Effect of solvent and extraction temperatures on the antioxidant potential of traditional stoned table olives “alcaparras”

This paper reports the first approach to the antioxidant potential evaluation of traditional stoned table olives “alcaparras”. This kind of olives are largely produced and consumed in Trás-os-Montes region (Northeast of Portugal). Different solvents and temperature extraction conditions were employed in order to achieve the best method to obtain phenolic compounds and a higher antioxidant activity. The optimum method (water at boiling temperature) was applied on 10 samples from the traditional market. The total phenol content ranged between 5.58 mg gallic acid equivalents (GAE)/g and 29.88 mg GAE/g and effective concentration (EC₅₀) values were in the range 0.36-1.64 and 0.34-1.72 mg/mL for reducing power and radical scavenging effect, respectively. A significantly negative linear regression was observed between the total phenol content found in the samples and its antioxidant activity.     

Bioactivity evaluations of ingredients extracted from the flowers of Citrus aurantium L. var. amara Engl

Citrus aurantium L. var. amara Engl, a member of genus Citrus (Rutaceae), widespread in China, is used as folk medicine for the treatment of helping digest, phlegm, enteritidis, stomachic and other deceases. In the present research, silica gel column, Sephadex LH-20, mass spectrometer (MS) and nuclear magnetic resonance (NMR) were used to separate and identify the chemical compounds from the flowers of C. aurantium var. amara, and several bioactivity assays were used to evaluate their antioxidant, anti-inflammatory, anti-virus and antitumour activities. Two major compounds, 5-hydroxy-6,7,3′,4′-tetramethoxyflavone (HTF) and limonexic acid (LA), were isolated and identified from C. aurantium var. amara for the first time. The results of the bioactivity assays showed that HTF and LA displayed significant antioxidant activities and showed significant inhibition effects on the B16 cell lines at a concentration range from 6.25 to 50 μg/ml, and on the SMCC-7721 cell lines from 12.5 to 200 μg/ml. The antitumour effect, anti-inflammatory activity and the inhibiting expression of HBsAg and HBeAg of 2.2.15 cells displayed the tendency in a concentration-dependent manner. These two compounds from C. aurantium var. amara could potentially be used as a promising natural agent in the pharmaceutical industries.     

蜂胶总黄酮的提取最佳工艺研究

对蜂胶毛胶的总黄酮提取工艺进行了研究,在单因素实验和正交试验的基础上,得出最佳的提取条件为:30℃下,100%乙醇为提取剂,料液比为1:14,,提取时间48h,一次提取率高达92.25%。     

烤烟烟叶淀粉的提取工艺优化

为揭示烤烟淀粉的结构与特性,降低烤烟的淀粉含量,采用响应面分析法(RSM)对鲜烟叶淀粉的提取条件进行了优化。结果表明:烤烟烟叶淀粉提取最优条件为:亚硫酸浓度0.19%,液固比为7,浸提时间16 h;淀粉中脂肪含量为0.61%,蛋白质含量为3.73%,灰分为1.59%,直链与支链结构比例约为3∶7。     

Extraction of phenolic compounds from grapes and their pomace using β-cyclodextrin

Use of aqueous cyclodextrins (CD) for recovery of selected bioactive phenolic compounds from grapes and their pomace was evaluated. When α, β and γ forms of CD were compared, β-CD was the most effective in recovering stilbenes, flavonols, and flavan-3-ols from grape pomace. The maximum quantified phenolics were obtained from the powder and the slurry of grape pomace when extracted with 2.5% (w/v) aqueous β-CD solutions at 60 °C for 12–24 h. With β-CD, total quantified phenolics obtained from the dry powder were 123 mg/100 g (DW) while from the slurry, they were 35.8 mg/100 g (FW). Incorporation of β-CD to grape mash prior to pressing for juice enhanced the recovery of phenolics in juice. Incorporation of β-CD was more effective in recovering flavan-3-ols than flavonols. Aqueous CD can effectively be used in recovering phenolics from by-products of fruit processing and therefore for functional foods and nutraceutical applications.     

Microwave-assisted extraction of sulforaphane from white cabbages: Effects of extraction condition,solvent and sample pretreatment

Sulforaphane is one of the most potent food-derived anticarcinogens and is abundantly found in Brassica vegetables, including cabbages. Due to its importance an ability to effectively extract sulforaphane from its source is desirable. This work investigated the feasibility of using microwave-assisted extraction (MAE) to extract sulforaphane from cabbages. The effects of various parameters, which are the type of solvent (dichloromethane and water), set microwave power (130, 260 and 390 W) and extraction time, on the extraction yield of sulforaphane were investigated. In addition, since it was previously shown that partially dried cabbages contain higher sulforaphane content than fresh cabbages, the effect of partial drying prior to MAE on the extractable amount of sulforaphane was investigated. A comparison between MAE and conventional extraction was also made. The results showed that MAE was more effective than the conventional extraction as the former led to higher yield of sulforaphane in a much shorter extraction time. There were no significant differences in the highest extractable sulforaphane contents from the fresh and semi-dried samples. Use of different solvents also did not lead to any significant effect on the MAE of sulforaphane, either from the fresh or semi-dried sample.     

葡萄籽中原花青素提取工艺研究

原花青素是葡萄籽中含有的一种重要的生理活性物质。通过对不同溶剂、不同浸提时间、不同乙醇浓度、不同料液比等单因素的浸提效果进行比较分析,确定了最佳的单因素水平。通过正交实验,得出了原花青素提取的最佳工艺条件是:60％乙醇,料液比1∶5,在常温密闭条件下浸提28h。     

绿原酸生物活性、资源及其提取纯化

绿原酸是一种重要的生物活性物质,是许多植物及中草药的主要有效成分之一.该文对绿原酸的生物活性、资源、提取、纯化及检测进行系统概述.     

Comparative evaluation of microwave‐assisted extraction and preheated solvent extraction of bioactive compounds from a plant material: a case study with cabbages

Preheated solvent extraction (PSE) was evaluated via the analysis of the extraction kinetics, microstructure of extracted samples and energy consumption as alternative to microwave‐assisted extraction (MAE). Cabbage outer leaves and ethanol were used as test material and extraction solvent, respectively. MAE was first optimised in terms of glucosinolates and phenolics yields; total antioxidant activity of the extracts was also assessed. MAE at a specific absorbed power of 0.37 W g^?1 for 9 min was selected as optimum condition to extract glucosinolates and phenolics, while PSE was optimised at 6 min of the extraction. The highest normalised total glucosinolates and phenolic contents as well as antioxidant activities of the extracts obtained via MAE were not significantly different from those obtained via PSE. Confocal laser scanning microscopy revealed no significant differences in cabbage cell damages rendered by MAE and PSE. PSE nevertheless exhibited slightly higher specific energy consumption than MAE.     

超临界CO_2萃取香料精油的研究

本文对熏衣草、百里香、野百里香和迷迭香４种香料单独或两种香料混合超临界ＣＯ２萃取和分级分离香料精油的工艺可行性，以及采用ＧＣ，ＧＣ－ＭＣ对萃取物的主要成分分析进行了初步研究。从两种香料混合物中革取所获产率等于从每种香料所获产率之平均值，混合萃取明显提高精油和树脂两种产品的分离效率，两种香料混合物的萃取物所含的主要成分与两种香料单独萃取的成分相同，但浓度有明显差别。