采后多胺处理对杏果实黑斑病的控制及贮藏品质的影响

以兰州大接杏果实为原料,研究了采后外源多胺处理对杏果实黑斑病的控制效果及对贮藏品质的影响。结 果表明采后多胺处理能显著抑制果实黑斑病的扩展,有效提高果实的抗病性,且控制效果存在多胺种类和浓度效 应,其中1.5 mmol/L精胺、1.5 mmol/L亚精胺和10 mmol/L腐胺的效果最佳,其病斑直径分别较对照减少了38.0%、 26.6%和34.2%。同时采后多胺处理能降低杏果实质量损失率,延缓硬度下降,抑制果实的呼吸强度和乙烯释放量 的升高,并且能有效延缓果实可溶性固形物含量的下降和颜色的变化。可见,多胺在杏果实防腐保鲜上具有较好的 应用前景。     

采后硅酸钠处理对杏果粉霉病的抑制及机理

为探讨采后硅酸钠处理对杏果粉霉病的抑制效果及机理,作者观察了体外条件下硅酸钠对杏果粉霉病病原物粉红单端孢(Trichothecium roseum)的抑制效果,并以"李杏"为试材,采用不同浓度的硅酸钠溶液(0、25、50、75 mmol/L)浸泡果实10 min,测定常温贮藏期间处理对T.roseum损伤接种果实病斑直径的抑制,以及对果实两种防御性酶过氧化物酶(POD)和多酚氧化酶(PPO)活性及抗性物质总酚和类黄酮含量的影响。结果表明,体外条件下硅酸钠可抑制粉红单端孢(Trichotethium roseum)的生长,其中以25 mmol/L处理效果最好,抑菌率可达85%。不同浓度硅酸钠浸泡可明显降低杏果损伤接种T.roseum的病斑直径,其中以50 mmol/L效果最好,且抑制效果可持续72 h。50 mmol/L硅酸钠处理还有效提高了果实体内过氧化物酶(POD)和多酚氧化酶(PPO)活性,促进了总酚的积累,但对类黄酮含量影响不大。由此表明,采后硅酸钠处理可通过直接抑菌和诱导果实抗性来抑制杏的粉霉病。     

采后亚硒酸钠处理对杏果黑斑病的控制及贮藏品质的影响

通过离体和体内实验研究亚硒酸钠对杏果黑斑病菌互隔交链孢（Alternaria alternata）的抑制作用及黑斑病的控制效果和贮藏品质的影响。结果表明,亚硒酸钠处理能显著抑制A. alternata菌落的生长和孢子萌发,且存在质量浓度效应,40 mg/L的亚硒酸钠能显著抑制A. alternata菌落的生长,其菌落直径较对照降低了30.8%,同时亚硒酸钠还能使A. alternata菌丝发生凹陷、扭曲等形态结构的改变;体内实验表明,采后亚硒酸钠处理能有效抑制损伤接种A. alternata的杏果黑斑病的扩展,其中20 mg/L亚硒酸钠的控制效果最佳,其病斑直径较对照减小了11%;采后亚硒酸钠处理还能够明显减少杏果乙烯的释放和呼吸强度的升高,延缓质量损失率和硬度的降低。可见硒在果蔬采后防腐保鲜中具有潜在的应用前景。     

采后草酸处理对杏果实黑斑病的控制及苯丙烷代谢的影响

为探究草酸对杏果实采后黑斑病的控制效果,该试验以“赛买提”杏为试材,采用2、4、6 mmol/L草酸对杏果实进行减压渗透处理,晾干后,置于温度和湿度为（1±1.0）℃、90%~95%的条件下,贮藏48 h后,损伤接种交孢链格孢（Alternaria alternata,A. alternata）并在相同条件下贮藏。定期测定苯丙烷代谢相关指标,孢子萌发率、菌落直径。损伤接种试验结果表明,在第49天时,与对照组相比,4 mmol/L草酸处理组接种发病率与病斑直径分别低了16.94%、19.44%。4 mmol/L草酸处理组的苯丙氨酸解氨酶（PAL）、4-香豆酸辅酶A连接酶（4CL）、肉桂酸-4-羟化酶（C4H）活性是对照组的1.06、1.04、1.07倍,有效促进了总酚、类黄酮、木质素含量的积累;体外试验结果表明,4 mmol/L草酸对A. alternata孢子萌发和菌丝生长有明显抑制作用。结果表明草酸处理可通过诱导苯丙烷代谢途径来增强杏果实对黑斑病的抗性。     

24-表油菜素内酯调控活性氧代谢增强杏果实采后抗病性

为研究24-表油菜素内酯(24-epibrassinolide,EBR)处理对杏果实采后黑斑病发生及活性氧代谢的影响,以'赛买提'杏果实为实验材料,用0.9 mg/L EBR对杏果实进行减压渗透处理,自然晾干后置于温度(1.0±0.5)℃、相对湿度90%～95%的条件下贮藏48 h,接种链格孢菌(Alternaria alternata)后于相同条件贮藏,定期取样测定EBR处理对杏果实采后黑斑病与活性氧代谢的影响。结果表明:EBR处理可显著提高杏果实接种前期H2O2含量(P0.05),显著提高杏果实接种贮藏期间超氧化物歧化酶、过氧化物酶和接种后期过氧化氢酶的活力(P0.05),明显抑制超氧阴离子自由基(O_2~-·)产生速率,有效降低丙二醛的含量、细胞膜渗透率和发病率的上升,显著抑制杏果实病斑直径的扩大。同时,透射电子显微镜结果显示,EBR处理能较好地维持杏果实线粒体、叶绿体等细胞器在贮藏过程中结构的完整性。说明EBR处理抑制杏果实采后黑斑病的发生与调控其活性氧代谢和维持其细胞器结构完整性密切相关。     

核黄素对厚皮甜瓜果实粉霉病和黑斑病的影响

研究不同浓度核黄素处理时厚皮甜瓜果实损伤接种粉红单端孢（Trichothecium roseum）和互隔交链孢（Alternaria alternata）的病斑直径,以及离体培养条件下核黄素处理对两种病原物孢子萌发和菌丝生长的影响。同时研究核黄素处理对厚皮甜瓜果实苯丙烷代谢的影响。结果表明：核黄素浓度为1.0 mmol/L时对甜瓜粉霉病和黑斑病病斑直径的抑制效果最佳。离体培养情况下核黄素处理对T. roseum和A. alternata的孢子萌发率和菌丝生长有抑制效果,其中以浓度为1.0 mmol/L效果最佳。核黄素处理显著提高了厚皮甜瓜果实过氧化物酶和苯丙氨酸解氨酶的活性,还显著提高了总酚、类黄酮、木质素的含量。由此表明,采后核黄素处理可活化苯丙烷代谢,增加相关酶活性及抗性物质的积累,从而强化果实细胞壁结构,抑制果实采后病害的发生。     

对羟基苯甲酸酯类对杏果采后病害的控制

通过离体和体内实验研究对羟基苯甲酸酯类处理对杏果采后黑斑病和软腐病的控制。离体实验结果表明,对羟基苯甲酸酯类对互隔交链孢（Alternaria alternata）和匍枝根霉（Rhizopus stolonifer）菌丝生长具有一定的抑制作用,其中对羟基苯甲酸乙酯和对羟基苯甲酸丁酯抑制效果较好,并随着处理剂量的增加抑制效果显著增加,100 μL/L对羟基苯甲酸丁酯对A. alternata和R. stolonifer菌落生长的抑制效果佳,其对菌落直径的抑菌率分别达到了23.70%和62.48%,同时发现对羟基苯甲酸酯类对R. stolonifer的抑制作用较强。体内实验结果表明,对羟基苯甲酸酯类能有效地控制损伤接种的杏果黑斑病和软腐病的扩展,对软腐病的控制效果较好。其中240 μL/L的对羟基苯甲酸乙酯对杏果黑斑病和软腐病的抑制效果最佳。进一步通过正交试验确定了对羟基苯甲酸酯类与热水复合对杏果的最佳防腐处理条件为32 μL/L的对羟基苯甲酸丙酯,在50 ℃热水中浸泡7 min,该复合对采后杏果的病害控制效果最佳,验证实验表明,其对黑斑病和软腐病的抑菌率分别达到了32.22%和51.84%。     

采前水杨酸处理对杏果实抗病性及苯丙烷代谢的诱导

以新疆赛买提杏为试材,在果实坐果期、膨大期、转色期及采收前48 h的4 个时期,采用1.0 mmol/L水杨酸对杏果实进行喷施处理,以喷清水处理作为对照。采收后的杏果实置于4 ℃、90%～95%相对湿度条件下贮藏,定期统计杏果实接种链格孢（Alternaria alternata）的病斑直径和接种发病率,测定苯丙氨酸解氨酶（PAL）、肉桂酸羟化酶（C4H）、4-香豆酰-辅酶A连接酶（4-CL）的活性及木质素、总酚和类黄酮的含量,研究采前水杨酸处理对杏果实抗病性和苯丙烷代谢关键酶活性及代谢产物积累的影响。结果显示：采前水杨酸处理能有效降低杏果实损伤接种的病斑直径和接种发病率,显著提高杏果实PAL、C4H、4-CL的活性和木质素、总酚、类黄酮的含量。     

采后β-氨基丁酸处理对梨果实黑斑病的抑制

本文研究了采后β-氨基丁酸(BABA)处理对苹果梨损伤接种互隔交链孢(Alternaria alternata)果实病斑扩展以及苯丙烷代谢的影响。结果表明,50μg/m L的BABA可有效抑制损伤接种果实病斑直径的扩展;用BABA浸泡果实10min,以及处理和损伤接种间隔12h的处理效果最佳。果实经BABA处理后,体内的苯丙氨酸解氨酶(PAL)活性明显提高,总酚和类黄酮含量也显著增加。由此表明,BABA可通过诱导果实体内的苯丙烷代谢来增强对黑斑病的抗性。     

外源褪黑素调控活性氧代谢诱导采后杏果实对黑斑病的抗性

以新疆‘赛买提’杏为试验材料,探究外源褪黑素对采后杏果实黑斑病抑制效果及活性氧代谢的影响。将杏果实分别置于50、100、200μmol/L褪黑素溶液进行减压(0.05 MPa)处理2 min后,常压状态下浸泡8 min,以蒸馏水同样处理作为对照,自然晾干后的杏果实转入温度(0±1)℃,相对湿度90%～95%条件下放置48 h后,损伤接种互隔交链孢(Alternaria alternata)于相同条件下贮藏,定期测定杏果实接种发病率和病斑直径及超氧化物歧化酶(Superoxide dismutase,SOD)、过氧化氢酶(Catalase,CAT)、过氧化物酶(Peroxidase,POD)酶活力,及超氧阴离子(Superoxide anion,O₂^-·)产生速率、细胞膜渗透率、过氧化氢(Hydrogen peroxide,H₂O₂)和丙二醛(Malondialdehyde,MDA)含量。结果表明：与对照组相比,不同浓度外源褪黑素处理显著延缓了杏果实发病率的上升(P<0.05),抑制了杏果实病斑...     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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