三种温州蜜柑果实香气成分的研究

 【目的】研究‘国庆1号’、‘宫川’和‘大叶尾张’3种温州蜜柑果实的香气成分及其差异。【方法】利用顶空固相微萃取技术-气质联用技术（HS-SPME-GC-MS）,对3种温州蜜柑果实的香气成分进行分析测定。【结果】从3种温州蜜柑果实中分别检测到65、36和55种挥发性成分,总含量分别为584.67 μg•g-1、505.29 μg•g-1和494.63 μg•g-1。在3种果实中有29种相同的成分。独有的香气成分中,‘国庆1号’有12种,‘宫川’有5种,‘大叶尾张’有2种。【结论】D-柠檬烯、γ-松油烯、β-月桂烯、α-蒎烯、芳樟醇和辛醛是3种果实中主要的特征香气成分。‘国庆1号’特征香气成分的含量高于‘宫川’和‘大叶尾张’的。     

蟠桃采后贮藏前后香气成分变化的研究

[目的]分析研究采后新疆蟠桃在贮藏前后期果实香气成分的变化.[方法]采用顶空-固相微萃取( HS - SPME)与气-质联用(GC - MS)技术对蟠桃果实香气成分进行提取和分析;比较溶剂萃取(LLE)、水蒸气蒸馏(SDE)和HS - SPME 3种提取方法对蟠桃香气成分分析的影响.[结果]HS - SPME最佳萃取条件为萃取头50/30μm DVB/CAR/PDMS灰色,萃取时间40 min,萃取温度50℃;HS - SPME - GC - MS在蟠桃果实贮藏前后期分别检测出53和44种挥发性物质.[结论]贮藏前后期蟠桃果实所含的挥发性成分有较大的差异,作为蟠桃香气的特征组分酯类和内酯类物质在贮藏第4周后含量显著减少.     

黄兰叶片和花瓣挥发性成分及其抑菌效果

采用顶空固相微萃取和气象色谱质谱技术研究了黄兰(Michelia champak L.)叶片和花瓣的挥发性成分;并提取叶、花挥发物精油,测定了不同质量分数的精油对大肠杆菌ATCC6739、金黄色葡萄球菌ATCC6538、枯草芽孢杆菌CMCC63501生长的影响。结果表明,黄兰叶片与花瓣的挥发性成分中都含有香叶烯、β-榄香烯、石竹烯等物质,叶片中的挥发性有机成分都是萜烯类物质,而花瓣的挥发性有机成分中除了萜烯类物质外,还含有较多的芳樟醇等醇类物质和安息香酸甲酯等酯类物质;黄兰叶片与花瓣的精油对大肠杆菌没有抑制作用,但质量分数为2.5%的精油对金黄色葡萄球菌、枯草芽孢杆菌具有明显的抑制作用,其中2.5%的叶片精油对枯草芽孢杆菌的抑菌率达到68.20%。     

绵羊中草药饲料添加剂预试初报

为了帮助我国北方旱区或半干旱区绵羊度过草枯严寒的漫长冬、春季，开发研制一种能够提高现有草料利用率的绵羊中草药饲料添加剂。根据中兽医药学的辨证施治理论，采用小鼠日粮添加倍量秸秆粉和不同中草药复方的方法，在120只小鼠上进行了增重率和重料比的中草药复方的筛选研究。结果表明，以益气养血和消食健胃为主的两个中草药复方能够较好地改善小鼠的增重率和重料比。     

德国及蒙古沙棘品种无性系生物学和观赏性价值评估

沙棘由于其有丰富的内含物和多方面的用途正被作为＂新兴水果＂而赢得了人们越来越多的重视和喜爱.通过在柏林Baumschulenweg的育种工作,到目前为止,已经育成不同成熟期的5个雌性和4个雄性沙棘品种.更多的由欧洲和蒙古原生种产生的杂交选育工作仍在进行中.将这些无性系按照其生物学和果实性状进行评估.就单个性状来讲,各品种之间的差异非常大（比如维生素的含量在17～340mg/100g之间变动,胡萝卜素的变动范围为6.5～23.8mg/100g）.这表明,进一步的育种改良完全有可能.所有用于比较的沙棘品种由在德累斯顿Pillnitz进行的育种工作获得,这些品种将被进一步研究.为了保险起见,以及为了解决后来有可能产生的育种及植物病理学方面的问题,必须尽可能保存现有的所有的某一品种的基因多样性.为此目的,由国家资助扶持的基因库的建立是很有必要的.     

膨大处理对鲜食葡萄酚类物质及抗氧化活性的影响

研究膨大处理对‘无核白’(Thompson Seedless)‘维多利亚’(Victoria)‘奥古斯特’(August)3种鲜食葡萄品种酚类物质及抗氧化活性的影响。将奇宝和益果灵按体积比1∶1混合后,稀释10 000倍,对葡萄浸穗处理1次,定期采样,分别测定3种鲜食葡萄处理组和对照组的总酚、总黄酮、总黄烷醇以及铜离子还原力、铁氰化钾还原力、金属螯合力、DPPH·清除力和羟自由基清除力。结果表明,膨大处理可减少‘无核白’葡萄果实酚类物质质量分数并减弱其抗氧化活性;可增加‘奥古斯特’葡萄果实酚类物质质量分数并增强其抗氧化活性;可减少‘维多利亚’葡萄果实酚类物质质量分数并减弱铜离子还原力、铁氰化钾还原力、DPPH·清除力,但会使金属螯合力、羟自由基清除力增强。     

低温风干工艺下酱鸭加工过程中品质特性变化规律研究

为改善酱鸭的质地、色泽和风味,本试验在传统酱鸭加工工艺的基础上,引入低温风干工艺制备酱鸭,并研究其加工过程中理化特性(水分含量、色泽、剪切力值、质构特性)和挥发性风味成分的变化。结果表明,在加工过程中,酱鸭水分含量从76.55%降至58.27%(P0.05);与原料肉相比,L~*值在风干6 h显著降低,a~*值在腌制和风干结束下降,b~*值和咀嚼性在酱制阶段增加,杀菌阶段下降,硬度在酱制阶段升高,而弹性和内聚性均在杀菌阶段降低;与风干24 h相比,胶着性在杀菌阶段降低(P0.05),剪切力值先升高后下降。酱鸭挥发性风味成分分析显示,酱鸭成品有70种挥发性风味成分,主要为萜烯类、醛类、呋喃类、酮类、烃类和醇类;其中,莰烯、己醛和2-戊基呋喃是酱鸭成品主要的特征风味成分,分别占总相对含量的16.51%、10.44%和11.88%。本试验结果为低温风干工艺下酱鸭品质变化特征的研究提供了一定的理论依据。     

Secretion of Natural and Synthetic Toxic Compounds from Filamentous Fungi by Membrane Transporters of the ATP-binding Cassette and Major Facilitator Superfamily

This review provides an overview of members of the ATP-binding cassette (ABC) and major facilitator superfamily (MFS) of transporters identified in filamentous fungi. The most common function of these membrane proteins is to provide protection against natural toxic compounds present in the environment of fungi, such as antibiotics produced by other microorganisms. In plant pathogenic fungi, these transporters can also be an important determinant of virulence on host plants by providing protection against plant defence compounds or mediating the secretion of host-specific toxins. Furthermore, they play a critical role in determining base-line sensitivity to fungicides and other antimycotic agents. Overexpression of some of these transporters can lead to the development of resistance to chemically-unrelated compounds, a phenomenon described as multidrug resistance (MDR). This has been observed in a variety of organisms and can impose a serious threat to the effective control of pathogenic fungi.     

Combined effect of generally regarded as safe (GRAS) compounds andTrichoderma harzianum on the control of postharvest diseases of rambutan

Botryodiplodia theobromae, Colletotrichum gloeosporioides andGliocephalotrichum microchlamydosporum are the causal fungi of the rambutan postharvest diseases stem-end rot, anthracnose and brown spot, respectively. Two different treatments of rambutan fruits(Nephelium lappaceum) against the three pathogens were compared: potassium metabisulphite (250 ppm) or cinnamaldehyde (30 ppm), each combined withTrichoderma harzianum (TrH 40). The application of TrH 40 and potassium metabisulphite effectively controlled the incidence and severity of the three postharvest diseases and maintained the overall quality and color of the fruit under low temperature storage at 13.5°C and 95% r.h. for 18 days. The greatest effect of this treatment was shown onG. microchlamydosporum. Cinnamaldehyde affected the growth and germination of TrH 40, whereas potassium metabisulphite did not. http://www.phytoparasitica.org posting Nov. 4, 2001.     

The discovery of HNPC‐A3066: a novel strobilurin acaricide

BACKGROUND: Although more than ten strobilurin analogues have been commercialized since 1996 as fungicides, only one was available as an acaricide as of 2003. To search for novel strobilurin analogues with unique biological activities, a synthetic screening programme was carried out. RESULTS: Syntheses of compounds analogous to the commercialized fungicide metominostrobin and the acaricide fluacrypyrim led to the discovery of a lead compound, (E)‐2‐{2‐[[3,5‐bis(trifluoromethyl)phenoxy]methyl]phenyl}‐2‐(methoxyimino)‐N‐methylacetamide (3b), that showed moderate acaricidal activity against Tetranychus urticae Koch. Compound 3b has a 3,5‐(CF₃)₂‐phenoxymethyl group instead of the unsubstituted phenoxy substituent in metominostrobin. Optimization of compound 3b was achieved by introducing an oxime ether bridge along with an alkylthio(alkyl) branch in place of the oxymethylene chain between two aromatic moieties, as well as by replacing the methoxyiminoacetamide group with a methoxyacrylate structure, leading to (E)‐ methyl 2‐{2‐[[[(Z)[1‐(3,5‐bis(trifluoromethyl)phenyl)‐2‐methylthioethylidene]amino]oxy] methyl]phenyl}‐3‐methoxyacrylate (6c) and (E)‐ methyl 2‐{2‐[[[(Z)[1‐(3,5‐bis(trifluoromethyl)phenyl)‐1‐methylthiomethylidene]amino]oxy]methyl]phenyl}‐3‐methoxyacrylate (9a, HNPC‐A3066). CONCLUSION: The above two compounds (6c, 9a) were shown to exhibit potent acaricidal and fungicidal activity. Compound 9a (HNPC‐A3066) also exhibits larvicidal and ovicidal activities against various acarids. The acaricidal potency is comparable with those of commercial acaricides such as fluacrypyrim, tebufenpyrad and chlorfenapyr. Copyright © 2008 Society of Chemical Industry