薏米酒发酵前淀粉液化及糖化条件的优化

以薏米为原料,以葡萄糖当量值(DE值)为评价指标,对薏米酒微生物发酵前淀粉液化及糖化工艺进行研究,考察酶添加量、pH值、温度、时间对DE值的影响。结果表明,最优的液化工艺条件为α-淀粉酶添加量2.0%、pH6.5、液化温度60℃、液化时间3.0h;糖化最优工艺条件为糖化温度55℃、pH4.5、糖化酶添加量2.5%、糖化时间2.5h。在此条件下,最终水解液的还原糖含量和DE值分别达到6.87g/100mL和76.4%。     

酶解辅助提取茶皂苷的工艺参数研究

为了进一步研究茶皂苷的优化提取工艺条件,使用多酶复合辅助提取法进行实验,通过单因素实验考察提取液的pH值、酶解时间、酶解温度、复合酶比例等对茶皂苷提取率的影响。利用单因素实验的最优结果进行正交试验,得出α-淀粉酶和糖化酶复合提取最优条件为:酶解温度T=51℃、缓冲液pH=5.4、α-淀粉酶和糖化酶的用量比为4:1、酶解时间t=135 min。     

新型青稞酒发酵前淀粉液化及糖化条件的优化研究

以青稞和贡米为酿酒原料,以葡萄糖当量值(DE值)为指标,对新型青稞酒发酵前淀粉液化和糖化工艺优化进行研究,主要研究不同因素对青稞和贡米混合料中的淀粉液化及糖化过程的影响。结果表明,最优液化条件为:温度65℃,时间5h,α-淀粉酶添加量4U/g,p H值6.0;最优糖化条件为:时间45h,温度60℃,p H值5.5,糖化酶添加量100U/g。在此工艺条件下水解液中还原糖的含量和DE值达到最大。     

响应面法优化酶解马铃薯淀粉工艺

采用中温型α-淀粉酶对马铃薯淀粉进行水解,以马铃薯淀粉水解液的DE值为评价指标,在p H、酶解温度、酶解时间单因素实验的基础上,采用响应面法优化了马铃薯淀粉酶解工艺条件。结果表明:p H7.90,酶解温度62℃,酶解时间60 min,在此最优条件下酶解马铃薯淀粉的DE值达57.93%。     

甜玉米发酵酒液化工艺的研究

以甜玉米为主要原料生产发酵酒,采用耐高温α-淀粉酶对甜玉米浆液进行液化,以DE值为评价指标,在单因素试验基础上,利用响应面法优化甜玉米发酵酒的液化工艺。结果表明:甜玉米发酵酒液化工艺最佳条件为淀粉酶的添加量110 U/g、pH 5.5、液化时间75 min,液化温度85℃。在此优化条件下,甜玉米汁水解液的DE值为14.5%。     

淀粉酶酶解大米淀粉制备低DE值脂肪替代物

采用酶法制备低DE值脂肪替代物,比较高温α-淀粉酶,中温α-淀粉酶,β-淀粉酶和糖化酶酶解大米淀粉制备的脂肪替代物-麦芽糊精的性质.结果表明,高温α-淀粉酶最适合用于制备低DE值麦芽糊精,其最佳制备工艺参数为酶用量3mL,pH6.2,酶解温度95℃,酶解时间10min.该条件下样品的流变试验结果表明,DE值在3左右的麦芽糊精形成凝胶时相应的凝胶温度为73.6℃.     

荔枝核淀粉双酶水解工艺研究

采用Ε-淀粉酶和糖化酶联合水解荔枝核淀粉,在单因素试验基础上,运用正交试验设计方法对荔枝核淀粉水解工艺进行优化。结果表明,荔枝核淀粉最佳液化工艺条件为Ε-淀粉酶添加量20u/g,温度70℃,时间1.5h,p H值6.0,液料比4:1,DE值为22.38%;最佳糖化工艺条件为糖化酶添加量150 u/g,温度60℃,p H 4.0,时间3h,DE值为84.56%。     

碎米制备果葡糖浆液化及糖化工艺

以碎米为原料制备果葡糖浆,研究液化和糖化的工艺条件.利用耐高温α-淀粉酶液化,通过单因素试验,得到最佳的液化工艺条件:料液比为1:5(g/mL),液化温度90℃,液化时间为35 min,加酶量40 U/g,pH6.5.此条件下的液化液葡萄糖值(dextrose equivalent,DE)为17.2％.利用含有糖化酶和...     

双酶法水解橡子淀粉工艺研究

为掌握中温α-淀粉酶和糖化酶联合水解橡子淀粉的工艺条件,该研究在单因素试验的基础上,运用正交试验设计方法对橡子中的淀粉水解工艺进行了研究和优化。结果表明,橡子淀粉最佳液化工艺条件为中温α-淀粉酶添加量30 U/g,液化温度70 ℃,CaCl2添加量0.3%,液化pH 7.5,液化时间120 min,葡萄糖当量（DE）值为27.79%;最佳糖化工艺条件为糖化酶添加量300 U/g,糖化温度50 ℃,糖化pH 4.5,糖化时间120 min,DE值为48.13%。     

酶法修饰对莲子粉黏度及复水性的影响

采用α- 淀粉酶对莲子粉中的淀粉进行适度水解降低其黏度,提高冷冻干燥的效率,并探讨黏度与复水性之间的关系。在研究酶解时间、温度、pH 值及酶添加量对莲子粉水解液黏度影响的基础上,通过正交试验优化确定最佳酶水解条件为酶添加量16.56U/mL、温度70℃、时间15min、pH6.5,水解液的黏度为77mPa·s,解液DE 值4.95%。4 个因素都对试验结果有极显著的影响(P ＜ 0.01)。同时发现黏度与复水性之间呈现负相关关系,并且酶解和冷冻干燥对莲子粉的复水性有显著影响(P ＜ 0.05)。     

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.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

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