千根草红色素的提取及其稳定性研究

研究了千根草红色素的提取条件和稳定性。以乙醇作提取剂,用紫外分析法研究色素的稳定性。得到乙醇提取的适宜工艺条件是:以pH=3的65%乙醇溶液,原料与乙醇的质量与体积比为1∶10,在室温下浸提24h。色素在320 nm有最大吸收峰,该色素水溶性较好,在pH值1~9时具有良好的稳定性,热稳定性也良好。蔗糖、葡葡糖和盐等食品添加剂对色素无影响,但淀粉对其影响较大,耐光性较差。影响明显的氧化剂有(NH4)2S2O8、还原剂有抗坏血酸,金属离子对其影响较大。     

天然楮果色素提取工艺的优化

以乙醇为溶剂从楮果中提取色素,测定了楮果色素的最大吸收波长及pH值稳定性,优化了提取工艺条件。结果表明,楮果色素的最大吸收波长为485nm,在pH值1～9的溶液中稳定性良好;通过单因素实验和正交实验确定最优提取工艺条件为：以80%乙醇作浸提液、料液比1∶35（g∶mL）、浸提温度40℃、浸提时间2h。为大规模开发利用天然楮果色素资源奠定了基础。     

玫瑰花色素的提取与稳定性研究

用单因素法和正交试验法研究玫瑰花色素的提取工艺及其稳定性。结果表明,影响提取的因素分别为pH〉料液比〉乙醇浓度〉温度;最佳提取工艺为：pH=2,料液比1：10,乙醇浓度为70％,提取温度为65℃。玫瑰花色素在弱酸性、中性及弱碱性环境中、在低于70℃或光照条件下具有较好稳定性,且柠檬酸、蔗糖、食盐等常见食品添加剂对色素无影响。     

枸杞食用色素的提取及稳定性研究

采用有机溶剂浸提法提取宁夏枸杞中的食用色素。实验表明,以乙醇为提取溶剂,枸杞食用色素制备的影响因素主次分别为提取温度乙醇浓度提取时间料液比。最佳提取工艺为:以无水乙醇为提取剂,料液比1∶9,45℃提取1. 5 h,此时枸杞色素的提取率最大。同时研究了枸杞色素的稳定性,研究表明:枸杞色素耐光性、耐高温性好,在酸性介质、还原剂以及常用食品添加剂存在的条件下也有较好的稳定性。     

天然紫背天葵红色素的初步研究

从紫背天葵中提取天然红色素的工艺条件是 :以体积分数是 30 %的乙醇 -水溶液作提取剂 ,温度为 5 0℃ ,时间为 3h ,原料与提取剂配比为 1g∶7mL。对该色素稳定性研究的结果表明 ,紫背天葵红色素在pH≤ 4的条件下对热的稳定性好 ,在此条件下加入果糖、葡萄糖、蔗糖、淀粉或Na+ 、K+ 、Mg2 + 、Zn2 + 、Ca2 + 等金属离子时色素颜色不变 ,但Fe3 + 的存在会使该色素颜色改变。pH≥ 5时 ,色素颜色发生变化。     

长春花红色素提取及稳定性研究

研究了长春花红色素的提取条件和稳定性。以乙醇作提取剂提取长春花红色素,比较了pH值、温度、食品添加剂、氧化剂和还原剂、金属离子以及光照对长春花红色素稳定性的影响。结果表明：最佳提取工艺条件是以pH=3的65％乙醇溶液为提取液,原料与乙醇的质量与体积比为1：250,室温下浸提24h;食品添加剂（淀粉）、还原剂（抗坏血酸）、金属离子、光照对长春花红色素稳定性有较大影响。     

天然茶叶染料的提取及其稳定性的研究

用水煮法提取了天然茶叶染料,研究了茶叶色素的吸收光谱。对固液比、提取温度、浸提剂酸度、反应时间等提取条件进行了研究,并测定了色素在不同pH、温度等条件下的稳定性。结果表明,提取茶叶色素的最佳工艺条件为固液比1∶20,在沸煮(100℃)的条件下提取50分钟。该色素受pH影响较明显,对氧化剂、还原剂较敏感,但耐热稳定性较好。金属离子Ca2+、Cu2+、Zn2+、Mg2+、Na+、K+、Pb2+、Sn2+、Ni2+的存在对色素色泽基本无影响,Al3+、Fe2+、Fe3+的存在对色素有不良影响。茶叶色素易溶于水、乙醇、低浓度乙酸等极性溶液,不溶于苯、丙酮、氯仿、乙醚等非极性溶剂,属水溶性色素。     

车前草色素提取及稳定性研究

研究了车前草色素的提取条件和稳定性。以水为提取剂提取车前草色素,比较了pH值、温度、食品添加剂、氧化剂和还原剂、金属离子以及光照对车前草色素稳定性的影响。结果表明：最佳提取工艺条件是以水为提取剂,料液比为1：80,在室温下浸提24h;食品添加剂（淀粉）、还原剂（抗坏血酸）、金属离子（Co^2＋、Fe^3＋）、光照对长春花红色素稳定性有较大影响。     

微波辅助提取牛蒡叶中绿色素及稳定性研究

采用微波提取法从牛蒡中提取绿色素，在单因素实验基础上，通过正交试验优化提取工艺条件。实验结果表明，以无水乙醇为提取剂，料液比为20：1，微波功率为500W，微波作用时间为90s，提取温度75℃，在此条件下绿色素提取效果最佳。各因素对牛蒡中绿色素提取率的影响为：乙醇体积分数〉料液比〉提取温度〉微波功率〉微波作用时间。对牛蒡中绿色素的稳定性进行考察，结果表明，温度对牛蒡中的绿色素影响不大；不同pH对牛蒡中绿色素稳定性几乎无影响；A1^3＋、Cu^2＋、Mg^2＋、Zn^2＋对牛蒡中绿色素的稳定性影响较大，而Fe^3＋对牛蒡中绿色素的稳定性影响较小；氧化剂对牛蒡绿色素的稳定性基本无影响，还原剂对牛蒡绿色素的稳定性影响较大。     

从高粱中提取红色素的研究

高粱红色素是一种安全无毒的色素,本文研究了用乙醇从高粱中提取红色素的方法,探讨了乙醇浓度、料液比、提取温度、提取时间及pH值对提取的影响,结果表明:用pH为3的60%乙醇液在料液比为1∶5(g/L)的条件下70℃回流提取2.0 h,提取效果最好。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。