银杏果粉在小麦粉馒头中的应用研究

文章研究了银杏果粉对小麦粉理化指标以及馒头营养、感官、质构、抑菌的影响。用粉质仪、湿面筋仪、降落数值仪测定银杏果粉对面粉的理化指标，包括稳定时间、湿面筋含量、降落数值的影响。同时用感官方法评价馒头的感官品质。用质构仪测定馒头的质构参数。用菌落总数测定方法测定馒头的菌落总数。试验结果表明，在小麦粉中添加0%～24%的银杏果粉，小麦粉理化指标，包括标稳定时间、湿面筋含量、降落数值呈下降趋势。馒头感官评分呈先增加后下降趋势，馒头中菌落总数呈下降趋势。馒头中蛋白质、脂肪、膳食纤维含量呈增加趋势。小麦粉中银杏果粉添加量为12%时，馒头的感官品质最佳，比空白提高了6.30%；馒头中蛋白质、脂肪、膳食纤维含量分别增加2.49%、7.58%、12.0%；菌落总数下降37.5%，霉菌计数下降40.9%。银杏果粉具有提高小麦粉馒头的感官品质、营养价值和抑菌作用，在小麦粉馒头中具有良好的应用价值。     

响应面法优化山药芋头食养面条的加工工艺研究

在传统面条制作的基础上添加不同比例的山药粉及芋头粉(预混粉)、谷朊粉、饮用水于小麦粉中制作山药芋头食养面条,以提高面条的营养价值和丰富面条的品种。以面条的蒸煮损失、感官评价及质构特性作为考察指标,通过单因素和响应面试验研究各因素对面条蒸煮品质、感官品质以及质构特性的影响,以优化山药芋头食养面条的加工工艺。结果表明:小麦粉中添加20%的预混粉(山药粉13%+芋头粉7%)即80%的小麦粉和20%的预混粉,谷朊粉1%,水34%时,面条的蒸煮损失率为3.71%,质构特性表明该面条硬度适中,黏度较小,感官评分为88.16。该工艺条件下制备的山药芋头食养面条具有淡淡的山药味和芋头味,与传统面条相比具有较好的蒸煮品质、感官品质及良好的质构特性。     

小麦粉中蛋白质和淀粉含量对面条品质的影响

对小麦粉中的蛋白质和淀粉组分进行了分离,将淀粉含量不同的混合粉制作成面条,分析其质构特性和食用品质。将面条煮制后,对熟面条进行了质构分析,测定了熟面条的硬拉伸性能、剪切性能和蒸煮损失,并进行了感官品质评价。研究结果表明:随着小麦粉中的淀粉含量的增加(蛋白质含量的降低),面条的质构特性、拉伸性能、剪切性能都呈现显著下降的变化趋势(P<0.05),而面条的蒸煮损失显著增加(P<0.05)。此外,面条的感官评价与质构分析的结果相一致。     

红小豆超微粉对面粉理化性质及鲜湿面条品质的影响

目的:探究红小豆超微粉在鲜湿面条中的适宜添加量。方法:采用粉质仪、拉伸仪、湿面筋仪、降落数值仪及面粉白度仪测定红小豆超微粉对面粉理化指标的影响,采用质构仪测定红小豆超微粉对鲜湿面条质构参数的影响,采用感官方法评价红小豆超微粉和红小豆粗粉对鲜湿面条感官品质指标的影响,采用理化分析法测定面条的蒸煮品质和营养成分。结果:红小豆超微粉适宜添加量为8%~12%。当红小豆超微粉添加量为12%时,面条中蛋白质含量提高了10.1%,膳食纤维含量提高了31.8%,红小豆超微粉面条比粗粉面条品质提高了13.9%。结论:红小豆经超微粉碎后,降低了对面粉品质和鲜湿面条品质的负面影响,可提高小麦粉面条的营养价值。     

玉米粉配比对玉米-小麦混合粉面条品质的影响

采用不同的配比将玉米粉与小麦粉混配,用混合粉制作面条,通过测定玉米-小麦混合粉鲜湿面条的蒸煮、质构及感官品质,研究玉米粉添加量对混合粉鲜湿面条品质的影响。结果表明:随着玉米粉配比的增大,面条的蒸煮损失率呈上升趋势,硬度、咀嚼性和剪切力则逐渐减小,而总评分呈先增加后降低的趋势。玉米粉、小麦粉质量比为25∶75及以下时,面条煮后没有断条现象,当二者质量比达30∶70时,开始出现断条现象,熟断条率为7.5%。各配比的玉米-小麦混合粉鲜湿面条总评分均比纯小麦粉的低,玉米粉、小麦粉质量比为15∶85时制作的鲜湿面条总评分最高,感官品质较好。     

脱脂花生蛋白营养面条的制作及品质特性研究

将小麦粉与脱脂花生蛋白粉按100:0、95:5、90:10、85:15、80:20 的比例分别混合,测定混合粉的糊化特性及面筋特性。将混合粉制成速冻面条,通过正交试验及感官评定确定脱脂花生粉与小麦粉的比10:90,加水量40%,加盐量2.5% 制脱脂花生蛋白营养面条。对脱脂花生粉速冻面条的品质特性进行评价显示：随着脱脂花生粉添加量的增加,混合粉的面筋含量及糊化性质降低,面条的质构特性下降,蒸煮损失率增加;分析0～28d 冷冻贮藏后品质特性：随着贮藏时间的增加,面条的硬度、拉伸强度、拉伸距离在贮藏前期呈下降趋势,16d 后趋势平缓。弹性、内聚性、回复性略有上升,但不显著,显示花生蛋白营养面条具有较好的耐贮藏性;按中国营养膳食营养要求及每人每日食用200g 面条计算,配方提供的蛋白质含量占儿童、老年人所需的60%、44%。添加脱脂花生粉使得面条质地松软,有着良好的食用品质和营养价值,宜被老年人和儿童接受。     

马铃薯全粉对面条品质影响的主成分分析研究

为了探讨马铃薯全粉对面条品质的影响,通过测定添加不同比例马铃薯全粉的面筋特性、蒸煮特性、质构特性和感官评价,并结合主成分分析进行综合评价。结果表明:随着马铃薯全粉添加量的增加,面条色泽呈暗红趋势变化,其面筋含量逐渐降低;面条的蒸煮特性、质构特性及感官品质呈现先增加后降低的趋势,说明适量添加马铃薯全粉可以在一定程度上提高面条的食用品质。应用主成分分析法对不同马铃薯全粉添加量的面条进行研究,确定了反映面条品质的3个主成分因子,3个主成分的累积贡献率达到88.35%。为进一步开发高含量马铃薯全粉面条提供数据支撑。     

柚皮桃胶营养鲜湿面的研制

柚子皮富含膳食纤维,桃胶具有益生菌样作用,两者对肠道菌群均有很好的调节作用,且能增加面条的品质。文中以面条的熟断率、面汤浊度、蒸煮损失、干物质吸水率及面条的感官评定为考察指标,通过添加不同比例的桃胶粉、柚子皮粉及食盐于小麦粉中制作面条,通过单因素实验和正交实验分析其对面条蒸煮品质和感官性能的影响,以加工研制出柚子皮桃胶营养面条。结果表明:当小麦粉中添加2%的柚皮粉、3%的桃胶粉和1.5%的食盐时,柚子皮桃胶营养面条的熟断率为0%,蒸煮损失率为3.31%,面汤浊度(OD460)为0.370,感官评定总分为89.1,TOM值为1.32,与普通面条相比具有较好的蒸煮品质和感官性能。同时,所得柚皮桃胶面条与普通面条相比显著增加了膳食纤维、类黄酮和多糖,具有一定的保健功能。     

瓜尔豆胶对面条品质特性的影响

研究了以小麦粉质量为基准,添加1%、3%、5%、7%的瓜尔豆胶对面条品质特性的影响,测定了面条的蒸煮品质、淀粉糊化度、质构特性以及感官品质。随着瓜尔豆胶添加量的增加,面条的蒸煮得率、淀粉糊化度呈先增加后降低的变化趋势,蒸煮损失率先降低后增加。添加瓜尔豆胶能够使面条的内部形成完全固结的结构,提升面条的品质特性。但是,当瓜尔豆胶的添加量为7%时,瓜尔豆胶的水合作用对面筋和淀粉结构产生负面影响,使面条的品质低于瓜尔豆胶添加量为5%的面条。     

挤压改性麦麸膳食纤维对面条品质的影响

分析挤压改性麦麸膳食纤维对面条品质的影响。以高筋面粉和经过挤压改性的麦麸膳食纤维为原料制成膳食纤维含量分别为0%、2%、4%、6%的混合粉,再用混合粉制成面条;采用质构剖面分析法(TPA)测试面条的质构特性,并测试面条的蒸煮特性且对面条进行感官评价。结果表明,面条的硬度、咀嚼性及胶黏性与膳食纤维含量呈显著正相关,黏性、弹性及内聚性随膳食纤维含量的增加而变化不大;吸水率与膳食纤维含量呈显著正相关,蒸煮损失率与膳食纤维含量呈显著负相关;膳食纤维的添加会降低面条的外观,但会改善其口感,提高总的感官评价。膳食纤维含量为6%时,面条有较好的品质。研究可以为挤压改性麦麸膳食纤维在面条中的应用提供参考和理论依据。     

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.