Optimization of extraction process for phenolic acids from black cohosh (Cimicifuga racemosa) by pressurized liquid extraction

An investigation to optimize the extraction of phenolic acids from black cohosh using a pressurized liquid extractor system was studied with the aim of developing a generalized approach for sample preparation of phenolic compounds from plant matrices. Operating parameters such as solvent composition, solid‐to‐solvent ratio, temperature, particle size distribution, and number of extraction cycles were identified as main variables that influence extraction efficiency. A mixture of methanol and water (60:40 v/v) was found to be the best solvent for total phenolics (TP) and individual phenolic acids. The four phenolic acids extracted from black cohosh were identified by HPLC and LC‐MS as caffeic acid, ferulic acid, sinapic acid and isoferulic acid. Over 96% of the measured phenolics were extracted in first two cycles. The extraction efficiency for black cohosh with MeOH:H₂O (60:40 v/v) was found to be maximum at a solid‐to‐solvent ratio of 80 mg ml^?1. TP content of the extract was found to increase with temperature up to 90 °C. Particle size was found to have a large impact on extraction efficiency of TP. Samples with particle size between 0.25 mm and 0.425 mm provided optimum extraction of phenolics from black cohosh. Published in 2005 for SCI by John Wiley & Sons, Ltd.     

Extractability of African yam bean (Sphenostylis stenocarpa) protein in acid, salt and alkaline aqueous media

Protein extractability from defatted Africa yam been (Sphenostylis stenocarpa) was studied under various conditions: solid/solvent ratio, time, pH, and salt. Extractable protein from S. stenocarpa was strongly dependent on all these factors. Maximum extractable protein was obtained after 2 h extraction time; the solid to solvent ratio in the range of 1:20–1:50 gave maximum protein extractability. The pH corresponding to maximum and minimum extractable proteins were 10 and 5, respectively, but addition of NaCl changed this slightly. Extractable protein of 92%, 88% and 84% were obtained in aqueous concentration of 0.01 MNa₂SO₄, 1.5 MNaCl and 0.01 MNaOH, respectively while other concentrations gave lower extractability. These salt concentrations, i.e. 0.01 MNa₂SO₄ and 1.5 MNaCl gave slightly lower extractable protein under alkaline condition. S. stenocarpa flour has a higher buffer capacity in acid medium than in alkaline medium.     

Heat Stability of Sunflower-Hull Anthocyanin Pigment

Anthocyanin pigment was extracted from hulls of a sunflower genotype, Neagra de Cluj, using aqueous SO₂ solutions of varying concentrations. Thermal stability of the pigment was studied between 65–95°C, and pH 1.0–5.0. Thermal degradation of the pigment followed first order kinetics. Calculated activation energy was 23.1 ± 2.2 kcal/ mole. Extraction of hulls with 1000 ppm SO₂ solution gave highest anthocyanin content and best thermal stability. The pigment was most stable at pH 3.0.     

Optimization of extraction of phenolic antioxidants from peanut skins

This work was conducted to optimize the extraction conditions for the best recovery of antioxidant compounds from peanut skins. The extracts from the peanut skins were obtained by different extraction methods. The extraction conditions were: different ethanol proportions as the solvent (0, 30, 50, 70 and 96% v/v in distilled water), different peanut skin particle sizes (0–1, 1–2 and 2–10 mm and non‐crushed skins), different proportions of solvent/skins (20, 30, 40, 50 and 60 ml g^?1), different extraction times (by maceration and shaking) and different numbers of extractions. The different extracts obtained under different extraction conditions were compared with special regard to yield, total phenolic compounds and radical scavenging activity. The results showed that the best delivery of phenolic compounds was reached using 70% ethanol, non‐crushed peanut skins, ratio of solvent/solid of 20 ml g^?1, at 10 min shaking and three extractions. The maximum yield of 0.118 g g^?1 was recorded for phenolic compounds when extracted at the optimum conditions. Copyright © 2004 Society of Chemical Industry     

Effect of extraction conditions on lycopene extractions from tomato processing waste skin using response surface methodology

Skin, rich in lycopene, is an important component of waste originating from tomato paste manufacturing plants. A central composite design with five independent variables, namely solvent/meal ratio (20:1, 30:1, 40:1, 50:1, and 60:1 v/w); number of extractions (1, 2, 3, 4 and 5); temperature (20, 30, 40, 50 and 60 °C); particle size (0.05, 0.15, 0.25, 0.35 and 0.43 mm); extraction time (4, 8, 12, 16 and 20 min) was used to study their effects on lycopene extraction. The experimental values of lycopene ranged between 0.639 and 1.98 mg/100 g. The second order model obtained for extracted lycopene revealed a coefficient of determination (R²) of 0.99 and a standard error of 0.03. Maximum lycopene (1.98 mg/100 g) was extracted when the solvent/meal ratio, number of extractions, temperature, particle size and extraction time were 30:1 v/w, 4, 50 °C, 0.15 mm and 8 min, respectively.     

Sequential Microwave-Ultrasound-Assisted Extraction for Isolation of Piperine from Black Pepper (<Emphasis Type="Italic">Piper nigrum</Emphasis> L.)

Piperine is the natural bioactive component of black pepper (Piper nigrum L.) with several astounding therapeutic properties. In this study, sequential microwave-ultrasound-assisted extraction approach was used for isolation of piperine from black pepper. The effect of various factors such as extraction solvent, particle size of pepper, solvent to solid ratio, microwave power and time and ultrasound temperature and time on the extraction yield of piperine was considered. The maximum extraction yield was 46.6 mg piperine/g pepper which was obtained using ethanol as solvent at the particle size of 0.15 mm, solvent to solid ratio of 20:1, microwave power of 100 W for 1 min, and ultrasound temperature of 50 ^° C for 30 min. This extraction yield was higher than those obtained by Soxhlet (39.1 mg/g), microwave-assisted (38.8 mg/g) and ultrasound-assisted (37.0 mg/g) extractions. The purity of the extracted piperine was 81.4% as determined by HPLC analysis. The FTIR and UV-vis analyses confirmed that the structure of piperine remained intact after extraction and purification which is very important for medicinal applications.     

基于因素最少化的槟榔多酚错流提取条件研究

有效提高槟榔多酚提取率,采用多种溶剂体系进行提取,探讨最佳提取溶剂。根据错流浸取工艺理论设计了料液比与浸取级数,并在单因素试验的基础上进行正交优化设计,最终确定了槟榔中多酚提取的最佳工艺条件。结果表明,最佳提取剂为混合溶剂（甲醇∶丙酮∶水=1∶2∶2）（V∶V）,料液比为1:20（g:mL）,pH值为4.0,在70 ℃下提取100 min,提取次数为2,槟榔多酚提取率达到34.46 mg/g。     

Extraction efficiency and validation of an HPLC method for flavonoid analysis in peppers

Efficient extraction procedures including solvent selection, sample to solvent ratio, extraction time, and hydrolysis condition were developed for the analysis of flavonoids in peppers. Maximum flavonoids were extracted in ethanol, while N-N-dimethylformamide was able to extract myricetin, which was rarely reported in peppers. Flavonoids were obtained at the 1:8 ratio of sample to solvent after 3 h of extraction time. The effective hydrolysis of glycosides to aglycones was observed in 3 M HCl at 60 min at 95 °C. The validated HPLC method was applied to quantify five flavonoids from peppers. The ethanol extract exhibited maximum total phenolics (1.39 mg of catechin equivalent/g), and the DPPH assay showed a similar free radical scavenging activity in MeOH, EtOH, and EtOH:water (80:20). Reducing property of the MeOH extract was higher than the EtOH extract. This study demonstrated that the developed methods for the extraction of pepper flavonoids could be useful for analysing large numbers of samples.     

Effect of Extraction Techniques and Solvent Systems on the Extraction of Antioxidant Components from Peanut (Arachis hypogaea L.) Hulls

This research work was carried out to investigate the effect of different extraction techniques on antioxidant potential of peanut (Arachis hypogaea) hulls. The antioxidant extracts of peanut hulls (PH) were prepared using different extraction methods such as soaking, stirring, shaking, and sonicated-assisted stirring with methanol/water (80:20) and ethanol/water (80:20) solvents systems. The antioxidant potential of extracts was measured using different in vitro antioxidant assays like estimation of total phenolic contents (TPC), estimation of total flavonoids contents (TFC), DPPH-scavenging capacity, percentage inhibition of linoleic acid peroxidations, and bleachability of ?-carotene in linoleic acid system. TPC and TFC of different PH extracts were found in range of 1.23–8.43 mg/g of dry plant material, measured as gallic acid equivalent, 0.33–5.06 mg/g of dry plant material, measured as catechin equivelent (CE), respectively. All the PH extracts exhibited good free radical scavenging potential and moderate inhibition of linoleic acid peroxidation. Significant (p ≤ 0.05) variations were observed in the antioxidant potentials of various extraction methods and solvent systems. Among all the extraction methods, sonicated-assisted stirring showed better yield and antioxidant capacity. In view of the present findings, it is reasonable to say that different extracts of peanut hulls exhibited varying degree of antioxidant activity, which might be attributed to various mechanisms involved in extraction procedures.     

The composition of lipids from rice hulls and from the surface of rice caryopsis

Samples of hulls, of whole and ground caryopsis and of bran obtained from the Brazilian rice variety IAC 1246, were extracted with hexane and the characteristics and composition of the corresponding lipids were determined. The lipids from rice hulls showed a four times higher content of unsaponifiable matter and of free fatty acids than those from rice bran and rice caryopsis. There were also differences in the fatty acid composition as evidenced by the presence of 2–3% of saturated C₂₂ and C₂₄ acids and a lower proportion of unsaturated acids in the rice hull lipids. On the other hand there was a close resemblance between the rice hull lipids and those on the surface of the caryopsis. Chromatographic analysis of the unsaponifiable matter of lipids from rice hulls and caryopsis surface disclosed the presence of hydrocarbons, alcohols and sterols in ascending order, the sterols consisting of about 50% of β-sitosterol, 20–40% of campesterol, 10–20% of stigmasterol and 2–3% of cholesterol. On the basis of the above results it was concluded that a preliminary solvent extraction of paddy rice in order to remove the waxy lipids from the hulls and the caryopsis surface would benefit the subsequent milling process and improve the quality of the brown rice and of crude rice bran oil.     

双水相萃取分离葡萄籽中原花青素

采用双水相萃取葡萄籽中原花青素,首先研究双水相萃取体系组成、辅助萃取方法、萃取策略对原花青素萃取效果的影响,并采用正交试验对原花青素萃取条件进行优化。结果表明,双水相萃取体系组成为无水乙醇/硫酸铵,辅助萃取方法为微波辅助法,萃取策略为乙醇+水+葡萄籽微波处理后加入硫酸铵,条件为无水乙醇/硫酸铵萃取体系为质量分数30%无水乙醇/质量分数20%硫酸铵,加入葡萄籽质量分数为3%,pH为4.0,微波功率100 W,微波时间5 min,在该条件下,葡萄籽中原花青素的萃取率为94.1%,得率为25.8mg/g;     

Cotton fabric dyeability assessment of floral extracts obtained from binary mixtures of Callistemon citrinus and Tagetes erecta L

Parameters affecting extraction of natural colorants from five binary mixtures of floral parts of Callistemon citrinus and Tagetes erecta L., like ratio of each flower in the binary mixture of powdered floral parts, amount of powdered binary mixture to liquor ratio and extraction time, were optimized for dyeing of cotton fabric. Optimum dyeing was obtained at 60°C with 70 g/L exhausting agent (Na₂SO₄), material to liquor ratio of 1:50 along with dyeing time of 100 min. The dyed fabric revealed good anti-bacterial activity and excellent ultraviolet protection factor (UPF).     

A systematic approach for extraction of phenolic compounds using parsley (Petroselinum crispum) flakes as a model substrate

The impact of extraction methodology and polarity of extraction solvents on the assay of phenolic compounds was investigated using parsley (Petroselinum crispum) flakes as a model substrate. This systematic study was undertaken to address substantial variations in the extraction procedures, solvents and conditions as described in the recent literature. Five different extraction procedures [shaking, vortex mixing, sonication, stirring and pressurized liquid extraction (PLE)] and three different solvents (methanol, ethanol and acetone), with five different solvent to water ratios per solvent, were used for extraction. Extracts were analyzed for phenolic content by high‐performance liquid chromatography and Folin–Ciocalteu assays. The yields of phenolic compounds extracted with a pressurized liquid extractor were comparable to or better than those of four classical extraction procedures. Optimum extraction efficiency with PLE was obtained when extractions were performed with four extraction cycles using ethanol–water (50:50, v/v). The amount of apiin (4,5,7‐trihydroxyflavone 7‐apiosylglucoside) and malonylapiin (apigenin malonylapiosylglucoside) isolated from parsley varied with the composition of extraction solvent. Apiin extractability was found to be a maximum when the solvent (ethanol, methanol or acetone) to water ratio was 30:70 (v/v), whereas higher amounts of malonylapiin were isolated with a reverse solvent to water ratio (70:30, v/v). Malonylapiin was not detected when parsley samples were extracted with organic solvent to water ratios of 10:90 (v/v) and 30:70 (v/v). Published in 2006 by John Wiley & Sons, Ltd     

An Improved Ultrasonic-Assisted Extraction Method by Optimizing the Ultrasonic Frequency for Enhancing the Extraction Efficiency of Lycopene from Tomatoes

In order to assess the optimization of the ultrasonic frequency in a range of 18–146 kHz for extracting lycopene from tomatoes and evaluate its influence on the extraction efficiency, an improved ultrasonic-assisted extraction (IUAE) method was proposed by using a novel ultrasonic extraction and detection system, in which the ultrasonic frequency information could be converted to intuitive waveforms that are easily identified by eyes. Additionally, to improve the extraction yield of lycopene, in this work, the optimization of various process parameters by ultrasonic treatment, including extraction time, solvent/material ratio, extraction temperature, and ultrasonic power for improving the yield of lycopene were investigated. These results indicated that all of the considered parameters had effected on the yield of lycopene significantly, and the optimum extraction conditions were as follows: extraction time duration 20 min; ratio of solvent to material 2:1; extraction temperature 25 °C; ultrasonic power 200 W; ultrasonic frequency 46–48 kHz. In comparison with other extraction methods, such as conventional solvent extraction (CSE), supercritical fluid extraction (SFE), supercritical carbon dioxide co-extraction (SC-CO₂), and existing UAE, the IUAE method achieved a far more extraction yield, a reduction of extraction time, and a smaller amount of solvent at lower temperature, which showed a great promising prospect in the extraction and separation of natural products.     

Carbohydrate Fiber from Orange Albedo

A process was developed for manufacturing dried orange albedo from fresh peel. Fresh albedo (nonpigmented portion) was recovered by shaving the flavedo (pigmented portion) from quartered peel after a commercial reamer juice extraction process. The albedo was then ground to reduce particle size, leached with water, treated with lime, pressed, and dried. Yield of dried (0% H₂O) albedo was 3.3 kg/100 kg ‘Valencia’ oranges. Wastewater analyses of liquids discharged from the leaching process indicated average values of 14,400 mg COD and 9,850 mg BOD based on producing 1 kg of dry albedo. Several albedo carbohydrate fiber components were estimated by determining the monomers soluble in boiling water, 5% H₂SO₄ and 72% H₂SO₄. These were as follows (g component/ l00g dry albedo): water-soluble fraction-hexose (11.2) and uronic acid (1.5), hemicellulose fraction-pentose (11.9), pectin fraction-uronic acid (12.9), and cellulose fraction-hexose (10.8) and uronic acid (3.6), respectively. Lignin (6.7) was estimated by ashing the residue remaining after the 72% H₂SO₄ extraction.     

Optimization of Anthocyanin Extraction from Saffron Petals with Response Surface Methodology

Optimum extraction conditions of anthocyanins from petals of saffron (Crocus sativus) using acidified ethanol as the solvent were revealed. The investigated factors were solvent to sample ratio (20:1–80:1), ethanol concentration (%), extraction temperature (25–45 °C), and time (8–24 h). Response surface methodology with Box–Behnken design was applied to determine optimum processing conditions leading to maximum extraction efficiency (mg cyanindin-3-glucoside/l). Obtained coefficients of variance showed that the linear effect of temperature was more pronounced for extraction yield than three other variables at 5 % level. Optimum extraction conditions that maximize the extracted anthocyanins were found to be a ratio of solvents to sample 20 ml/g, ethanol concentration of 25.02 %, temperature 25.8 °C, and extraction time 24 h which gave 1609.11 mg/l anthocyanins. A quadratic regression equation describing the effects of independent process variables on anthocyanin extraction from saffron petals can be used for finding optimum conditions to achieve desired extraction yield in similar conditions.     

Optimization of bioactive compounds extraction from jabuticaba (Myrciaria cauliflora) skins assisted by high pressure CO2

Important bioactive compounds from Brazilian jabuticaba skins were effectively extracted by High Pressure Carbon Dioxide Assisted Extraction (HPCDAE). Statistical design was used to optimize the extraction variables: extraction pressure (65–135 bar), temperature (40–80 °C) and volume ratio of solid–liquid mixture/pressurized CO₂ (RS‐L/CO₂(%) (20–80%). The analysis performed to predict the optimum values for the extraction variables, in order to obtain the condition that result in an extract with high anthocyanin (2.2 ± 0.3 mg cyanidin-3-glucoside/g dry skins) and phenolic compound contents (13 ± 1 mg gallic acid equivalents/g dry skins), gave as best conditions, 117 bar extraction pressure, 80 °C extraction temperature and 20% volume ratio of solid–liquid mixture/pressurized CO₂ (RS‐L/CO₂(%)). Compared to Pressurized Liquid Extraction (PLE) and to control experiment the experimental results obtained using optimum HPCD Assisted-Extraction conditions were much more effective and faster in extracting total anthocyanins and phenolic compounds.Industrial relevance: Industrially, there is an increasing demand for faster extraction procedures with reduced organic solvent consumption to lower pollution burden. HPCD Assisted-Extraction combines the advantages of enhanced mass transfer rates increasing secondary metabolite diffusion from the vegetable matrix into the environmentally friendly solvent extraction. High pressure extraction methods, such as HPCD Assisted-Extraction, have other advantages that should be considered, such as the fact that native enzymes, which degrade phenolic compounds, are inhibited by extraction pressure increasing and CO₂ addition, and that processed vegetable materials do not require additional sterilization steps.     

沙田柚柚子籽油提取工艺优化及性质研究

以沙田柚柚子籽为原料,通过超声波辅助溶剂法提取沙田柚柚子籽油。以柚子籽油的得率为评价指标,在单因素的基础上,选取超声温度、超声时间和料液比进行Box-Behnken响应面法试验设计,对其提取工艺参数进行优化。结果表明:超声波辅助溶剂法提取沙田柚柚子籽油的最佳工艺条件为料液比1∶8 g/mL,超声温度41℃,超声时间38.6 min,该条件下沙田柚柚子籽油得率为33.1%。沙田柚柚子籽油的脂肪酸主要由棕榈酸、油酸、亚油酸、亚麻酸和硬脂酸组成。沙田柚柚子籽油颜色较浅,密度为0.917 g/mL,碘值为103.5 g I_2/100 g,属于半干性油脂。     

Role of Lactic Acid in Corn Steeping and Its Relation with Starch Isolation

Corn grains were steeped in fresh SO₂ solution (300 ppm), old SO₂ solution (100 ppm, 0.55 g lactic acid per 100 ml) and fresh SO₂ with chemically pure lactic acid (100 ppm SO₂ + 0.55 g lactic acid per 100 ml). The water absorption rate in all trials using old SO₂ or low SO₂ with lactic acid in the first stage of the steeping process was higher. The solubilization and diffusion of protein was stronger in corn grains steeped completely in old SO₂ or low fresh SO₂ with lactic acid. Such treatments gave the highest starch recovery with lowest protein content in the isolated starch. The low starch content in hulls and fibers confirms the important role of lactic acid in presence of a low concentration of SO₂ (0.01%).     

Supercritical fluid extraction of<Emphasis Type="Italic"> Cucurbita ficifolia</Emphasis> seed oil

Pumpkin, Cucurbita ficifolia, seed oil was extracted with supercritical carbon dioxide (SC-CO₂) in the temperature range of 308–318 K and in the pressure range of 18–20 MPa. In addition, the influence of the superficial velocity within a tubular extractor was studied. The oil content determined by a Soxhlet apparatus was 43.5%. Physical and chemical characteristics of the oil were obtained. The results in terms of free fatty acids contents were compared with those obtained when n-hexane was used as the solvent, and no significant differences between the oils extracted by both methods were found. The main fatty acid was 6-linoleic acid (about 60%), followed by palmitic acid (about 15%) and oleic acid (about 14%). Oxidative stability was studied by using the induction time determined by the Rancimat method. The oil obtained by supercritical fluid extraction (SFE) was less protected against oxidation (4.2 h for SFE-extracted oil and 8.3 h for the pumpkin seed oil extracted with n-hexane). The oil extracted by SC-CO₂ was clearer than that extracted by n-hexane, showing some refining. The acidity index was 5.5 for the n-hexane extracted oil. For the oils extracted by SC-CO₂, two analyses were made: for the oils obtained at 15 min of extraction time, for which the acidity indices varied from about 15 to 20, and for the remaining oils (extracted until 150 min), for which the acidity indices varied from about 2 to 2.6. The central composite nonfactorial design was used to optimise the extraction conditions, using the Statistica, version 5, software (Statsoft). The best results, in terms of oil recovered by SC-CO₂, were found at 19 MPa, 308 K and a superficial velocity of 6.0×10^–4 ms^–1.