry (ESI-MS) direct infusion and nuclear magnetic resonance (NMR) spectroscopy, may have contributed to the antibacterial effect of purified PKC fraction. This study suggests that the antibacterial PKC compound may be not a pure peptide but instead a peptide-containing compound high in lauric acid derivative.     

Supercritical carbon dioxide extraction of seed oil from Opuntia dillenii Haw. and its antioxidant activity

Supercritical carbon dioxide extraction of seed oil from Opuntia dillenii Haw. and its antioxidant activity were investigated in this study. The effects of main operating parameters including extraction pressure, temperature, time and CO₂ flow rate on the extraction yield of seed oil were studied. The maximum extraction yield of 6.65% was achieved at a pressure of 46.96 MPa, a temperature of 46.51 °C, a time of 2.79 h and a CO₂ flow rate of 10 kg/h. The chemical composition of the seed oil was analysed by GC–MS. The main fatty acids were linolenic acid (66.56%), palmitic acid (19.78%), stearic acid (9.01%) and linoleic acid (2.65%). The antioxidant activity of seed oil was assessed by means of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay and β-carotene bleaching test. Both methods demonstrated notable antioxidant activity of seed oil, which is nearly comparable to the references ascorbic acid and butylated hydroxytoluene (BHT). The antioxidant activity of the seed oil was also found to be concentration-dependent.     

超临界二氧化碳萃取猕猴桃籽油的研究

采用超临界萃取方法，以二氧化碳作为溶剂，从猕猴桃籽中提取猕猴桃籽油，着重探讨了萃取压力、萃取温度、萃取时间等参数对萃取结果的影响，并确定了最佳的工艺条件；在此条件下萃取效率可达97％以上，与传统工艺进行比较，超临界萃取是一种优异的提油方法。     

Supercritical carbon dioxide extraction of volatile oil from Italian coriander seeds

Supercritical CO₂ fluid extraction of the volatile oil from Italian coriander seeds was carried out under different conditions of temperature (40 and 50 °C), pressure (90, 100 and 150 bar), mean particle size (0.4, 0.6 and 0.8 mm) and CO₂ flow rate (0.79, 1.10 and 1.56kg/h) in order to evaluate their influence on the yield and composition of the volatile oil. Hydrodistillation with the same mean particle sizes was performed and used as a comparative method. The best supercritical fluid extraction conditions were found to be 90 bar, 40 °C, 1.10 kg/h and 0.6 mm. The chemical composition of each supercritical fluid extraction sample was analysed by GC and GC–MS and the global composition was compared with that obtained by hydrodistillation. The dominant components were linalool (65–79%), γ-terpinene (4–7%), camphor (3%), geranyl acetate (2–4%), α-pinene (1–3%), geraniol (1–3%) and limonene (1–2%). Moreover, supercritical fluid extraction samples were collected at specific intervals of amount of CO₂ consumed, during each extraction, and the contribution of the main volatile components from each sample, for the global volatile compositions, was evaluated. In general, the first sample of each extraction contained up to 50% of the mass of each component.     

Supercritical carbon dioxide extraction of lycopene: A review

Lycopene is a powerful antioxidant and potential high-value compound for the nutraceutical and pharmaceutical sectors. Its low solubility in water and high solubility in toxic organic solvents has led to a number of studies being carried out on using supercritical carbon dioxide to extract lycopene, with a majority of the studies focusing on extraction from tomatoes or tomato-derived preparations. Parameters such as temperature, pressure, flow rate, extraction time, sample moisture content and sample particle size influence the yield of lycopene via the exertion of different mechanisms. The use of co-solvents and modifiers can greatly enhance the lycopene yield beyond optimization of the parameters previously mentioned, while the co-extraction method offers a new way of enhancing lycopene yields. The scope of this review covers the effects of various parameters on lycopene extraction by supercritical carbon dioxide.     

超临界流体CO2萃取南瓜籽油的初步研究

以超临界流体CO2萃取技术对南瓜籽中的油脂提取进行了初步研究.研究了不同物料粒度、萃取压力、萃取温度、萃取时间及CO2流量对南瓜籽油萃取率的影响.     

Extraction of lipids from cherry seed oil using supercritical carbon dioxide

 Cherry seeds (Prunus avium L.) were extracted with compressed carbon dioxide at 313 K and 333 K in the pressure range 18–22 MPa. The influence of superficial velocity was also analysed using values of 0.02, 0.06 and 0.08 cm/s. The extraction yield was increased by a reduction in particle size. The physical and chemical characteristics of the oil were determined. The results, in terms of free fatty acids and sterol compositions, were compared with those obtained when hexane was used as solvent. Other physical and chemical characteristics were also compared with refined hexane-extracted oil. Received: 29 February 2000 / Revised version: 19 April 2999     

Rheological behaviour of aerated palm kernel oil/water emulsions

The interactions between emulsion droplets containing solid fat are important for the rheology and functionality of the emulsion as a whole, particularly for aerated emulsion systems where partial coalescence plays a role in the overall structure of the product. In this study, the interactions between emulsion droplets appeared to be sensitive to the relative amounts of solid fat and liquid oil, thus changing the rheology of the whole system. Incorporation of air had a major effect on these interactions as it appeared to force the emulsion to adopt a stronger structure by encouraging partial coalescence. The rheological behaviour of a non-aerated emulsion and an aerated emulsion was compared. Non-aerated samples did not show major changes in viscosity with increasing temperature. In contrast, the aerated emulsion seemed to be considerably more temperature sensitive, showing a dramatic increase of viscosity as the temperature was increased above a critical value. The effect of temperature ramp rates was investigated. Higher temperature ramp rates resulted in delayed changes in viscosity. The phase behaviour of the fat is both time and temperature dependent; therefore, a faster temperature ramp means that a higher temperature could be reached before critical phase changes in the fat could take place. The rheological behaviour of the emulsions was also dependent on the shear rate applied during the experiment.     

Supercritical carbon dioxide fluid extraction of Hibiscus cannabinus L. seed oil: A potential solvent-free and high antioxidative edible oil

The supercritical fluid extraction (SFE) trends and antioxidant activities of Hibiscus cannabinus seed oils were studied. SFE results indicate that extraction pressure is the major factor determining the oil yield. In comparison, classic Soxhlet extraction (SOX/L) yielded higher oil content than SFE (P < 0.05). However, no significant differences in oil content were observed in SFE at 600 bars/80 °C, rapid Soxhlet extraction (SOX/S) and conventional ultra-sonic assisted solvent extraction (SONIC) (P > 0.05). Antioxidant activities of H. cannabinus seed oils were compared with 7 types of commercial edible oils. DPPH scavenging activity test indicated that H. cannabinus seed oil extracted by SFE at 200 bars/80 °C possessed the highest antiradical activity whereas beta-carotene bleaching (BCB) assay revealed that all H. cannabinus seed oils (except for SFE at 400 bars/80 °C and 600 bars/80 °C) exhibited higher antioxidant activity than all commercial edible oils (P < 0.05). Thus, SFE – H. cannabinus seed oil may serve as an excellent source of solvent-free edible oil with high antioxidant properties.     

大蒜超临界CO2萃取物成分分析

对大蒜超临界CO2萃取物进行了GC-MS分析，借助NTST98.L数据库的质谱图数据，参考文献和人工解析对其中的20多种组分进行，定性鉴定，并利用峰面积归一化法进行了初步定量。大蒜风味物的GC-MS分析表明：大蒜超临界CO2萃取物中含有许多水蒸汽蒸馏蒜油中没有检测到的风味成分，其中最显蔷的是蒜素色谱分析中脱水衍生的3-乙烯基-l，2-二硫杂-4-环已烯(3．96％)及3-乙烯基-1．2-二硫杂-5-环己烯(17．88％)，此外还含有少量的亚油酸及油酸。     

Supercritical carbon dioxide extraction of carrot fruit essential oil: Chemical composition and antimicrobial activity

Isolation of carrot fruit (Daucus carrota L., cultivar “Chanteney”) essential oil by supercritical carbon dioxide was investigated from the pretreatment of herbaceous matrix and extraction conditions to the chemical composition of obtained extract and its antimicrobial activity. The qualitative and quantitative analyses of the supercritical extract, as well as of the essential oil obtained by hydrodistillation, were done by GC/FID and GC/MS methods. Antimicrobial properties of both samples were investigated against ten species of microorganisms. Experimental results showed that the particle size had no influence on the extraction process. The highest yield was obtained at 40 °C and 10 MPa. The main component of the supercritical extract, as well as of the essential oil was carotol. The supercritical extract was characterized by the presence of heavier molecular weight compounds, while some lighter compounds, e.g. pinenes, were not detected. The supercritical extract and the essential oil were the most effective against Gram-positive bacteria.     

香榧子油超临界CO2萃取工艺及脂肪酸成分分析

为优化超临界CO2萃取香榧子油的工艺条件,研究了萃取时间、萃取温度及萃取压力对香榧子油得油率的影响。在单因素实验的基础上利用正交实验进行工艺优化,结果表明,最适萃取工艺条件为:萃取时间4h、萃取温度50℃、萃取压力45MPa,在该萃取条件下的得油率为94.57%。利用GC分析香榧子油脂肪酸组成,共鉴定出18个组分,不饱和脂肪酸含量为87.28%,其中亚油酸、油酸和二十碳三烯酸含量分别为42.02%、32.14%和9.80%。     

超临界CO2流体萃取米糠油研究

通过超临界CO2流体萃取米糠油研究,总结萃取压力、萃取温度、萃取时间和物料水分含量对米糠出油率影响。结果表明,最适宜萃取条件为:萃取压力30 MPa、萃取温度45℃、萃取时间80 min、物料水分含量为5％～6％,出油率达14．32％;同时测定超临界CO2流体萃取米糠油中脂肪酸甘油酯组成,得出油酸甘油酯、亚油酸甘油酯和棕榈酸甘油酯占总脂肪酸甘油酯90％以上,其中,油酸甘油酯和亚油酸甘油酯占总脂肪酸甘油酯70％以上;通过超临界CO2法与压榨法比较,超临界CO2流体法萃取米糠油不饱和脂肪酸含量较高,理化指标也优于压榨法,因萃取温度低,防止提取过程中油脂氧化,因此超临界CO2流体萃取是一种较好提取米糠油方法。     

Supercritical fluid extraction of fish oil from fish by-products: A comparison with other extraction methods

Fish and fish by-products are the main natural source of omega-3 polyunsaturated fatty acids, especially EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), both of them with a great importance in the food and pharmaceutical industries. Comparing to conventional fish oil extraction processes such as cold extraction, wet reduction or enzymatic extraction, supercritical fluid extraction with carbon dioxide under moderate conditions (25 MPa and 313 K) may be useful for reducing fish oil oxidation, especially when fish oil is rich in omega-3 such as salmon oil, and the amount of certain impurities, such as some species of arsenic. Furthermore, taking profit of the advantages of supercritical carbon dioxide as extractive solvent, a coupled extraction-fractionation process is proposed as a way to remove free fatty acids and improve fish oil quality, alternatively to physical and chemical refining procedures.     

Fractionation of buffalo butter oil by supercritical carbon dioxide

Buffalo butter oil was fractionated by supercritical carbon dioxide into four fractions (F₁-F₄). Fractionation was performed at 50 and 70 °C over a pressure range of 10.9-40.1 MPa. Short chain fatty acids (C₄-C₈), medium chain fatty acids (C₁₀-C₁₄) and saturated fatty acids were decreased from F₁ to F₄, while long chain fatty acids (C₁₆-C_18:3) and unsaturated fatty acids were increased. Triacylglycerol molecular species exhibited a similar trend as fatty acids. Cholesterol was concentrated in F₁, and with increasing the fluid density, it decreased by more than 50% in F₄. Substantial changes occurred in the chemical composition of the fractions led to distinctive differences in their thermal profile and solid fat content. Fractions obtained in the initial stages of the fractionation exhibited lower melting behavior that obtained in the late stages.     

超临界二氧化碳萃取黄柏挥发油工艺

使用超临界二氧化碳技术对经过超声-微波处理过的黄柏中的挥发油进行萃取,并对萃取工艺进行响应面优化。在单因素预实验的基础上,以萃取压力、萃取温度、萃取时间为响应因素,黄柏挥发油的萃取量为响应值,根据中心组合(Box-Behnken)实验设计原理,采用三因素三水平的响应面分析法,确定各工艺条件对萃取量的影响,并用扫描电子显微镜(SEM)对萃取前、未超声-微波处理超临界萃取后及超声-微波处理超临界萃取后的黄柏进行比较观察,对萃取效果进行了微观解释。结果表明,经过超声-微波处理过的黄柏中的挥发油超临界二氧化碳萃取最佳工艺条件为:萃取压力为34MPa,萃取温度为41℃,萃取时间为66min,萃取率达6.03%。     

Supercritical carbon dioxide extraction of astaxanthin and other carotenoids from the microalga Haematococcus pluvialis

Supercritical carbon dioxide extraction of astaxanthin and other carotenoids from Haematococcus pluvialis was carried out, for several experimental conditions, using a semi-continuous apparatus. The microalga was previously freeze-dried and ground with a ball mill. The effects of pressure (200 and 300 bar), temperature (40 and 60 °C), degree of crushing, as well as the use of ethanol as a co-solvent (10%) on the extraction efficiency were assessed. Organic solvent extractions, using acetone, were also carried out in a vortex, on ground cells mixed with very small glass beads. Supercritical extraction from the completely crushed alga was compared with acetone and the highest recovery of carotenoids (92%) was obtained at the pressure of 300 bar and the temperature of 60 °C, using ethanol as a co-solvent.The extraction recovery increased with the pressure at 60 °C. On the other hand, the increase in temperature, at 300 bar, led to a slight improvement. The main carotenoid of Haematococcus pluvialis is the esterified astaxanthin (about 75%). Other carotenoids present are lutein, astaxanthin (free), β-carotene and canthaxanthin. All of them were recovered through supercritical fluid extraction with values higher than 90%, with the exception of canthaxanthin (about 85%), at a pressure of 300 bar and a temperature of 60 °C.     

Studies on the physicochemical characteristics of volatile oil from pepper (Piper nigrum) extracted by supercritical carbon dioxide

Pepper (Piper nigrum L) volatile oil was extracted with supercritical fluid carbon dioxide at pressures of 8 and 10 MPa and at two different temperatures, 40°C and 60°C. The mass transfer rates are presented at different supercritical conditions of extraction, together with the fractionation effect that was observed. The volatile oil obtained was analysed for its physical constants: specific gravity, refractive index and optical rotation. The samples were fractionated by column chromatography, and both the samples and fractions were subjected to TLC, gas chromatography and sensory analysis. It was observed that pepper oil obtained with supercritical fluid carbon dioxide at 10 MPa and 60°C was superior to steam-distilled oil.