龙井绿茶咖啡碱的提取工艺研究

通过研究龙井绿茶中咖啡碱的几种提取方法,选择和优化工艺条件,为从绿茶中提取咖啡碱的工业化提供一定的参考,首先验证了索氏抽提法提取龙井绿茶中咖啡碱的有效性,其次分别研究了微波辅助和超声波辅助提取茶叶中咖啡碱的优化工艺。结果表明：微波浸提咖啡碱的最佳浸提条件为：液固比20∶1,微波解冻档辐照3min,浸提3次,最高浸提率为3.69%;超声波最佳浸提条件为：超声功率100%,超声波处理时间为25min,浸提2次,液固比为25∶1,超声温度为80℃,最高浸提率为3.77%。微波和超声波浸提效果明显高于索氏浸提,但微波浸提与超声波浸提的提取率相差不大。     

紫甘蓝色素提取方法研究

采用传统水浴提取法、超声波辅助提取法和微波萃取法对紫甘蓝天然色素的提取工艺条件进行研究。得到各方法的较优化提取条件：传统水浴提取法最佳工艺条件为25%乙醇溶液为溶剂、pH2、55℃水浴浸提4h;超声波辅助提取法最佳工艺条件为25%乙醇为溶剂、pH2、55℃水浴、超声波辅助浸提45min;微波萃取法最佳工艺条件为25%乙醇为溶剂、pH2、55℃水浴、微波功率300W、微波萃取时间3min。后两种方法的提取效果基本一致并优于传统水浴提取法,提高了生产效率。该色素具有良好的应用前景。     

速溶凤凰单丛茶超声波辅助浸提工艺优化

以凤凰单丛茶副产品为原料,采用响应面法优化凤凰速溶茶的超声波辅助浸提工艺,对影响浸提效果的主要因素包括茶水比、超声功率、超声时间、超声温度进行研究.结果表明,凤凰速溶茶超声波浸提最佳工艺参数为茶水比1∶17(m∶V),超声温度73℃,超声时间34 min,超声功率550 W.该条件下茶多酚提取率为16.13％、游离氨基酸总量提取率为0.40％、咖啡因提取率为0.33％.与传统水提法相比,超声波提取法是一种简单快捷、高效可行的提取方法.     

超声波辅助恒温动态循环腌制盐焗鸡翅技术研究

针对盐焗鸡生产工艺中腌制工序时间长、效率低的缺点,以冰冻鸡翅为研究对象,进行超声波辅助恒温动态循环腌制技术研究。考察了超声作用时间、超声波功率、腌制温度和盐水浓度等因素对鸡翅中Na Cl含量、游离氨基酸和挥发性盐基氮的含量的影响,通过正交实验优化了腌制工艺条件。结果表明:各因素对Na Cl含量、游离氨基酸和挥发性盐基氮的含量均有明显影响。超声波辅助恒温动态循环腌制鸡翅的最佳工艺参数为超声作用时间为60min,超声波功率为335W,超声腌制温度为50℃,腌制液盐浓度为6%。此条件下测得鸡翅肉中Na Cl含量为2.01%,游离氨基酸为94.35mg/100g,挥发性盐基氮9.31mg/100g。超声波辅助恒温动态循环腌制能促进食盐的渗透速率,缩短腌制时间,提高游离氨基酸的含量,有利于产品滋味和风味的形成。     

超声辅助处理高温淀粉酶水解玉米淀粉制备麦芽糊精的工艺研究

本文目的在于借助超声波预处理,提高玉米淀粉酶解制备麦芽糊精的反应效率。以麦芽糊精的DE值和液化得率为指标．研究了超声波预处理。高温淀粉酶水解玉米淀粉制备低DE值糊精的工艺。通过对超声辅助处理的正交试验和酶水解正交试验得到了最优工艺：超声频率为80kHz,超声功率为2kW,超声时间为40min,超声温度为90℃,加酶量为40U／g,水解时间为40min。在此条件下,糊精的DE值为18．3％,液化得率为80．2％。与未超声的对照组相比,经过超声辅助处理的结果在DE值和液化得率方面都有提高,这说明经过超声辅助处理提高了酶水解的能力,是一种具有开发和应用价值的技术。     

沙棘、雪菊保健饮料的加工工艺研究

以沙棘、昆仑雪菊为主要原料,研究了沙棘、雪菊保健饮料的制作工艺,并着重研究了复合酶解榨汁技术的工艺条件、双频超声波辅助浸提技术的工艺条件和饮料的调配配方,确定了饮料最佳的工艺参数。最佳的复合酶解榨汁工艺条件为:p H3.0、复合酶制剂添加量0.6%、酶解温度50℃、酶解时间2.5 h;最佳的双频超声浸提工艺条件为:超声复合频率为20 k Hz/50 k Hz,声强为0.7 W/cm2,超声浸提温度为55℃,浸提时间为1.5 h;最佳配方组合是:沙棘汁20%、雪菊浸提液30%、砂糖10.0%、柠檬酸0.3%。制得的产品风味独特,营养丰富。     

超声波辅助水浸提啤酒废酵母细胞中海藻糖工艺研究

为了开发利用啤酒废酵母资源,本实验以啤酒废酵母为实验材料,以海藻糖为研究对象,蒸馏水为提取剂对影响超声波技术辅助水浸提工艺的多个因素进行了研究,优化了料液比、超声波作用时间、超声功率、浸提时间、浸提温度五个工艺条件。通过L9(34)正交试验,结果表明各因素影响程度依次为:浸提温度>浸提时间>超声功率>超声时间,得到最佳参数为:超声时间20min,超声功率600W,水浸提时间6h,浸提温度100℃。在此参数条件下海藻糖得率达到7.72%。与乙醇浸提法相比,超声波技术辅助水浸提法极大地降低了成本。     

正交试验法优选石参总黄酮的超声波辅助浸提工艺

采用超声波辅助浸提法提取石参中的黄酮类化合物,通过单因素试验和正交试验设计对浸提工艺条件进行优化。结果表明:石参总黄酮超声辅助浸提的最佳工艺条件为乙醇浓度70%、料液比1∶30(g/mL)、浸提时间75 min、浸提温度60℃,在此工艺条件下,石参总黄酮浸提率为(3.528±0.061) mg/g,优化工艺稳定可行,可作为石参总黄酮浸提的一种有效手段。     

超声波辅助酶法制备辣木籽ACE抑制肽工艺优化

为进一步提高辣木籽蛋白资源的开发利用,采用盐提法提取辣木籽蛋白,再采用超声波辅助酶法制备辣木籽ACE抑制肽。以水解度和ACE抑制率为评价指标,通过单因素实验探究超声波功率、超声酶解时间、超声酶解温度及料液比对制备ACE抑制肽的影响,采用响应面法对制备工艺条件进行优化。结果表明：超声波辅助酶法制备辣木籽ACE抑制肽的最佳酶解工艺条件为碱性蛋白酶添加量5.5 mg/mL、pH 9、超声波功率500 W、超声酶解时间1.7 h、超声酶解温度55℃、料液比1∶45,在此条件下制备的酶解物ACE抑制率达到78.32%,水解度为7.78%。以辣木籽为原料制备ACE抑制肽作为功能性蛋白肽产品,可有效提高辣木籽蛋白资源的开发利用。     

正交优化超声辅助法提取杜仲叶中绿原酸的工艺研究

对杜仲叶中的绿原酸采用超声波辅助技术进行提取研究。根据6种因素对提取结果的影响趋势,采用正交试验优化提取工艺。结果表明最佳提取条件:溶剂pH 4.5、超声浸提时间25 min、超声浸提温度40℃、溶剂中乙醇浓度70%,测得提取物的得率为4.06%。     

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.