山药罐头加工中护色条件的研究

目的 研究山药罐头加工中最佳的护色条件。方法用柠檬酸、维生素C及氯化钙为护色剂进行护色实验。结果最佳护色条件为：0．5％柠檬酸＋1．0％维生素C＋0．25％氯化钙。结论3种护色剂配合处理后可防止山药褐变，提高山药罐头质量。     

山药罐头加工中护色条件的研究

目的研究山药罐头加工中最佳的护色条件。方法用柠檬酸、维生素C及氯化钙为护色剂进行护色实验。结果最佳护色条件为:0.5%柠檬酸 1.0%维生素C 0.25%氯化钙。结论3种护色剂配合处理后可防止山药褐变,提高山药罐头质量。     

山药板栗营养保健软罐头的工艺技术研究

以山药和板栗为主要原料,通过脱壳试验、护色试验、杀菌方式的确定和正交试验设计,探讨了其生产工艺与技术条件,研制出一种具有多种营养成分和保健功效新型软罐头。     

山药中多酚氧化酶的活性测定及其护色研究

研究了山药中多酚氧化酶(PPO)的最适pH值、最适温度,设计了不同护色方案,以确立山药的最佳护色条件。采用分光光度法研究pH值、温度对酶活性的影响;比较不同护色液对酶活力的影响;将山药经不同护色条件护色后,低温烘干,粉碎过筛得山药粉,用分光光度法测定其甲醇-水溶液(1∶1)的吸光度。结果表明,以邻苯二酚为底物,山药PPO的最适pH值为5.6,最适温度为35℃,山药的最佳护色条件为:以0.25%的Na2SO3为抗氧化剂,并配以0.25%的柠檬酸和1.5%的NaCl为护色液。     

山药罐头加工工艺的研究

通过单因素多水平、多因素多水平的正交实验,对山药罐头的加工工艺进行了研究。结果表明,加工条件为护色液CaCl2浓度为1.5%,65℃下预煮30min,装罐液中黄原胶浓度为0.3%,糖酸比为133,杀菌时间20min,在此条件下罐头产品感官与品质最佳。     

产乳酸芽孢杆菌发酵液对山药护色及多糖免疫活性的影响

结合单因素试验和响应面法优化产乳酸芽孢杆菌发酵时间、发酵液添加量、护色时间对山药多糖得率和山药相对褐变度的影响,并对比该护色液和亚硫酸钠护色液对于山药中酶促褐变和山药多糖免疫活性的影响。结果表明,最佳护色工艺为采用添加10%发酵时间为34 h的产乳酸芽孢杆菌发酵液配制的护色液、护色时间为1 h,在此条件下,多糖得率为12.44%,相对褐变度为43.05%。该护色工艺能够有效抑制山药中多酚氧化酶(polyphenol oxidase,PPO)和过氧化物酶(peroxidase,POD)活性。该工艺护色后的山药多糖刺激小鼠巨噬细胞RAW264.7分泌肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白细胞介素1(interleukin-1、IL-1β)的水平显著高于传统亚硫酸钠护色后的山药多糖。说明,采用该工艺护色后山药多糖的免疫活性显著优于采用亚硫酸钠护色后的山药多糖。     

均匀设计法优化鲜切山药的护色工艺

鲜切山药在空气中容易被氧化产生褐色素,影响其品质。通过单因素实验,研究了常用护色剂EDTA-2Na、抗坏血酸、氯化钠及柠檬酸对鲜切山药的护色效果,并确定了其单独使用时的较佳浓度。通过均匀设计安排实验,对鲜切山药的护色工艺进行优化,得到优化护色配方:0.8%EDTA-2Na,2.0%柠檬酸,0.2%抗坏血酸。通过对照实验,研究了不同前处理0.005%,0.010%Na Cl O消毒及65℃烫漂对鲜切山药的护色效果,结果表明:0.005%,0.010%Na Cl O消毒及65℃烫漂对鲜切山药均具有良好的护色效果,其中0.005%Na Cl O效果优于0.010%Na Cl O。     

不同品种板栗罐头加工的特性

通过正交设计研究对16种板栗罐头进行护色条件的优化。试验发现板栗罐头的适宜护色液组成为:添加0.3%的柠檬酸、0.2%的抗坏血酸、0.1%的乙二胺四乙酸二钠(EDTA)、0.1%的NaCl;适宜护色温度为40℃。另外,通过模糊数学法对16个不同品种的板栗罐头进行综合评价,筛选出了最适宜加工成板栗罐头的优良品种。燕光、燕晶、早丰、达1-3和燕奎更适合作为板栗罐头的原材料。     

低糖山药罐头的加工

低糖山药罐头的加工沈冠清康正平李传军（陕西省果品加工厂，泾阳７１３７０２）（镇巴县罐头厂，７２３６００）１工艺流程与制作１．１工艺流程原料选择→去皮→护色（硬化）→预煮→漂洗→切分、整理→装罐→注汤汁→封口→杀菌→擦罐→检验→装箱、入库１．２制作１．...     

低糖保健型葡萄罐头的生产工艺

以木糖醇为主要甜味剂，代替蔗糖生产低糖保健型葡萄罐头的生产工艺，研究了硬化处理、排气方式和护色处理对葡萄罐头品质的影响，对一些工序进行了改进，从而成功地研制出了集风味、保健、低糖型于一体的葡萄罐头。     

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.     

Detection of adulteration of locust bean gum with guar gum by capillary electrophoresis and polarized light microscopy

Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH₃CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH₂PO₄-20.6 mM Na₂B₄O₇ buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.     

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%.