Antioxidant activity of extracts of black sesame seed (Sesamum indicum L.) by supercritical carbon dioxide extraction

Antioxidant activities of extracts derived from sesame seed by supercritical carbon dioxide (SC-CO(2)) extraction and by n-hexane were determined using alpha,alpha-diphenyl-beta-picylhydrazyl (DPPH) radical scavenging and linoleic acid system methods. The highest extracted yield was given at 35 degrees C, 40 MPa, and a CO(2) flow rate of 2.5 mL min(-1) by an orthogonal experiment. The yields of extracts increased with increasing pressure, and yields at 40 and 30 MPa were higher than that by solvent extraction at 46.50%. Results from the linoleic acid system showed that the antioxidant activity follows the order: extract at 35 degrees C, 20 MPa > BHT > extract at 55 degrees C, 40 MPa > extract at 55 degrees C, 30 MPa > Trolox > solvent extraction > alpha-tocopherol. The SC-CO(2) extracts exhibited significantly higher antioxidant activities comparable to that by n-hexane extraction. The extracts at 30 MPa presented the highest antioxidant activities assessed in the DPPH method. At 20 MPa, the EC(50) increased with temperature, which indicated that the antioxidant activity was decreased in a temperature-dependent manner. The significant differences of antioxidant activities were found between the extracts by SC-CO(2) extraction and n-hexane. However, no significant differences were exhibited among the extracts by SC-CO(2) extraction. The vitamin E concentrations were also significantly higher in SC-CO(2) extracts than in n-hexane extracts, and its concentrations in extracts corresponded with the antioxidant activity of extracts.     

乙醇溶剂与超临界CO_2相结合提取高纯度卵黄磷脂的研究

采用乙醇溶剂首先提取蛋黄粉中的卵黄油 ,然后用超临界 CO2 萃取方法脱除卵黄油中的中性脂肪 ,获得高纯度的卵黄磷脂。考察了工艺参数对提取效果的影响。试验表明 :在乙醇溶剂提取卵黄油阶段 ,乙醇浓度是影响卵黄油提取率的最主要因素 ,温度是影响卵黄磷脂提取率的最主要因素 ;在超临界 CO2 萃取阶段 ,磷脂的溶解度随萃取温度的升高而降低 ,中性脂质在 5 5℃时溶解度最大。采用此工艺 ,卵黄磷脂得率为 17.6 6 % ,纯度 94.41% ,且不含胆固醇。     

Supercritical CO(2) and subcritical propane extraction of pungent paprika and quantification of carotenoids, tocopherols, and capsaicinoids.

Ground paprika (Capsicum annuum L.) was extracted with supercritical carbon dioxide (SC-CO(2)) and subcritical propane at different conditions of pressure and temperature to estimate the yield and variation in carotenoid, tocopherol, and capsaicinoid contents and composition. The yield of paprika extract was found to be affected by the extraction conditions with SC-CO(2) but fairly constant at different conditions with subcritical propane. The maximum yields of oleoresin were 7.9 and 8.1% of ground paprika by SC-CO(2) and subcritical propane, respectively. The quantitative distribution of carotenoids, tocopherols, and capsaicinoids between paprika extract and powder was influenced by extraction conditions. SC-CO(2) was inefficient in the extraction of diesters of xanthophylls even at 400 bar and 55 degrees C, whereas tocopherols and capsaicinoids were easy to extract at these conditions. Under mild conditions subcritical propane was superior to SC-CO(2) in the extraction of carotenoids and tocopherols but less efficient in the extraction of capsaicinoids.     

Extraction of pharmaceutical components from Ginkgo biloba leaves using supercritical carbon dioxide

Ginkgo biloba extract (GBE) has many remarkable pharmacological and clinical effects, and it is the most frequently used product as a phytomedicine in many countries. The combination of primary extraction with 70% ethanol followed by extraction using supercritical carbon dioxide provides an efficient and economical means for obtaining flavonoids and terpenoids from Ginkgo biloba leaves. The supercritical fluid extraction (SFE) is affected by pressure, temperature, and the concentration of modifier in the extractant. At the most favorable experimental conditions of 300 MPa, 60 degrees C, and carbon dioxide containing 5% ethanol as modifier, the yield of GBE powder is 2.1% (based on the air-dry weight of Ginkgo biloba leaves) compared to a yield of only 1.8% by conventional solvent extraction. The contents of flavonoids and terpenoids in SFE products are 35.9% and 7.3%, respectively, which are significantly higher than the general standards of 24% and 6%, respectively.     

Comparative analysis of the oil and supercritical CO2 extract of Elettaria cardamomum (L.) Maton

The volatile oil of Elettaria cardamomum (L.) Maton seeds was obtained by supercritical CO(2) extraction (SC-CO(2)). The effect of the extraction conditions on the yield and composition of the resulting cardamom volatile oil was examined by testing two pressure values, 9.0 and 11.0 MPa; two temperatures, 40 and 50 degrees C; two flow rate values, 0.6 and 1.2 kg/h; and two particles size values, 250-425 and >850 microm. The extraction conditions that gave the highest yield, Y (grams of extract per gram of seeds), of 5.5%, were as follows: pressure, 9.0 MPa; temperature, 40 degrees C; carbon dioxide flow, phi = 1.2 kg/h; and particles sizes in the range of 250-425 microm. Waxes, recovered as traces, were entrapped in the first separator set at 9.0 MPa and -10 degrees C. The oil was recovered in the second separator working at 1.5 MPa and 10 degrees C. The main components were as follows: alpha-terpinyl acetate, 42.3%; 1,8-cineole, 21.4%; linalyl acetate, 8.2%; limonene, 5.6%; and linalool, 5.4%. A comparison with the hydrodistilled oil, obtained at a yield of 5.0%, did not reveal any consistent difference. In contrast, the extract obtained using hexane, Y = 7.6%, showed strong composition differences. Indeed, the volatile fraction of the extract was made up mainly of the following: limonene, 36.4%; 1,8-cineole, 23.5%; terpinolene, 8.6%; and myrcene, 6.6%.     

Anti-inflammatory effects of supercritical carbon dioxide extract and its isolated carnosic acid from Rosmarinus officinalis leaves

Rosemary (Rosmarinus officinalis) leaves possess a variety of bioactivities. Previous studies have shown that the extract of rosemary leaves from supercritical fluid extraction inhibits the expression of inflammatory mediators with apparent dose-dependent responses. In this study, three different extraction conditions (5000 psi at 40, 60, and 80 °C) of supercritical carbon dioxide (SC-CO(2)) toward the extraction of antioxidants from rosemary were investigated. Furthermore, simultaneous comparison of the anti-inflammatory properties between rosemary extract prepared from SC-CO(2) under optimal conditions (5,000 psi and 80 °C) and its purified carnosic acid (CA) using lipopolysaccharide (LPS)-treated murine RAW 264.7 macrophage cells was also presented. Results showed that the yield of 3.92% and total phenolics of 213.5 mg/g extract obtained from the most effective extraction conditions showed a high inhibitory effect on lipid peroxidation (IC(50) 33.4 μg/mL). Both the SC-CO(2) extract and CA markedly suppressed the LPS-induced production of nitric oxide (NO) and tumor necrosis factor-α (TNF-α), as well as the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), phosphorylated inhibitor-kappaB (P-IκB), and nuclear factor-kappaB (NF-κB)/p65 in a dose-dependent manner. The five major compounds of verbenone, cirsimaritin, salvigenin, carnosol, and CA existing in the SC-CO(2) extract were isolated by semipreparative HPLC and identified by HPLC-MS/MS analysis. CA was the most abundant recorded compound and the most important photochemical with an anti-inflammatory effect with an IC(50) of 22.5 μM or 7.47 μg/mL presented to the best inhibitory activity on NO production better than that of the 14.50 μg/mL dosage prepared from the SC-CO(2) extract. Nevertheless, the effective inhibition of LPS-induced NF-κB signaling in RAW 264.7 cells from the SC-CO(2) extract extends the potential application of nutraceutical formulation for the prevention of inflammatory diseases.     

Supercritical CO2 extraction of beta-carotene from a marine strain of the cyanobacterium Synechococcus species

Dynamic extraction of carotenoids from a marine strain of Synechococcus sp. (Cyanophyceae) with supercritical CO2 (SC-CO2) was investigated with regard to operation pressure and temperature effects on extraction efficiency. Extraction yield (milligrams of pigment per gram of dry weight) for SC-CO2) was compared with the extraction yield for dimethylformamide (DMF). Carotenoids extracted with SC-CO2 were beta-carotene (Ct), zeaxanthin (Z), beta-cryptoxanthin (Cr), and equinenone; chlorophyll a was poorly extracted, whereas myxoxanthophyll, another major carotenoid, was not extracted under any experimental condition. The highest relative yield, which is defined here as y(r) = [(mg of pigment(SC-CO2)/mg of pigment(DMF))] x 100, was 76.1 +/- 8.6% for Ct, but it rose to 87.0 +/- 3.4% when 15% ethanol was used as cosolvent. The pressure effect on y(r) was found to be significant (p < 0.05) for both Cr and Z, along with total carotenoids, whereas the effect of square T (TT) was significant for only Ct. From empirical correlations, pairwise pressure (bar) and temperature (degrees C), respectively, for optimal extraction were determined to be (358, 50) for Ct, (454, 59) for Cr, and (500, 60) for Z. Cell disruption by sonication or detergent treatment of the biomass did not improve the extraction efficiency. Matrix structure together with material state could explain the low carotenoid extraction yield obtained with SC-CO2 as compared to DMF in Synechococcus sp. However, the process can be applied to selective extraction of different carotenoids.     

Supercritical fluid extraction of limonoid glucosides from grapefruit molasses

Limonoid glucosides (primarily limonin 17-beta-D-glucopyranoside, LG) were extracted from grapefruit molasses by supercritical fluid extraction using a supercritical carbon dioxide-ethanol (SC CO(2)-ethanol) system. Extraction conditions to maximize the yield of LG were determined by varying pressure, temperature, ethanol concentration, and extraction time. The highest yield of LG at 0.61 mg/g molasses was obtained at a pressure 48.3 MPa, a temperature of 50 degrees C, 10% ethanol (X(Eth) = 0.1), and 40 min of extraction time at a flow rate of 5.0 L/min. The results demonstrated that SC CO(2) extraction of limonoid glucosides from grapefruit molasses has practical significance for commercial production.     

Optimization of solid-liquid extraction of resveratrol and other phenolic compounds from milled grape canes (Vitis vinifera)

Optimization of the solid-liquid extraction conditions for trans-resveratrol, trans--viniferin, ferulic acid, and total phenolics from milled grape canes has been investigated. The temperature and ethanol concentration were found to be major process variables for all responses, whereas the solvent to solid ratio was found not to be significant for any of the responses studied. The yields of trans-resveratrol, trans--viniferin, and total phenolics increased with increasing temperature. Maximum yields of trans-resveratrol (4.25 mg/g dw), trans--viniferin (2.03 mg/g), and total phenolics (9.28 mg/g dw) were predicted from the combination of a moderate ethanol concentration (50-70%) and the highest temperature (83.6 degrees C), whereas an ethanol concentration of 35% at the lowest temperature studied (16.4 degrees C) was optimal for the extraction of ferulic acid (1.05 mg/g dw). Effective diffusivity values of resveratrol in the solid phase, D eff for different extraction conditions, were calculated by fitting the experimental results to a model derived from the Fick's second law. Effective diffusivity of resveratrol in the solid phase varied from 3.1 x 10 (-13) to 26.6 x 10 (-13) m (2) s (-1) with changing extraction conditions. The increase in effective diffusivity of resveratrol was observed with increasing temperature, and the highest predicted level was obtained when using 54% ethanol/water mixture at 83.6 degrees C. The increase in ethanol concentration exhibited the favorable effect up to 50-55%, thereafter effective diffusivity decreased with a further increase in concentration.     

Supercritical CO(2) extraction of beta-carotene and lycopene from tomato paste waste

Lycopene and beta-carotene were extracted from tomato paste waste using supercritical carbon dioxide (SC-CO(2)). To optimize supercritical fluid extraction (SFE) results for the isolation of lycopene and beta-carotene, a factorial designed experiment was conducted. The factors assessed were the temperature of the extractor (35, 45, 55, and 65 degrees C), the pressure of the extraction fluid (200, 250, and 300 bar), addition of cosolvent (5, 10, and 15% ethanol), extraction time (1, 2, and 3 h), and CO(2) flow rate (2, 4, and 8 kg/h). The total amounts of lycopene and beta-carotene in the tomato paste waste, extracts, and residues were determined by HPLC. A maximum of 53.93% of lycopene was extracted by SC-CO(2) in 2 h (CO(2) flow rate = 4 kg/h) at 55 degrees C and 300 bar, with the addition of 5% ethanol as a cosolvent. Half of the initially present beta-carotene was extracted in 2 h (flow rate = 4 kg/h), at 65 degrees C and 300 bar, also with the addition of 5% ethanol.     

Antimutagenicity of supercritical CO2 extracts of Terminalia catappa leaves and cytotoxicity of the extracts to human hepatoma cells

Natural antimutagens may prevent cancer and are therefore of great interest to oncologists and the public at large. Phytochemicals are potent antimutagen candidates. When the Ames test was applied to examine the antimutagenic potency of supercritical carbon dioxide (SC-CO(2)) extracts of Terminalia catappa leaves at a dose of 0.5 mg/plate, toxicity and mutagenicity were not detected. The antimutagenic activity of SC-CO(2) extracts increased with decreases of temperature (60, 50, and 40 degrees C) and pressure (4000, 3000, and 2000 psi) used for extraction. The most potent antimutagenicity was observed in extracts obtained at 40 degrees C and 2000 psi. At a dose of 0.5 mg of extract/plate, approximately 80% of the mutagenicity of benzo[a]pyrene (B[a]P, with S-9) and 46% of the mutagenicity of N-methyl-N '-nitroguanidine (MNNG, without S-9) were inhibited. Media supplemented with SC-CO(2) extracts at a range of 0-500 microg/mL were used to cultivate human hepatoma (Huh 7) and normal liver (Chang liver) cells. The viability of the cells was assayed by measuring cellular acid phosphatase activity. A dose-dependent growth inhibition of both types of cells was observed. The SC-CO(2) extracts were more cytotoxic to Huh 7 cells than to Chang liver cells. The observation that SC-CO(2) extracts of T. catappa leaves did not induce mutagenicity at the doses tested while exhibiting potent antimutagenicity and were more cytotoxic to human hepatoma cells than to normal liver cells is of merit and warrants further investigation.     

Whey liquid waste of the dairy industry as raw material for potable alcohol production by kefir granules

Kefir granular biomass was used in the fermentation of sweet whey and proved to be more effective compared to single-cell biomass of kefir yeast. The operational stability of the biocatalyst was assessed by carrying out 20 repeated batch fermentations. Levels of ethanol productivity reached 2.57 g L(-1) h(-1)), whereas the yield was 0.45 g/g. The fermentation time was only 8 h. Mixtures of sweet whey with molasses were fermented at initial densities ranging from 4.2 to 10.2 degrees Be and resulted in ethanol yield factors between 0.36 and 0.48 g of ethanol/g of utilized sugar. Lower degrees Be values led to an increase of percentages of ethyl acetate on total volatiles determined and a reduction of amyl alcohols. The addition of 1% black raisin extract to whey appears to promote whey fermentation, whereas the same was not observed in the case of white sultana extract addition. It was finally established that it is preferable to ferment mixtures of whey-molasses by adding molasses in whey after the completion of whey fermentation.     

Supercritical fluid extraction of fat from ground beef: effects of water on gravimetric and GC-FAME fat determinations

This study investigated the supercritical carbon dioxide (SC-CO(2)) extraction of fat from ground beef and the effects of several factors on the gravimetric determination of fat. The use of ethanol modifier with the SC-CO(2) was not necessary for efficient fat extraction; however, the ethanol did increase the coextraction of water. This coextraction of water caused a significant overestimation of gravimetric fat. Oven-drying ground beef samples prior to extraction inhibited the subsequent extraction of fat, whereas oven-drying the extract after collection decreased the subsequent gas chromatographic fatty acid methyl ester (GC-FAME) fat determination. None of the drying agents tested were able to completely prevent the coextraction of water, and silica gel and molecular sieves inhibited the complete extraction of fat. Measurements of collection vial mass indicated that CO(2) extraction/collection causes an initial increase in mass due to the density of CO(2) (relative to displaced air) followed by a decrease in vial mass due to the removal of adsorbed water from the collection vial. Microwave-drying of the empty collection vials removes approximately 3 mg of adsorbed water, approximately 15-20 min is required for readsorption of the displaced water. For collection vials containing collected fat, microwave-drying effectively removed coextracted water, and the vials reached equilibration after approximately 10-15 min. Silanizing collection vials did not significantly affect weight loss during microwave-drying. SC-CO(2) can be used to accurately determine fat gravimetrically for ground beef, and the presented method can also be followed by GC-FAME analysis to provide specific fatty acid information as well.     

Phytosterol and tocopherol components in extracts of corn distiller's dried grain

As the ethanol industry continues to grow, it will become very important to develop value-added markets for its coproducts in order for the industry to remain profitable. Corn distiller's dried grain (DDG) is a major coproduct of ethanol fermentation from corn processed by dry-milling and is primarily sold as livestock feed. The objective of this research was to determine if valuable phytochemicals found in corn oil and corn fiber oil, such as phytosterols and their saturated equivalents, phytostanols, ferulate phytosterol esters (FPE), tocopherols, and tocotrienols, are retained in DDG. Hexane and supercritical carbon dioxide (CO2) extracts of DDG were similar in their concentrations of total phytosterols (15.8-17.3 mg/g of extract), FPE (3.75-3.99 mg/g of extract), and tocols (1.7-1.8 mg/g of extract). Ethanol extracts were slightly lower in concentration of phytosterols (8.9-11.4 mg/g of extract), FPE (1.62-1.98 mg/g of extract), and tocols (0.73-0.76 mg/g of extract).     

Solvent Extraction of Zein from Dry‐Milled Corn

Batch extraction of zein from dry‐milled whole corn with ethanol was optimum with 70% ethanol in water, an extraction time of 30–40 min, and temperature of 50°C. High yields (60% of the zein in corn) and high zein contents in the extracted solids (50%) were obtained at a solvent‐to‐solids ratio of 8 mL of 70% ethanol/g of corn. However, zein concentration in the extract was higher at lower ratios. Multiple extraction of the same corn with fresh ethanol resulted in a yield of 85% after four extractions, whereas multiple extractions of fresh corn with the same ethanol resulted in high (15 g/L) zein concentration in the extract. Optimum conditions for batch extraction of zein were 45°C, with 68% ethanol at a solvent‐to‐solids ratio of 7.8 mL/g for an extraction time of 55 min. Column extractions were also best at 50°C and 70% ethanol; a solvent ratio of 1 mL/g resulted in high zein concentrations in the extract (17 g/L) but yields were low (20%).     

Valorization of cauliflower (Brassica oleracea L. var. botrytis) by-products as a source of antioxidant phenolics

The present study reports the development of two extraction protocols, with potential industrial applicability, to valorize cauliflower (Brassica oleracea L. var. botrytis) byproducts as a source of antioxidant phenolics. In addition, the nonionic polystyrene resin Amberlite XAD-2 was used to obtain purified extracts. The extract yield, phenolic content, phenolic yield, and correlation between the antioxidant activity and the phenolic content were studied. The water and ethanol protocols yield a phenolic content of 33.8 mg/g freeze-dried extract and 62.1 mg/g freeze-dried extract, respectively. This percentage increased considerably when the extracts were purified using Amberlite XAD-2 yielding a phenolic content of 186 mg/g freeze-dried extract (water extract) and 311.1 mg/g freeze-dried extract (ethanol extract). Cauliflower byproduct extracts showed significant free radical scavenging activity (vs both DPPH(*) and ABTS(*)(+) radicals), ferric reducing ability (FRAP assay), and capacity to inhibit lipid peroxidation (ferric thiocyanate assay). In addition, the antioxidant activity was linearly correlated with the phenolics content. The results obtained indicate that the cauliflower byproducts are a cheap source of antioxidant phenolics very interesting from both the industrial point of view and the possible usefulness as ingredients to functionalize foodstuffs.     

Evaluation of the efficiency of three different solvent systems to extract triterpene saponins from roots of Panax quinquefolius using high-performance liquid chromatography

Despite the wide availability of liquid herbal extracts using mixtures of alcohol, glycerin, and water, or glycerin and water as solvents, no data on the chemical composition of such extracts is readily available. In this study, the amount and the stability of the major saponins in Panax quinquefolius root extracts, made either with 50% (v/v) aqueous ethanol, a mixture (v/v/v) of 20% ethanol, 40% glycerin, and 40% water, or with 65% (v/v) aqueous glycerin, were evaluated by HPLC-UV analysis. The amount of total saponins was highest in the 50% aqueous ethanol extract (61.7 +/- 0.1 mg/g dry root), although similar to the ethanol-glycerin-water extract (59.4 +/- 0.5 mg/g dry root). Saponins were significantly lower in the 65% aqueous glycerin extract (51.5 +/- 0.2 mg/g dry root). Interestingly, the amounts of individual saponins were quite variable depending on the solvent. This is in part due to enzymatic cleavage of ginsenosides in the glycerin containing extracts during the maceration process. Storage of the extracts at 25 degrees C over the period of a year led to a 13-15% loss of saponins with all three types of extractions.     

Optimization of a supercritical fluid extraction/reaction methodology for the analysis of castor oil using experimental design

The aim of this work was to optimize a supercritical fluid extraction (SFE)/enzymatic reaction process for the determination of the fatty acid composition of castor seeds. A lipase from Candida antarctica (Novozyme 435) was used to catalyze the methanolysis reaction in supercritical carbon dioxide (SC-CO(2)). A Box-Behnken statistical design was used to evaluate effects of various values of pressure (200-400 bar), temperature (40-80 degrees C), methanol concentration (1-5 vol %), and water concentration (0.02-0.18 vol %) on the yield of methylated castor oil. Response surfaces were plotted, and these together with results from some additional experiments produced optimal extraction/reaction conditions for SC-CO(2) at 300 bar and 80 degrees C, with 7 vol % methanol and 0.02 vol % water. These conditions were used for the determination of the castor oil content expressed as fatty acid methyl esters (FAMEs) in castor seeds. The results obtained were similar to those obtained using conventional methodology based on solvent extraction followed by chemical transmethylation. It was concluded that the methodology developed could be used for the determination of castor oil content as well as composition of individual FAMEs in castor seeds.     

Use of adsorbent and supercritical carbon dioxide to concentrate flavor compounds from orange oil.

Orange oil is composed largely of terpene hydrocarbons but is a source of flavor and fragrance compounds (oxygenated) that are present in low concentrations. To increase the ratio of oxygenated compounds to terpene hydrocarbons, orange oil was partially fractionated by adsorption of the oxygenated compounds onto porous silica gel, with full utilization of its adsorbent capacity, and then further purified by desorption into supercritical carbon dioxide. The desorption of 24 compounds was monitored by GC and GC-MS. Adsorption alone removed three-fourths of the terpene hydrocarbons, and fractional extraction by supercritical carbon dioxide (SC-CO(2)) improved the separation further. Response surface methodology was used in the experimental design, and regression analysis was used to determine the effects of process variables. Extraction at low temperatures and flow rates improved separation by SC-CO(2). Decanal was concentrated to 20 times that of the feed oil by using SC-CO(2) at 13.1 MPa, 35 degrees C, and 2 kg/h. The systems were operating at close to equilibrium conditions because of the fine dispersal of the oils and the excellent mass transfer properties of supercritical carbon dioxide.     

Optimization of simultaneous saccharification and fermentation for the production of ethanol from lignocellulosic biomass

Simultaneous saccharification and fermentation (SSF) of alkaline hydrogen peroxide pretreated Antigonum leptopus (Linn) leaves to ethanol was optimized using cellulase from Trichoderma reesei QM-9414 (Celluclast from Novo) and Saccharomyces cerevisiae NRRL-Y-132 cells. Response surface methodology (RSM) and a three-level four-variable design were employed to evaluate the effects of SSF process variables such as cellulase concentration (20-100 FPU/g of substrate), substrate concentration (5-15% w/v), incubation time (24-72 h), and temperature (35-45 degrees C) on ethanol production efficiency. Cellulase and substrate concentrations were found to be the most significant variables. The optimum conditions arrived at are as follows: cellulase = 100 FPU/g of substrate, substrate = 15% (w/v), incubation time = 57.2 h, and temperature = 38.5 degrees C. At these conditions, the predicted ethanol yield was 3.02% (w/v) and the actual experimental value was 3.0% (w/v).