微波辐照巴旦杏核壳制备活性炭及其吸附性能研究

以巴旦杏核壳为原料,采用微波辐照法制备活性炭。考察了活化条件对活性炭得率和吸附性能的影响。研究结果表明,在活化剂种类、活化剂用量、微波功率和辐照时间4个因素中,微波辐照时间对活性炭质量指标影响最大,延长时间可以提高其产品的得率和吸附性能。巴旦杏核壳基质活性炭的最佳制备工艺：巴旦杏核壳10g,固液比1：3（g：mL）,磷酸质量分数40％、浸溃24h,微波功率640W、活化时间16min。在此条件下制得的活性炭的亚甲基蓝吸附值为231．5mg/g,活性炭得率为56．8％。二级动力学模型能很好的描述巴旦杏核壳活性炭对亚甲基蓝大分子的吸附动力学过程。吸附符合Freundlich吸附等温线方程。     

Myrtle hydroalcoholic extracts obtained from different selections of Myrtus communis L.

Hydroalcoholic extracts obtained from myrtle berries of five different selections were studied to obtain unique clones. During the typical 40 day maceration period, dry matter, pH, colour, and anthocyanins, were analyzed. Variability among myrtle selections was observed both in fresh berries (yield berries/plant, weight of the berries, number and weight of seeds per berry) and in the hydroalcoholic extract physical–chemical characteristics (dry matter, colour intensity, tint and anthocyanins). Reversed-phase high performance liquid chromatography (RP-HPLC) analysis with photodiode array detection (PDA) was used for anthocyanins characterization in myrtle hydroalcoholic extracts. Anthocyanin qualitative composition was the same in all selections, but varied strongly in its total amount. D was the selection with the characteristics most suitable for industrial use.     

新疆特色休闲小食品开口巴旦杏的工艺研究

以巴旦杏为原料,通过适宜的处理,浸泡、漂洗、烘干等方法,获得特色风味的休闲开口巴旦杏产品,应用单因素试验和正交试验对巴旦杏开口最佳工艺参数进行研究。通过开口率和感官评价结果,确定盐酸浓度为20%、在60℃条件下浸泡40min为巴旦杏开口的最佳工艺参数。     

Octane-1,3-diol and its derivatives from pear fruits

 In extracts obtained by liquid-liquid extraction from seven pear (Pyrus communis L.) cultivars, octane-1,3-diol, 5(Z)octene-1,3-diol, methyl 3-hydroxyoctanoate, ethyl 3-hydroxyoctanoate and ethyl 5(Z)-3-hydroxyoctenoate were identified by capillary gas chromatography-mass spectrometry. Evaluation of the absolute configuration was achieved by multidimensional gas chromatography, using a polar achiral column (DB-Wax) and a chiral main column (2,3-di-O-acetyl-6-O-tert-butyldimethylsilyl-β-cyclodextrin/OV 1701). Comparison of retention times of synthesized optically enriched reference compounds with those of isolated diols and hydroxy esters revealed (R)-configurations for the 3-hydroxy derivatives, exhibiting enantiomeric excesses greater than 99%. In addition, (2S, 4R)- and (2R, 4R)-2-methyl-4-pentyl-1,3-dioxane as well as (2S, 4R)- and (2R, 4R)-2-methyl-4-(2′(Z)-pentenyl)-1,3-dioxane, products formed by acetaldehyde and octane-1,3-diol or 5(Z)-octene-1,3-diol, respectively, were detected in pear fruits. Received: 13 February 1997     

The specific chemical profile of Mediterranean propolis from Malta

Seventeen Maltese propolis samples were studied by GC–MS after silylation. They exhibited the typical Mediterranean chemical profile, rich in diterpene compounds (18–92% of TIC, GC–MS): 32 individual diterpenes were identified; 22 of them were present in each specimen. The other abundant compound group was that of sugars and sugar derivatives. In some samples, however, another compound group was observed (0–12% of TIC, GC–MS); the corresponding mass spectra were consistent with mono- and sesquiterpenyl esters of substituted benzoic acids. Two new propolis constituents of this group, daucane diterpene esters of hydroxybenzoic acids, were isolated. Their origin is suggested to be Ferula communis, as they are taxonomic markers for this species. All propolis samples were active against Staphylococcus aureus but only those with high concentrations of terpenyl esters showed antifungal activity against Candida albicans. The present results confirm that Mediterranean propolis is a valuable natural product with potential to improve human health.     

Evaluation of Castor Oil Samples for Potential Toxin Contamination

Castor oil and its derivatives are widely used as a chemical feedstock for production of lubricants and greases, engineering plastics, plasticizers and surfactants. It also has wide application in consumer goods such as lipstick, deodorants and medicinal uses. Due to concerns about the possible presence of the ricin toxin in the oil, we have tested a collection of castor oils processed using different approaches, including cold‐pressed, US Pharmaceutical (USP) grade, and neutralized oils. Water soluble proteins were extracted from oil samples into phosphate‐buffered saline containing 0.05 % bovine serum albumin (PBSB) and analyzed for potential ricin contamination by ELISA. Our results indicate that only the cold‐pressed castor oil contained measurable levels of the toxin, estimated to be 35 ± 13 μg/l. A normal oral dose of castor oil for laxative use is 14 ml, so even cold‐pressed castor oil would be well below the toxic level of 1–5 μg/kg body weight. However, the presence of the toxin indicates that other soluble proteins, including allergens, may be present in cold‐pressed castor oil.     

芦苇叶黄酮类提取物体内体外抗氧化性研究

研究醇提芦苇叶黄酮类提取物的体内体外抗氧化性。通过测定芦苇叶黄酮类提取物对体外大鼠肝组织匀浆、肝线粒体丙二醛（malondialdehyde,MDA）生成量及大鼠红细胞溶血的影响。结果表明：芦苇叶黄酮类提取物在0.5～10 mg/mL范围内能抑制大鼠肝组织匀浆及肝线粒体MDA的生成,抑制大鼠红细胞溶血,具有量效关系,表明芦苇叶黄酮类提取物具有体外抗氧化效果。随着剂量的增加,芦苇叶黄酮类提取物可提高S180荷瘤小鼠血清中谷胱甘肽过氧化物酶（glutathione peroxidase,GSH-Px）和超氧化物歧化酶（superoxide dismutase,SOD）活性,降低MDA含量,从而提高其体内抗氧化活性,当剂量达到300 mg/（kg·d）时,芦苇叶黄酮类提取物与10 mL/（kg·d）的氟尿嘧啶均可促进荷瘤小鼠体内抗氧化能力的提高,且二者间没有显著性差异。     

Effect of different technological processes on the chemical composition of myrtle (<Emphasis Type="Italic">Myrtus communis</Emphasis> L.) alcoholic extracts

Several technological processes were applied to improve the extraction efficiency in the production of myrtle (Myrtus communis L.) liqueur. The variations in the chemical composition of myrtle hydroalcoholic extracts were monitored in a laboratory scale for 40 days after the application of: double dose of berries; ultrasonic extraction; enzymes, to improve either the color or aroma extraction; and atmosphere saturated with nitrogen to improve the stability against oxidative degradations during extraction. Moreover, freezing at −20 °C was applied to myrtle berries as a technological strategy to prolong the use of berries, and macerates were obtained after 4, 8, and 12 months. Chemical investigation of macerates was performed using different analytical methods such as GC and GC-MS for the volatile compounds, HPLC-PDA for free anthocyanins, and spectrophotometric analysis for CIE L*a*b* coordinates and total anthocyanins. Dry matter and pH were also monitored during maceration. Among the different technological processes, the nitrogen-modified atmosphere was the most suitable technique to be applied in industrial scale. An industrial trial was applied with this process and alcoholic extracts and liqueurs have been obtained. The liqueur maintained a higher amount of anthocyanins, better CIE L*a*b* parameters and superior organoleptic characteristics compared to the traditional storage.     

蓖麻LEA基因家族的全基因组鉴定、分类及其进化分析

基于已公布的基因组和EST数据对蓖麻LEA基因家族进行全面鉴定和系统命名,并在此基础上分析了其基因结构、生化特征、进化关系和表达特性。结果显示,蓖麻基因组中存在27个LEA基因,分属于LEA_1、LEA_2、LEA_3、LEA_4、LEA_5、LEA_6、dehydrin和SMP 8个亚家族,它们散布于24条scaffold上,含有0～2个内含子不等,且其中有3个基因存在可变剪接;根据编码蛋白中的Pfam结构域类型及其进化关系,将这些LEA基因依次命名为RcLEA1-1和-2、RcLEA2-1和-2、RcLEA3-1至-3、RcLEA4-1至-7、RcLEA5-1和-2、RcLEA6-1和-2、RcLEA7-1至-5和RcLEA8-1至-4;利用BLAT分析基因表达谱显示,在叶片、花、II/III期胚乳、V/VI期胚乳和种子等组织中,所有RcLEA基因都有表达;启动子分析表明,RcLEA基因的启动子区富含LTRE、ABRE、MYC、MYB和W-box等逆境应答相关顺式作用元件。     

蓖麻花序特征及花芽分化的初步研究

对蓖麻花序特征、顶芽分化及内源IAA和ABA含量变化进行初步研究,结果表明：不同品种（系）间雌花率及雌花密度均存在极显著差异。蓖麻雌花并非完全单性花,各品种（系）雌花均存在退化雄蕊痕迹,但其发生率不同,单雌后代品系明显高于供试品种。单雌花序与两性花序的雌花中均存在退化雄蕊,且无显著差异,但花序中下部与上部之间差异显著。顶芽石蜡切片观察表明：蓖麻在5叶期以前,其顶芽基本处于叶芽生长阶段;在6～9叶期,顶芽逐渐进入花芽分化、生长阶段,顶芽内源IAA、ABA含量变化也十分明显。不同性别花序和花的内源激素含量显示：IAA含量,单雌花序〉雌花〉两性花序〉雄花;ABA含量,雄花显著高于雌花,但两性花序却明显低于单雌花序;IAA/ABA值,雌花〉单雌花序〉两性花序〉雄花;说明IAA含量和IAA/ABA相对含量可能在花性分化中具有较为重要的作用。