超高压处理对烟草香味成分的影响

为改善烟叶的吸味品质,在100～700MPa和30℃下对烤烟叶片进行了超高压处理,并采用同时蒸馏萃取和毛细管气相色谱法测定了处理前后的烟叶香味成分的变化,进行了感官质量评价。结果表明:随着处理压力的增大,香味成分的总量逐渐增大,在500MPa时达到最大,而后开始下降;酮类成分的变化与香味成分总量的变化趋势相似;β-苯乙醇、苯甲醇、丁香酚和芳樟醇等随着处理压力升高而持续增加;苯乙醛、糠醛、5-甲基糠醛等在300MPa时达到峰值,随后有所下降。当超高压力达到500MPa时,感官质量最佳。超高压处理对于改善烤烟烟叶香味品质具有一定的作用。     

超高压处理对黄酒陈化的影响

研究了在200~350 MPa下,处理时间为0.5~2.0 h,介质温度为10~40℃条件下超高压处理(UHP)对黄酒感官品质、理化指标的影响。实验结果表明,当压力为300 MPa时酒的感官品质较好,保压时间为0.5 h即具备良好陈化效果,常温下进行高压处理即可具备陈化特征。通过对黄酒中总酯、总酸、总醛,杂醇油,挥发性香气成分及氨基酸总量的检测可发现,经超高压处理的酒液中醇类物质减少,酯类与醛类含量增加,酸类变化不明显,证明超高压可促进醇、醛等物质的氧化作用,酯化作用效果明显,可有效改善黄酒风味,加速陈化过程。同时,处理后黄酒中氨基酸总量增加,说明超高压处理并不会显著破坏黄酒中氨基酸成分。     

低浓度有机溶剂提取技术对造纸法再造烟叶品质的影响研究

为进一步改善造纸法再造烟叶内在品质,提高造纸法再造烟叶产品在卷烟配方中的适用性,本研究分别采用低浓度乙醇、三甘醇水溶液提取3种不同烟草原料,研究分析不同提取条件下烟草香味成分提取率及产品感官质量的差异。研究结果表明,随着乙醇浓度的增加,烟草原料中酮类、酯类等香味成分提取率明显提高;随着三甘醇浓度的增加,烟草原料中酮类、高级脂肪酸、新植二烯等香味成分提取率明显提高,但可溶性总糖、总植物碱提取率呈现先增加后降低趋势;结合感官质量对比评价发现,乙醇提取浓度的增加有利于提升产品感官质量,而采用三甘醇水溶液提取时,在浓度为1.5%时产品感官质量最佳,其后呈下降的趋势。     

云南烤烟复烤叶片陈化过程香味成分的变化及与感官评价的关系研究

使用同时蒸馏萃取装置、以及气相色谱仪(GC)和气相色谱/质谱联用仪(GC/MS),对约3年自然陈化过程云南中部和上部烤烟复烤叶片的香味成分进行了分析研究,并进行了感官质量评价。结果表明,烤烟复烤叶片在约3年的自然陈化过程中,4-环戊烯-1,3-二酮、二氢猕猴桃内酯等香味成分含量持续增加;茄酮、β-苯乙醇等陈化前期含量增加,达到峰值后含量开始缓慢下降;2,4-庚二烯醛含量一直降低。复烤叶片陈化过程吸食品质有所改善,到30个月左右,感官质量最好。另外,进行了复烤叶片陈化过程香味成分的变化与感官质量的相关性研究,陈化过程两种烟叶香味物质总量、酮类物质总量与感官质量的相关性良好,相关系数均大于0.90。      

复烤后烟叶分切方式对烘后烟丝品质的影响

目的：研究复烤加工后烟叶分切方式对烘后烟丝质量指标的影响。方法：取某规格的配方烟叶平均分成4份,经不同的分切处理后制丝,取烘后烟丝测定烟丝结构、填充值、石油醚提取物含量、香味成分总量。为消除不同质量指标之间的关联性,利用主成分分析对烘后烟丝质量指标进行降维处理,最后对不同分切方式下的烘后烟丝进行感官质量评价。结果：① 不同的烟叶分切方式下烘后烟丝结构、填充值、石油醚提取物含量、香味成分总量存在差异;② 主成分1可反映短烟丝（＜2.8 mm）、填充值、石油醚提取物含量、香味成分总量的信息,主成分3可以反映整丝（2.8～4.0 mm）的信息,主成分分析结果表明：C工艺处理条件（筛分出2/3大于42 mm的超大烟片进行分切处理）下主成分1结果最优,明显优于其他工艺处理条件,D工艺处理条件（筛分出大于42 mm的超大片烟叶进行分切处理）下主成分3的结果最优,C工艺处理次之,明显优于其他两个工艺处理条件;③ 感官评价的结果表明：A（对照样,不做分切处理）与C工艺处理条件下烘后烟丝香气质、香气量、口感表现较好,明显优于其他两个工艺处理条件。结论：不同的烟叶分切方式可以改变烘后烟丝的品质,因此可以通过烟叶分切来控制烘后烟丝的结构,进而减少烟叶原料的浪费,提升卷烟品质。     

“干头干尾”烟丝挥发性香味物质的主成分聚类分析

为研究薄板叶丝干燥过程"干头干尾"烟丝挥发性香味物质的变化特征,以在产三类卷烟牌号不同含水率"干头"烟丝、"干尾"烟丝的21种挥发性香味物质为指标,利用主成分集合选择法,选取12种挥发性香味物质进行主成分分析;按累积贡献率超过88%提取3个主成分指标,求得烟丝样品的3个主成分得分,并采用以平方欧氏距离衡量烟丝样品间差异大小的方法,对"干头"烟丝、"干尾"烟丝进行聚类分析和感官质量评价验证。结果表明:113个烟丝样品分为两类。2与正常生产的烟丝相比,"干头干尾"烟丝含水率在9.00%~12.50%之间时,挥发性香味物质含量及感官质量与正常烟丝相近,聚为一类;另一类"干头干尾"烟丝含水率9.00%,烟丝挥发性香味物质及感官质量有显著变化。对比法检验两类烟丝感官质量后,进一步验证了依据挥发性香味物质量将不同含水率"干头干尾"烟丝聚为两类的可行性。     

烘焙条件对白肋烟重要致香成分的影响

选择适宜的烘焙温度、空气含湿量和终端含水率等配套参数,以不同烘焙条件处理白肋烟,测定了处理后白肋烟中脯氨酸-葡萄糖Amadori化合物和13种碱性香味成分的含量,结合白肋烟处理前后两类致香成分总量的变化和感官质量评吸结果确定了白肋烟最优工艺处理条件.结果表明:①经不同条件烘焙处理后,白肋烟样品脯氨酸-葡萄糖Amadori化合物的含量均有不同程度的增加,即烘焙处理有利于Amadori化合物的生成.②碱性香味成分的总量在低温(100℃)下随空气含湿量的增大而呈现下降趋势,在高温(140℃)下随空气含湿量的增大则呈现上升趋势.③感官评吸结果与白肋烟中Amadori化合物和碱性香味成分总量的实验测定结果一致,即,最佳工艺处理条件为:烘焙温度120℃,空气含湿量400 g/kg,终端含水率8％.该工艺处理条件下,白肋烟致香成分含量较高,香气质量明显改善.     

超高压对峰甘板栗风味物质及理化性状的影响

目的研究超高压(UHP)处理对峰甘板栗风味成分及理化性状的影响,对其感官品质评价提供数据支撑。方法将峰甘板栗分别在200、300、400和500 MPa条件下16℃保压10 min,采用超临界CO_2流体萃取(SCFE)技术对其进行提取,采用气相色谱-质谱方法(GC-MS)检测其风味成分的变化及测定各理化指标。结果在200~500 MPa条件下峰甘板栗风味物质分别保留了89.98%、36.86%、7.63%、40.38%;经过超高压处理,峰甘板栗中酯类、醇类物质的种类及含量均下降,而酮类和酸类化合物均有所增加。随着压力增加,峰甘板栗褐变度、硬度、可溶性总糖和水分含量都呈现不同程度的增长趋势。结论在峰甘板栗微生物数量不超过卫生安全限量前提下,300 MPa处理对峰甘板栗理化性状影响较小,风味保持较好,且新增加的风味物质对感官品尝具有积极作用,其感官质量评价较高。     

不同调制方式对万源晒烟化学成分含量的影响

为探究适宜万源晒烟新品种的调制方式,以四川省万源市新品种"万毛9号"为材料,研究了不同调制方式对烟叶品质、安全性的影响。结果表明,调制方式对烟叶化学成分、感官品质有显著影响。晾制下,烟叶总糖、还原糖含量(质量分数)较低,烟碱转化率、降烟碱和N-亚硝基降烟碱(NNN)的含量(质量分数)、4种烟草特有亚硝胺(TSNAs)总量较高,烟叶杂气较轻。折晒下,4种TSNAs总量显著降低,烟叶安全性较高,且吸食余味较好。索晒下,烟叶香味物质总量及重要香味成分含量显著升高,烟叶风格较为突出、香气质较好,感官质量较优。     

不同水分工夫红茶贮藏过程中主要内含成分及感官品质变化研究

目的研究不同水分工夫红茶贮藏品质变化规律,为工夫红茶贮藏的适宜水分条件提供理论参考。方法系统比较不同水分工夫红茶(国家标准范围内)在自然贮藏条件下其主要内含成分及感官品质的变化。结果 1年贮藏期内,初始水分含量越低,含水率增长速度越快,总体上,茶叶初始水分含量高低决定贮藏过程中水分的高低。在短期贮藏(≤6月)时含水量越高的红茶中茶多酚、水浸出物保留量越多;长期贮藏(6月)时水分较低的红茶中茶多酚、水浸出物保留量越多。咖啡碱、可溶性糖在短期贮藏(≤6月)中水分含量适中的红茶中下降速度越慢;长期贮藏(6月)含水量较高的保留量越高。氨基酸含量在含水量越低的红茶中越高。初始水分含量高的红茶L*、a*、b*值均稍高于水分低的红茶。结论从综合品质的变化来看,本实验中以处理3含水率为5.93%的处理最好,处理2含水率为4.1%次之,处理1含水率为2.33%最差。     

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.     

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     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.