猪油控制氧化的工艺研究

通过正交实验和单因素实验对以制备肉味香精为目的的猪油控制氧化工艺进行了优化,并对猪油控制氧化的规律进行了探讨.实验结果表明,猪油控制氧化的较优化工艺条件是:反应温度130℃,反应时间4 h,空气流速0.012 m3/(h·100g猪油);较合适的氧化状态为:POV 270～400meq/kg,p-AV大于200,AV小于4.0 mgKOH/g,在此状态下氧化猪油经热反应可获得肉香前体物和肉香风味.     

脂肪氧化在鸡肉昧香精中的应用研究

实验的目的是以过氧化值和酸值表征鸡脂氧化状态,通过实验研究了氧化温度、氧化时间等因素对鸡脂控制氧化的影响,确定了以制备肉味香精前体物为目标的氧化鸡脂的较优工艺:氧化温度120℃、氧化时间2 h.热反应条件固定为加热温度110℃,时间40 min,W(氧化鸡脂)=1%,感官评价了各氧化鸡脂在各热反应条件下产物气味特征,通过感官评价和正交实验确定了热反应制备鸡肉香精的最佳配方:木糖2.8 g,L-半胱氨酸1 g,水20 g,葡萄糖1.2 g.     

牛脂氧化制备肉味香精的研究进展

综述了脂质氧化降解及其与Maillard反应之间的相互作用在生成不同肉类的特征香味中的重要作用；并对牛脂氧化产物成分进行了初步的统计，约有10类241种有机化合物，同时总结了主要氧化产物的形成机理；重点介绍了牛脂氧化制备肉味香精的工艺和牛脂氧化的条件。     

制备鸡肉香精用的鸡脂酶解—温和氧化条件研究

基于生物酶解技术使精炼鸡脂酶解后适度温和氧化,产生鸡肉特征风味前体,进而制备热反应鸡肉香精。以脂解率、脂香味与油腻味为评价指标,研究得到鸡脂酶解—温和氧化最佳条件为:鸡脂底物浓度为30%,每克鸡脂添加60 U脂肪酶,在pH 8. 0、40℃条件下酶解6 h时,获得的鸡脂脂解率高达45. 18%。气质联用-嗅闻技术分析显示:相比于天然清炖鸡汤,商用鸡脂制备的香精鸡肉特征风味不足,高温氧化鸡脂制备的香精异味明显,而酶解-温和氧化鸡脂制备的香精相似度高达98. 65%。     

植物蛋白水解及在热反应肉味基料中应用进展

植物蛋白来源广泛、品种繁多、价格低廉,早期以水解植物蛋白为原料制备热反应肉味基料再辅以调香所得肉味香精产品肉风味不佳。随后以动物蛋白水解物和动物脂肪为主要原料制备肉味基料再辅以调香的产品,因肉风味像真性好,成为行业主流。近年来,随着人们健康与环保意识的提高,替代动物性原料制备植物性肉味香精（素肉香精）得到青睐,从而如何以水解植物蛋白为原料制造理想的肉味基料再次成为肉味香精行业亟需解决的课题。本文综述了国内外迄今报道的植物蛋白水解工艺、以水解植物蛋白为原料制备肉味基料工艺及检测的风味物质,将为新型植物性热反应肉味基料工艺的研发提供参考。     

氧化猪脂制备肉味香精前体物质的研究

以猪脂为主要原料制备肉味香精前体物质,通过单因素实验和正交实验确定氧化反应的最佳条件。得到的氧化猪脂最佳反应条件是:氧化温度130℃,氧化时间3 h,VE添加量1.0%,不添加水和NaCl。在最佳反应条件下进行氧化实验,得到氧化猪脂的酸值(KOH)和过氧化值分别为1.549 mg/g和207.4 mmol/kg,肉味香精前体物质的感官评价分值为4.925。     

猪脂控制氧化及挥发性氧化产物研究

通过单因素试验和正交试验研究以热反应制备肉味香精前体物为目的的猪脂肪控制氧化工艺条件。以过氧化值(POV)、硫代巴比妥酸值(TBA)和酸值(AV)表征油脂的氧化状态。结果表明,猪脂肪控制氧化的较佳工艺条件为：反应温度120℃、反应时间2h、氧气流速0.025m3/h。采用固相微萃取- 气质联用技术对猪脂肪控制氧化产物中的挥发性成分进行分析,共鉴定出32 种化合物,其中醛类化合物占52.52%,为猪脂肪控制氧化产物中的主要挥发性成分。     

基于豆粕酶解液和脂肪控制氧化技术制备猪肉味香精的研究

以豆粕酶解液为原料,采用气质联用法(GC-MS)、电子鼻法和感官评价法,确定脂肪控制氧化技术制备肉味香精的工艺条件,并分析氧化脂肪对挥发性香气成分的影响。结果表明:肉味香精的最佳工艺条件:脂肪氧化温度130℃,氧化时间2 h,氧化脂肪的添加量5 g/100 mL酶解液;GC-MS和电子鼻分析结果可知,氧化脂肪能有效调控美拉德反应,生成较低量的含硫化合物、糠醛等美拉德反应的典型挥发性香气成分,同时生成大量的醇类、醛类等脂肪降解产物、美拉德反应产物和脂肪氧化降解的相互作用的产物。     

中国第三代肉味香精生产技术

中国第一代肉味香精生产技术始于1983年前后,采用酵母抽提物、水解植物蛋白和还原糖为主要原料,通过热反应法制备,所得产品香味浓郁、头香饱满,成本较低,但缺少肉类的特征风味。中国第二代肉味香精生产技术始于上世纪90年代中期,采用肉、骨为主要原料,通过一次酶解和热反应法制备,所得产品肉香浓郁,但不同种动物肉的特征风味差异不明显。中国第三代肉味香精生产技术遵循"味料同源"的中国特色肉味香精制造新理念,融合了脂肪调控氧化、肉类蛋白多级靶向酶解和低度热反应等3项核心技术,产品肉香味柔和、自然,肉类特征风味突出,原汁原味感强。     

鸡肉香精最适风味前体PLSR分析与研究

本实验以新疆泰昆鸡肉加工副产物资源鸡脂为原料,通过酶解和调控氧化技术分别制备酶解、氧化和3种不同复合酶解-氧化处理的鸡脂样品,并以此为前体制备鸡肉香精。描述性感官分析、电子鼻和GC-MS分别对上述香精样本进行比较分析。结果表明:由不同处理获得的鸡脂为前体所制备的热反应产物其在鸡肉风味感官属性的呈现和香气组成上均存在显著差异,温和酶解-氧化(底物浓度50%、酶活200 U/g、酶解时间2 h,氧化时间2 h、温度100℃、空气量0.6 L/min)制备出的鸡肉香精更接近于天然鸡肉味。最后利用PLSR对其感官属性与挥发性化合物进行相关性分析。辛醛、(E)-2,4-癸二烯醛、烯丙基正戊基甲醇等与香气强度呈正相关;仿真度与2-十一烯醛呈正相关,肉味与2-十一烯醛、4-乙基环己醇、壬酸等呈正相关;烧烤味与苯甲醛、香叶基丙酮、2,4-二叔丁基苯酚呈正相关。     

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