辛烯基琥珀酸淀粉酯的制备与性质研究

以木薯淀粉为原料,以取代度为衡量标准,采用单因素和正交试验方法研究湿法工艺制备辛烯基琥珀酸淀粉酯,从淀粉乳的初始浓度、体系pH、反应温度、反应时间和酸酐浓度5个方面研究辛烯基琥珀酸淀粉酯最佳制备工艺。其最佳条件为:淀粉乳浓度35%、pH8.5、反应温度35℃、反应时间3.5h、酸酐加入量为4%,采用最佳工艺所得产品取代度为0.02。在同类研究中,降低了淀粉乳初始浓度,提高了产品取代度。利用红外分析方法和差示量热扫描仪对辛烯基琥珀酸淀粉酯的结构进行了表征,并与木薯淀粉的结构做了对比。     

辛烯基琥珀酸荸荠淀粉酯的制备与理化性质研究

以荸荠淀粉为原料,以辛烯基琥珀酸酐为酯化剂,湿法制备辛烯基琥珀酸荸荠淀粉酯,研究反应温度、反应时间、反应pH、辛烯基琥珀酸酐用量及反应初始淀粉乳浓度对辛烯基琥珀酸荸荠淀粉酯的取代度和反应效率的影响。通过单因素试验与正交试验方法,以取代度和反应效率为衡量指标,确定辛烯基琥珀酸荸荠淀粉酯最佳制备工艺。采用最优组合工艺条件制备改性淀粉酯,并与原荸荠淀粉进行理化性质比较分析。结果表明,以取代度为衡量指标,最佳制备工艺条件(优化组合1)为:反应温度40℃,反应时间6 h,pH 8.0,辛烯基琥珀酸酐用量5%,初始淀粉乳浓度40%。该条件下产品取代度为0.022 8,反应效率为59.14%。以反应效率为衡量指标,最佳制备工艺条件(优化组合2)为:反应温度40℃,反应时间6 h,pH 8.0,辛烯基琥珀酸酐用量2%,初始淀粉乳浓度40%。该条件下产品取代度为0.011 4,反应效率为73.75%。理化性质试验结果表明,与天然淀粉相比,优化组合1、优化组合2酯化改性淀粉的透明度,吸水率吸油率、抗老化性、抗凝沉性、冻融稳定性等理化性质均得到明显改善。     

辛烯基琥珀酸淀粉酯制备条件的研究

采用正交实验方法研究湿法工艺制备马铃薯辛烯基琥珀酸淀粉酯，目的在于从淀粉乳的初始浓度、反应温度、pH值和时间四个方面来研究马铃薯辛烯基琥珀酸淀粉酯最佳制备工艺。其结果为：淀粉乳浓度35%、温度35℃、pH值8．0、反应时间5h。     

辛烯基琥珀酸碎米淀粉酯的制备

以碎米淀粉为原料,采用湿法制备辛烯基琥珀酸碎米淀粉酯,以取代度为评价指标,确定辛烯基琥珀酸酐添加量为3%,通过单因素与正交试验确定辛烯基琥珀酸碎米淀粉酯的最佳制备工艺。结果显示：淀粉乳质量分数30%、pH8.5、反应时间5h、反应温度35℃为最佳工艺条件,在此条件下所得产品取代度可达0.01445。     

辛烯基琥珀酸甘薯淀粉酯的制备

采用水相法制备辛烯基琥珀酸甘薯淀粉酯,详细研究了淀粉乳质量分数、辛烯基琥珀酸酐用量、温度、pH、反应时间等因素对产品取代度的影响.实验发现,在6%以下,辛烯基琥珀酸酐用量增加,产品取代度几乎成线性增加.固定辛烯基琥珀酸酐用量为3%,通过正交实验确立了最佳工艺参数为:淀粉乳质量分数35%、温度35℃、反应pH 8.5、反应时间6 h,产品取代度0.016.     

非晶颗粒态玉米淀粉制备辛烯基琥珀酸淀粉酯

以乙醇法制备的非晶颗粒态玉米淀粉、辛烯基琥珀酸酐为原料,研究辛烯基琥珀酸淀粉酯(SSOS)的合成工艺条件。探讨了反应时间、反应温度、碱用量、辛烯基琥珀酸酐、淀粉乳的浓度、水分含量对取代度(DS)和反应效率(RE)的影响。结果表明:在淀粉乳浓度为0.25g/mL,乙醇溶剂含水35%时,pH为8.5,反应温度为35℃时反应2h为最佳反应条件,得到取代度为0.0166。     

银杏辛烯基琥珀酸淀粉酯的制备及消化性能评价

以银杏淀粉为原料,对水相法制备辛烯基琥珀酸淀粉酯的工艺进行了研究。在辛烯基琥珀酸酐添加质量分数为3.0%不变的情况下,通过单因素试验考察淀粉乳浓度、反应时间、反应温度、p H等因素对产品取代度和反应效率的影响。在此基础上,通过正交试验优化了制备银杏辛烯基琥珀酸淀粉酯的最佳工艺参数:银杏淀粉质量分数40.0%,反应温度45.0℃,p H 8.0,反应时间4.0 h。在此工艺条件下,银杏辛烯基琥珀酸淀粉酯取代度可以达到0.019 36,反应效率74.42%。淀粉消化性能试验表明银杏辛烯基琥珀酸淀粉酯对胰淀粉酶水解作用具有良好的抵抗能力,慢消化及抗消化特性显著。     

辛烯基琥珀酸淀粉酯的制备研究

对水相体系法制备辛烯基琥珀酸淀粉酯的工艺过程中,淀粉乳农度、辛烯基琥珀酸酐用量、体系pH、反应温度和反应时间等因素对产品取代度的影响进行了详细讨论,并通过一次回归正交试验设计方案确立了最佳工艺参数为:淀粉孔浓度30％,OSA用量5％(对淀粉干重),体系pH8.5～9.0,反应温度30℃,反应时间8h。     

辛烯基琥珀酸交联淀粉酯合成工艺研究

以木薯淀粉为原料,用环氧氯丙烷作交联剂,辛烯基琥珀酸酐作酯化剂,采用湿法工艺合成辛烯基琥珀酸交联淀粉酯.探讨了淀粉乳浓度、反应温度、反应时间、pH和沉降积对辛烯基琥珀酸交联淀粉酯取代度的影响,确定制备辛烯基琥珀酸交联淀粉酯的最佳工艺参数为:淀粉乳浓度35%,酯化pH 8.0,酯化温度35℃,酯化时间3 h.交联淀粉的沉降积对酯化取代度影响较小,在生产中可根据最终产品的用途选用合适沉降积的交联淀粉进行酯化复合变性.复合变性淀粉符合食品行业标准,可以在食品工业中应用.扫描电镜对其结构进行观察显示淀粉中受侵蚀颗粒增多,颗粒表面的小凹痕数量增加.     

乙酰化辛烯基琥珀酸蜡质玉米淀粉酯的制备及性质研究

以蜡质玉米淀粉为原料,选取乙酸酐和辛烯基琥珀酸酐对其进行双重酯化改性,以取代度为衡量标准,确定了蜡质玉米双重酯化淀粉的制备顺序是先进行乙酸酐的乙酰化再进行辛烯基琥珀酸酐的酯化,得到产物乙酰化辛烯基琥珀酸蜡质玉米淀粉酯。按照确定好的酯化顺序,以实验室自制取代度为0.0768的乙酰化淀粉为原料,采用单因素和正交实验的方法研究湿法工艺制备乙酰化辛烯基琥珀酸蜡质玉米淀粉酯,得出最佳工艺条件为:在辛烯基琥珀酸酐加入量为3%的情况下,淀粉乳初始浓度30%,反应体系pH8.5,反应温度35℃,反应时间4h。采用最佳工艺条件所得产品辛烯基琥珀酸酐酯化取代度为0.0197,利用红外光谱分析方法对乙酰化辛烯基琥珀酸蜡质玉米淀粉酯的结构进行了初步表征,并对产品的乳化性及乳化稳定性、透明度、表观黏度等性质做了测定和分析。     

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