Optimization: Microwave irradiation effect on polyphenolic compounds extraction from winter savory (Satureja montana L.)

Microwave-assisted extraction of polyphenols with elevated antioxidant activity from winter savory was optimized by simultaneous maximization of total phenolics, total flavonoids yields, and antioxidant activity (measured by two assays—DPPH and reducing power assay). For optimization of microwave assisted extraction, Box–Behnken experimental design coupled with response surface methodology was applied. Independent variables were extraction time, ethanol concentration, and irradiation power. Analysis of variance was used to evaluate model fitness and determine optimal conditions.     

响应面法优化大豆荚壳异黄酮超声-回流萃取工艺

利用超声萃取和回流萃取方法进行单因素实验,选取提取温度、超声时间和乙醇体积分数为影响因子,应用响应面法(RSM)优化大豆荚壳异黄酮的提取条件。结果表明,大豆荚壳异黄酮优化浸提条件为:提取温度83℃、乙醇体积分数为84%、超声时间30min、大豆荚壳颗粒150μm、液料比25:1、回流萃取时间90min、超声功率108W,大豆荚壳总异黄酮的得率为3.5mg/g。响应面法大豆荚壳总异黄酮的提取条件优化合理可行,为提高大豆荚壳总异黄酮的提取率提供了依据。     

响应曲面法优化超声辅助提取油菜籽皮中的原花青素

以乙醇为提取剂,用超声辅助的方法从油菜籽皮中提取了原花青素。在讨论了提取剂体积分数、提取时间、液料比(每克原料加入提取剂的毫升数,简称液料比,以下同)和超声波功率等单因素实验的基础上,运用Box-Behnken中心组合实验和响应曲面法分析了提取剂体积分数、提取时间和液料比3个因素对原花青素提取率的影响,并优化了提取工艺。结果表明,最佳的工艺条件为:乙醇体积分数62.9%,提取时间20.8 min,液料比25 mL/g。在该条件下,原花青素提取率的预测值为5.055 mg/g,验证实验值为5.02 mg/g,说明响应曲面法优化油菜籽皮中原花青素提取工艺是可行的。     

Oil composition of pistachio nuts (Pistacia vera L.) from Turkey

The oil content, fatty acid and sterol compositions and other parameters of pistachio nut (Pistacia vera L.) samples corresponding to five different varieties, all cultivated in Turkey were determined. Mean values were 59.69 ± 1.80% for fat content, 0.9143 ± 0.006 for specific gravity of the oil, 1.4693 ± 0.004 for refractive index, 94.23 ± 1.510 for iodine value, and 188.2 ± 3.80 for saponification value. Fatty acids identified in the oil samples were palmitic, palmitoleic, stearic, oleic, and linoleic acids with oleic acid as the dominant fatty acid (68.78 ± 2.05%). Halebi variety had the highest level of oleic acid among the varieties studied. The sterols isolated from the unsaponifiable fraction were campesterol, stigmasterol, β-sitosterol, and Δ⁵-avenasterol with β-sitosterol as the major constituent (84.95 ± 2.80%). Higher levels of β-sitosterol were found in Kιrmιzι variety. The high level of oil, oleic acid and β-sitosterol content was found in all the varieties studied. Fat content, iodine value, palmitic acid and oleic acid content significantly differed between varieties.     

The removal of cationic dyes from aqueous solutions by adsorption onto pistachio hull waste

The efficacy of pistachio hull powder (PHP) prepared from agricultural waste was investigated in this study as a novel adsorbent for the elimination of dye molecules from contaminated streams. Removal of methylene blue (MB) as a cationic model dye by PHP from aqueous solution was studied under different experimental conditions. The selected parameters were solution pH (2–10), PHP dosage (0.5–3 g/L), MB concentrations (100–400 mg/L), contact time (1–70), and solution temperature (20–50 °C). The experimental results indicated that the maximum MB removal could be attained at a solution pH of 8. The dosage of PHP was also found to be an important variable influencing the MB removal percentage. The removal efficiency of MB improved from 94.6 to 99.7% at 70 min contact time when the MB concentration was decreased from 300 to 100 mg/L at a pH and PHP dosage of 8 and 1.5 g/L, respectively. The kinetic analysis showed that the pseudo-second-order model had the best fit to the experimental data. The Langmuir equation provided the best fit for the experimental data of the equilibrium adsorption of MB onto PHP at different temperatures. In addition, the maximum adsorption capacity increased from 389 to 602 mg/g when the temperature was increased from 20 to 50 °C. The thermodynamic evaluation of MB adsorption on PHP revealed that the adsorption phenomenon under the selected conditions was a spontaneous physical process. Accordingly, pistachio hull waste was shown to be a very efficient and low-cost adsorbent, and a promising alternative for eliminating dyes from industrial wastewaters.     

Influence of Temperature and Air Velocity on Drying Time and Quality Parameters of Pistachio (Pistacia vera L.)

Drying is one of the important steps in pistachio processing. In this step kernel moisture content is decreased from 50 to less than 5% (d.b.) which will result in suitable condition for storage. Study of effective parameters in pistachio drying is important since these parameters influence drying time and kernel quality. In this research, a mono layer of pistachios was dried at three different temperatures (60, 75, and 90°C), and three levels of drying air velocity (1.5, 2, and 2.5 m/s). Changes of drying time, protein, fat and peroxide value were investigated for two common Iranian pistachio varieties Kalehghouchi and Fandoghi. Sensory tests were also used to check flavor of pistachios dried at the three temperature levels (60, 75, and 90°C). Statistical analysis of the data indicated that increasing the temperature to 90°C reduced drying time down by about 37% and caused a change in pistachio flavour. Taste tests indicated a consumer preference for pistachios dried at 75°C. If the air velocity is increased from 1.5 to 2.5 m/s, drying time reduces about 10 percent. Changes in temperature and air velocity have no significant effects on protein and fat content of pistachios, but if temperature reaches 90°C, peroxide value will increase to 0.55 meq/kg, which is still within the permissible limit for processed pistachios.     

Influence of Temperature and Air Velocity on Drying Time and Quality Parameters of Pistachio (Pistacia vera L.)

Abstract

Drying is one of the important steps in pistachio processing. In this step kernel moisture content is decreased from 50 to less than 5% (d.b.) which will result in suitable condition for storage. Study of effective parameters in pistachio drying is important since these parameters influence drying time and kernel quality. In this research, a mono layer of pistachios was dried at three different temperatures (60, 75, and 90°C), and three levels of drying air velocity (1.5, 2, and 2.5 m/s). Changes of drying time, protein, fat and peroxide value were investigated for two common Iranian pistachio varieties Kalehghouchi and Fandoghi. Sensory tests were also used to check flavor of pistachios dried at the three temperature levels (60, 75, and 90°C). Statistical analysis of the data indicated that increasing the temperature to 90°C reduced drying time down by about 37% and caused a change in pistachio flavour. Taste tests indicated a consumer preference for pistachios dried at 75°C. If the air velocity is increased from 1.5 to 2.5 m/s, drying time reduces about 10 percent. Changes in temperature and air velocity have no significant effects on protein and fat content of pistachios, but if temperature reaches 90°C, peroxide value will increase to 0.55 meq/kg, which is still within the permissible limit for processed pistachios.     

Development of green extraction process to produce antioxidant-rich extracts from purple coneflower

The present study was conducted to develop subcritical water extraction (SWE) of Echinacea purpurea flowers. The influence of temperature and extraction time on quality of extracts considering total phenols content, total flavonoids content, antioxidant capacity and extraction yield, was determined. Optimized extraction parameters for maximised investigated responses were as follows: 147.56 °C and 8.43 min. The experimental values agreed with the values predicted, thus indicating the adequacy of central composite experimental design for modelling the SWE of bioactive compounds from E. purpurea. Results of the study also highlighted the potential application of E. purpurea subcritical water extracts as a source of valuable bioactive compounds.     

Optimization of Microwave-Assisted Extraction of Puerarin from Radix Puerariae using Response Surface Methodology

Statistical experimentical designs were applied to optimize microwave-assisted extraction of puerarin from Radix Puerariae. The most important factors affecting the extraction procedure were determined using a Plackett-Burman design. Results indicated that the concentration of ethanol, solvent-material ratio, extraction time, and microwave power were the main factors affecting the extraction yield. These factors were further optimized using a central composite design and response surface methodology. The optimal extraction parameters were ethanol concentration of 52.36%, microwave irradiation time of 60 s, microwave power of 184.8 W and solvent-material ratio of 25:1(mL/g). The average experimental puerarin yield under the optimum conditions was found to be 11.97 mg/g, which agreed with the predicted value of 11.8 mg/g. The proposed method shows high degree of reproducibility.     

Polyphenols of Pistachio (Pistacia vera L.) Oil Samples and Geographical Differentiation by Principal Component Analysis

The phenolic compounds of Italian and Turkish pistachio oil samples were investigated by gas chromatography–mass spectrometry (GC–MS) with the aim of identifying substances also present in very low concentration; 21 compounds were identified by means of the mass spectra of the trimethylsilyl (TMS) derivatives. Benzoic acid derivatives (protocatechuic acid, gallic acid, 4‐hydroxybenzoic acid) were the main components; 14 polyphenols were detected in pistachios for the first time. The concentrations of the compounds found were in the range 0.02–5.64 μg/g of fresh pistachio. No appreciable qualitative differences were found between samples of different origin; a multivariate approach was successfully tried to differentiate the samples according to their geographical origin, using Principal Component Analysis (PCA). Finally, Canonical Discriminant Analysis (CDA) was further conducted to classify different pistachio samples.     

Optimization of simultaneous carotenes and vitamin E (tocols) extraction from crude palm olein using response surface methodology

In this study, response surface methodology was utilized to determine the optimal conditions for the extraction of carotenes (α- and β-carotene) and tocols (α-tocopherol, α-, γ-, and δ-tocotrienol) from crude palm olein using ethyl lactate (EL) and ethanol (EtoL) in a temperature-controlled mixer-settler system. Central composite design with four factors including temperature (X₁), mixing time (X₂), volume fraction (VF) of olein (X₃), and VF of EtOL (X₄) was used to investigate the multivariate relationship with the five responses including enrichment factor and recovery of both carotenes and tocols. The optimum extraction conditions were determined at 20°C, 10?min of mixing, 48% of crude palm olein, 31.2% of EL and 20.8% of EtoL (corresponding to 0.5 VF of olein and 0.4 VF of EtoL). The enrichment factors of carotenes and tocols were 0.88 and 2.56, respectively while 11.3% of carotenes and 31.2% of tocols were recovered.     

Effect of inhibitory compounds on the anaerobic digestion performance of diluted wastewaters from the alimentary industry

BACKGROUND: Up to now the effect of inhibitory compounds on the anaerobic digestion performance of urban and industrial wastewaters has been mostly studied in fluidized bed and upflowing anaerobic sludge blanket (UASB) bioreactors but not in upflow packed‐bed biodigesters. RESULTS: In this paper, response surface methodology (RSM) was used to quantify the effect of various inhibitory compounds (olive oil, ethanol and phenol) on chemical oxygen demand (COD) removal and biogas production rate from synthetic solutions and real industrial wastewaters by anaerobic digestion. The synthetic solutions possessed the same composition in these inhibitory compounds as diluted effluents from olive oil mill and winery industries. The process was performed in a laboratory scale digester containing anaerobic sludge from the Urban Reclamation Station of Toledo (Spain). The comparison of both individual factors and interactions between factors showed that the addition of olive oil at moderate concentrations (up to 0.5% w/w) did not change the performance of the process in comparison with that observed when feeding to the system a model solution (51.5% COD removal, 0.65 L biogas day^?1). However, low concentrations of ethanol or phenol (250 and 150 mg L^?1, respectively) almost completely inhibited the methanogenic phase. Moreover, a strong interaction between ethanol and phenol concentrations on COD removal was observed. CONCLUSION: The experimental results showed quantitatively the importance of some inhibitory compounds on anaerobic treatment of both synthetic solutions and real wastewaters from olive oil mill and winery industries. Inhibitory effects are closely related to both the organic loads and the anaerobic bioreactor used. Copyright © 2009 Society of Chemical Industry     

Optimization of extraction parameters of bioactive components from defatted marigold (Tagetes erecta L.) residue using response surface methodology

Response surface methodology (RSM) was used to estimate the optimum extraction parameters, in which the antioxidant activity (AA) of the extract from the defatted marigold residue was the strongest. The AA of marigold extracts was investigated by the radical scavenging activity assays ((2,2-azinobis-(3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH)). Results demonstrated that AA was significantly affected by the content of total phenolics (TP) and total flavonoids (TFA) (p < 0.0001). The optimal extraction parameters of marigold extracts for the highest AA by ABTS method were ethanol concentration of 79.7%, extraction temperature of 74.2 °C and time of 8.1 h, and by DPPH assay with 89.3% of ethanol concentration at 81.5 °C for 11.1 h, AA values were 2.42 and 1.86 mmol TE/g, respectively.     

Optimization of ultrasound-assisted extraction of anthocyanins from mulberry, using response surface methodology

Mulberry is one of the most widely used traditional Chinese medicines. Anthocyanins are the main bioactive components of mulberry, and possess important biological activities, such as antimicrobial, anti-inflammatory and antioxidant activities. This study investigated the ultrasound-assisted extraction (UAE) of anthocyanins from mulberry by using response surface methodology (RSM). The extraction conditions associated with anthocyanin yield, including extraction solvent, liquid-to-solid rate, temperature and extraction time, are discussed. The optimal conditions obtained by RSM for UAE from mulberry include 63.8% methanol contains 1% (v/v) trifluoroacetic acid (TFA), 43.2 °C temperature, 23.8 (v/w) liquid-to-solid ratio, and 40 min time for the maximum yield (64.70 ± 0.45 mg/g). The results indicated that the UAE can be an effective method for the extraction of some active components from plant materials.     

响应曲面法优化蜂胶中的活性黄酮提取

探讨了超声波辅助技术提取蜂胶中的活性黄酮类化合物的工艺。实验以芦丁为标样,在单因素实验基础上,采用Box-Behnken实验设计方法,以提取温度、固液比、提取时间以及乙醇浓度为自变量,黄酮提取率为响应值,研究各自变量及其交互作用对黄酮提取率的影响。利用Design expert软件,建立了提取率与超声波处理各因素的二次多项式数学模型,获得了蜂胶中黄酮的最佳提取条件为:提取温度51.32℃,固液比1∶10,提取时间12.88 min,乙醇浓度88.86%,最佳黄酮提取率为52.39%。经过实验验证,黄酮提取率可达51.98%。     

Optimization of oil extraction from Pitanga (Eugenia uniflora L.) leaves using simplex centroid design

Simplex centroid design (SCD) was employed to optimize the mixing of petroleum ether, n-hexane, methanol and ethanol for the extraction of oil (PLO) from Pitanga (Eugenia uniflora L.) leaves, via Soxhlet extraction. The highest yield (54%) of Pitanga leaf oil (PLO) was obtained with 100% ethanol and the lowest yield (16%) from the mixture of methanol (33.3%)/hexane (33.3%)/ethanol (33.3%). The coefficient of determination (R²) of the model equation obtained was 0.91, while the adjusted R² and predicted R² were 0.8729 and 0.951, respectively. The saponification value (S.V.), iodine value, acid value and free fatty acid (FFA) are 35.34 mgKOH/g, 72.97 mgI₂/g oil, 32.41 and 16.30 mgKOH/g, respectively.     

Obtaining phenolic compounds from jatoba (Hymenaea courbaril L.) bark by supercritical fluid extraction

The extraction of polyphenol compounds from jatoba (Hymenaea courbaril L. var stilbocarpa) bark using supercritical fluid extraction (SFE) with CO₂ and cosolvents has been investigated. Among the solvent systems studied, SFE using CO₂ and water (9:1, v/v), at 323 K and 35 MPa, presented the best results, with extract yield of 24%, and with high antioxidant activity (IC₅₀ of 0.2 mg/cm³). This solvent system was used to determine global yield isotherms, which were built at 323 and 333 K, and 15, 25, and 35 MPa, using a second lot of jatoba. The highest yield was 11.5% at 15 MPa and 323 K, with maximum total phenolic compounds (TPC) of 335.00 mg TAE/g extract (d.b.) and total tannins content of 1.8 g/100 g raw material. A kinetic experiment was performed using optimized conditions, yielding 18% extract, and the kinetic parameters were used to scale-up the process from laboratory to pilot scale. Chemical analyses showed high content of phenolic compounds in the extracts of jatoba bark mostly due to the presence of procyanidins.     

微波辅助下从泥炭中提取黄腐酸类物质的研究

在微波辅助下,以泥炭为研究对象,水为抽提溶剂,采用正交试验考察了抽提温度、时间、固液比及压力对黄腐酸类物质（泥炭水溶酸性抽提物）提取率的影响。结果显示,影响抽提率最主要的因素是压力。较佳的抽提条件为压力0.6MPa、抽提温度150℃、固液比1：10g／ml）、抽提时间20min,并采用红外光谱、元素分析及官能团测定的方法分析了抽提物的组成。采用微波辅助法从泥炭中提取医用黄腐酸可能为一种有效的环境友好的方法。