香气强度和香比强值

在调香实践和香料香精贸易中，经常要接触到“香气强度”问题，有人认为可以参照阈值衡量一个香料或香精的香气强度，闰值低的香气强度大，阈值高的香气强度小。实践证明，阈值和香气强度二者并不显示一定的数学关系。1964年，APPel．L发表了有关香强度的研究论文，将！00％柠檬酸的香强度定为5，按照他的计算和表示方法，1％柠檬酸的香强度值为0，而0‘4％柠檬酸的香强度为一1。显然，这个表示方法只有理论研究的意义，在实践中是难以应用的。笔者认为有必要创造一个新的香气强度值表示方法，为了同“香强度值”区别，暂时称之为“香比强…     

香气分维公式的一个推论

本文通过对林翔云教授的香气分维公式的分析,推导出更多的结论以指导调香实践,根据分形数学理论提出了"随着香料种类的增多,对主题香气的贡献增加率递减"的结论.文中也讨论了杂气对主题香气的影响及其解决办法.关建词     

香料香精工业中的多孔可塑萃取技术

在创拟香精中,要取得完全有天然产物的感官效应,始终被认为是理想的目标。成功地加入有天然香气香味的商品,应该毫无疑异地能满足消费者犹如从新鲜水果、蔬菜,辛香料和花朵中取得的同样的风味和香气的“真实”感。“返回大自然”的趋向的日益深化和人们对特异口味的奢望,向香料香精工业提出了挑战,要求我们提供最高的质量、合理的价格的天然香料品种来满足多种多样香气香味的要求。     

祝贺我刊编委纪红兵教授获2014年度国家科学技术进步奖二等奖

香料香精广泛应用于食品、化妆品和纺织品等行业,香料香精及其相关行业的工业生产总值超过15万亿元。目前我国香精行业整体技术水平与国外相比差距明显,集中体现在香精的香气质量、稳定性和缓释性,其核心关键技术表现在香精制备、香气品质表征和控制等三个方面。国内具有自主知识产权的高品质香精产品技术缺乏,高端产品约80%来自进口,严重制约了我国香料香精及相关行业的发展。     

香料香精实用价值的综合评价

本文首次提出香料香精的“香品值”（Ｐ）、“留香值”（Ｌ）两个概念，同作者早先提出的“香比强值”（Ｂ）共同组成了香料香精的三个基本属性。用三值的乘积考察香料香精的实用价值，ＢＰＬ／１０００以“综合评价分数”（Ｚ）表示，它同该香料或香精的市场销售价格直接相关。文中指出“调香工作就是大幅度提高配合香料的香品值”。     

欢迎您在本杂志投放广告

正全国香料香精工业信息中心为您服务热门书籍邮购《2013新版食品添加剂手册》《食品感官分析》《天然产物化学》《风味、香气和气味分析》《食品风味化学》《食品添加剂应用与检测技术》《香气王国——精油健康疗法》《国内外烟用添加剂法律法规汇编》《食品添加剂安全使用指南》新版《英汉香料香精技术词汇》《全国香料香精产品目录》     

中国香料香精行业的新突破

香料香精行业是一个科技与艺术相结合的行业。香料是配制香精的原料,只有具备香味香气丰富与高品质的香料才能获得高品质的香精产品。截至目前,我国香料产品的开发均采用了消化吸收国外品种的方法,这在一定程度上影响了产品发展,特别使高品质香精产品的开发受到了制约。眼     

2,5—二甲基—4—羟基—3（2H）—呋喃酮的合成

2,5—二甲基—4—羟基—3(2H)—呋喃酮(以下简称DMHF),具有强烈的果香焦糖香气或“焦香菠萝”的芳香香气。它是美国食用香料制造者协会(FEMA)已认可的食用香料之一,因而广泛用作食用香料和香精以及食品添加剂。 DMHF天然存在于菠萝、橙桔、     

欢迎您在本杂志封面、封底投放广告

正全国香料香精工业信息中心为您服务热门书籍邮购《2013新版食品添加剂手册》《食品感官分析》《天然产物化学》《风味,香气和气味分析》《食品风味化学》《食品添加剂应用与检测技术》《香气王国——精油健康疗法》《国内外烟用添加剂法律法规汇编》《食品添加剂安全使用指南》新版《英汉香料香精技术词汇》《全国香料香精产品目录》《全国调香师对若干食用香料的评价(一、二)》《欧盟化妆品管理法规及检测方法与指南》《芳香植物栽培学》等     

牙膏原料技术理论(待续)

正6牙膏用香精6.1定义与作用牙膏用香精是参照天然植物的香味,采用天然香料和合成香料调配而成,具有天然风味和各种香型的原料成分。牙膏香精的主要作用有:(1)赋予牙膏稳定的香型和清凉口感。牙膏用香精不但要赋予牙膏一定类型的香气,而且要赋予一定类型的口味,使消费者在使用时口腔感到愉快舒     

Direct image-based fractal characterization of micromorphology of calcium carbonate fouling crystals

Researches on macroscopic fouling behavior and micromorphology are usually conducted separately. In this paper, the relationship between the macroscopic fouling behavior and micromorphology on different materials is established. A direct fractal-characterization approach based on the micrographs of calcium carbonate fouling crystals is presented. The box-counting method is used to characterize the fouling crystals. For fractal measurements, t-distribution tests of linear regression hypothesis are performed at the significance level of 0.01. If all listed absolute t-statistics with the minimum of 164 are higher than the corresponding t value, the fouling crystals are determined as fractal, with a confidence level of 99%. The fractal dimensions obtained from the micrographs of different visual fields of a specimen are demonstrated to be almost identical, with maximum and minimum relative values of 4.42% and 0.75%, respectively, and standard deviations ranging from 0.0062 to 0.0266. The irregularity of the crystal morphology indicates larger fractal dimensions. Comparison and analysis of the relationship between macroscopic fouling behavior and micromorphology show that the larger fractal dimension of crystal morphology suggests a small amount of surface fouling. Thus, the reasons for the differences in the macroscopic fouling behaviors of different materials are revealed geometrically.     

The use of fractal analysis in the textural characterization of coals

The materials studied were four bituminous coals as well as the corresponding coal samples oxidized in air at 543 K for different periods of time. The method proposed by Friesen and Mikula, the procedure of Neimark and the methodology of Zhang and Li were successfully employed to analyze mercury porosimetry data from a fractal perspective. Fractal dimensions as well as fractal profiles are sensitive to oxidation treatment, being useful to follow the changes undergone by the coal samples. The evolution of the fractal dimension of coals with oxidation is determined by a balance between two main mechanisms of pore development: the oxidation of the pore surface itself that tends to lower the fractal dimension and the access of mercury to previously non-accessible regions that tends to increase this dimension.     

分形理论在耐火材料生产中的应用

介绍了分形理论在耐火材料生产过程中的应用 ,提出 :(1)在耐火材料破粉碎工序之前加一个冷却处理工序 ,应用分形理论研究矿石碎裂机制 ,可提高耐火原材料尤其是硬质耐火原料的破粉碎效率 ;(2 )研究粉体颗粒的分形结构 ,既可以预测超微粉体的流动性 ,也可以预测粉体在压制过程中的充填状况 ,从而改良粉体的制备、存储、输送和运输等过程 ;(3)建立受压状态下矿石的分形裂纹结构、矿石构造特征以及施加给矿石的应力应变方式这三者之间的联系 ,对完善磨矿工序中的前馈质量控制有帮助 ;(4 )确定分形级配的颗粒配比 ,将有利于提高材料的性能 ;(5 )在耐火材料中添加分形结构的弥散粒子或纤维 ,能有效提高耐火材料的强度和韧性 ;(6 )加强吸入粉尘分形结构研究 ,防治耐火材料行业的职业病。     

Identification of Pheromone Synergists in American Palm Weevil, Rhynchophorus Palmarum, and Attraction of Related Dynamis Borassi

Thirteen host-plant kairomone blends, including 28 compounds, were tested and showed moderate to high synergy with rhynchophorol. The blends plus rhynchophorol also attracted the related Dynamis borassi. Ethanol–ethyl acetate blends in various ratios showed moderate synergy. Two blends, including "characteristic coconut" odor molecules, were as efficient as sugarcane in synergizing rhynchophorol and field luring American Palm weevils (APWs). Preliminary olfactometer tests of natural host-plant volatiles demonstrated the role of fermentation in primary APW attraction. The synergists were chosen from a comparative study of the odors emitted by four plant materials attractive to the APW: sugarcane, coconut, Jacaratia digitata tree and Elaeis guineensis (Oil palm). The volatiles were isolated during 6 days of sequential trappings onto Supelpak-2 adsorbent. The highly volatile fraction of sugarcane volatiles was sampled by solid-phase microextraction (SPME). Odors were analyzed and identified by gas chromatography and mass spectrometry. Electroantennogram responses to the plant odors were recorded to help in screening for bioactivity. The odor compositions between plants prior to and during fermentation were compared using a principal component analysis (PCA) to determine common odor features of the plants and to design simplified blends for field activity screening. About 100 components were identified in the >4-carbon fraction of the odors, among which 65% were fermentation volatiles. Fermentation generated a strong increase in the amount and variety of the volatiles emitted. The palm materials emitted two- to threefold greater odor amounts than the other plants. The odors from each plant were distinct according to PCA, with few common abundant components: isopentanol, 2-methylbutanol, their acetates, acetoin, isobutyl acetate, 2,3-butanediol, and 2-phenylethanol. Ethanol and ethyl acetate accounted for 80–90% in the highly volatile fraction of sugarcane odors. Coconut odor was mainly characterized by phenol, guaiacol, 1,2-dimethoxybenzene, ethyl esters of tiglic and 3,3-dimethylacrylic acids, 2-hexanone, 2-nonanone; and, to a lesser extent, by 2-heptanone, menthone, -phellandrene, ethyl octanoate and decanoate, which were also present in other plants.     

Do Pine Voles (Microtus pinetorum) Use Numerous Types of Olfactory Cues to Discriminate Gender?

Olfactory cues can contain information for discrimination of gender that can affect subsequent social interactions. Social rodents are hypothesized to use more olfactory cues than nonsocial rodents to distinguish males from females. The generality of this hypothesis was tested using the pine vole (Microtus pinetorum), a social vole. We examined nine possible sources of odors. A slide containing an odor from a male and a female was presented to each test subject for 3 min. We recorded the amount of time each test subject spent investigating each odor. Females spent significantly more time investigating male urine and male anogenital odors; however, they did not use any other odor sources to discriminate gender. In contrast, males did not use any odor sources to discriminate gender. Our results do not support the hypothesis that all social rodents use numerous odor sources to discriminate gender. Instead, our results are consistent with the alternative hypothesis that use of odor sources to convey information about gender may differ in rodents that live in different microhabitats.     

Self-assembly and Fractal Feature of Chitosan and Its Conjugate with Metal Ions: Cu (II)/Ag (I)

In this paper, we investigated the self-assembly and fractal feature of chitosan and Ag (I), Cu (II)-chitosan due to the theoretical and practical importance of chitosan in biomedical engineering, biomaterials and environmental sciences etc. The self-assembly and fractal structures of chitosan and Ag (I), Cu (II)-chitosan were observed using atomic force microscope (AFM), and the fractal dimensions of chitosan and Ag (I)-chitosan were calculated. The results indicate that their fractal dimension is approximate 2 and relates with the accumulation degree: the fractal dimension decreases with the accumulation degree increases. In addition, a new self-assembly strategy was presented to study the lyotropic liquid crystals (LLC) of chitosan and the formation mechanism of LLC was primarily analyzed and discussed. All of these results are valuable for the structure/function relationship study of chitosan and useful for application in biomedical materials.     

无机粒子填充高分子复合材料断口的分形特征及其测定方法

无机粒子填充高分子复合材料的断口具有有限层次的分形结构。对比分析了测算无机粒子填充高分子复合材料断口分形维数的方法,并讨论了影响断口分形维数的因素以及断口分形维数与复合材料力学性能之间的关系。     

Effects of magnesite addition on the properties and structure of foam ceramics

Foam ceramics were fabricated by using sand shale, steel slag and magnesite as raw materials and SiC as foam agent. Influences of magnesite on crystalline phases, porosity, mechanical properties and pore structures were investigated via XRF, XRD, high-temperature microscope, Micro-CT and fractal dimension. Magnesite, benefits the formation of diopside and reduces fractal dimension. When 5% magnesite additions is added, the foam ceramics exhibit the optimized properties: bulk density of 1.12 g/cm³, total porosity of 56.79%, closed porosity of 50.71%, bending strength of 13.43 MPa and fractal dimension value of 1.11. Formation mechanism of diopside phase based on Gibbs free energy is also discussed in this paper.     

Odor considerations in the use of frying oils

Odors generated into cooking and serving areas during use of oils in pan frying and deep-fat frying are of concern to home and institutional consumers and, in some respects, to industrial users. Odor considerations are factors in the selection of types of oils to be used in both domestic and foreign markets. Comparative techniques have been developed to evaluate room odor characteristics of frying oils. Evaluation research has been done on various oils and cooking fats for room odors developed during frying. Improved odor characteristics contributed by additives to oils have been studied, as well as relationship between the linolenate content of soybean oil and its characteristic room odor. The nature of the volatile constituents which contribute to room odors during frying is the subject of continuing research efforts. Presented at AOCS meeting, St. Louis, Missouri, May 1978.     

Effects of surface topography of material on nucleation site density of dropwise condensation

Heterogeneous nucleation is very important for the initial droplet formation of dropwise condensation, and it is directly related with the surface properties of materials. In this paper, the relationship of nucleation site density with surface topography in nanometer scale for dropwise condensation was experimentally studied on surfaces of magnesium in view of that magnesium can react with hot water (condensate) and make the chemical compositions of the surface changed, and thus leave the nucleation sites in nanometer on the surface. The differential box-counting was used to calculate the fractal dimension of these magnesium surfaces. And condensation experiments were carried out on the magnesium surfaces with different topography under same subcoolings and condensation time. The results showed that surface topography has a great influence on nucleation site density. The larger the fractal dimensions the more the nucleation sites. A new formula to calculate the nucleation site density was proposed based on the modification of Rose's formula with the experimental data. And this new formula can reflect the effect of surface fractal dimension on the nucleation sites.