低糖西瓜皮果脯的生产工艺

以西瓜皮为原料,研究护色、硬化、烫漂、糖制方法对低糖西瓜皮果脯品质的影响.最佳工艺条件为采用1%食盐和0.1%柠檬酸的复合护色液进行2 h的护色处理;氯化钙进行硬化处理;95℃下烫漂5 min;0.085 MPa的真空度下,将瓜条在25%糖液中煮制5 min,自然降温糖渍15 h,然后于35%糖液中在相同真空度下煮制5 min,自然降温糖渍24 h,糖液中柠檬酸的添加量为总糖量的0.5%,此种方法制作的西瓜皮果脯酸甜适口、透明饱满、色泽自然.     

工艺参数对苹果果脯护色效果的影响

以山东红富士为原料,以感官评价、亮度(L值)、褐变度为评价指标,考察切片厚度、植酸浓度、微波漂烫功率、微波漂烫时间、热风干燥温度及干燥时间对苹果果脯护色效果的影响,并比较植酸与其他护色剂对果脯贮藏性的影响。结果表明:苹果果脯护色的最佳条件为切片厚度8mm、植酸浓度0.12%、微波漂烫功率为中高火、微波漂烫时间80s、干燥时间4h、干燥温度70℃,此时苹果果脯护色效果最佳,且口感好。贮藏期间不同护色剂的护色效果依次为植酸抗坏血酸柠檬酸NaCl。     

低糖雪莲薯果脯真空渗糖工艺条件的优化

研究低糖雪莲薯果脯的加工工艺条件,对护色、漂烫和硬化等渗糖前预处理过程进行研究,得出最佳条件:用0.4%浓度的柠檬酸溶液对原料护色,沸水漂烫10min,0.5%浓度氯化钙溶液对原料进行硬化2 h.采用真空渗糖的方法对原料糖渍处理,并对真空渗糖温度、渗糖时间、柠檬酸用量和糖液浓度等因素设计正交试验,得出最佳工艺条件:温度35℃、时间120min、柠檬酸0.20%及蔗糖45%.     

低糖无硫草莓果脯生产工艺技术的研究

对影响低糖无硫草莓果脯品质的烫漂、硬化、护色、渗糖、浸糖、干燥等关键工艺技术进行了研究。结果表明:最佳烫漂时间为2min,温度为90℃;护色剂采用1%的柠檬酸和0.2%的VC混合液,时间为15～20min;采用4%的δ-葡萄糖酸内酯硬化4h;糖液配制用50%的淀粉糖浆取代50%的蔗糖,同时添加0.5%的果胶,3%的磷酸钠和氯化钾混合液;用50%的糖液常压渗糖20min,常温浸糖9h;干燥在65℃下先烘干4h,翻转过来整形后再干燥4h;为最佳工艺制得的草莓果脯品质最好。     

三叶木通果皮制作果脯加工工艺

以三叶木通果皮为原料,运用模糊综合评判法感官评价量化影响,采用单因素及正交试验优化烫漂、护色、去苦、糖制、干燥工艺,确定三叶木通果皮果脯的最佳加工工艺,并对成品的水分含量进行测定。结果表明:果皮经100℃烫漂3 min后于0.5%柠檬酸、2%维生素C、2.5%氯化钠的混合溶液中护色、去苦5 h,再于含糖量为50%的糖液中糖煮10 min、糖渍24 h,最后60℃下干燥12 h果脯品质最佳。所得成品色泽金黄,酸甜适口,饱满度好,平均水分含量为18.52%。     

利用莲雾落果加工低糖果脯

以莲雾落果为原料,探索低糖莲雾果脯的加工工艺,并重点研究护色、硬化、烫漂、渗糖等过程对低糖莲雾果脯品质的影响。结果表明:采用0.15%抗坏血酸进行护色,2%的氯化钙进行硬化,放入90℃热水中烫漂15min;在含量为25%蔗糖,10%葡萄糖,0.3%柠檬酸,0.6%明胶的溶液中,0.085MPa真空环境下渗糖15min,常压浸糖5h;将充分浸糖后的莲雾放入干燥箱内[前期50℃～60℃(2h),后期60℃～80℃(约2h)]至水分含量约20%左右。制得的低糖莲雾果脯酸甜适口、饱满透明、色泽自然、质量优良,果脯风味最佳。     

菠萝果粒加工工艺的研制

以菠萝为主要原料,研制菠萝果粒的加工工艺。实验结果表明:青熟期或完熟期的菲律宾品种菠萝,经焦亚硫酸钠浓度为0.5%、浸泡时间为8h、烫漂温度为100℃、烫漂时间为6min的联合护色工艺处理,采用常温常压强制循环糖渍法进行糖渍及热风逆流变温烘干法进行烘干,产品保质期在常温避光贮存条件下达到12个月。     

毛酸浆果果脯的研制

以鲜毛酸浆果为原料,确定了毛酸浆果果脯的生产工艺,并重点研究了护色、硬化、烫漂、糖制、保型及干燥过程对毛酸浆果果脯品质的影响,优选出较佳的工艺条件.     

低糖树莓果脯生产工艺的研究

以红树莓或速冻树莓为原料,对影响树莓果脯的烫漂、硬化、护色、渗糖、浸糖、干燥等关键工艺技术进行研究.试验表明:最佳烫漂时间为2min,温度为85℃;护色剂采用1%的柠檬酸,时间20min～30min:用0.1%的氯化钙和0.2%的亚硫酸氢钠的混合溶液浸泡4 h;糖液配置用50%的淀粉糖浆、0.5%的果胶、0.15%的柠檬酸:真空度在0.085 MPa,维持真空时间20 min、充气时间为60min;常温浸糖4 h;在70℃下干燥4 h.整形后再干燥4 h;为最佳生产工艺条件.     

洋葱果脯生产工艺的优化

以洋葱为原料,经过切片、硬化、糖煮、糖渍、干燥等工艺过程,研制洋葱果脯.研究氯化钙浓度、柠檬酸浓度、蔗糖浓度、硬化时间、煮制时间、糖渍时间等因素对洋葱果脯品质的影响,筛选出最佳的产品配方及生产工艺.试验结果表明.洋葱果脯的最佳生产条件为:0.3%的氯化钙硬化2 h,60%的蔗糖和0.4%的柠檬酸混合糖液糖煮1.5 h,糖渍时间为10 h.     

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.     

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.     

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.     

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.     

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.