烹调对常见蔬菜抗氧化活性与成分的影响

对常见的21种蔬菜,以爆炒、炖煮、微波3种烹调方法处理,采用相关方法测定比较其烹调前后的抗氧化活性,以及VC、总多酚及总类黄酮含量,比较不同烹调方法对蔬菜抗氧化活性及相关物质含量的影响,为评价人群实际抗氧化物质摄入量及相关研究提供参考.结果表明:炖煮导致蔬菜抗氧化活性及相关物质损失较多,微波及爆炒损失较少,且有部分指标出现了增加现象.     

烹调加工对食物营养价值的影响

用中式烹调方法烹制出的食物,不仅味道鲜美,口感美妙,而且还能促进人体对食物的消化吸收。然而,由于我们有时候使用的初加工及烹调方法不当,也常常会导致食物营养素的损失,从而降低食物营养价值。首先是初加工不当而造成食物营养损失。在日常生活中,人们总爱把米反复淘洗干净;蔬菜切后再洗;对肉类原料也总是用水冲洗后再烹制,看起来这是讲究卫生,实际上用这样的初加工方法却造成了食物营养素的大量流失。据有关资料介绍:淘米会造成维生素B1损失30%～60%、无机盐损失70%、蛋白质损失15.7%、碳水化合物损失2%,如果淘米的次数越多,其营养物质…     

健康吃肉注意三点

正爱吃肉食是人之天性,要吃得健康,在烹调和搭配上一定要下工夫,以下三个要点或许能帮到你。第一点:尽量采用不额外添加油的烹调方法,如蒸、煮、炖、烤,肉类菜肴即使白煮、清炖也很美味。做肉时还要少放盐,肉类本身含钠就高,烹调时就要淡一点。炖煮后,最好除去浮油,可以减少脂肪和胆固醇的摄入。第二点:肉类最好配合低脂、高纤维的食材共同烹调,可减少脂肪和胆固醇在体内的吸收,比如菌类、藻类、蔬菜等都是不错的选择。第三点:香浓美味的肉类,通常是高脂肪食物,不可食用过量,最好浅尝辄止。中国居民膳食指南要求,每天只能摄入50~75 g肉类。吃高脂肉类时,还要搭配一些低脂菜肴和主食,保证一天的脂肪摄入量不超标。     

烹调方式及4℃模拟配送中青椒营养品质及亚硝酸盐含量变化

本实验通过测定同一烹调成熟度下我国主要烹调方式及模拟餐饮冷藏配送过程中青椒营养品质和亚硝酸盐含量的变化,确定青椒最佳冷藏配送时间以及准确评估我国居民营养素的摄入量。以青椒为原料,以硬度作为烹调成熟度的统一标准,以传统烹调方式炒制、蒸制、煮制、微波为烹调方法,研究青椒在烹调后及模拟4℃冷藏配送0、1、4、8、12、24 h复热青椒的营养品质及亚硝酸含量变化。结果表明:烹调使VC含量显著降低,烹调后其真实保存率为76.3%~84.0%;总酚含量和抗氧化活性烹调后显著增加,总酚含量的真实保存率、1,1-二苯基-2-三硝基苯肼自由基清除能力的真实保存率、铁离子还原能力的真实保存率分别为97.7%~130.6%、156.76%~203.79%、156.94%~172.53%;除煮制使青椒可溶性固形物含量显著降低22.06%,其他几种烹调方式可以很好地保存可溶性固形物。烹调还会使亚硝酸盐含量显著降低6%~18%,更利于人体健康。在统一烹调标准下,不同烹调方式对VC含量影响无显著差异,炒制较其他几种方式相比能更多地增加总酚含量,蒸制和煮制能更多地增加抗氧化活性,煮制可以更多地减少亚硝酸盐的含量。综合而言,蒸制处理的青椒能更好地保持青椒的营养品质,且显著降低亚硝酸盐含量,更利于人体健康,建议对青椒的食用以蒸制处理后食用为好。在24 h模拟配送过程中,烹调青椒的营养品质呈下降趋势,亚硝酸盐含量呈缓慢上升趋势;蒸制和微波处理的青椒品质变化相对缓慢,更适宜作为模拟冷配送的前处理过程;营养物质在前8 h内快速下降,亚硝酸盐含量在模拟配送24 h显著增加,建议以青椒为原料的餐饮冷藏配送时间不宜超过24 h,且应在前8 h内采取保护措施。     

利用交叉分组设计研究热烫处理对鲜食玉米保鲜的效应

以鲜食糯玉米为材料,采用交叉分组试验设计研究热烫对鲜食玉米贮藏品质的影响,寻求最佳技术工艺。热烫处理后进行保鲜,分析鲜食玉米的含水量、质量损失率与硬度等,通过方差分析研究热烫处理的保鲜效应。结果表明,最优热烫处理为热烫温度85℃,热烫时间120 s。此条件下,鲜食玉米水分含量为63.6%,显著高于对照(61.3%);质量损失率为7.3%,虽高于对照(6.4%)但无显著差异;硬度极显著高于对照。热烫处理可抑制鲜食玉米水分散失,延缓质量损失,保鲜效果显著。     

富硒小麦面制品中硒及其损失的研究

目的：研究富硒小麦从籽粒到面粉以及不同面制品中的硒及其损失的变化规律。方法：富硒小麦是通过对河南省目前推广的优质强筋、中筋、弱筋等小麦采取叶面喷施外源亚硒酸钠溶液以获得,随后对其采取磨粉、发芽和蒸、煎、煮、炸、烤、炒等方式加工成不同面制品以检测分析硒及其硒形态含量。结果：富硒小麦籽粒被磨成面粉后,其面粉中的硒、麸皮中的硒和加工过程中的硒损失分别占籽粒总硒含量约65.18%、22.20%和12.62%;而富硒小麦籽粒经发芽培养制成麦芽粉后,总硒含量增加约4.74%;富硒面粉制成不同面制食品后,面条、馒头、面包、油条、油饼中硒损失分别占面粉总硒约1.51%、3.10%、6.87%、8.90%、11.42%,硒损失大小依次为油饼(煎)>油条(炸)>面包(烤)>馒头(蒸)>面条(煮),而土馍中增加硒占面粉总硒约8.12%;富硒小麦籽粒、麸皮、面粉及各种面制品中有机硒形态以硒代蛋氨酸为主。结论：富硒小麦籽粒加工成面粉后,总硒含量平均减少约34.82%,麸皮硒和加工过程中硒损失是富硒面粉总硒含量减少的主要因素;富硒小麦籽粒发芽制成麦芽粉后总硒含量略有增加但不显著;采用煮和蒸...     

深圳居民膳食中硒的测定及其摄入量评估

检测了深圳市居民膳食中硒的含量,并进行统计分析。结果表明,深圳市居民膳食中常见食品的硒含量范围在0~196 mg/100 g,其中,硒含量高低水平为:水产品肉类蛋及其制品鲜(干)食用菌坚果籽类豆类及其制品鲜(干)藻类谷物乳制品谷物制品蔬菜。深圳市外来劳务工的日均硒摄入量为77.9 mg/d。其中,硒摄入量的主要来源为肉类,硒摄入贡献率分别为46.5%,种类较单一。深圳市常住居民的日均硒摄入量为128.9 mg/d,高于外来劳务工的硒摄入水平,且主要来源丰富,分别是肉类和水产类,硒摄入贡献率分别是42.9%和25.8%。研究结果为深圳市加强劳务工营养膳食指引和科学补硒提供参考。     

加工方式对富硒大豆制品中硒含量的影响

大豆中的植物蛋白是硒元素存在的主要场所,因此豆制品是重要的有机硒食物来源。目前已经有不少关于富硒大豆蛋白、大豆芽及豆腐等大豆制品的研究,但主要集中于制品中硒含量的分布,而对于生产过程中硒含量的变化却鲜有提及。研究主要分析了制备富硒大豆芽、富硒豆浆和富硒豆腐3种大豆制品过程中硒含量的变化,结果表明硒含量较高的大豆样品发芽情况较好,发芽过程中硒含量呈现先增加后缓慢下降并趋于稳定的趋势,大豆芽经热烫处理后,3种大豆样品的硒含量均大量减少。磨浆时,水豆比的不同影响了硒在豆浆和豆渣中的分布,豆浆中的硒所占的比重随着加水量的增加而增加。在以不同凝固剂制作的3种豆腐中,硒含量顺序为:内酯豆腐石膏豆腐盐卤豆腐,即内酯豆腐保存硒的能力最强。实际生产中,应选择合理的加工方式以便最大限度地减少硒的损失。     

各种肉类的营养和烹饪方法

猪肉维生素B1多配栗子补脑营养特点:按照《中国食物成分表》,同等质量下,猪肉的维生素B1含量是牛肉的4倍多,是羊肉和鸡肉的5倍多。维生素B1与神经系统的功能关系密切,能改善产后抑郁症状,还能消除人体疲劳。适用人群:猪肉性平,一年四季均可食用,各种体质的人都能吃,但其脂肪含量比其他肉类高,因此更适合消瘦的人,体态较胖和高血脂的人则要适当控制吃的量。烹调方法:猪肉脂肪高,不适合煎炸,以炖煮为宜,炒     

富硒紫花苜蓿挂面的研制

在挂面生产中添加适量富硒紫花苜蓿浆,制成了具营养功能的翠绿色挂面,对紫花苜蓿挂面吸水率、烹调时间、弯曲断条率、烹煮损失率、熟断条率及感官评价进行测定;确定最佳工艺为面粉100%、变性淀粉10%、富硒紫花苜蓿浆汁10%、食盐3%～5%、纯碱0.2%～0.3%、草酸锌适量.     

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.     

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.     

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.     

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.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the