超声波-表面活性剂协同提取桑叶总黄酮

研究桑叶中总黄酮的超声波-表面活性剂协同提取的工艺条件。以总黄酮得率为考察指标,在单因素的基础上,利用正交试验优化提取工艺条件为:Tween 80的质量分数为1.5%,提取时间45min,料液比1:30,提取温度30℃。超声波-表面活性剂协同提取是一种快速、高效的提取方法。     

酶-微波联用法提取枸杞总黄酮

研究酶-微波联用法提取枸杞总黄酮的最佳工艺条件。采用纤维素酶提取枸杞总黄酮,在单因素试验基础上利用正交试验研究乙醇浓度、酶解温度和酶解p H值对提取率的影响,确定最佳酶解条件。在单因素试验基础上,通过正交试验确定微波提取的最佳工艺参数,采用微波法进一步提取酶解液中的枸杞总黄酮。酶解阶段最佳工艺参数为:乙醇浓度45%,酶解温度50℃,酶解p H4.0;微波阶段的最佳工艺参数为:液固比30 m L/g,微波温度65℃,微波时间4 min。该酶-微波联用法提取枸杞总黄酮的提取率达1.560%。     

超声波-表面活性剂协同提取竹叶总黄酮的工艺

研究超声波-表面活性剂协同提取竹叶总黄酮的工艺。在单因素试验的基础上,采用响应面法研究超声功率、表面活性剂浓度和液固比对竹叶总黄酮得率的影响。结果表明,在超声频率40kHz和常温下,超声波-表面活性剂协同提取竹叶总黄酮的最佳工艺为超声功率420W、十二烷基硫酸钠物质的量浓度25.20×10-3mol/L、液固比23:1(mL/g,表面活性剂溶液:竹叶粉末),此时竹叶总黄酮得率达2.30%。     

BP神经网络结合响应面优化罗布麻总黄酮的提取工艺

为研究酶法辅助超声波提取罗布麻总黄酮的提取工艺,以总黄酮提取率为评价指标,考察酶用量、酶解pH值、酶解温度、超声时间对罗布麻总黄酮提取率的影响,在单因素试验基础上,利用响应面法优化总黄酮提取工艺,以响应面试验数据作为BP神经网络的输入值,对主要影响因素进行仿真优化。结果显示,罗布麻总黄酮的最佳提取工艺条件为：酶用量0.11 g/g、酶解pH5.1、酶解温度67 ℃、超声时间33 min。在此工艺条件下,罗布麻总黄酮提取率为32.26%。     

超声波-阴/阳离子表面活性剂协同提取茅岩莓总黄酮的工艺研究

优化超声波协同阴/阳离子表面活性剂提取茅岩莓总黄酮的工艺,通过单因素实验,考察表面活性剂浓度、阴/阳离子表面活性剂摩尔质量比、提取温度、乙醇浓度和提取时间对茅岩莓总黄酮得率的影响。在此基础上,固定阴/阳离子表面活性剂摩尔质量比为40∶1(SDS∶CTAB)、料液比1∶20(g/m L)和提取温度60℃,采用响应面实验考察表面活性剂浓度、乙醇浓度和提取时间对茅岩莓总黄酮得率的影响。结果表明最佳提取工艺参数为:表面活性剂浓度1.1%、乙醇浓度40%、提取时间57 min,此条件下茅岩莓总黄酮得率为23.27%,与预测理论值23.45%相差较小,说明该实验方法可行。     

表面活性剂协同超声提取陈皮中总黄酮的工艺研究

为研究表面活性剂协同超声提取陈皮总黄酮的提取工艺,采用单因素试验法考察了表面活性剂的种类及用量、乙醇浓度、料液比、超声温度等因素对总黄酮提取率的影响,结合正交试验对工艺条件进行了优化。结果表明:最佳提取工艺条件为表面活性剂选择质量分数0.5%的Tween 20、乙醇浓度60%、料液比1∶50(g/mL)、超声温度70℃,此条件下黄酮提取率可达6.83%。该法具有工艺条件简单、黄酮提取率高、成本低等优点。     

复合酶解法协同超声波法提取山楂中总黄酮的工艺条件优化

采用复合酶解法协同超声波法提取山楂中总黄酮。通过单因素和正交实验对工艺进行优化,优化后条件为:复合酶量(3%纤维素酶和4%果胶酶),酶解pH为6,酶解温度为60℃,酶解时间为1.5h,乙醇浓度为70%,料液比为1∶40g/mL,40℃超声提取30min。在此条件下的总黄酮提取量为85.5mg/g。相对超声波提取总黄酮提高了46.1%,比单纤维素酶酶解辅助超声波法提取总黄酮量提高了27.6%。     

泡桐花总黄酮的提取工艺优化及抗氧化活性

该研究采用超声波辅助纤维素酶法提取泡桐花总黄酮。在单因素试验的基础上,选择酶解温度、超声功率、液料比和酶解时间进行Box-Benhnken试验设计,响应面法优化泡桐花总黄酮提取工艺,并测定其抗氧化能力。结果表明,泡桐花总黄酮最佳提取工艺条件为酶解温度50 ℃,超声功率240 W,液料比40∶1（mL∶g）,酶解时间36 min。在该优化提取条件下,总黄酮的提取得率为7.82%,与模型预测值8.01%接近。抗氧化试验结果表明,泡桐花总黄酮对DPPH自由基、羟自由基和ABTS自由基的半抑制浓度（IC50）值分别为214.2 μg/mL、200.7 μg/mL和328.5 μg/mL,在总黄酮质量浓度为800 μg/mL时,总黄酮对三者的清除率分别为83.1%、75.4%和64.3%。     

超声波协同酶法提取芹菜中总黄酮的工艺优化

为提高芹菜中总黄酮的得率,采用超声波-纤维素酶协同方法醇提芹菜总黄酮,研究了酶解pH值、加酶量、超声功率、料液比、超声时间对芹菜总黄酮得率的影响。在单因素试验的基础上,通过正交试验优化确定了芹菜中黄酮提取的最佳工艺条件,即酶解pH 值为4.0、加酶量210 U/g、超声功率200 W、料液比为1∶25（g∶mL）、超声时间40 min,在此条件下总黄酮得率为1.018 4%。     

酶法提取金樱子总黄酮的研究

对金樱子黄酮类化合物的酶法提取工艺进行了研究.采用单因素实验考察了纤维素酶、果胶酶、木瓜蛋白酶、复合酶(纤维素酶+果胶酶+β-葡聚糖酶+半纤维素酶+木瓜蛋白酶)对总黄酮提取率的影响及酶解温度,酶解液pH值,酶解时间和酶用量对总黄酮产量的影响,通过正交试验设计确定了酶法提取金樱子总黄酮的最佳提取工艺条件:酶解温度为50℃,酶解液初始pH=4.5,酶解时间为120min,酶的用量为0.35mg/mL的复合酶(纤维素酶+果胶酶+β-葡聚糖酶+半纤维素酶+木瓜蛋白酶).实验结果表明:在一定条件下,复合酶的酶解效果比单一酶好,纤维素酶酶解效果比果胶酶好,木瓜蛋白酶在单独使用时基本没有效果.根据正交实验确定的最佳酶提取工艺条件与传统的直接醇提取工艺相比,金樱子总黄酮产量提高了26.2%.     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.