微波复热对竹笋鸡汤品质的影响

目的 探究微波复热对竹笋鸡汤品质的影响。方法 采用不同微波功率(300、500和700 W)对竹笋鸡汤进行复热处理，分析竹笋鸡汤水溶性蛋白质、脂肪、游离氨基酸含量和挥发性风味物质，探究微波复热后竹笋鸡汤间品质差异。结果 随着微波功率增加，700 W处理下水溶性蛋白质含量和脂肪含量最高。300 W组的总游离氨基酸含量和鲜味氨基酸显著高于700 W和500 W，且其谷氨酸和丙氨酸味觉活度值(Taste Active Value, TAV)最大。随着微波功率的增加，竹笋鸡汤中挥发性风味物质总量和醛类总量呈现逐渐下降趋势；醇类和酮类物质总量先增加后下降，在500 W功率时达到最高值。结论 综合各项指标，采用300 W微波复热后的竹笋鸡汤品质更佳。该研究为预制汤品的复热工艺提供了理论指导。     

微波煲汤对黄芪炖鸡品质的影响

为探讨微波加工对鸡汤品质的影响,以鸡胸肉、黄芪为原料,通过正交试验以营养指标水溶性蛋白为评价指标对微波黄芪鸡汤煮制工艺进行优化,最优煲制条件为保温功率300 W,保温时间60 min,料液比1:5,此时煲制出的鸡汤中水溶性蛋白含量为1.66mg/g。采用传统电煲锅与微波最优煲制条件下鸡汤进行对比分析两者的营养风味物质(水溶性蛋白、游离氨基酸、多糖)和健康安全性指标(嘌呤含量)。结果表明:微波加热不会对食品中重要的营养成分(蛋白质、脂肪等)产生破坏,满足人们对煲汤营养的需求。微波最佳煲制条件下汤中营养、风味与传统电煲锅4 h煮制时相当。微波煲制鸡汤中嘌呤含量显著少于电煲锅煲制,总嘌呤含量基本保持不变。比较两种煲汤模式,发现微波煲汤是一种更加节能的煲汤方式。     

微波对天麻鱼头汤营养和安全性影响

为探讨微波加工对药膳鱼汤品质影响,以天麻、鱼头为原料,分别采用微波炉和传统电炖锅加热的方法,研究其水溶性蛋白、游离氨基酸、矿物质、天麻素、嘌呤和感官品质的变化规律。结果表明:微波加热更有利于小分子物质的溶出,如氨基酸、矿物质、天麻素和嘌呤等,微波煲汤中游离氨基酸含量甚至高达电炖锅的1.5倍,对蛋白质等大分子物质的影响较小;在安全性方面,微波200 W小功率的煲汤或者400 W大功率短时间煲汤产生的嘌呤含量均不超过15 mg/L,既符合痛风病人安全需求又改善了鱼汤的风味;在感官评价方面,采用微波炉400 W煲汤1 h的感官得分可以达到与电炖锅煲汤3 h相类似的效果,可以将煮制周期缩短2 h,微波加热可大大缩短煲制时间,是一种更加高效的煲汤方式。     

鳀鱼蒸煮液的主要营养成分分析

研究通过测定鳀鱼蒸煮液的主要营养成分、蛋白质分子量及风味物质组成,评价鳀鱼蒸煮液的营养价值,为进一步开发利用鳀鱼蒸煮液资源奠定基础.结果表明,鳀鱼蒸煮液中,蛋白质含量为0.385g/100mL,非蛋白氮含量为0.275g/100mL,氨基酸态氮含量为0.110g/100mL,蛋白质分子量主要分布在35ku以上;游离氨基酸总量为370.64mg/100mL,呈味氨基酸含量高,呈现鲜甜滋味;经GC/MS风味物质分析,对其风味起主要贡献的化合物为醛类.     

不同益生元对酸奶游离氨基酸及风味的影响

为研究添加不同益生元发酵对酸奶游离氨基酸及风味的影响,以用低聚木糖、低聚异麦芽糖、低聚半乳糖、蔗糖发酵的酸奶为研究对象,在利用乳品综合成分指标分析仪检测蛋白质含量、脂肪含量、非脂乳固体含量等基本营养成分的基础上,利用电子舌技术、高效液相色谱-质谱联用技术对游离氨基酸进行检测,并结合味道强度值、主成分分析法、相关性分析、氨基酸评分进行综合评价。结果表明,添加不同益生元酸奶的蛋白质、脂肪、总固形物、非脂乳固体含量均符合国家标准;各组分间除酸味外,其他风味差异较小,酸味大小依次为:低聚木糖低聚半乳糖低聚异麦芽糖对照组;添加益生元发酵酸奶中共检测出17种游离氨基酸,添加低聚木糖酸奶中总游离氨基酸含量为119.31 mg/g,显著高于其他益生元添加组及对照组,且对照组中总游离氨基酸含量为112.49 mg/g,显著高于低聚半乳糖中的79.48 mg/g,但与低聚异麦芽糖中的108.93 mg/g差异不大;低聚木糖组甜味、鲜味、苦味氨基酸含量显著高于对照组及其他实验组,对照组甜味与苦味氨基酸含量高于低聚异麦芽糖及低聚半乳糖组,低聚半乳糖组各呈味氨基酸含量均最低;各组分氨基酸模式评分值大多数高于氨基酸模式标准值。综合来看,并非全部益生元均会对酸奶发酵产生正向影响,添加低聚木糖酸奶中游离氨基酸含量最高且风味较好。这为益生元酸奶的工业生产过程中基本营养成分及风味调控提供参考。     

清鸡汤中营养物质浸出规律的探讨

以清远麻鸡为原料,按传统工艺制备清鸡汤,分析鸡汤在不同熬汤时间内其主要营养浸出物质含量的变化规律。结果表明:熬汤时间对鸡汤中主要营养成分浸出有显著影响(p<0.05);熬制4 h后,含氮总物质、游离氨基酸及必需氨基酸的浸出率趋于平衡,其中必需氨基酸在4 h达(48.929±0.644)mg/100 mL;鸡汤中的还原糖呈下降趋势,汤中风味氨基酸含量4 h达到最高,不饱和脂肪酸的含量在4 h达到最大,为61.545%,熬煮时间过长会影响鸡汤的鲜味。综合营养、风味及能耗考虑,鸡汤熬制(3~4)h为佳。     

低苯丙氨酸花生肽混合物的制备

为了制备适合开发低苯丙氨酸特膳食品的原料,花生蛋白经碱性蛋白酶Alcalase2.4L及木瓜蛋白酶降解后,通过单因素及正交试验分别确定了风味蛋白酶Flavourzyme水解及活性炭吸附工艺。结果显示,在50℃,pH 6.5及添加3 500U/g风味蛋白酶水解5h,水解所得游离苯丙氨酸可达28.65mg/100mL。添加7g/100g活性炭,于35℃、pH 3.0条件下吸附2.5h,苯丙氨酸去除率可达98.64%。经氨基酸及分子量分析显示,产物中苯丙氨酸含量大幅下降(0.61mg/100mL),主要为600Da以下的寡肽和游离氨基酸,适合将来为苯丙酮尿症患者制备特殊医学配方食品。     

松茸菌汤熬制工艺参数优化及风味成分分析

以云南产新鲜松茸菌为主要原料,研究松茸菌汤熬制的主要工艺参数。以菌汤中固形物溶出率和蛋白质溶出率为考察指标,通过单因素试验和正交试验分析和讨论,确定松茸菌汤熬制工艺参数,并对松茸菌汤中的氨基酸、呈味核苷酸和风味成分进行分析。结果表明：松茸菌汤熬制的最佳工艺为料液比1∶60（g/mL）、熬制时间90 min、熬制火力中火（1 000 W）,此时菌汤中固形物溶出率为49.68%,蛋白质溶出率为45.74%;菌汤中总氨基酸和游离氨基酸均为17 种,含量分别为109.60 mg/100 mL和41.20 mg/100 mL;呈味核苷酸5’-肌苷酸二钠和5’-鸟苷酸二钠含量分别为2.0 μg/mL和28.4 μg/mL;气相色谱-质谱联用测得菌汤中挥发性物质共28 种,其中醇类物质所占比例最大。     

微波加热对大麻哈鱼汤营养及感官品质的影响

研究了微波功率(240、480、720、960W)与微波时间(20、40、60、80min)对大麻哈鱼汤营养及感官品质的影响。通过测定水溶性蛋白质、游离氨基酸、固形物、色度、风味以及感官评价得出:当微热功率为720W、微波时间为60min时,大麻哈鱼汤具有较好的营养及感官品质,与传统工艺制得的鱼汤较为相近。在此条件下加热的大麻哈鱼汤香气浓郁、美味可口。     

企鹅珍珠贝全脏器的营养成分分析与评价

对企鹅珍珠贝全脏器的营养成分进行了分析和评价,主要对其一般营养成分、氨基酸组成、脂肪酸组成及其无机质含量进行了检测和营养学评价。结果表明:企鹅珍珠贝肉的蛋白质含量为81.1%(干基),蛋白质组成氨基酸总量为13.0%,必需氨基酸种类齐全,第一限制氨基酸是缬氨酸,氨基酸价为84.3;富含Glu、Asp和Gly等呈味氨基酸;游离氨基酸中牛磺酸的含量高达722mg/100g,占游离氨基酸总量的47.2%;脂肪含量较低,且以多不饱和脂肪酸为主,其EPA和DHA的含量分别为12.61%和30.28%;无机质含量丰富,尤其是微量元素Zn(435mg/kg)和Se(0.68mg/kg)。因此,企鹅珍珠贝是具有独特鲜味和较高营养价值的优质海产品。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press