红薯叶饮料的研究

利用正交试验对红薯叶的浸提条件、原料配比和稳定性进行研究.在浸提时间5h、温度60℃、红薯叶∶水为1∶35、糖10%、盐0.3%、柠檬酸0.015%时,研制出了以红薯叶为原料,色、香、味俱佳的保健饮料,该饮料风味浓郁,口感柔和,清凉止渴.     

无糖山楂饮料的研制

本试验以山楂为原料，对果汁的关键工艺技术及最适甜味剂配比进行了研究。结果表明，山楂饮料浸提的最佳工艺为：山楂水为1：6，加热温度85～90℃，时间30min、浸渍3h；最适甜味剂配比为：木糖醇5％，蛋白糖0．6‰，甜蜜素0．0‰，安赛蜜0．12%。其制品糖酸适口、风味浓郁、营养丰富。而总糖含量仅为2％，对糖尿病人的血糖几乎无影响。     

红薯叶和马齿苋复合饮料的研究

利用正交实验设计,对红薯叶、马齿苋复合饮料制作进行探讨．确定浸提的工艺参数和最佳配比，从而研制出具有一定保健作用的红薯叶马齿苋复合饮料。     

采用烘烤酶解方法生产枣汁饮料

以山西大枣为主要原料，采用烘烤预处理结合果胶酶酶解技术对枣中的营养及生理活性成分进行浸提，通过正交试验筛选出理想取汁工艺，确定出最佳工艺参数为：加酶量0．2％，浸提时间4h，浸提温度50℃，料水比1：3。     

枸杞菊花胡萝卜复合饮料的研制

研究了以枸杞、菊花、胡萝卜为原料生产复合保健饮料的工艺。通过对原料浸提条件及饮料配方的优选试验，筛选出枸杞汁、菊花汁、胡萝卜汁的浸提条件分别为：料水比1：15、1：30、1：1．5；浸出时间3．5h、30min、80min；浸提温度70℃、90℃、55℃。饮料的最佳配方为：枸杞汁6．0％、菊花汁7．7％、胡萝卜汁10．3％、乙基麦芽酚0．015％、柠檬酸0．1％、白砂糖6％、黄原胶0．1％。开发出一种营养丰富、酸甜适口，具有枸杞、菊花香味、稳定性较好、对视力具有保健作用的新型饮料。     

蘑菇-海带低热能复合饮料的研制

以海带蘑菇汁为原料，采用浸提复合加工工艺，生产出一种口味纯正，营养丰富的低热能天然保健饮料，并通过正交实验设计筛选出产品的最佳配比。结果表明最佳配比为：总蔬菜汁70％，两蔬菜汁的比例是1：1；稳定剂0．01％，比例是CMC：海藻酸钠为1：1；甜蜜素0．45％，柠檬酸0．4％，色素0．002％。     

元宝枫叶总黄酮的提取研究

用乙醇作为溶剂，采用常规浸提法及超声辅助法对元宝枫叶总黄酮的提取进行了对比研究。通过单因素及正交试验结果得到浸提法的优化条件为：溶剂为体积分数50％的乙醇溶液，料液比1g：25mL，提取时间1．5h，浸提温度70℃。按照此条件提取两次，第一次提取率94．16％，第二次1．36％；超声辅助法的优化条件为：溶剂为体积分数50％的乙醇溶液，料液比1g：15mL，提取时间0．5h，浸提温度60℃。按照此条件提取两次，第一次提取率为96．29％，第二次提取率为3．11％．     

桑叶叶蛋白提取工艺的研究

对桑树叶蛋白提取条件的优化进行了研究。结果表明，桑树叶蛋白提取的优化工艺条件为：室温下，以水为浸提荆，打浆时间3min，浸提时间4min，料液比1：5（叶片重比浸提剂体积，即g：m1），漫挺剂pH值8．0，絮凝温度75℃，调节提取液pH为5．0、8．0和13．0得到沉淀物，在60℃干燥。该工艺提取桑树鲜叶叶蛋白得率为：5．17％。     

辣木叶总黄酮乙醇提取工艺的研究

对辣木叶中总黄酮的乙醇提取工艺进行了研究。探讨乙醇浓度、浸提温度、料液比、浸提时间、浸提次数对辣木叶中总黄酮提取效果的影响，在单因素试验的基础上,通过正交试验确定最佳提取工艺条件。结果表明：辣木叶中总黄酮类物质的最佳提取条件为70％的乙醇溶液作提取剂，提取温度60℃，料液比1：20，提取3次，每次1h，在此条件下，提取液中的总黄酮含量达到3．95％。     

红薯叶滋补酒的工艺研究

试验以红薯叶为主要原料,以白砂糖、玉米糖浆为碳源,以活性白酒干酵母为发酵液,采用液体发酵法酿造红薯叶滋补酒,并通过对比试验找出最优糖化条件:浸提温度80℃,浸提时间2h,加水比1:40.实现了红薯叶的进一步利用,便于工业化的推广.     

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.     

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.