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。     

马齿苋红色素的提取及其稳定性研究

为生产各种食用品、化妆品、医药药品等色素新产品提供重要原料,研究马齿苋红色素的提取条件和稳定性。以水作提取剂,在室温下浸提24h,用紫外分析法研究色素的稳定性。结果得到在干燥的马齿苋植物粉末中加适量水,在室温下浸提24h,可以得到所需的水提取液。由此可知色素在320nm有最大吸收峰,该色素水溶性较好,pH值对色素的稳定性影响较大,但热稳定性良好。苯甲酸钠、柠檬酸、醋酸、蔗糖及葡萄糖等食品添加剂对色素无明显影响,淀粉对其影响较大,耐光性较差。氧化剂、还原剂中除抗坏血酸对色素的影响明显外,其他均无明显影响,金属离子对其影响较小。     

紫红色四季报春花色素的提取及稳定性研究

以紫红色四季报春花为原料提取色素,并对该色素的稳定性进行研究。结果表明,适宜的提取溶剂为pH=1的95%乙醇溶液,该色素在382 nm处有最大吸收峰;该色素热稳定性差,有较强的耐光性,耐氧化性,还原性差,在酸性条件下不稳定;金属离子Na+、K+、Mg2+、Zn2+对色素的影响较小,而Fe3+对该色素稳定性的影响较大;常用食品添加剂(葡萄糖、蔗糖、可溶性淀粉和柠檬酸)对该色素色泽无不良影响。     

鸡骨草色素的超声提取及稳定性研究

采取超声波辅助提取鸡骨草色素的单因素实验和正交试验,确定最佳工艺条件,并研究色素的稳定性。超声提取法的优化工艺条件为:料液比为(g∶mL)1∶50,超声辅助功率140W,提取时间30min,提取温度为70℃,提取剂为50%乙醇。鸡骨草色素对光的稳定性较好;在室温下亦很稳定,温度升高其降解速度加快,对热稳定性较差;食品添加剂对其稳定性影响较小;耐氧化性较好,耐还原性稍差;K+、Na+、Mg2+和Ga2+等离子对色素基本无影响,Fe3+、Zn2+和Cu2+等对其稳定性有一定影响。该方法提取色素缩短了提取时间,更有效、更经济。     

金银忍冬果实色素的提取及稳定性研究

以金银忍冬果实为原料,研究其色素的提取工艺及稳定性。结果表明：金银忍冬果实色素易溶于乙醇、丙酮、石油醚,是脂溶性色素。质量分数为95％的乙醇是最佳提取剂。酸、碱、光、热稳定性较好。60℃条件下色素的提取效果最佳。Na^＋、Al^3＋、Mn^2＋、Zn^2＋金属离子对色素的稳定性无影响,且有不同程度的护色作用。而Fe^3＋、Cu^2＋对色素的影响较大。氧化还原剂、食品添加剂对其稳定性影响较小。     

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。     

桔皮色素的超声提取及其稳定性的研究

对桔皮色素的超声提取及其稳定性进行了研究。研究结果表明,桔皮色素对还原剂Na2SO3的耐受性强,对氧化剂H2O2的耐受能力较差;pH为3-9时,色素稳定性好;温度对桔皮色素的影响较小;强光对色素的影响较大;而Na^＋、Mg^2＋、Mn^2＋、Ca^2＋、Cu^2＋、Fe^3＋等金属离子对色素的稳定性均有一定程度的影响,其中Fe^3＋对色素影响作用最大。     

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。     

紫番薯色素和紫洋葱色素的稳定性比较研究

文章研究了温度、pH值、金属离子、氧化剂和还原剂等对紫番薯色素和紫洋葱色素两种色素稳定性的影响。实验结果表明,紫番薯色素和紫洋葱色素的热稳定性好;紫洋葱色素在酸性环境下具有更好的稳定性,而紫番薯色素则在碱性环境下具有更好的稳定性;金属离子K+、Na+、Mg2+对两种色素的影响均不大,但Fe3+、Cu2+对色素的影响较大。紫番薯色素受氧化剂和还原剂的影响较大,而紫洋葱色素耐受氧化剂和还原剂的能力较强。总之,两种色素均具有较好的化学物理稳定性,具有良好的开发利用前景。     

一串红色素的提取及其稳定性研究

研究了一串红色素的提取原理和方法,并对该色素的稳定性进行了验证。结果表明：该色素在酸性条件下对热、光均具有良好的稳定性,具有开发应用价值。     

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。