气相色谱-质谱法分析蜂胶和杨树胶的化学成分

利用GC-MS分析方法分别对蜂胶和杨树胶进行了分离鉴定,两种物质各鉴定出80多种化合物。蜂胶中芳香酸、醇及酯类物质明显高于杨树胶中的含量,杨树胶中总黄酮和萜烯类化合物的含量略高于蜂胶中总黄酮和萜烯类化合物的含量。另外,可以初步确定苯甲醇、3,4-甲氧基肉桂酸、3-苯基-2,3-二甲基环丙烯、2,6-二羟基-4-甲氧基查耳酮和柯因等几种物质在蜂胶和杨树胶中的含量有较大的差异。因此,可以把它们作为蜂胶中的标志性物质进行检测、辨别。     

获准用作食品乳化剂,稳定剂和增稠剂的树胶分泌物

概述了一种天然产物被批准作为有明确技术效果的食品添加剂以前须经历的审定程序和大量与安全有关的毒性，探讨了被视为重要林产品的某些树胶分泌物所涉及的专门问题。很多热带树种，特别是生长在世界最热和最干燥地区的一些树种，能够分泌树胶，在被采割或因动物啃食，白蚁和大风等原因受到伤害的情况下分泌更多。只有三种可以得到的商品树胶分泌物被允许作食品添加剂，它们是：阿拉伯树胶，刺苹波树胶，黄芪胶。     

Drought tolerance of Acacia karroo, a native tree species to South Africa, in Beijing

Acacia karroo is an indigenous, strong drought-tolerant and widely planted tree in South Africa. In order to match the plant with its adaptation to forest sites in China, it is important to know the drought-tolerance of this species under Chinese forest site conditions. Our study was carried out in cinnamon soils in Beijing and with Platycladus orientalis, the most drought-tolerant tree in Beijing, as control. Physiological parameters of young plants of the trees were measured and divided into three groups in response to soil drying. The first group included root activity, ABA content in roots and peroxidase (POD) activity in leaves. Their values changed similarly to those of P. orientalis and dramatically increased to maximum values when the soil water content (SWC) decreased from its normal level of 20% to 7.6% where the three indices decreased dramatically when SWC was reduced further from 7.6%. The second group of parameters included the contents of proline, soluble protein and malondialdehyde (MDA). Their values showed greater variation than those of P. orientalis and significantly increased when SWC decreased from 20% in response to soil drying. However, the proline and soluble protein contents fluctuated in A. karroo at a lower level than those in P. orientalis. In contrast, the content of MDA in A. karroo was much higher than that in P. orientalis which almost did not increase in the drying soil. The third group of parameters consisted of soluble sugar, superoxide dismutase (SOD) and catalase (CAT). These parameters showed greater diversity and fluctuations among the three varieties of A. karroo compared with the control in response to soil drying. These results suggest that A. karroo is characterized as a strong, drought tolerant species in most of physiological parameters but weaker than P. orientalis in membrane lipid antioxidation.     

无灰磁性粉笔制作法

一、原料配方（重量份）碳酸钙60，聚乙二醇7．5，阿拉伯树胶15，三氧化二铁粉12．5。水40，颜料30。二、制作方法将阿拉伯树胶溶解于水中，加入碳酸钙、聚乙二醇、三氧化二铁粉，混合搅拌60分钟。然后在70℃温度下干燥30分钟，放入模具中挤压成型。这样生产出来的粉笔白中微带红色。     

用加拿大树胶制备永久性植物螨类标本的方法

笔者前文介绍了植物螨类简易玻片标本及扫描电镜标本的制作方法（见《农业新技术新方法译丛》１９９５，Ｎｏ１，编者注），本文是前文的续篇，介绍应用新的固定方法采用加拿大树胶制备以往无法制成的永久性玻片标本。     

天然食用树胶的开发利用研究

近年来,在天然食用树胶特性和开发利用研究方面不断取得了一些新的成果和突破。综述这些研究进展对天然食用树胶的进一步利用具有重要意义。     

吃莴苣叶的日本蜜蜂

蜜蜂采集花粉和花蜜之外,西方蜜蜂还采集来源于植物嫩芽的树胶。日本蜜蜂和西方蜜蜂不同,日本蜜蜂不采集树胶,观察发现当日本蜜蜂受胡蜂袭击后,很多蜜蜂啃咬蜂巢前植物的叶子。     

2018版蜂胶国家标准解读

近日,蜂胶国标起草组对2019年2月1日实施的2018版蜂胶国家标准进行了解读。其中,新国标与2009版国标的不同和亮点有两个:一、在蜂胶真实性要求中,增加了蜂胶真实性的鉴别方法。采用国家标准《蜂胶中杨树胶的鉴别方法》(GB/T34782)和行业标准《蜂胶真实性鉴别方法》(GH/1087),这两个方法能够有效的检测出是否用杨树胶冒充蜂胶或掺入蜂胶,以及是否在蜂胶中掺入非蜂胶物质。     

三亚市黄秋葵栽培技术初探

<正>黄秋葵(Hibiscus esculentus L.)又名黄葵、羊角菜、咖啡黄葵等,属于锦葵科秋葵属一年生草本植物。一般认为原产于非洲,但最近调查发现我国也有野生种,现在     

气相色谱-质谱法分析蜂胶与杨树胶化学组分及鉴别研究

以气相色谱-质谱联用仪分别对蜂胶和杨树胶的化学组分进行了分离鉴定,共鉴定出75种物质。初步确定两种样品中2,6-二羟基-4-甲氧基查耳酮、高良姜素和柚木柯因的含量有明显差异,而且仅在杨树胶中发现了愈创木醇、1-甲基-4-(6-甲基-5-庚烯-2-基)苯、2-苯基苯并咪唑。结果表明,可将上述物质作为蜂胶中的标志性物质进行检测与辨别。