葡萄采后紫外线(UV)处理对白藜芦醇的诱导作用

采用不同剂量的紫外线(254nm)照射处理采后赤霞珠、玫瑰香葡萄,室温避光贮藏24小时后检测葡萄果皮中白藜芦醇的含量变化,以及葡萄可溶性固形物、总酸、总酚和花色素的含量,结果发现:1)在赤霞珠、玫瑰香葡萄果皮中检测到反式白藜芦醇,但未检测到顺式白藜芦醇;2)UV照射处理显著影响了葡萄的花色素、可溶性固形物含量;3)低剂量的UV照射对葡萄果皮中白藜芦醇具有诱导作用,明显提高了白藜芦醇含量,而高剂量UV处理后白藜芦醇含量呈降低趋势.     

乙磷铝和紫外线照射对葡萄叶片中芪类化合物的诱导作用

用乙磷铝(fosetyl-Al)和紫外线(UV)照射处理葡萄叶片,通过测定处理组织中白藜芦醇(resveratrol)的含量调查葡萄中芪类化合物的诱导水平,以评价葡萄的抗毒素诱导反应.试验表明,离体的葡萄叶片用乙磷铝和UV处理后,白藜芦醇的含量明显提高,最大白藜芦醇诱导量出现在UV照射后的48小时;而单独使用乙磷铝对葡萄叶片的白藜芦醇的诱导没有明显反应,并且乙磷铝喷洒和UV照射两处理间没有表现出附加效应.乙磷铝处理田间生长的叶片,结果与离体叶片处理不同,白藜芦醇的含量大大的增加.进一步用乙磷铝和UV照射处理田间叶片,也表明乙磷铝对白藜芦醇有明显的诱导作用.因此,我们认为,乙磷铝对白藜芦醇的诱导性对离体组织没有影响,只发生在正常生长的组织中.     

紫外光对葡萄皮中白藜芦醇的诱导作用

本实验用不同剂量的紫外光(UV-C和UV-B)对采后葡萄进行照射处理,并于不同的暗处理时间收集葡萄果皮,采用HPLC法分析其中白藜芦醇的含量.结果表明:UV-B对白藜芦醇的诱导作用不是很大, 用UV-C照射20min暗处理48h后, 白藜芦醇含量可提高15倍以上,鲜重达到155μg/g.因此可以考虑采用UV-C照射处理采后葡萄,把其作为高白藜芦醇含量的食物源.     

干化葡萄酒酿造中不同干化处理对白藜芦醇的影响

研究以宁夏贺兰山东麓赤霞珠葡萄为原料酿制干化葡萄酒时3种不同干化处理方法(日光下晒制、日光下隔离紫外线晒制、阴制)对葡萄及葡萄酒中白藜芦醇含量的影响,以及干化处理时天气的温度、紫外线强度及葡萄水分损失对白藜芦醇含量的影响。采用高相液相色谱法(HPLC)测定葡萄及葡萄酒中白藜芦醇的含量。结果表明:以未处理的鲜葡萄做对照,3种干化方法都可以提高葡萄以及用它们酿制的葡萄酒中白藜芦醇的含量。相比未处理的鲜葡萄,3种干化方法使葡萄中的白藜芦醇含量分别提高了206.17%、187.65%、138.27%,所酿制的干化葡萄酒中白藜芦醇含量分别提高了139.46%、116.22%、75.30%,干化过程中温度对白藜芦醇含量影响较大,日光下紫外线及葡萄水分含量对白藜芦醇含量影响较小。     

贮藏条件对葡萄酒中白藜芦醇的影响

采用HPLC方法研究贮藏条件(贮藏温度、光照)对葡萄酒中四种白藜芦醇异构体含量的影响,发现:1)高温贮藏条件引起白藜芦醇总量的降低,其中反式白藜芦醇减少了45.8%;2)日光照射引起白藜芦醇含量的降低,而灯光照射后白藜芦醇总量未见明显降低;3)光照具有促进白藜芦醇向白藜芦醇糖苷转化的趋势.实验结果证明高温贮藏不利于葡萄酒中白藜芦醇的保存,商业流通中的灯光照射对葡萄酒中白藜芦醇含量无明显影响.     

短波紫外照射对玫瑰香葡萄品质和白藜芦醇及其衍生物含量的影响

采用超高效液相色谱-串联质谱法对玫瑰香葡萄中白藜芦醇及其衍生物的含量进行测定。结果表明,当玫瑰香葡萄经过剂量为4.5 k J/m~2的短波紫外照射后,20℃贮藏至48 h时,白藜芦醇和白藜芦醇苷含量达到最高,分别为90.29 μg/g和163.28 μg/g;贮藏至72 h时,紫檀芪含量达到最高38.67 μg/g。短波紫外照射也可以降低可溶性固形物、VC、可滴定酸等品质评价指标的下降速率。     

不同强度紫外线(UV)-B辐射对葡萄品质影响

以欧洲葡萄"赤霞珠"为材料,通过人工增加辐射量0μW/cm2(CK组)、10.2μW/cm2(T1组)、20.7μW/cm2(T2组)和30.5μW/cm2(T3组),研究紫外线-B(UV-B,280nm～320nm)增强对葡萄品质及采收后所酿酒的相关影响.结果表明:随着长时间不同强度紫外线(UV)-B的照射,葡萄果实大小及产量降低,葡萄着色指数下降;还原糖、滴定酸、糖酸比(A/S)、可溶性固形物(TSS)下降趋势显著(CK>T1>T2>T3);采后酒发酵状态较为一致,但单宁含量逐渐降低,色度显著减少.紫外线-B辐射影响葡萄酒的质量.     

水杨酸对蛇龙珠葡萄白藜芦醇诱导合成的影响

为了研究水杨酸(SA)对蛇龙珠葡萄白藜芦醇合成的影响,以蛇龙珠葡萄果实为试材,在浆果生长期设置0 mg/L、25 mg/L、50 mg/L、100 mg/L的水杨酸处理,测定果皮和果籽中白藜芦醇的含量,并探讨白藜芦醇与苯丙氨酸解氨酶(PAL)、肉桂酸-4-羟基化酶(C4H)活性的关系。结果表明:在蛇龙珠葡萄发育过程中,果皮和果籽中的白藜芦醇含量出现2次高峰,分别出现在花后35 d和花后80 d;PAL和C4H活性的变化与白藜芦醇含量变化相似;不同质量浓度的水杨酸处理对蛇龙珠葡萄有明显的诱导效果,其中果皮中白藜芦醇含量以50 mg/L水杨酸诱导效果最佳,果籽中白藜芦醇含量以25 mg/L水杨酸诱导效果相关最佳。由此推断,适量的水杨酸处理能够激活PAL和C4H的活性,进一步提高白藜芦醇的含量。     

短波紫外线照射对苹果采后灰霉病抗性诱导作用

为探究短波紫外线（ultraviolet C,UV-C）照射对苹果采后灰霉病的防治效果与抗性诱导机理,以红富士苹果为材料,采用剂量分别为3.5、7.0、10.5 kJ/m2 的UV-C（280 nm）进行照射,常温条件下放置2 d 后接种灰葡萄孢菌,以不经UV-C照射直接接种灰葡萄孢菌的果实作为对照。结果表明：照射剂量为3.5 kJ/m2 和7.0 kJ/m2的UV-C照射可显著降低果实灰霉病的发生率,抑制病斑直径的扩展（P＜0.01）,其中照射剂量为7.0 kJ/m2 UV-C处理的效果更好;而照射剂量为10.5 kJ/m2 的UV-C照射处理在接种后贮藏前期对病害有抑制作用,后期却加快病害发展。3.5 kJ/m2 和7.0 kJ/m2 UV-C处理能诱导苹果果实几丁质酶、β-1,3-葡聚糖酶、过氧化物酶（POD）、多酚氧化酶（PPO）和苯丙氨酸解氨酶（PAL）等抵御酶活性的提高,诱导酚类物质的合成,进而增强果实的抗病性,其中7.0 kJ/m2 UV-C处理诱导效果更明显,与对照差异显著（P＜0.01）。10.5 kJ/m2 UV-C照射仅在接种后前期诱导POD、PPO、PAL和几丁质酶的活性迅速上升,提高总酚和类黄酮含量,但对β-1,3-葡聚糖酶活性没有诱导作用。     

紫外照射对采后花生根中自藜芦醇的影响

目的:研究紫外照射对采后花生根中白藜芦醇含量的影响.方法:将采后的花生根经不同处理(剪碎、干燥、新鲜等)后接受紫外照射(照射时间、照射距离、照射后处理方法等),对比白藜芦醇含量的变化情况.结果:采后的新鲜花生根受到紫外照射后,组织中白藜芦醇含量提高65%～120%.当花生根距离紫外灯1～2 m时,白藜芦醇含量变化较大;而在距离紫外灯1 m以内和2 m以外时,白藜芦醇含量变化较小;紫外照射20 min时,白藜芦醇含量最高.紫外照射花生根放置10h后才逐渐产生白藜芦醇.结论:紫外照射可刺激未失活花生根组织产生白藜芦醇.     

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.