模式体系Maillard反应肉类（牛肉）香精的挥发性成份分析

本研究采用固相微萃取(SPME)与同时蒸馏萃取(SDE),对模式体系Maillard反应肉类 (牛肉 )香精的挥发性成份进行分离,然后应用GC MS对反应产物进行分析,共分离鉴定出 98种挥发性化合物,尤其是分离鉴定出吡嗪、2,6- 二甲基吡嗪、2- 呋喃甲硫醇、2- 甲基 3 -呋喃硫醇、甲基(2 -甲基 3- 呋喃基)二硫醚、双(2- 糠基)二硫醚、双 (2 -甲基 3 -呋喃基 )二硫醚、4 -甲基噻唑、2- 甲基 2 -环戊烯 -1 酮与 -3-甲基- 2 -噻吩基甲醛等关键性肉香(牛肉)化合物等肉香或特征性牛肉风味化合物。     

供应信息

<正>(1)上海志浦化工有限公司供应:2-甲基-3-甲硫基呋喃、吡嗪基乙硫醇、反,反-2,4-癸二烯醛、反,反-2,4-壬二烯醛、双(2-甲基-3-呋喃基)二硫醚、4-甲基-4-巯基-2-戊酮、3-甲基-2-丁硫醇、2-甲基四氢呋喃-3-酮、硫代乳酸、2-乙酰基吡啶、2,3,5,6-四甲基吡嗪、4-甲基-5-乙酰氧乙基噻唑、2,4,5-三甲基噻唑、四氢噻吩-3-酮、香兰素、3-巯基-2-丁醇、二糠基二硫、甲基(2-甲基-3-呋喃基)二硫醚、2-乙酰基噻唑、呋喃酮乙酸酯、2-乙酰基吡嗪、4-甲基-5-羟乙基噻唑、二丙基二硫醚、2,3,5-三甲基吡嗪、糠基     

磷脂与Maillard模型反应体系的相互作用

综述了磷脂与Maillard反应体系的相互作用.磷脂与Maillard反应体系相互作用,导致磷脂氧化降解产物发生变化,醛的量明显减少;而Maillard反应挥发性产物中酰基噻吩类、杂环硫醇类、噻吩酮类、双环噻吩类、巯基酮类以及部分噁唑类减少.磷脂氧化降解产物与Maillard反应中间体发生反应,形成一些新的挥发性产物,包括2-戊基吡啶、2-烷基噻吩、烯基噻吩、戊基噻喃以及脂肪硫醇.而且加入磷脂后的Maillard反应体系能产生更好的肉香味.     

尿素对抗坏血酸-半胱氨酸模式反应形成香味化合物的影响

以固相微萃取-气相色谱-质谱联用(SPME-GC-MS)技术对抗坏血酸与半胱氨酸(ASA-Cys)的模式反应产物进行鉴定,考察了尿素对模式反应形成香味化合物的影响。鉴定出了呋喃、吡嗪、噻吩、噻唑、噻吩并噻吩及脂环硫化物在内的47个香味化合物,其中,含硫化合物(噻吩、噻吩并噻吩、脂环硫化物)是最为丰富的香味成分。尿素加入到模式体系中(pH=8.00),一方面使一些含硫化合物的产量显著降低,甚至消失;另一方面却促进了几个含氮化合物,如吡嗪、甲基吡嗪、乙基吡嗪、2,6-二甲基吡嗪及其他烷基吡嗪的生成。表明在模式反应中,尿素受热能够释放出NH3,NH3与H2S和ASA降解产物发生竞争反应形成含氮化合物如烷基吡嗪,从而导致含硫化合物的产量降低。     

4,5-二甲基-3-腈基呋喃Schiff碱的合成与表征

以自制的4,5-二甲基-3-腈基-2-氨基呋喃与取代芳醛为主要原料,以乙醇为溶剂、醋酸为催化剂,通过回流反应合成了新型4,5-二甲基-3-腈基呋喃Schiff碱化合物。目标化合物通过IR、1HNMR、MS进行了表征。     

S-(2-甲基呋喃-3-基)巯乙酰腙类化合物的合成

以2-甲基-3-呋喃硫醇为原料,经酯化,肼解,得S-(2-甲基呋喃-3-基)巯乙酰肼,再与芳香醛反应,非常方便合成了标题化合物。其结构经IR、1HNMR、MS和元素分析确证。     

食用香料香精的应用现状和发展前景（二）

（接上期P21）三，研究食品特征香味化合物的前体，对于开发新香料具有重要意义比如，肉香味的主要前体。氨基酸和糖类在加热过程中生成呋喃类化合物达百种以上；前体硫胺素热解以后生成多种噻吩类以及具有肉香味的噻唑类化合物；牛肉中的前体核糖核酸经酶解以后，加热转化为巯基呋喃类和3-巯基噻吩类特征香味化合物；前体不饱和脂肪酸氧化降解为较小分子的不饱和醛类在烧鸡特征香气中起了重要作用，醛类也可以进一步发生硫化和氨化反应生成重要的香味成分，如甲基硫代乙醇等.     

两种新型羰基呋喃类香料前体的制备及其热性能

为开发羰基呋喃类香料前体，分别以2-乙酰基吡啶、2-乙酰基噻吩和糠醇为起始原料，在iprPNP型Pincer锰催化剂的催化作用下经脱氢偶联反应一步合成3-(呋喃-2-基)-1-(吡啶-2-基)丙-1-酮 (Ⅲa)和3-(呋喃-2-基)-1-(噻吩-2-基)丙-1-酮 (Ⅲb)。通过1H NMR、13C NMR、HRMS表征目标化合物的结构，并对其热性能进行鉴定。结果表明，目标化合物Ⅲa从99.9 ℃开始降解，主要失重区间为99.9~875 ℃，在259 ℃失重速率最大，总失重为97.31%；目标化合物Ⅲb从116.2 ℃开始降解，主要失重区间为116.2~875 ℃，在274 ℃失重速率最大，总失重为98.41%。在300~900 ℃的有氧裂解氛围下，目标化合物Ⅲa裂解后主要有烷基呋喃类、烷基吡啶类、2-乙酰吡啶等特征香味物质；目标化合物Ⅲb裂解后鉴定出烷基呋喃类、烷基噻吩类、2-乙酰呋喃等特征香味物质。通过对单料烟进行加香效应评价，确定目标化合物Ⅲb的最适宜添加量为3mg/kg。     

3-异烷氧基噻吩的合成

以CuB r为催化剂,NMP为溶剂,在110℃下,3-溴噻吩与过量的甲醇钠反应2.5 h生成3-甲氧基噻吩,产率为82%。再以无水NaHSO4为催化剂,在108~115℃下,3-甲氧基噻吩分别与异丁醇、异戊醇、异辛醇发生取代反应合成了3-(2-甲基丙氧基)噻吩、3-(3-甲基丁氧基)噻吩、3-(2-乙基己氧基)噻吩,反应时间分别为:3、3.5、4h,收率分别为72%、67%、63%。这些化合物结构都通过IR、1HNMR和MS进行了表征,并对其进行了初步香味评价,结果表明,它们都具有基本肉香味的特征。     

最新消息

第 2 1批FEMAGRAS化合物 :美国香料和萃取物生产商协会 (FEMA)日前公布了第 2 1批GRAS化合物 ,共 4 5个 ,它们是 :乙醛二异戊缩醛、戊基甲基二硫醚、己酸苄酯、丁基乙基二硫醚、β-环糊精、二乙基三硫醚、(+ / - ) -顺 /反 - 3,5 -二乙基 - 1,2 ,4 -三噻烷、(+ / - ) -二氢金合欢醇、(+ / - ) -二氢薄荷内酯、二羟基丙酮、2 ,5 -二甲基 - 3-呋喃硫醇乙酸酯、2 ,5 -二甲基噻唑、顺 - 4-十二烯醛、4 ,5 -环氧 -反- 2 -癸烯醛、(+ / - ) - 3-乙酰氧基 - 2 -甲基 -丁酸乙酯、2 -乙酰氨基乙酸乙硫醇酯、乙基甲基二硫醚、乙基丙基二硫醚、…     

Kinetics studies and characterization of poly(furfuryl alcohol) for use as bio‐based furan novolacs

Poly(furfuryl alcohol) (PFA) is an attractive target for the development of bio‐based novolac resins. However, control of the polycondensation reaction is not well understood and side reactions are an important factor for PFA and the development of new resins. The polymerization reactions and kinetics of furfuryl alcohol and 2‐furyl ethanol into polymeric resins are detailed in this work. Nuclear magnetic resonance spectroscopy analysis of reaction kinetics, molecular weight analysis, and rheology analysis confirm that the polymerization reaction rate of 2‐furyl ethanol is much faster than that of furfuryl alcohol because the addition of this methyl group serves to stabilize the carbocation transition state. Side reactions, such as Diels–Alder crosslinking and in particular branching, are quantified and were found to be much more prevalent in the polymerization of PFA. The glass transition temperature was measured to be 376 K for PFA and only 294 K for poly(2‐furyl ethanol). Molecular dynamics simulations showed that the alternative structure that forms in PFA that causes branching results in greater backbone rigidity causing its higher glass transition temperature. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46608.     

酮肟和乙炔成环(吡咯环)反应的研究

在ＫＯＨ ＤＭＳＯ强碱性催化体系中，酮肟和乙炔能够发生成环（吡咯环）反应。研究了甲基 （５ 甲基 ２ 呋喃）基酮肟及甲基 ２ （５′ 甲基 ２ 噻吩基）乙基酮肟和乙炔作用，形成同时含有呋喃环（或噻吩环）和吡咯环的杂环化合物：２ （５′ 甲基 ２′ 呋喃）基吡咯、１ 乙烯基 ２ （５′ 甲基 ２′ 呋喃）基吡咯及２ 甲基 ３ （５′ 甲基 ２′ 噻吩基）甲基吡咯、１ 乙烯基 ２ 甲基 ３ （５′ 甲基 ２′ 噻吩基）甲基吡咯。产物的产率分别为４７７％、６１８％和４６８％、３３５％。产物的ＩＲ及１ＨＮＭＲ均符合于文献值。     

硝呋烯腙的合成

介绍了由 5 硝基糠醛二乙酸酯与丙酮以摩尔比为 1∶1,在 5 0 %的硫酸介质中 ,温度为 80℃的条件下反应得到 1,5 双 (5 硝基 2 呋喃基 ) 1,4 戊二烯 3 酮 (I) ,然后I与氨基胍碳酸氢盐 ,在浓HCl作用下 ,于DMF和乙醇中回流得到硝呋烯腙。产品总产率达 6 5 0 %     

Dyeing of cotton with a bifunctional disulphide bis(ethylsulphone-sulphatoethylsulphone) disazo reactive dye

A new bifunctional disazo reactive dye of a temporarily high molecular structure based on a disulphide bis(ethylsulphone-sulphatoethylsulphone) reactive system was synthesised and applied to cotton fabric. This dye displayed good primary exhaustion under different neutral exhaustion conditions. The results assessed for the alkaline exhaust dyeing indicate that the disulphide bis(ethylsulphone-sulphatoethylsulphone) dye showed higher exhaustion and fixation values compared to those obtained with the commercial CI Reactive Black 5. The fastness properties of the disulphide dye were similar to those of the commercial dye. Received: 24 March 2005; Accepted: 15 June 2005.     

Solid acid-catalyzed conversion of furfuryl alcohol to alkyl tetrahydrofurfuryl ether

The acidic zeolite HZSM-5 (Si/Al = 25) achieved 58.9% selectivity of methyl furfuryl ether (MFE) and 44.8% selectivity of ethyl furfuryl ether (EFE) from etherification of furfuryl alcohol with methanol and ethanol. MFE and EFE were quantitatively hydrogenated into methyl tetrahydrofurfuryl ether (MTE) and ethyl tetrahydrofurfuryl ether (ETE) using a Raney Ni catalyst.     

Lewis Acid‐Catalyzed [3+4] Annulation of 2‐(Heteroaryl)‐ cyclopropane‐1,1‐dicarboxylates with Cyclopentadiene

A novel Lewis acid‐catalyzed [3+4] annulation of 2‐(heteroaryl)cyclopropane‐1,1‐dicarboxylates with cyclopentadiene is reported. This reaction proceeds via an electrophilic attack of the Lewis acid‐activated donor‐acceptor cyclopropane onto cyclopentadiene followed by Friedel–Crafts intramolecular alkylation of the heteroarene substituent. This is the first general example of reactions of donor‐acceptor cyclopropanes wherein the donor substituent serves as a nucleophile. The described annulation represents a convenient approach to bicyclo[3.2.1]octa‐2,6‐dienes with heteroarenes annulated to C(2)‐C(3) bond. Its efficiency was demonstrated for a series of furyl, thienyl, pyrrolyl, benzofuryl, benzothienyl, and indolyl substituted cyclopropanes. Additionally, in the case of 2‐(5‐methyl‐2‐furyl)cyclopropane‐1,1‐diester we observed the predominant formation of product of the [3+4] annulation or the tetracyclic 5,8‐methanocyclopenta[a]azulene derivative, depending on the reaction conditions.     

Dyeing of nylon 6 and silk fabrics with a model disulphide bis(ethylsulphone) reactive disperse dye

The synthesis of a new reactive disperse dye containing the disulphide bis(ethylsulphone) group is described. The dye has been applied to nylon 6 and silk fabrics at a variety of pH and temperature conditions. Optimum dye exhaustion and fixation were achieved at pH 8 and 130 °C. The results of dyeings on both substrates indicate that the model disulphide bis(ethylsulphone) reactive disperse dye shows a higher degree of exhaustion and fixation on silk than on nylon 6. The fastness and levelling properties on both fabrics were good.     

Synthesis and characterization of new aromatic polyimides containing well‐defined conjugation units

A series of aromatic polyimides composed of well‐defined conjugation units were synthesized form 5,5′‐bis(4‐aminophenyl)‐2,2′‐bifuryl (PFDA) and 2,2′‐bis(furyl) benzidine (FurylBZ) with various dianhydrides. The synthesized polyimides emit blue to green light with a quantum yield of 7.3–14.9%, depending on the polymer backbone. In particular, PFDA‐based polymers exhibit extremely narrow photo‐luminescence. The structure, thermal stability, refractive index and dielectric properties of the polymer films were also determined.     

Structure-Activity Relationships for Some Diamine, Triamine and Schiff Base Derivatives and Their Copper(II) Complexes

Ethylenediamine (en), putrescine (pu), diethylenetriamine (dien), dipropylenetriamine (dpta), spermidine (spmd) and their Cu(II) compounds as well as the Schiff bases with 2-furaldehyde (dienOO), 2- thiophenecarboxaldehyde (dienSS) and pyrrole-2-carboxaldehyde (dienNN) of dien and that of dpta with 2- thiophenecarboxaldehyde (dptaSS), were prepared and characterised. They were tested against Bacillus substilis, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Proteus vulgaris and Xanthomonas campestris as antibacterial reagents, the highest activity being exhibited by Cu(dptaSS)(NO(3))(2) complex, which acts as antibiotic. In the antiproliferative tests (vs. T(47)D,L(929) and BHK(21/c13) cell lines) the best results were obtained with Cu(dptaSS)(2+) and Cu(dienSS)(2+). Electronic structure calculations gave for dptaSS and dienSS the higher negative charges on the N atoms. The counter-ions (Br(-), NO(3) (-) and SO(4) (2-)) play an important role by modulating the reagent's selectivity versus the bacteria [Gram(+) or Gram(-)], but they have no effect on the antiproliferative activity.