响应面法优化陕产枇杷核多酚的提取及体外抗氧化活性研究

在单因素实验的基础上,以多酚提取率为响应值,以乙醇浓度、提取时间、提取次数、液料比为考察因素,优化枇杷核多酚提取工艺,并对提取物进行体外抗氧化活性研究。结果表明,枇杷核多酚的最佳提取工艺为:乙醇浓度70%、提取时间163 min、提取次数2次、料液比1∶23(g∶mL),多酚平均提取率为1.527%。对该条件下提取的多酚进行DPPH自由基清除率测定,结果表明,枇杷核多酚的抗氧化活性显著优于VC。该法优化的提取工艺条件合理,得到的多酚抗氧化活性较强,可进一步开发利用。     

从紫苏中提取迷迭香酸与抗氧化面膜的制备

紫苏中富含酚类物质,主要有咖啡酸、迷迭香酸、阿魏酸等,其中迷迭香酸含量丰富,且迷迭香酸具备很强的抗氧化性。以紫苏作为提取原料,以具有抗氧化功能的维生素C作为标准参照,研究紫苏中迷迭香酸的抗氧化性,并将紫苏迷迭香酸提取液添加到面膜中,研制具有抗氧化功效的活性面膜产品,为紫苏资源应用指出新方向。     

DPPH法评价大黄提取物的抗氧化活性

采用超声波法提取大黄抗氧化物质,以DPPH法评价大黄抗氧化活性。结果表明,大黄抗氧化物质最佳提取工艺为:以70%乙醇为溶剂,料液比为1∶40 g/mL,超声提取2次,每次提取30 min;大黄抗氧化活性物质主要分布于石油醚和乙酸乙酯提取物,为该药材的开发提供参考。     

超声波法提取紫苏中迷迭香酸条件的研究

用超声波法从紫苏中提取迷迭香酸,通过正交实验确定最佳提取工艺和最大影响因素,结果表明:超声波法提取迷迭香酸的最佳提取工艺为:提取时间40min,乙醇浓度60%,料液质量体积比1:20,提取温度60℃,低频率超声波(25～28kHz);该方法中提取温度对得率的影响最显著。     

响应面法优化山樱桃多酚提取工艺及其抗氧化活性研究

对山樱桃多酚的乙醇回流提取工艺条件进行了优化并研究了其抗氧化活性。以多酚得率为评价指标,采用分光光度法测定吸光度,通过单因素实验筛选得到山樱桃多酚乙醇回流提取工艺的主要影响因素为液料比、乙醇浓度、回流时间;然后采用星点设计-响应面法确定最佳提取工艺为:液料比16∶1(mL∶g)、乙醇浓度68%、回流时间90min、回流温度90℃,在此条件下多酚得率预测值为1.172%,实测平均值为1.166%,RSD为0.55%;山樱桃多酚具有较强的抗氧化活性,对羟基自由基及超氧阴离子自由基均有较强的清除作用。     

正交法优化肾茶提取工艺和滴丸制剂工艺

目的:优化肾茶的提取工艺和滴丸的制剂工艺;方法:通过单因素实验和正交设计筛选最优提取和制剂工艺。采用L9(34)正交试验法筛选最佳提取工艺并进行验证,以迷迭香酸和熊果酸为标准物质,通过HPLC检测迷迭香酸和熊果酸的含量;结果:当乙醇浓度65%,料液比为1∶15,提取次数2次,提取时间2h时,提取液中迷迭香酸和熊果酸含量最高;最优工艺参数为滴丸载药量30%,PEG4000为和PEG6000比例为7:13,硬脂酸镁3%,化料温度90℃,滴距2cm,冷却剂为液体石蜡;结论:此研究确定了肾茶提取工艺和滴丸制剂工艺,为大批量生产肾茶滴丸提供参考。     

化橘红黄酮提取及膏状抗氧化面膜的制备

采用乙醇浸提法将化橘红中的黄酮提取分离得到乙醇提取物。研究了提取温度、料液比、乙醇体积分数对黄酮提取率的影响。以单因素试验为基础,通过正交试验优化了化橘红中黄酮的乙醇浸提工艺。确定较佳工艺条件为:提取温度80℃,料液比1∶50(g∶m L),乙醇体积分数80%。在此条件下,黄酮的提取率为3.19%。以具有抗氧化功能的VC和没食子酸丙酯(PG)作为标准参照,将化橘红提取液加到面膜中,研制出具有抗氧化活性的面膜产品,为化橘红资源应用指出新方向。     

响应面设计优化桑白皮黄酮提取工艺及抗氧化活性研究

采用响应面法优化桑白皮黄酮提取工艺。选择了料液比、乙醇体积分数、提取时间为影响因子,进行了三因素三水平Box-Benhnken试验设计。得到最佳工艺条件为料液比1︰20,80%乙醇,温度70℃,每次提90 min,提取两次。在此条件下,桑白皮黄酮得率为23.88 mg/g。并对桑白皮黄酮的抗氧化活性进行研究。结果表明其还原能力和清除ABTS自由基能力的强弱:桑白皮黄酮桑叶黄酮Vc。由此可见,桑白皮黄酮抗氧化活性较好,具有较好的开发价值。     

布渣叶多酚的提取工艺初探及其活性研究

以乙醇为浸提溶剂,以多酚提取率为评价指标,采用加热回流方法提取布渣叶多酚,通过单因素实验和正交实验探讨了提取温度、提取时间、乙醇体积分数及料液比对布渣叶多酚提取率的影响;利用DPPH自由基、超氧阴离子自由基抗氧化检测模型和LPS诱导的RAW264.7巨噬细胞炎症模型分别评价了最优提取工艺下布渣叶多酚的抗氧化与抗炎活性。结果表明,布渣叶多酚的最优提取工艺为:料液比1∶40(g∶mL)、提取温度80℃、乙醇体积分数50%、提取时间60min,在此条件下,布渣叶多酚提取率达到(75.4±0.56)mg·g~(-1)。提取得到的布渣叶多酚具有较强的抗氧化和抗炎活性,是一种极具保健价值的天然提取物。     

百香果果皮的微波预处理-超声波提取工艺及其抗氧化活性研究

研究了百香果果皮提取物的微波预处理-超声波提取工艺及其抗氧化活性。以黄酮得率、多酚得率、花色苷得率、ABTS自由基清除能力为考核指标,采用总评归一值法,结合正交实验设计,优选百香果果皮的微波预处理-超声波提取工艺,并对不同提取方法所制备的百香果果皮提取物进行有效成分得率和抗氧化活性的对比分析。优选的微波预处理-超声波提取工艺条件为:超声时间25min、微波时间90s、乙醇浓度70%、料液比1∶50、解吸剂比1∶7。百香果果皮提取物具有一定的体外抗氧化活性,微波预处理-超声波提取法的有效成分含量和抗氧化活性,均优于超声波提取法和直接水浴提取法,具有效率高、操作简便和成本低等优点,可作为百香果果皮有效物提取的新方法。     

Application of organic solvent nanofiltration for concentration of antioxidant extracts of rosemary (Rosmarinus officiallis L.)

The present investigation revealed the potential benefits of nanofiltration application in herbal extracts processing. Nanofiltrations of modelling solution of caffeic and rosmarinic acid in ethanol and ethanolic rosemary extract were carried out in a laboratory cross-flow system. Duramem™ 200 nanofiltration membrane was selected based on screening experiments. The experimental data and model predictions demonstrated the efficacy of a semi-batch cross-flow diafiltration process for concentration of fresh rosemary extracts. The observed absence of significant loss of antioxidant capacity in the retentate during the process and the degree of extract concentration achieved may allow retentate direct application as preservative and functional ingredient in the foods, cosmetics, neutraceuticals and medicines. The capability of the selected membrane to separate monophenolic acids from higher molecular weight antioxidant compounds in the extracts was also discussed. The dry solids content in the permeate was found sufficiently low as to permit its direct re-use in the extraction process thus bringing additional economical benefits.     

Use of rosemary extract in preventing oxidation during deep-fat frying of potato chips

The effect of using a rosemary extract on the stability of oil used for frying potato chips has been evaluated. Sliced potatoes were fried intermittently in soybean oil containing a natural extract from rosemary. The conditions used for frying were 185°C for 90 s. Two separate experiments, with and without replenishment of oil, were carried out. Oil samples were taken each day, not only from the frying pans but also by extraction with hexane from the chips. Changes in the induction period of the oil samples (Rancimat method) were determined. The induction period decreased as frying progressed. The reduction in the induction period was higher in the oil free of rosemary extract, and the chips were much darker in color. The oil containing the extract showed greater antioxidant activity, and reduced darkening and rancidity of the oil. Potato chips fried in the oil with added rosemary extract were more acceptable than chips fried in oil containing no extract until the last frying. The free radical scavenging activity of rosemary extract in comparison to other natural antioxidants was also determined by the reduction of O₂ ^.- in a hypoxanthine/xanthine oxidase system.     

Kinetic study of pilot-scale supercritical CO2 extraction of rosemary (Rosmarinus officinalis) leaves

Rosmarinus officinalis (rosemary) extracts were obtained in a supercritical pilot-scale plant. Based on experimental information available in the literature for analytical or low-scale processes, extraction temperature and pressure were selected to be 313 K and 30 MPa. At these extraction conditions, the kinetic behavior of the pilot-scale overall extraction curve were determined with respect to yield, antioxidant activity and carnosic acid content. The overall extraction curve was represented using Sovova's model; the average deviation between measured and calculated yields was lower than 2%. Mass transfer coefficients in the fluid and solid phases were determined and were compared with previous data reported in the literature for low-scale rosemary supercritical extraction.A two-stage depressurization procedure was accomplished and the effect of both on-line fractionation and extraction time on the antioxidant activity of the samples collected was studied. The antioxidant activity of the different fractions could be straight correlated with the carnosic acid content with a regression coefficient of 0.92.     

Antioxidant activities of hot water extracts from various spices

Recently, the natural spices and herbs such as rosemary, oregano, and caraway have been used for the processing of meat products. This study investigates the antioxidant activity of 13 spices commonly used in meat processing plants. The hot water extracts were then used for evaluation of total phenolic content, total flavonoids content and antioxidant activities. Our results show that the hot water extract of oregano gave the highest extraction yield (41.33%) whereas mace (7.64%) gave the lowest. The DPPH radical scavenging ability of the spice extracts can be ranked against ascorbic acid in the order ascorbic acid > clove > thyme > rosemary > savory > oregano. The values for superoxide anion radical scavenging activities were in the order of marjoram > rosemary > oregano > cumin > savory > basil > thyme > fennel > coriander > ascorbic acid. When compared to ascorbic acid (48.72%), the hydroxyl radical scavenging activities of turmeric and mace were found to be higher (p < 0.001). Clove had the highest total phenolic content (108.28 μg catechin equivalent (CE)/g). The total flavonoid content of the spices varied from 324.08 μg quercetin equivalent (QE)/g for thyme to 3.38 μg QE/g for coriander. Our results indicate that hot water extract of several spices had a high antioxidant activity which is partly due to the phenolic and flavonoid compounds. This provides basic data, having implications for further development of processed food products.     

Elucidation of the chemical structures of natural antioxidants isolated from rosemary

A natural antioxidant extract with activity greater than BHA and equal to BHT was isolated from rosemary leaves. The extract was separated into 7 primary fractions with liquid chromatography, using silicic acid as an adsorbent followed by gradient elution. Each fraction was rechromatographed to yield a total of 16 subfractions. Two compounds, carnosol and ursolic acid, were identified by infrared, mass and nuclear magnetic resonance spectrometry. Carnosol was shown to be one of the active antioxidant components in rosemary. Ursolic acid was not an effective antioxidant. Further fractionation of the most active antioxidant subfractions by high performance liquid chromatography and the elucidation of the chemical structures of these fractions are now in progress. Presented at the AOCS meeting, May 1978, St. Louis. Paper of the Journal Series, New Jersey Agricultural Experiment Station, Cook College, Rutgers, The State University of New Jersey, New Brunswick, NJ 08903.     

Simultaneous extraction of rosemary and spinach leaves and its effect on the antioxidant activity of products

Mixed vegetal extracts are interesting target of new products as nutraceuticals, superior ingredients for the design of functional food, singular ingredients for cosmetics, etc. In this work the extraction of a mixture of spinach and rosemary leaves (50 wt.% of each plant) was investigated in terms of its antioxidant activity, and compared with the extraction of the separate species. Phenolic diterpenes of rosemary and carotenoids of spinach were target compounds due their recognized biological activities. Two different extraction techniques were applied, namely pressurized liquid extraction using hexane at two different temperatures (100 and 150 °C) and supercritical fluid extraction with pure carbon dioxide at 40 °C and two different pressures (20 and 30 MPa). For each extraction technique and conditions three different raw materials were employed: spinach leaves, rosemary leaves and the mixture 50:50 of spinach and rosemary leaves.The antioxidant activity of the samples produced was evaluated with the ABTS assay and showed to be enhanced when the species are simultaneously extracted, with antioxidant values around 20% higher than the values corresponding to mixing the extracts obtained by separate. A possible synergic effect between carotenoids and phenolic diterpenes was studied, although no specific synergic activity could be observed. However, the enhanced antioxidant activity could be attributed to a definite increase of the concentration of carnosic acid, which was observed in the samples produced by the simultaneous extraction.     

Solvent extraction and purification of rosmarinic acid from supercritical fluid extraction fractionation waste: Economic evaluation and scale-up

Industry is increasingly interested in natural food preservatives, antimicrobial, and antioxidants due to their beneficial effects. The use of plant waste also presented itself to be a great opportunity in recovered bioactive compounds remaining in the residue. In this work, bioactive compounds were obtained from Rosmarinus officinalis in two different ways: firstly the supercritical fractionated rosemary extract with different composition was obtained from the plant material, and secondly a potent antioxidant-rosmarinic acid (RA) – was successfully extracted from the plant waste. A purification process scale-up of RA was proposed using GRAS solvent, and an economic evaluation was made for the overall process. A complete process to obtain bioactive compounds, antimicrobial (supercritical fluid extraction and fractionation extraction) and antioxidant (solvent extraction) was developed.     

Microwave-Assisted Extraction of Phenolic Compounds from Caper

In this study, it was aimed to extract phenolic compounds from caper by using microwave and to compare the results with conventional extraction. For microwave-assisted extraction, power, extraction time, solid to solvent ratio, and solvent type were selected as independent variables. Dependent variables were total phenolic content (TPC), antioxidant activity, and concentration of phenolic compounds. The increase in solvent amount increased TPC. The highest TPC was obtained by using extraction conditions of 5 min at 400 W, solid to solvent ratio of 1:30, and ethanol-water mixture at a ratio of 50:50. There was no significant difference between microwave and conventional extraction on TPC and antioxidant activity (AA). However, microwave-assisted extraction decreased extraction time significantly.     

Antioxidant Properties of Three Aromatic Herbs (Rosemary, Thyme and Lavender) in Oil-in-Water Emulsions

Lipid oxidation is the major form of deterioration in foods because it decreases food quality and nutritional value, and may have negative health implications. Selected aromatic plant extracts from leaves, flowers and stems of rosemary, thyme and lavender were investigated for their antioxidant activity. The total polyphenol content was determined by the Folin–Ciocalteu assay and the antioxidant capacity was determined by the Trolox equivalent antioxidant capacity, 1,1-diphenyl-2-picrylhydrazyl, oxygen radical absorbance capacity and ferric-reducing antioxidant power assays. For all four antioxidant assays, the extracts from thyme flowers, lavender leaves and thyme leaves had the highest antioxidant activity, followed by rosemary stems, rosemary leaves, and lavender stems, and the lavender flowers and thyme stems had the lowest antioxidant activity. The antioxidant activity was correlated with the polyphenol content, although minor deviations were observed. In oil-in-water emulsion, extracts from rosemary leaves and thyme leaves were most effective at retarding oxidation followed by the rosemary stems and thyme flowers. Extracts from thyme flowers and lavender leaves were less effective in the emulsion than predicted by the homogeneous antioxidant assays. This study demonstrated the potential use of plants extract as substitutes for synthetic antioxidants.     

Antioxidant Activity of Osage Orange Extract in Soybean Oil and Fish Oil during Storage

The food industry is seeking natural antioxidants for edible oils that have comparable activity to synthetic counterparts. In this study, Osage orange extract (OOE) rich in osajin (42.9%) and pomiferin (30.0%) was obtained after hexane extraction of the fruit, and its antioxidant activity was examined in stripped soybean oil (SBO) and fish oil (FO), in which antioxidants and polar compounds were removed. The antioxidant activity of OOE was compared with commercial natural antioxidants (i.e., rosemary extract and mixed tocopherols) and a synthetic antioxidant, butylated hydroxytoluene (BHT), during storage at 25 and 40 °C. The 0.1% OOE had stronger antioxidant activity than 0.1% rosemary extract and 0.1% mixed tocopherols in both oils at 25 and 40 °C. Its activity was similar to 0.02% BHT in SBO and was similar or slightly stronger than 0.02% BHT in FO. When OOE was studied at 0.05, 0.1, and 0.2%, there was a weak dose–response in SBO but a stronger dose–response in FO. Headspace volatile analysis using solid phase micro-extraction (SPME) combined with GC–MS indicated that 0.1% OOE was very effective in preventing the formation of volatile oxidation products in both oils. Although it should be further tested for safety before the actual use, this study shows that OOE can be developed as an antioxidant for edible oils.