硅藻土附载丁香酚缓释处理对不同品种草莓品质影响的比较

以4个品种草莓(晶瑶、晶玉、甜查理和宁丰)为试验材料,将丁香酚附载于硅藻土缓释,研究了不同品种、丁香酚缓释处理下草莓的保鲜效果。研究表明,晶瑶草莓贮藏保鲜效果优于晶玉、甜查理和宁丰三个品种草莓,货架期更长,保鲜品质由优至劣依次为:晶瑶、甜查理、宁丰、晶玉。在冷藏(4±1℃)过程中,丁香酚缓释可抑制草莓果实腐败,延缓果实质量损失和果肉可溶性固形物、可滴定酸、还原糖、Vc含量的降低,还能抑制MDA含量的上升以及SOD、POD、CAT等抗氧化酶类活性下降,对保持草莓果实的感官品质也具有积极作用;贮藏9 d时,经丁香酚缓释处理的晶瑶草莓腐烂率和失重率分别为31.50%和1.33%,可溶性固形物、可滴定酸、还原糖、Vc含量分别为8.83%、0.577%、5.72%和31.46 mg/100 g,MDA含量为23.11 nmol/g、SOD、POD、CAT活性分别、261.68 U/mL、1.65 U/mg、52.49 U/g。总而言之,硅藻土附载丁香酚缓释处理对草莓具有一定的保鲜作用,且不同品种草莓之间具有一定差异。     

不同保鲜剂对蓝莓保鲜效果的比较

为了延长蓝莓的贮藏期,本研究以蓝莓为原料,研究了丁香酚缓释保鲜、丁香提取液、乙醇熏蒸、气调保鲜、丁香酚缓释结合气调保鲜5种不同保鲜剂对其贮藏期品质的影响。结果显示,这5种保鲜剂能显著抑制蓝莓果实腐烂和质量损失率,有效缓解可溶性固形物、可滴定酸、还原糖、Vc含量的降低,抑制MDA含量的上升,同时,可使蓝莓果实保持较高的SOD活力。贮藏49 d时,经丁香酚缓释结合气调包装的蓝莓腐烂率和失重率分别为50.13%和2.71%,可溶性固形物、可滴定酸、还原糖、Vc、花色苷含量分别为7.06%、7.26 g/kg、4.14 g/100 g、0.93 g/100 g和117.48 mg/100 g,MDA含量为26.84 nmol/g,SOD活力为176.34 U/mL。与对照组相比,丁香酚缓释结合气调包装能延长蓝莓14 d贮藏期。结果表明,5种保鲜处理对蓝莓具有一定的保鲜作用,其中丁香酚缓释结合气调包装保鲜方式最好。     

不同包装结合硅藻土附载丁香酚缓释对草莓贮藏品质的影响

采用聚乙烯（polyethylene,PE）、聚偏二氯乙烯（polyvinylidene chloride,PVDC）、低密度聚乙烯（low-density polyethylene,LDPE）、线性低密度聚乙烯（linear low-density polyethylene,L-LDPE）4 种不同材质的保鲜膜以及气调包装结合硅藻土附载丁香酚缓释处理对草莓进行包装处理,研究草莓4 ℃贮藏期间品质的变化。结果表明：不同保鲜膜以及气调结合丁香酚缓释处理能不同程度地抑制草莓腐烂以及质量的损失,延缓可溶性固形物、可滴定酸、还原糖以及VC的流失,抑制丙二醛含量的上升以及超氧化物歧化酶、过氧化物酶活力的下降;其中以气调包装结合丁香酚缓释处理效果最佳,PVDC结合丁香酚缓释处理其次,其能将草莓货架期分别延长至15 d和12 d。本实验结果可为草莓的保鲜提供参考。     

Nisin在草莓保鲜中的应用研究

研究Nisin对草莓保鲜的影响.使用浓度为0.1,0.2,0.3 g/kg的Nisin悬浮液喷洒的草莓,对贮藏期间草莓的腐烂率、失重率、可滴定酸含量、Vc的含量进行测定.结果表明:保鲜箱中喷洒0.1 g/kg Nisin的草莓保鲜效果最好,将其放置6 d后腐败率为40%,重量损失率达到24%,Vc的损失率小于10%、总酸含量为原始含量的75%.说明使用Nisin对草莓进行保鲜能保持其光鲜的色泽和Vc、可滴定酸等营养成分.     

硅藻土附载植物精油缓释对树莓保鲜作用

为了延长树莓的贮藏时间和维持果实品质,采用丁香酚、香芹酚和芳樟醇3种植物精油附载硅藻土缓释对树莓进行保鲜处理,在4℃条件下贮藏27 d,每3 d测定缓释保鲜剂对树莓腐烂率、质量损失率和营养成分以及抗氧化酶等的影响.结果表明:与空白组相比,3种植物精油缓释保鲜处理处理均有效降低树莓的腐烂率、质量损失率,减缓树莓的可溶性固...     

银杏叶提取物/阿拉伯胶复合涂膜对草莓保鲜效果的影响

本研究采用不同浓度（0.25、0.50、0.75 mg/mL）的银杏叶提取物（Ginkgo biloba leaves extracts,GBLE）与100 mg/mL阿拉伯胶（gum arabic,GA）复合配制保鲜液，通过测定贮藏期间草莓感官品质、失重率、可滴定酸含量、可溶性固形物含量、Vc含量、硬度、腐烂率以及丙二醛含量的变化，探究GA-GBLE复合涂膜对草莓果实的保鲜效果。研究表明：单一GA涂膜和GA-GBLE复合涂膜较CK组相比对草莓保鲜效果均有显著性差异，均能显著的延缓草莓果实的感官品质、可滴定酸含量、可溶性固形物含量、Vc含量和硬度的下降，有效缓解失重率、腐烂率、丙二醛含量的上升。其中GA-GBLE复合涂膜液保鲜效果优于单一GA涂膜，且GA-0.50 mg/mL GBLE复合涂膜液保鲜效果最佳，可有效延缓草莓的贮藏期。因此，阿拉伯胶/银杏叶提取物复合涂膜作为保鲜剂，在果蔬贮藏保鲜方面具有一定的参考价值。     

保鲜纸箱对樱桃常温贮藏品质的影响研究

为了研究保鲜纸箱对樱桃常温贮藏保鲜效果的影响,采用两种保鲜纸箱(MS1和MS2),另一种普通纸箱(CK)作为对照组,测定在室温条件(15℃~23℃)下,3种纸箱包装内樱桃腐烂率、失重率、果实硬度、可溶性固形物、可滴定酸和维生素C含量等各项理化品质指标的变化。试验结果表明在常温下普通纸箱内樱桃的货架期为6 d,而保鲜纸箱内可以达到9 d。常温贮藏9 d后,MS2试验组对樱桃保鲜效果最佳,其腐烂率、失重率分别为11.1%和8.9%,果实硬度保持在1.36 kg/cm~2,可溶性固形物、可滴定酸的质量分数分别为11.33%和0.21%,维生素C含量为10.97 mg/100 g。     

蜂胶提取物对草莓室温保鲜效果的研究

为研究蜂胶乙醇提取物对草莓室温下的保鲜作用,以1%、2%、4%、6%浓度的蜂胶提取物作为保鲜剂,对草莓进行涂膜并在室温(24.5℃±)条件下贮藏,对不同涂膜处理后的草莓进行硬度、呼吸强度、可溶性固形物含量、可滴定酸含量、Vc含量、失重率、腐烂率等生理指标的测定。结果表明:在室温(24.5℃±)条件下,2%蜂胶提取物可以显著降低果实的呼吸强度、失重率和腐烂率,有效保持果实硬度,延缓可溶性固形物的降解,延缓果实可滴定酸和Vc含量的下降速度,维持果实原有品质,延缓果实成熟衰老。     

臭氧结合气调冷藏对草莓保鲜品质的影响

草莓是一种易腐水果,贮藏期的失水、腐烂和软化严重影响了草莓的品质。采用臭氧处理介导的气调贮藏草莓果实,观察其对草莓贮藏保鲜品质的影响。首先,通过实验确定了草莓臭氧处理的最佳浓度为30 mg/m3,处理时间为30 min。分析了3种不同贮藏方式下(单独冷藏为对照,气调箱包装冷藏和臭氧处理结合气调冷藏)样品在18 d贮藏期内的腐烂率、可滴定酸、可溶性固形物、丙二醛含量等指标的变化情况,结果显示臭氧结合气调贮藏组及气调贮藏均能显著延缓草莓在贮藏过程中的品质降低,18 d后这2组草莓果实其腐烂率、SSC含量、MDA含量均低于对照组,而硬度和TA含量均高于对照组,臭氧结合气调贮藏组的各项品质指标最好,说明臭氧对气调保鲜具有增效作用。该研究结果有利于进一步改进草莓采后保鲜措施,提高草莓商品价值,具有一定应用前景。     

壳聚糖复合涂膜对草莓保鲜的影响

迷迭香提取物、CaCl2、亚硫酸钠分别与壳聚糖复配涂膜研究草莓的贮藏保鲜技术,通过测定贮藏过程中草莓果实的营养成分、感官品质等指标,探究草莓在低温冷藏条件下的成熟衰老过程和不同保鲜剂处理对草莓贮藏品质的影响。结果表明:壳聚糖复配迷迭香提取物和壳聚糖复合CaCl2涂膜保鲜液均可显著地(P<0.05)减缓草莓的可溶性固形物、可滴定酸、Vc、还原糖含量的下降,抑制草莓细胞膜渗透率变化和果实的腐烂软化,保持草莓的硬度等贮藏品质。亚硫酸钠-壳聚糖处理可维持草莓的还原糖含量,延缓可滴定酸和Vc含量的下降。其中,1.5%壳聚糖+0.3%迷迭香提取物溶液浸渍涂膜5 min保鲜草莓效果最好,1.5%壳聚糖+2.0%CaCl2溶液浸渍涂膜5 min次之。     

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