线性插值优化多指标芦荟—玉米粉挤压膨化工艺

针对芦荟加工过程副产物利用率较低的问题,提出将芦荟叶皮干燥制粉后,加入玉米粉中进行挤压膨化试验,制备芦荟—玉米功能膨化食品。采用单因素及五因素四水平正交试验方法,研究了芦荟添加量、物料含水率、螺杆转速、喂料速度以及膨化温度等工艺参数对膨化产品品质的影响规律;采用线性插值法对芦荟—玉米粉挤压膨化产品指标进行综合评价,得出添加芦荟超微粉体后的混合物料挤压膨化最优工艺参数为:喂料速度30r/min,螺杆转速115r/min,水分含量14%,芦荟含量4%,膨化温度150℃。     

大米、玉米复合膨化食品生产工艺的研究

本文探讨了大米、玉米复合膨化食品的生产工艺，研究了水份含量、挤压过程中的温度、挤压螺杆的转速，以及大米与玉米的配比等四个因素对产品膨化率的影响。结果表明：当物料的水分含量为14％，挤压温度为140℃，螺杆转速为70rpm，大米：玉米＝1：4时，挤出物的膨化效果最佳。     

爆裂玉米的化学成分对微波膨化率的影响

通过测定黄玫瑰型３种不同产地的爆裂玉米的水分，淀粉，蛋白质含量，研究其对微波膨化效果的影响，同时对乙醇处理后的爆裂玉米的微波膨化效果，进行了初步探讨，结果表明，爆裂玉米的微波膨化率随淀粉含量的增加而提高，尤其是支链淀粉的含量；蛋白质和水分通过与淀粉之间的相互作用，影响爆裂玉米的微波膨化效果，微波膨化后，爆裂玉米的淀粉含量减少，低聚糖含量增加，蛋白质含量不变，乙醇浸渍后，可提高爆裂玉米的微波膨化率。     

玉米膨化产品质量与系统参数关系研究

以玉米珍子为材料,采用DSE-25型双螺杆挤压膨化实验室工作站加工挤压膨化食品,对径向膨化率、产品水分、水溶性指数、质构等产品质量指标和扭矩、压力等设备系统参数进行相关分析,研究各个指标间的相关关系,筛选出玉米挤压膨化食品的主要评价指标。研究结果表明,径向膨化率、产品水分与a*、b*、4区压力、4区和5区压差P4-5呈极显著正相关,与水溶性指数、L*呈极显著负相关。产品水分与产品最大应力、破碎能量呈极显著正相关。径向膨化率、产品水分可以作为玉米挤压膨化食品的主要评价指标。     

玉米挤压膨化机理的研究

本文以经过挤压膨化后的玉米为研究对象,在膨化倍数、碘蓝值、α-化度、还原能力等指标上进行对照试验,得出结论：玉米经过挤压膨化后,淀粉粒解体,糊精和还原糖增加,蛋白质变性,氨基酸和缩氨酸含量增加,脂肪减少,水溶性成分增加,从而为挤压膨化技术在玉米深加工领域中的应用提供了理论依据。     

强化钙铁锌的膨化米果的工艺研究

本文探讨大米、玉米复合膨化食品的生产工艺,研究水分含量、挤压过程中温度、挤压螺杆转速以及大米与玉米的配比４个因素对产品的膨化率的影响。同时还重点讨论钙铁锌的营养强化训练的选择。结果表明,当物料水分含量为１４％,挤压温度为１５０℃,螺杆转速为７０ｒｐｍ,大米：玉米＝１：４时,挤压物的膨化效果最佳。     

薏苡仁玉米果膨化制作工艺优化

以薏苡仁为主要原料,添加玉米粉及其他辅料,采用挤压膨化技术,研制出一种营养丰富、风味独特、易被人体消化吸收,方便食用的薏苡仁玉米膨化食品。选择薏苡仁与玉米粉比例、物料含水量、膨化温度、螺杆转速、白砂糖含量因素,以感官评价和膨化度为指标,通过单因素和正交试验对薏苡仁玉米膨化食品的加工工艺和优化配方进行研究,确定最优配方为:薏仁粉与玉米粉比例为1:4,白砂糖7%,食盐1%,食用油3%;制备的最佳工艺参数:物料含水量为18%,膨化温度170℃,螺杆转速10 Hz。成品水分含量4.03%,蛋白质含量8.69%,脂肪含量5.87%,多糖含量4.43%,卫生指标符合GB/T 22699—2008膨化食品卫生标准。     

保健食品

含玉米糖粉的高纤维膨化食品为了使谷物膨化食品的纤维含量达到1.5%以上，在原料中添加玉米糖粉。玉米糖粉经过细粉碎．能全部通过420微米筛孔。膨化过程的温度与     

双螺杆挤压机的性能分析及应用

介绍了食品挤压加工的原理，对双螺杆挤压机的工作性能进行了分析。通过试验，论述了螺杆转速、原料含水量、加热温度等参数对膨化产品质量的影响、确立了玉米膨化食品的生产数据。     

板栗膨化食品配方的研究

以板栗粉、玉米糁为主要原料,以感官评价、膨化度、硬度为评价指标对板栗膨化食品进行研究。结果表明:当板栗粉:玉米糁为2:8时,板栗膨化食品感官评分为92,径向膨化度为2.75,硬度为12.7,水分含量为6.5%,产品酥脆适口,接受程度最好。     

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.     

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.     

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.     

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.     

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.