叔戊基蒽醌法双氧水生产过程中部分降解产物的合成

合成了叔戊基蒽醌法生产双氧水工作液中主要的氢化和氧化降解产物。以苯和叔戊基氯为原料,合成了氢化降解产物:2-叔戊基-9-蒽酮、2-叔戊基蒽,当以2-叔戊基蒽醌(20mmol,5.56g)为基准,分12次间隔10min每次加入nHCl∶nSn=5.6mmol∶2.8mmol时,2-叔戊基-9-蒽酮的收率最高,达到65.8%,2-叔戊基蒽的收率达到16.4%;合成了氧化降解产物:2-叔戊基四氢蒽醌环氧化物,当nNaOH∶nH2O2=1∶1时,收率达到95.0%,后处理简单。     

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。     

Maillard反应香料的制备工艺优化及加香应用研究

以高粱酒基和丙二醇为反应底液,以葡萄糖和天冬氨酸为原料通过Maillard反应制备烟用香料,利用正交设计优化Maillard反应工艺,剖析Maillard反应产物香味成分,考察其在卷烟加香中的应用效果。结果表明,Maillard反应最优工艺条件为n(葡萄糖)∶n(天冬氨酸)=2∶1、反应体系pH 10.5、反应温度95℃、反应时间6 h,糖氨物质的量比对Maillard反应产物的影响最大,反应体系pH、反应时间次之,反应温度对Maillard反应产物的影响相对较小。Maillard反应香料中检出的香味成分主要有12种吡嗪、3种呋喃类化合物及呋喃酮、吡嗪酮类化合物各4种。葡萄糖和天冬氨酸制备的Maillard反应产物以烟丝质量1.0‰的比例添加到卷烟中,可改善卷烟的香气质、香气量,增补甜感,抑杂降刺,提升卷烟吸食品质。     

甘-谷二肽与葡萄糖的Maillard反应及在卷烟中的应用

运用正交试验研究反应温度、反应时间、反应物摩尔比以及初始pH对甘-谷二肽与葡萄糖的Maillard反应产物致香成分的影响,甄选出较佳反应条件,并将反应产物应用于卷烟中。结果表明:较佳的反应条件为采用质量分数85%的丙二醇-水溶液体系,反应温度130℃,反应时间4 h,葡萄糖与甘-谷二肽的摩尔比3∶1,初始pH为8。产物的主要致香成分为吡嗪、2-甲基吡嗪、乙烯基吡嗪、糠醛、5-羟甲基糠醛等。加香试验表明,甘-谷二肽与葡萄糖的Maillard反应产物具有提升卷烟香气质、减少杂气、使烟气柔和细腻等作用。     

催化裂化汽油氧化-萃取脱硫

采用催化裂化(FCC)汽油氧化-萃取深度脱硫工艺,考察了氧化反应条件、萃取剂的种类、萃取剂中的含水量以及剂油比对萃取脱硫效果的影响,并对氧化-萃取前后硫含量及类型硫进行了分析。结果表明:杂多酸/相转移剂/H2O2催化氧化体系是非常有效的氧化脱硫体系;随着油剂比、萃取剂含水量的增加,汽油的脱硫率下降,收率增加,在剂油比1∶1、溶剂的含水量10%条件下,汽油的脱硫率达到80%以上,收率97.5%以上;杂多酸/相转移剂/H2O2催化氧化体系对噻吩环被破坏电子效应强的苯并噻吩及甲基苯并噻吩类硫化合物有很好的反应活性,对电子效应弱的噻吩类硫化合物反应活性较低。     

金属钠形态调控对噻吩金属化反应的影响规律

在以噻吩为原料制备2-噻吩乙醇的反应过程中,减少同分异构体3-噻吩乙醇的生成,关键在于提高中间产物2-噻吩钠的产率.主要研究金属钠的形态对噻吩金属化反应的影响,实现了金属钠颗粒尺寸的调节;当m(油酸):m(钠)=1:50时,2-噻吩钠的产率最高可达851.％.     

pH对L-抗坏血酸与L-脯氨酸/L-丙氨酸Maillard反应产物抗氧化活性的影响

在L-抗坏血酸-L-脯氨酸/L-丙氨酸模型体系中研究了pH对Maillard反应产物的抗氧化活性的影响。Maillard反应产物通过控制不同初始pH(pH=4、5、6、7、8)于140℃加热搅拌2h的条件下制备,并以还原力、1,1-二苯基-2-苦基偕腙肼自由基(DPPH)清除能力和Fe2+螯合能力为指标对其产物抗氧化活性进行分析评价。结果表明,产物的还原力、DPPH自由基清除能力在pH=5时达到最大,Fe2+螯合能力随着pH的增大而增大,而且Maillard反应产物的还原力与在294nm处的紫外吸光度密切相关。     

pH值对L-抗坏血酸与L-脯氨酸/L-丙氨酸Maillard反应产物抗氧化活性的影响

在L-抗坏血酸-L-脯氨酸/L-丙氨酸模型体系中研究了pH值对Maillard反应产物的抗氧化活性的影响。Maillard反应产物通过控制不同初始pH值（pH=4.0、5.0、6.0、7.0、8.0）在140 ℃下加热搅拌2h的条件下制备,并以还原力、1,1-二苯基-2-苦基偕腙肼自由基（DPPH）清除能力和Fe2 螯合能力为指标对其产物抗氧化活性进行分析评价。结果表明：产物的还原力、DPPH自由基清除能力在pH=5时达到最大,Fe2 螯合能力随着pH值的增大而增大,而且Maillard反应产物的还原力与在294nm处的紫外吸光度密切相关。     

1-L-丙氨酸-1-脱氧-D-果糖的合成及在卷烟中的应用

为进一步研究Maillard反应,以丙氨酸、葡萄糖为原料,在甲醇甘油体系中加入一定催化剂进行反应,经分离纯化得到Maillard反应中间体,再运用IR、MS、NMR进行了结构表征,并将这一产物加入卷烟中进行评吸.结果表明:这一单一产物为目标化合物,即1-L-丙氨酸-1-脱氧D-果糖(ADF),其产率为62.7％;ADF在卷烟中具有增浓、增香、减少杂气、改善余味等作用,可以提高卷烟感官质量.     

超临界甲醇中氧化脱除模型物中噻吩硫的研究

传统加氢脱硫往往难以脱除重油中的噻吩类硫化物。利用噻吩类硫化物氧化后的极性增加,在超临界甲醇条件下强化其在极性溶剂中的溶解度,可深度脱除重油中的噻吩硫。以二苯并噻吩(DBT)与十四烷为模型油,甲醇为超临界介质,考察了无催化时反应条件对超临界氧化脱硫性能的影响,不同催化氧化体系的脱硫效率。利用红外光谱、气相色谱-质谱联用对反应产物进行分析以研究脱硫机理。结果表明,在无催化时,反应温度260℃、反应压力8.5～9.0 MPa、反应时间3 h、过氧化二叔丁基作氧化剂且氧硫摩尔比为3:1时,噻吩模型物的脱硫率最高,达42%。在催化氧化体系中,催化剂用量与硫的摩尔比为1:10时催化剂使用效率最高,3种脱硫效果较好的催化氧化体系脱硫率分别达到了47%、45%、45%。FTIR、GC-MS结果表明二苯并噻吩被氧化为相应亚砜并转移至甲醇相,从而实现了硫化物的脱除。     

Improving the Oxidative Stability of Krill Oil-in-Water Emulsions

A positively charged protein (fish gelatin) or a negatively charged protein species (heat-treated milk protein–carbohydrate mixture) was added to a primary krill oil (KO) emulsion stabilized by the phospholipids inherent in KO, with the aim of improving the oxidative stability of KO-in-water emulsions at pH 8.0 (10 % KO). The positively charged fish gelatin deposited on the primary interface of the oil droplets in the primary KO-in-water emulsion improved the oxidative stability of the KO-in-water emulsion as evidenced by the higher eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) remaining and lower propanal produced after accelerated oxidation (40 °C, 25 days). The addition of the negatively charged heat-treated milk protein–carbohydrate mixture containing Maillard reaction products (MRP) to the bulk phase of the emulsion also enhanced the oxidative stability of the KO-in-water emulsion. The addition of MRP to the aqueous phase of phospholipids stabilized emulsion droplets offered more protection to EPA and DHA of the KO emulsions compared to the formation of an additional layer at the interface of the KO emulsion droplet. This suggests that interventions based on addition of antioxidant species to the formulation were more effective for arresting oxidation than increasing the thickness of the droplet interface. The addition of proteins into KO containing emulsion formulations is a promising strategy for protecting omega-3 marine phospholipids against oxidation.     

Antioxidant properties of individual phospholipids in a salmon oil model system

The antioxidant properties of phospholipids (PL) in a refined salmon oil model system were measured by determining changes in the 2-thiobarbituric acid number and decreases in the ratio of docosahexaenoic acid (DHA)/palmitic acid (22:6/16:0) of a fish oil system incubated at 180°C for up to 3 h. The more phosphatidylcholine (PC) added to the oil system, the higher the oxidative stability obtained. The order of effectiveness of commercial phospholipids in inhibiting oxidation and the loss of polyunsaturated fatty acids was as follows: sphingomyelin (SPH)=lysophosphatidylcholine (LPC)=phosphatidylcholine (PC)=phosphatidylethanolamine (PE)>phosphatidylserine (PS)>phosphatidylinositol (PI)>phosphatidylglycerol (PG)>control salmon oil. Nitrogen containing PL, including PE, PC, LPC and SPH, were equally effective in exerting greater antioxidant properties than PS, PG and PI. The inverse relationship observed between the oxidation index (C22:6/C16:0) and color intensity for treatments following 2 h of heating suggests that Maillard-type reaction products may have contributed to the oxidative stability of PL-supplemented fish oils.     

Reducing and stabilizing the viscosity of natural rubber by using sugars: Interference of the Maillard reaction between proteins and sugars

This work is an extension of previous work elucidating the reduction and stabilization of solid natural rubber (NR) viscosity by using sugars. Various amounts of glucose, fructose, sucrose, and maltose were incorporated into fresh NR (FNR), deproteinized NR (DPNR), and synthetic polyisoprene (IR) latexes. The results revealed that all sugars cannot decrease the Mooney viscosity of FNR, while only monosaccharides, that is, glucose and fructose, can significantly decrease the Mooney viscosity of both DPNR and IR by way of a lubrication mechanism. The proteins in FNR can diminish the capability of glucose and fructose to decrease the Mooney viscosity. Furthermore, glucose was found to reduce the occurrence of storage hardening in DPNR by interacting with polar groups of phospholipids at the rubber chain ends. Measurements of browning intensity as well as analysis of Maillard reaction products together with the NR protein–glucose model compound were utilized to confirm that the reduction and stabilization of the viscosity of NR using monosaccharides were interfered by the Maillard reaction between the proteins in NR and the monosaccharides.     

美拉德反应在酱油香精中的应用

本文从美拉德反应的基本原理出发 ,以美拉德反应的产物为基质 ,添加适量的合成或天然香料 ,调配成酱油香精。     

葡萄糖／脯氨酸Maillard反应模型及其产物的烟草加香评价

为开发特色烟用香原料,针对葡萄糖／脯氨酸Maillard反应模型体系,通过正交试验考察了反应时间、反应温度、体系pH和溶刹中乙醇体积分数对产物的紫外可见吸收、挥发性成分及烟草加香效果的影响,确定了适宜的反应条件。结果表明：各因素对产物紫外可见l吸收的影响大小依次为pH〉反应时间〉反应温度〉乙醇体积分数;GC—MS鉴定出33种挥发性成分,多种成分对香气有重要贡献;感官评价表明反应温度105℃、反应时间4h、pH10、乙醇体积分数40％的条件下生成的产物具有良好的烟草加香效果,香气量、香气质较好,杂气、刺激性小。研究表明,葡萄糖／脯氨酸Maillard反应产物具有良好的烟草加香应用价值。     

Effect of two-stage dehydration on retention of characteristic flavor components of flue-cured tobacco in rotary dryer

Two-stage dehydration method of flue-cured tobacco in rotary dryer was experimentally evaluated and compared to the single-stage dehydration process. The characteristic flavor components in dried cut tobacco, including major Maillard reaction compounds and carotenoid degradation products, as well as drying rate were analyzed for different two-stage dehydration operations. The results showed that both the pre-drying temperature and intermediate moisture content had a significant effect on the overall drying rate of cut tobacco during two-stage drying. On the other hand, the retention of characteristic flavor components in tobacco, especially Maillard reaction compounds retention, was influenced significantly by the final drying temperature as well as intermediate moisture content. The 10°C increase in the final drying temperature from 100 to 110°C reduced the retentions of Maillard reaction compounds and carotenoid degradation products by 14.5 and 9.4%, respectively. Change of intermediate moisture contents from 19 to 15% reduced the Maillard reaction compounds retention by 14.7%. Given the consideration of characteristic flavor components’ retention and drying process efficiency, two-stage dehydration of cut tobacco in rotary dryer could reach a better performance as compared with the single-stage dehydration. The cylinder-wall temperature combination of 140/100°C with the 17% intermediate moisture content could be used as the optimal two-stage condition for the investigated flue-cured tobacco.     

Maillard反应及其产物在烟草加香中的作用

制备了甘氨酸等18种单一氨基酸与葡萄糖进行的美拉德反应产物以及复合氨基酸粉．动物水解蛋白与葡萄糖进行的美拉德反应产物,筛选出了两组适合于烤烟加香的混合氨基酸(混合氨基酸A,混合氨基酸B),并以混合氨基酸A为例．初步研究了反应条件(pH、反应温度等)对反应产物性质(如香味特征)的影响。     

美拉德反应产物的抗氧化性及在烟草中应用研究进展

美拉德反应是烟草中一类重要的致香反应,美拉德反应的产物在卷烟工业中有着重要的应用。为进一步推动美拉德反应产物在烟草中的应用研究,对此类反应的机理和影响因素、其反应产物的抗氧化活性及测定方法进行了综述,在此基础上对美拉德反应及其产物在烟草中的进一步利用进行了展望,提出美拉德反应产物在消除卷烟主流烟气自由基方面存在较好的应用前景。     

烟用香料研究进展简介

本文对近十多年来国外烟用香料的研究作一简介 ,内容包括烟叶中香味成分研究 ,烟用香原料合成 ,二萜化合物的开发 ,Maillard反应产物 ,释放型香料及其它。     

液相体系制备乳清蛋白-低聚异麦芽糖复合物

该文将低聚异麦芽糖(IMO)通过糖基化反应引入乳清浓缩蛋白(WPC),制备WPC-IMO复合物。通过测定WPC-IMO复合物的接枝度确定反应条件。应用响应面分析法对WPC-IMO Maillard反应过程中的各影响因素进行分析,优化各反应条件参数,以获得最大的接枝度。结果表明,在温度90℃,底物配比m(WPC)∶m(IMO)=1∶3.125、pH=9.86、反应时间78.57 min的条件下复合物的接枝度最大,达25.75%。并对该条件进行了验证实验,证实了通过响应面法的预测值和实际值一致。最后,通过SDS-PAGE验证了WPC-IMO Maillard反应的发生。