发芽糙米的富硒及其微波干燥与挤压膨化工艺优化

以普通粳稻为原料,探讨了发芽糙米的富硒效果和微波干燥、挤压膨化对富硒发芽糙米营养品质的影响。结果发现,硒质量浓度为10 mg/L时,可以获得较高质量的富硒发芽糙米,此条件下糙米的发芽率为97.9%,有机硒含量为977.6 μg/kg（质量分数98.5%）,γ-氨基丁酸含量为445.9 mg/kg;40 ℃的低温微波干燥有利于保持发芽糙米的硒和γ-氨基丁酸含量;挤压膨化产品中有机硒和γ-氨基丁酸的含量与原糙米相比,分别提高到其29 倍和5 倍。研究认为,亚硒酸钠可以作为富硒试剂实现发芽糙米的有效富硒,富硒发芽糙米可以用于开发相关的营养膨化食品。     

富硒发芽糙米加工工艺的研究

本文以江苏省所产的武育粳7号-富硒糙米为原料,研究了富硒发芽糙米的生产工艺,并对生产过程中的浸泡温度、浸泡时间、发芽温度、发芽时间等相关参数对糙米发芽率的影响进行了研究探讨,得出了该品种富硒发芽糙米生产工艺的优化参数。试验研究结果显示:最适宜的富硒糙米发芽工艺条件为发芽时间24～28h、发芽温度30℃、浸泡时间20～24h、浸泡温度25～30℃;试验检测结果表明,通过上述工艺加工出来的富硒发芽糙米,不仅含有丰富的有机硒元素,而且γ-氨基丁酸含量可达400mg/kg以上,同时富积了γ-氨基丁酸和有机硒。     

富硒发芽糙米加工工艺的研究

本实验以江苏省所产的武育粳7号一富硒糙米为原料，研究了富硒发芽糙米的生产工艺。并对生产过程中的浸泡温度、浸泡时间、发芽温度、发芽时间等相关参数对糙米发芽率的影响进行了研究探讨，得出了该品种富硒发芽糙米生产工艺的优化参数。     

富硒发芽糙米生产工艺的优化

目的：研究富硒发芽糙米的最佳生产工艺。方法：通过单因素试验及Box-Behnken 组合设计考察浸泡液中亚硒酸钠质量浓度、发芽时间、发芽温度以及它们之间的交互作用对糙米发芽率及重要营养物质γ- 氨基丁酸含量的影响,通过软件分析得到使发芽率及γ- 氨基丁酸含量均达到最大值的最佳生产工艺。结果：建立富硒发芽糙米发芽率与γ- 氨基丁酸含量的数学模型,富硒发芽糙米的最佳工艺参数为：浸泡液中亚硒酸钠质量浓度5mg/L,浸泡时间9h,浸泡温度28℃,培养时间21h,培养温度31.5℃。该条件下得到发芽率77.67%,GABA 含量330mg/kg,硒含量0.5mg/kg 的富硒发芽糙米。     

氢化物发生-原子荧光光谱法测定富硒发芽糙米中的硒含量

对氢化物发生-原子荧光光谱法(HG-AFS)测定富硒发芽糙米硒含量的方法.研究表明:其检出限为0.2μg/L,相对标准偏差RSD为0.94%,平均回收率为99.74%,精密度高、稳定性好、简便快速,适合于富硒发芽糙米中硒的定量分析.通过测定采用不同浓度亚硒酸钠溶液富硒处理的发芽糙米的总硒、有机硒和无机硒含量,确定选择硒浓度为50 mg/L的溶液富硒处理后的发芽糙米品质较好.     

富硒发芽糙米加工工艺的研究

本文以江苏省所产的武育粳7号-富硒糙米为原料，研究了富硒发芽糙米的生产工艺，并对生产过程中的浸泡温度、浸泡时间、发芽温度、发芽时间等相关参数对糙米发芽率的影响进行了研究探讨，得出了该品种富硒发芽糙米生产工艺的优化参数。试验研究结果显示：最适宜的富硒糙米发芽工艺条件为发芽时间24-28h、发芽温度30℃、浸泡时间20-24h、浸泡温度25-30℃；试验检测结果表明，通过上述工艺加工出来的富硒发芽糙米，不仅舍有丰富的有机硒元素，而且γ-氨基丁酸含量可达400mg／kg以上，同时富积了γ-氨基丁酸和有机硒。     

富硒发芽糙米饮料的研制

以糙米为主要原料制备富硒发芽糙米,以有机硒含量为指标,通过正交试验确定了富硒发芽糙米的最佳工艺条件为:发芽时间19 h,发芽温度32℃,亚硒酸钠浓度15 mg/L,得到有机硒含量为0.532 mg/kg。以葡萄糖当量为指标,通过正交试验确定了富硒发芽糙米的最佳酶解反应条件为:酶解温度85℃,酶浓度35μg/m L,酶解时间60 min。以富硒发芽糙米为主要原料,添加适量蔗糖、β-环糊精,采用单因素和正交试验设计,以产品感官评价为指标,确定富硒发芽糙米饮料的最佳工艺配方。结果表明:料液比为1∶6(g/m L),蔗糖添加量为8%,β-环糊精添加量为1.5%,加入0.06%黄原胶和0.10%海藻酸丙二醇酯。该饮料具有营养、保健的功能,色泽、香味、口感俱佳。     

不同处理糙米储藏期间脂肪酸及总酸的变化

在不同储藏温度下,研究糙米、发芽糙米及富硒发芽糙米储藏期间脂肪酸值和总酸值的变化。结果表明:随着储藏温度的升高,3种样品的脂肪酸值和总酸值均显著升高;不同储藏温度下,随着储藏时间的延长,3种样品的脂肪酸值均基本呈现先增加后减小的趋势,而总酸值则呈现先减小后增加的趋势。在各储藏温度条件下,未发芽糙米的脂肪酸值及总酸值变化最小,但富硒发芽糙米的储藏品质明显优于发芽糙米,提示硒对糙米储藏期脂质氧化具有抑制作用。     

富硒发芽糙米蛋白的抗氧化活性

采用碱提酸沉法提取了糙米和富硒发芽糙米中的蛋白,对其抗氧化活性进行分析测定,并与对照品芦丁和VC进行了比较。结果表明：富硒发芽糙米蛋白的总抗氧化能力（total antioxidant capacity,T-AOC）、1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除率、超氧阴离子自由基（O2－·）清除率和还原力低于芦丁和VC,氧化自由基吸收能力（oxygen radical absorbance capacity,ORAC）显著低于芦丁（P＜0.05）,但是显著高于糙米蛋白（P＜0.05）;富硒发芽糙米蛋白的羟自由基（·OH）清除能力与芦丁和VC相当,但显著高于糙米蛋白（P＜0.05）。富硒发芽后的糙米蛋白抗氧化能力显著提高。     

响应曲面法优化糙米富硒发芽工艺研究

为优化糙米富硒发芽工艺,以糙米发芽率及有机硒含量为指标,通过单因素和Box-Behnken组合设计,研究了亚硒酸钠质量浓度、培养温度、培养时间及其交互作用对糙米发芽和富集硒的影响,优化后的工艺参数为:亚硒酸钠质量浓度68 mg/L、培养温度30℃、培养时间31 h。在此条件下糙米发芽率达到81.9%,有机硒含量达到0.870 mg/kg。     

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.