电子束辐照对冷鲜鸡肉的杀菌效果

以冷鲜鸡肉为试材,研究了冷鲜鸡肉经电子束辐照后的鼠伤寒沙门氏菌、金黄色葡萄球菌及大肠杆菌的灭菌效应（D10值）及菌落总数和感官品质在贮藏期的变化。结果表明：电子束辐照后冷鲜鸡肉中鼠伤寒沙门氏菌、大肠杆菌和金黄色葡萄球菌的D10值分别为0.483、0.932、0.715 kGy。在0～4 ℃贮藏条件下,4 kGy剂量辐照贮藏14 d、6 kGy及以上剂量辐照贮藏28 d后菌落总数均低于规定限值5×105 CFU/g,且感官品质无显著影响。     

不同清洗液对鲜切哈密瓜品质的影响

为了明确不同清洗条件对鲜切哈密瓜贮藏品质的影响,选择自来水、酸性电解水、近中性电解水和Na Cl O溶液处理鲜切哈密瓜后,置于4℃贮藏,考察贮藏期间残留菌落数、可溶性固形物、维生素C、可滴定酸、丙二醛和感官品质的变化。结果表明:酸性电解水抑菌效果明显,能同时较好地降低可溶性固形物、维生素C和可滴定酸的消耗,抑制丙二醛的增加,而近中性电解水和Na Cl O溶液清洗处理效果虽优于自来水,但却比不上酸性电解水。综合考虑各项指标,酸性电解水能较好地维持鲜切哈密瓜的商品价值,延长货架期。     

天然复合抗氧化剂对鲜切马铃薯的保鲜效果

为探究天然复合抗氧化剂对鲜切马铃薯的保鲜效果,采用香椿叶、山楂叶、葡萄籽提取物以及海藻酸钠为材料,以总酚含量、DPPH·和ABTS+·清除率、菌落总数以及对大肠杆菌、沙门氏菌、金黄色葡萄球菌的生长抑制情况为指标,研究0～8 d内各试验组对鲜切马铃薯抗氧化活性及抑菌性能的影响。结果表明,在储藏期内,各试验组虽能够抑制马铃薯总酚含量的增加,保持较高的DPPH·和ABTS+·清除率水平,抑制总菌落数的增长,但复合处理效果更佳（P＜0.05）;对大肠杆菌、沙门氏菌、金黄色葡萄球菌的增殖有不同程度的抑制作用,其中天然复合抗氧化剂的处理效果最佳。综上,在0～8 d储藏期内,经天然复合抗氧化剂处理后,试验组鲜切马铃薯总酚含量和微生物数量均得到抑制,更加有效地延缓了酶促褐变的发生。     

紫色马铃薯花青素的抑菌性及其对草莓保鲜效果的研究

为研究紫色马铃薯花青素的抑菌性及其对草莓保鲜的作用,考察了紫色马铃薯花青素对大肠杆菌、金黄色葡萄球菌、青霉菌和酵母菌的抑菌能力、最低抑菌浓度和紫色马铃薯花青素与山梨酸钾、对羟基苯甲酸乙酯及其混合液的抑菌效果;测定紫色马铃薯花青素对室温贮藏条件下的草莓失重率、腐败率、可溶性固形物含量和菌落总数的影响。结果表明:紫色马铃薯花青素的抑菌能力为金黄色葡萄球菌>大肠杆菌>青霉菌>酵母菌;对四种菌的最低抑菌浓度分别为5.625、11.25、22.5和45 mg/mL。25 mg/mL紫色马铃薯花青素+0.5 μg/mL对羟基苯甲酸乙酯混合液处理组草莓的失重率、腐败率显著低于对照CK（P<0.05）,可溶性固形物含量显著高于对照CK（P<0.05）,菌落总数极显著低于对照CK（P<0.0001）。保鲜能力为对羟基苯甲酸乙酯+花青素>对羟基苯甲酸乙酯>花青素>对照。综上,紫色马铃薯花青素具有一定的抑菌和保鲜效果,但效果差于对羟基苯甲酸乙酯,与其联合使用效果最佳。     

高压二氧化碳处理对鲜切哈密瓜微生物与品质的影响

本实验以哈密瓜为原料,优化了清洗工艺,研究了高压二氧化碳（high pressure carbon dioxide,HPCD） 处理对鲜切哈密瓜贮藏期间（4 ℃避光贮藏8 d）微生物（菌落总数、霉菌和酵母菌总数）、感官指标（质量损失 率、质构、感官评价）、品质指标（可溶性固形物含量、pH值、VC含量）、酶（多酚氧化酶（polyphenoloxidase, PPO）、过氧化物酶）活力的影响。本研究首先确定了强酸电解水清洗25 min为最佳清洗工艺,清洗后鲜切哈密 瓜的菌落总数下降了0.81（lg（CFU/g））。2.5、3.5、4.5 MPa处理8 min后的鲜切哈密瓜在贮藏期间微生物数量显 著增加,PPO活力上升,且在贮藏8 d时,质量、硬度和VC含量分别下降了16.45%～42.70%、30.38%～48.97%和 96.25%～96.73%。本研究为HPCD技术应用于鲜切哈密瓜加工提供了理论依据。     

生物保鲜剂对提高鲜切荔枝果肉冰温贮藏品质的效果

研究了冰温贮藏条件下,乳酸链球菌素Nisin和溶菌酶2种生物保鲜剂对鲜切荔枝果肉冰温贮藏品质的影响。通过测定2种生物保鲜剂不同浓度及组合对鲜切荔枝果肉菌落总数、霉菌和酵母数、褐变度及多酚氧化酶活性变化可知,与对照组相比,经0.05%乳酸链球菌素和溶菌酶浸泡预处理可显著降低鲜切荔枝果肉贮藏期间菌落总数及霉菌和酵母的增加幅度;乳酸链球菌素对细菌的抑制效果优于溶菌酶,而溶菌酶对霉菌和酵母菌的抑制效果优于乳酸链球菌素,且溶菌酶对果肉有一定的护色作用。2种生物保鲜剂复配处理的综合效果优于单独处理,其中0.025%nisin+0.025%溶菌酶复合处理的抑菌效果和保持鲜切荔枝果肉色泽的效果均优于其他处理。     

不同清洗方式对鲜切鸡毛菜保鲜效果的影响

实验采用臭氧水、电解水、次氯酸钠、超声波对鲜切鸡毛菜进行清洗,自来水清洗作为对照。通过测定贮藏期间叶绿素、VC、亚硝酸盐、细菌总数、感官品质等来比较清洗效果。实验结果表明,臭氧水和超声波处理的样品在杀菌、保持营养物质及感官上的效果相对其他处理的样品要好,贮藏至14d仍有商品价值和食用价值,可作为鲜切鸡毛菜加工过程中的处理方式。     

壳聚糖涂膜对鲜切哈密瓜品质的影响

将鲜切"西州蜜"哈密瓜用2%的壳聚糖处理,研究壳聚糖涂膜处理对鲜切瓜块冷藏期间品质影响。结果表明,壳聚糖涂膜可有效降低鲜切哈密瓜贮藏期间果实失重率,延缓硬度下降,同时,壳聚糖涂膜还能有效维持瓜块的色泽,以及可溶性固形物和可滴定酸的含量,此外,壳聚糖涂膜还能显著抑制果块表面菌落总数、酵母菌、霉菌、大肠菌群数的增长。感官评价结果表明经壳聚糖涂膜处理的鲜切哈密瓜果实的良好食用品质可维持至9 d,比对照组延长3 d。     

姜黄素介导的光动力技术对鲜切马铃薯的杀菌效果

本文运用光动力技术（Photodynamic technology,PDT）对鲜切马铃薯进行非热杀菌,实验选用姜黄素为光敏剂,420 nm LED蓝光为激发光源。探究了光照功率、光照时间、孵育时间以及光敏剂浓度等因素对鲜切马铃薯表面大肠杆菌、金黄色葡萄球菌杀菌效果的影响,并确定最优杀菌条件。结果表明,该技术对大肠杆菌的最优杀菌条件分别为:光照功率40 W、光照时间20 min、孵育时间15 min、姜黄素浓度30 μmol/L;金黄色葡萄球菌的最佳杀菌条件分别为:光照功率40 W、光照时间10 min、孵育时间15 min、姜素浓度30 μmol/L。与对照组相比,光动力技术处理后的大肠杆菌与金黄色葡萄球菌菌落总数分别为降低3.60与5.23 lg CFU/mL。     

不同清洗剂对鲜切马铃薯贮藏过程品质变化的影响

通过电解水和次氯酸钠两种不同清洗剂对鲜切马铃薯进行清洗杀菌处理,探讨了其对鲜切马铃薯贮藏过程品质的影响.清洗切分后的马铃薯丝于4℃冰箱中贮藏7d,每天对其色差(L*,a*,b*值)、褐变度(BD)、失重率、多酚氧化酶(PPO)活性和整体感官质量(OVQ)进行检测与评定,每隔一天对菌落总数进行测定.研究表明:强酸电解水清洗能够较好地保持鲜切马铃薯丝的色泽(较高的L*和b*值及较低的a*值)和OVQ,减少表面微生物的数量,抑制贮藏期内褐变现象的产生及降低PPO活性;而次氯酸钠对降低贮藏期内样品失重率的效果稍优于电解水,但两者在保持鲜切马铃薯色泽品质、降低失重率、抑制表面褐变及PPO活性方面的差异性不具有显著性(p＞0.05).综合方便、安全、环保等因素,得出结论为电解水的清洗效果优于次氯酸钠,其对鲜切马铃薯丝在贮藏期内的品质有一定的保持作用.     

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