白茅根-甘蔗饮料的研制

采用壳聚糖将白茅根浸提液和甘蔗汁进行澄清处理,通过正交试验确定最佳澄清工艺条件。结果表明,最佳澄清工艺条件为壳聚糖添加量0．2g/L、调浸提液 pH 值3．0、澄清时间2．0 h。取白茅根澄清浸提液、甘蔗澄清汁、砂糖进行正交调配试验,以白茅根澄清浸提液0．08 mL/mL、甘蔗澄清汁0．27 mL/mL、砂糖45mg/ mL 和饮用纯净水调配出一种天然、营养、保健的新型饮料。     

澄清型银杏复合饮料的工艺研究

为了创新银杏在食品加工领域的高附加值、低成本利用途径,通过单因素实验和正交试验,以多糖含量和透光率为指标,以壳聚糖固定化复合酶为澄清剂,确定了澄清型银杏浸提液的最佳制备工艺,并以感官品质为指标,优化了银杏复合饮料的工艺配方。实验结果表明,银杏浸提液最佳制备条件为料液比1∶4,浸提温度60℃,浸提时间70min,壳聚糖固定化复合酶添加量2%。澄清型银杏复合饮料的最佳工艺为银杏浸提液∶玉米须浸提液体积比为3∶7,白砂糖的添加量为8%,柠檬酸的添加量为0.05%,海藻酸钠的添加量为0.06%。壳聚糖固定化复合酶对银杏浸提液的澄清稳定和多糖提取都起到了较好作用,因此在食品加工行业具有广阔的应用前景。     

蛹虫草菌丝体保健酒的研制

以蛹虫草菌丝体为原料、浓香型白酒为基酒研制蛹虫草菌丝体保健酒。通过实验研究蛹虫草菌丝体保健酒的最佳浸提工艺和最适澄清剂。结果表明,最佳浸提工艺条件为:浸提酒精度50%vol,浸提时间21 d,浸提料液比1∶40;最适澄清剂为壳聚糖,最佳添加量为1%的壳聚糖12 m L/L。成品酒为淡黄色,澄清透明,香味协调,风格独特,并具有一定的保健功效。     

菊花饮料的研制

以“滁菊”为原料,研究了原料处理、浸提时间、浸提温度对浸提液中黄酮类化合物含量及总抗氧化活性的影响,并对浸提液的澄清和稀释工艺进行了研究。结果表明,在1∶50的花水比条件下,最佳浸提条件是100℃、30min,向浸提液中加入0.5%的壳聚糖,并在0～5℃的冷藏条件下进行澄清,再经4倍稀释并经调配后,得到澄清型菊花饮料产品。     

玉米须牛蒡复合饮料的工艺研究

为创新玉米须和牛蒡的高附加值利用途径,通过单因素试验和正交试验,以吸光度为指标,确定玉米须浸提液和牛蒡浸提液的最佳制备工艺,并以感官品质为指标,优化玉米须牛蒡复合饮料的加工工艺。试验结果表明,玉米须浸提液最佳制备条件为料液比1∶50（g/mL）,浸提时间80 min,浸提温度80℃,pH 7.0;牛蒡浸提液最佳制备条件为料液比1∶50（g/mL）,浸提时间70 min,浸提温度60℃,pH值为6.5。玉米须牛蒡复合饮料的最佳工艺为牛蒡浸提液和玉米须浸提液体积比3∶7,柠檬酸添加量0.10%,白砂糖添加量8%,壳聚糖固定化复合酶添加量2.8%。壳聚糖固定化复合酶对饮料感官品质无不利影响,澄清效果较好,可反复使用,操作稳定性较好,可用于降低工业化生产成本。     

松针饮料的研制

以马尾松为原料研制松针饮料,经过试验得出饮料研制的适宜工艺.以黄酮提取量为指标测定最佳浸提工艺,结果为浸提温度90℃、浸提时间120mim、料液比1∶24.选用壳聚糖做澄清剂,测其透光率确定最佳澄清工艺,结果为壳聚糖添加量为0.2g/L、澄清处理温度40℃、澄清时间50min.澄清液经精滤调配杀菌成成品,成品经感官评价得最佳配方,结果为松针汁加入量为70％,然后以调过的松针汁为100％,加糖量为10％,加柠檬酸量为0.1％.     

两种浸提液的澄清脱色效果优化

以罗汉果和陈皮为原料,分别采用冷凝回流和超声提取工艺得到浸提原液。通过单因素实验研究硅藻土、明胶、壳聚糖和活性炭4种材料作为澄清脱色剂在不同添加量时的澄清脱色效果,获得罗汉果、陈皮浸提液最佳的澄清脱色工艺条件。最佳澄清脱色条件为:罗汉果浸提液选用澄清脱色剂为活性炭,活性炭加入量为4 g/L,透光率达到最大值93.8%,色度为最小值3.24;陈皮浸提液选用澄清脱色剂为明胶,1%明胶溶液加入量为0.24%,透光率达到最大值98.3%,色度为最小值1.375。     

红枣汁的澄清工艺研究

将红枣浸提原汁分别采用果胶酶和壳聚糖进行澄清处理,并对2种澄清剂的澄清效果进行比较,确定较好的澄清剂及其澄清工艺条件。试验表明,壳聚糖的澄清效果较好,确定壳聚糖澄清红枣汁的最佳工艺条件为:壳聚糖添加量0.4g/L、50℃下澄清30min,所得澄清汁透光率达到95%以上,枣汁清澈透明、色泽自然、枣香浓郁。     

三根汤凉茶的工艺研究

以芦根、白茅根、蒲公英根为原料,通过水浸提、调配和高温杀菌等工艺处理,制备三根汤凉茶。研究表明,最佳浸提工艺为:芦根:94℃、浸提74min、料液比1:15.8g/mL;白茅根:96℃、浸提58min、料液比1:19.4g/mL;蒲公英根:86℃、浸提65min、料液比1:14.2g/mL。最佳配方为芦根汁40%,白茅根汁40%,蒲公英汁13%,白砂糖7%,柠檬酸0.1%。该产品色泽淡黄、澄清透明、具有三根汤凉茶特有的香味。     

太子参皂甙提取工艺研究

主要对太子参块茎中皂甙组分的浸提工艺进行了研究。结果表明,太子参皂甙最佳浸提条件为:太子参块茎粉碎后,用10倍水沸腾浸提3次,1h/次,同时超声波处理20min。浸提液经壳聚糖澄清后,对DPPH表现出有较好的抑制活性。     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

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.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.