Airborne differences in odors emitted byRattus norvegicus in response to reward and nonreward

To test the hypothesis that rats (Rattus norvegicus) emit airborne, differential odors in response to reward and nonreward, donor rats received random sequences of rewarded and nonrewarded placements in small compartments and an airstream transported odors from these compartments to test rats in a separate chamber. When donors remained in the compartments during, or were removed just prior to, air transport, test rats utilized transported odors as discriminative cues signaling their own reward and nonreward for a lever-press response. When the airstream was passed through a clean compartment containing paper flooring extracted from donor compartments, test rats were not able to discriminate. Test trials to assess for control by food odors suggest that donor-produced odors, rather than food odors per se, provided the discriminative signals for test rats. Results confirm the existence of somewhat volatile, although apparently stable, odors emitted in response to reward and nonreward, and implicate a differential in amount and/or type of odor produced by donors to these two events as the source of discriminative control.     

Chromatographic analysis of species specific odor profiles inMastomys natalensis andM. coucha (Rodentia: Muridae)

Whole-body volatiles from males of the cryptic multimammate mouse speciesMastomys natalensis andM. coucha were analyzed by dynamic solvent effect sampling and capillary gas chromatography. One compound, 3-nonene-2-one, was always present, sometimes as the major component, in volatiles fromM. coucha and absent, or present only at low levels, in volatiles fromM. natalensis. The mean ±SD of the 3-nonen-2-one peak area forM. coucha was 8599 ±9630 and forM. natalensis 148 ±486. Chromatographic analysis was more reliable in identifying a male's species than were a female's in a two-choice olfactorium.     

啤酒中挥发性含硫化合物的检测方法及在啤酒硫化味品尝的相关性研究

在国内首次建立啤酒中挥发性含硫化合物的HS—SPME—GC—FPD色谱检测方法,该方法可同时检测啤酒中8种挥发性含硫化合物,方法重复性、回收率满足痕量检测要求。根据检测结果,结合啤酒感官品尝,找出了检测和品尝量级的对应关系,确定了影响啤酒硫化味的含硫化合物主要是甲硫醇、乙硫醇、二甲基二硫及二甲基三硫,为提高啤酒风味纯净性提供了有益的指导。     

Electronic Sensing of Aromatic Volatiles for Quality Sorting of Blueberries

An electronic sniffer using semi-conductor gas sensors that nondestructively measured aromatic volatile gas emissions from fruit was developed to assess blueberry quality. The sniffer detected soft and damaged fruit in packaged containers at a 5% level of damage and distinguished four of five fruit ripeness classes: (1) mature-green and green-pink; (2) blue-pink; (3) blue; and (4) ripe fruit. Sniffer response increased as fruit ripened, as did total concentration of aromatic volatiles. Sniffer response correlated with berry firmness, pH, titratable acidity, and color, and detected differences among 10 cultivars, as did impact response analysis. The electronic sniffer is rapid, nondestructive and may be used to sort and quality check for presence of unripe or damaged fruit in closed packs of fresh berries.     

老抽酱油储存期间关键气味物质分析及其风味特征的变化

为阐明老抽酱油在不同储存期的关键气味化合物及其风味特征的变化,采用液液萃取与气相色谱-嗅闻-质谱(GC-O-MS)相结合提取并鉴定不同储存期老抽酱油中的挥发性气味化合物,并利用香味提取物稀释分析(AEDA)鉴定关键气味化合物。结果表明:在老抽酱油样品中共检测到56种气味活性物质,其中FD因子>1024的化合物分别为2-甲基吡嗪、2,6-二甲基吡嗪、5-甲基-2(3H)-呋喃酮、2-乙酰基呋喃、2-乙酰基-5-甲基呋喃、1,4-丁内酯、5-甲基-2-呋喃甲醇、2-羟基-3-甲基-2-环戊烯酮、愈创木酚、麦芽酚和4-羟基-2,5-二甲基-3(2H)-呋喃酮 (HDMF),其中,2,6-二甲基吡嗪、5-甲基-2(3H)-呋喃酮、2-羟基-3-甲基-2-环戊烯酮、麦芽酚和HDMF的香气活性值>1,对老抽酱油整体香气起主要贡献作用。感官评价结果表明,老抽酱油随着储存时间的延长,烤香味和烟熏味的气味强度得分升高。该研究分析了老抽酱油的关键气味化合物以及在储存过程中气味特征变化,为老抽酱油相关风味研究提供了理论参考。     

干腌火腿中致腐败微生物的研究进展

综述了干腌火腿腐败的类型、致腐败微生物的种类、食盐浓度和温度等因素对腐败菌的影响、腐败火腿中挥发性化合物的成分以及防止火腿腐败的措施等方面的研究进展。     

浅谈汽车内饰纺织品有害物质的检测标准

概述汽车内饰纺织品有害物质对车内环境的影响及国际上相关的检测标准,并举例说明。     

化学方法消除制浆造纸厂恶臭气体

介绍了制浆造纸厂恶臭气体来源,分析了恶臭气体组成成分,并阐述了消除恶臭气体的化学方法,以期为制浆造纸工业消除恶臭气体提供指导。     

我国非木材纤维制浆与碱回收的现状和发展前景(续)

3碱法麦草制浆和碱回收的现状与发展前景 3.1我国麦草资源现状 小麦是我国主要粮食作物之一,全国小麦产量9954万t,麦草产量约8000万t,可生产纸浆3000万t.麦草资源在我国极为丰富,主要产区有:河南、山东、河北、江苏、安徽等.小麦产区就是天然的麦草原料基地.