氮肥用量和基追肥比例对白肋烟化学成分和香气物质含量的影响

以达白1号为材料,研究了不同施氮量和基追肥比例对四川达州白肋烟化学成分及香气物质含量的影响.结果表明,施氮量和基追肥比例对烟叶化学成分和中性香气物质都有不同程度的影响.随着施氮量的增加,白肋烟的总氮、烟碱、K+、K+/Cl-均有增加趋势,总糖、还原糖、Cl-、氮碱比呈下降趋势.各处理中部叶总中性致香成分含量随施氮量的增加呈现出先增加,之后又有所降低的趋势.较低施氮量处理(120～255 kg/hm2)增加追肥所占比例能增加中性香气物质总量.较高施氮量处理(300 kg/hm2),基追肥比例对香气物质总量的影响不明显.当施氮量超过255 kg/hm2时,烟叶的总氮、烟碱含量过高,化学成分不协调.0～210 kg/hm2施氮量范围内,相同施氮量下随着基肥比例的减小,总氮、烟碱、K+含量,K+/Cl-有增加趋势,当施氮量超过255 kg/hm2时基追肥比例对总氮、烟碱的影响不明显.从烟叶化学成分和中性香气物质方面分析,以施纯氮210～255 kg/hm2,基肥比例60％表现最优.     

施氮量对烤烟产量和品质的影响

通过在福建三明和南平的田间试验研究了施氮量对烤烟产量和品质的影响.结果表明,不同施氮量对烟株农艺性状、烟叶产量、产值、化学成分、外观品质和评吸质量均有显著影响.株高、茎围、最大叶面积、单叶重和产量随施氮量的增加而上升,产值、均价和上等烟比例在适宜的施氮量下表现较好.不同部位烟叶烟碱含量随施氮量增加显著提高,还原糖含量和还原糖/烟碱比值降低.综合烟叶内在化学分析、外观品质和评吸结果,三明试验点以施N76.5kg/hm2和102kg/hm2处理较好,而南平试验点则以施N102kg/hm2和127.5kg/hm2较好.     

不同栽培措施组合对白肋烟TSNAs含量及品质的影响

为揭示不同栽培措施组合对烟草特有亚硝胺(TSNAs)含量(质量分数)及品质的影响,采用正交试验研究了白肋烟品种、施氮量、仿生型信号分子(Bionics signal molecule,BSM)剂量三因素组合对上部烟叶TSNAs、生物碱、硝态氮、常规化学成分与感官品质的影响。结果表明:品种是影响TSNAs及其前体物生物碱含量的主要因素,低烟碱转化率品种TSNAs含量低于其他品种;施氮量对TSNAs及其前体物含量影响差异较大,施氮量210 kg·hm~(-2)时烟叶中生物碱、硝态氮以及TSNAs含量均低于施氮量270 kg·hm~(-2)和施氮量330 kg·hm~(-2)时的含量;打顶后涂抹BSM,上部烟叶的N-亚硝基降烟碱(NNN)和TSNAs总量均较低,烟叶的感官品质改善。因此,在湖北恩施白肋烟产区鄂烟1号LC、施氮量210 kg·hm~(-2)、0.1μmol·L-1BSM涂抹或鄂烟3号LC、施氮量210 kg·hm~(-2)、清水涂抹的组合表现较好,是降低白肋烟上部叶TSNAs含量的有效措施。     

施氮量对翠碧1 号生长发育及烟叶质量风格的影响

通过田间试验和化学分析,研究了不同施氮水平对翠碧1 号烤烟生育期、烤后烟叶产质量和烟叶风格的影响。结果表明,不同施氮量对烤烟生育期、经济性状、外观质量、化学成分和感官评吸质量均有显著的影响。施氮量增加,烟株大田生育期明显延长;烤后烟叶产量、不同部位单叶重、总氮和烟碱含量明显增加,总糖和还原糖含量、还原糖/烟碱和总氮/烟碱比值表现下降的趋势;烟叶“清香型”风格彰显趋向弱化。施氮量大于78 kg/hm² 时,烤后烟叶产值增加不显著;施氮量在58.5～97.5 kg/hm² 时,烟叶内在化学成分较协调,外观质量和感官评吸质量较好,烟叶“清香型”风格彰显较明显。     

氮钾施用量对生长在安大略邦北部轻壤土上CM-12(KA)烤烟产质量的影响

1993～1995年间,在安大略邦北部的轻壤土上,选用16/103和CM-12(KA)2个品种、2个施钾水平(80kg K2O/hm2和120kg K2O/hm2)和5个施氮水平(60kg N/hm2、70kg N/hm2、80kg N/hm2、90kg N/hm2和100kg N/hm2)进行了本项试验.试验的目的是为了找出适合于CM-12(KA)品种种植的施氮量和施钾量.除施氮量外,其它因素对烟叶产量和质量的影响均没有达到显著水平.施氮量从60kg N/hm2增加到80kgN/hm2,鲜烟叶的产量显著增加,施氮量为100kg N/hm2时,产量最高.施氮量80kg N/hm2、90kgN/hm2和100kg N/hm2处理的烟叶(烘烤的烟叶)明显高于其它处理.施氮量60kg N/hm2和70kg N/hm2的等级指数最高.施氮量从60kg N/hm2增加到100kgN/hm2,从下到上不同部位(P、X、L和T)烟叶的糖含量减少,氮和烟碱含量增加.不同施氮量之间,烟叶的物理性状差异不显著.结论是就烟叶的产量和质量综合评定而言,适宜于CM-12(KA)烤烟品种种植的施氮量和施钾量分别为80kg N/hm2和80kg K2O/hm2.     

施氮量与留叶数对烤烟产量质量影响的研究

采用二次饱和 D—最优设计,试验研究了施氮量与留叶数对烤烟产量、效益及烟叶化学成分含量的影响。结果表明:亩施氮量3.50～5.73kg、单株留叶数16～18片,烟叶亩产量可达150～200kg,亩产值400元以上,烟碱含量2.5%～3.0%,还原糖含量15%～17%。主因素效应以施氮量对产量、产值、还原糖的影响最大,留叶数次之,二因素对烟碱的主效应大小相近。     

施氮量对烤烟常规化学成分含量及主流烟气中7种有害成分释放量的影响

以烤烟豫烟12号为材料,通过田间试验研究不同施氮量对烤烟化学成分和主流烟气中7种有害成分的影响。结果表明,施氮量不同不仅影响烟叶常规化学成分的含量,而且对主流烟气中有害成分的释放量产生了影响;随施氮量增加,烟叶中蛋白质、烟碱和总氮的含量增加,总糖和还原糖含量减少,钾和氯含量影响不明显;主流烟气中7种有害成分随施氮量的增加变化趋势不同,随施氮量增加,巴豆醛的释放量减少,氨和NNK的释放量增加;施氮量在55 kg/hm2时,烟叶常规化学成分协调,主流烟气中7种有害成分的危害性指数最低,烟草质量安全性较高。      

烤烟新品种云烟97的氮肥效应

为促进烤烟新品种云烟97的推广应用,采用田间小区试验,研究了不同施氮量(不施肥、6 g/株、8 g/株、10 g/株)对云烟97氮素吸收利用以及产质量的影响。结果表明,施氮量不仅影响烟株各部位氮素的含量,也影响氮素在烟株各部位的分配和转运。随着施氮量的增加,中部叶和下部叶氮的分配率降低,相同部位烟叶氮和烟碱含量增加,总糖、还原糖含量和糖碱比呈下降趋势。氮量、烟叶部位以及二者之间的交互作用对烟叶内在化学成分均有影响。综合考虑产量、产值因素以及烟叶中的化学成分含量,在试验区域内,确定云烟97的最适施氮量为8 g/株。     

施氮量与留叶数对万源晒红烟产质量和香气成分的影响

为探究施氮量与留叶数对万源晒红烟产质量和香气成分的影响,以主栽晒红烟品种"万毛3号"为材料,设计不同施氮量与留叶数的栽培试验,对晒红烟农艺性状、经济性状和香气成分等进行测定分析。结果表明,随施氮量和留叶数增加,万毛3号的产量和产值上升,均价和上、中等烟比例先升高后降低。施氮量增加,烟叶的烟碱、钾含量显著上升,糖含量显著下降;中性致香成分总量显著升高,多种质体色素降解产物、苯丙氨酸转化产物和茄酮含量上升。留叶数增多,烟叶糖和钾含量显著升高,烟碱、总氮含量下降;中性致香成分总量和新植二烯、类胡萝卜素降解产物含量呈下降趋势,而苯丙氨酸类转化产物和棕色化产物含量显著上升。综合分析,在施氮15 kg/667 m²、留叶18片处理下,烟叶的产量较高,品质较优,感官质量评价好。     

四川白肋烟不同品种中性香气成分含量及感官品质分析

采用气质联用仪对四川白肋烟不同品种晾制后上部叶和中部叶的中性香气物质含量进行定量分析,并卷制单料烟进行感官评吸。结果表明,总中性香气物质含量高低排序为达白1号鄂烟1号TN90达所24宣汉-5;达白1号巨豆三烯酮、大马酮等类胡萝卜素降解产物和腺毛分泌物降解产物茄酮含量丰富,TN90和鄂烟1号大部分香气成分与达白1号接近;宣汉-5的类胡萝卜素降解产物含量以及上部叶的茄酮含量显著低于其他品种,但大部分苯丙氨酸裂解产物和中部叶糖的裂解产物含量较高。评吸结果表明,达白1号的风格程度、香气质和香气量得分均为最高,香气品质较好,其次为TN90、鄂烟1号;宣汉-5的白肋烟风格程度较低,香气量少,香味品质较差。     

EVOH的流变性能

为研制新型PET/EVOH复合吸湿纤维,确定合理的复合纺丝工艺参数,对芯层组分EVOH熔体的流动性能进行了系统研究.结果表明,EVOH属假塑性流体,非牛顿指数小于1,表观黏度随温度的升高或剪切速率的增加呈下降趋势.与加工温度为250、260℃时相比,当EVOH在加工温度为240℃进行挤出时,非牛顿指数为0.712,最接近牛顿流体.在240、250、260℃进行挤出时,EVOH的黏流活化能在400～500 J/mol之间,且黏流活化能随剪切速率增加而增加.     

纤维素氨基甲酸酯纤维纺丝工艺探讨

通过研究纤维素氨基甲酸酯（CC）溶液中CC与NaOH配比（质量比）、溶液纺前处理时间及温度、纺丝凝固浴及再生浴的组成和温度对纤维素氨基甲酸酯溶液可纺性及其纤维性能的影响,得到湿纺工艺制备纤维素氨基甲酸酯纤维的最佳纺丝工艺条件.结果表明：配制CC质量分数为7%,CC与NaOH质量比为1的纤维素氨基甲酸酯的氢氧化钠溶液,在15℃以下进行纺前处理10～12h,溶液可纺性良好．这种溶液在温度为40℃的含H₂SO₄（150g/L）、Na₂SO₄（200g/L）、AI₂（SO₄）₃（50g/L）的凝固浴中成形后,在温度为85℃、质量分数为1%的氢氧化钠水溶液中再生,可得到具有一定强度及伸长率的再生纤维素纤维．     

不同第二单体共聚丙烯腈纤维的性能

利用FT-IR、DSC、TG、DMA测试技术对第二单体分别为醋酸乙烯酯和丙烯酸甲酯的2种共聚丙烯腈纤维进行结构和性能测试,并对2种纤维的染色性能进行研究.DSC测试结果表明,以醋酸乙烯酯为第二单体的共聚丙烯腈纤维的玻璃化转变温度低于以丙烯酸甲酯为第二单体的共聚丙烯腈纤维,且二者分解温度接近,都高于300℃．TC测试结果显示二者热稳定性差异不大,在相同条件下以醋酸乙烯酯为第二单体的共聚丙烯腈纤维较以丙烯酸甲酯为第二单体的共聚丙烯腈纤维有更好的染色性能．     

Improving the quality of minced beef by using mulberry leaves extract

The aim of this research was to study the use of different concentrations (2, 4 and 6% w/w) of methanolic extract of mulberry leaves (Morus spp.) to increase the shelf life of minced beef. Treated samples were compared with the control and gamma irradiated sample at dose level of 5 kGy during cold storage at (4?±?1?°C) for 24 days. Microbiological, chemical and sensory characteristics of treated minced beef were determined every 2 days during the cold storage. Obtained results showed that minced beef treated with different concentrations of mulberry leaves methanolic extract reduced the initial total bacterial count, psychrophilic bacteria, enterobacteriaceae and total mold & yeast as well as prolonged the shelf-life of minced beef compared to the control. Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis and Escherichia coli counts were reduced. The mulberry leaves methanolic extract caused slight increase in the thiobarbituric acid reactive substances and total volatile nitrogen contents of minced beef during the cold storage. Sensory results showed that the shelf life of minced beef was 6 days for the control, and 8, 10, and 14 days for minced samples treated with mulberry leaves methanolic extract (2, 4 and 6%) respectively compared to gamma irradiated (22 days).     

Untersuchungen und Betrachtungen zum Insecticideinflu? auf Autoxydationsprozesse

Zusammenfassung Nach den Ergebnissen spektralphotometrischer Untersuchungen verläuft die Oxydation von-Carotin in zwei bedingt unabhängigen Phasen. In der Phase A findet eine Oxydation an den-Iononringen statt. Indem der hierfür benötigte Sauerstoff der Umgebung entzogen wird, wirkt-Carotin gegenüber Begleitstoffen antioxydativ. In der Phase B, welche in der Autoxydation der Polyenkette besteht, entscheiden Protonenaufnahme- und -abgabeprozesse im gesamten System über die anti- oder prooxydative Wirksamkeit von-Carotin. DDT und DDE greifen in diese Vorgänge ein.

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Investigations on the influence of insecticides on autoxidation processes. I. Oxidation of-carotene in the presence of lipids and chlorinated hydrocarbon-insecticides

Summary According to spectral-photometrical results, the oxidation of-carotene takes place in two relatively independant phases. During phase A oxidation of the-iononrings occurs; by removal of the oxygen from the surrounding-carotene acts as an antioxidant. In phase B which, exists of autoxidation of the polyen-chain, the proton acceptance and donation in the whole system decides over anti- or pro-oxidant effectiveness of-carotene. DDT and DDE participate in these reactions.

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Für die finanzielle Unterstützung der Arbeit danken wir der Alexander von Humboldt-Stiftung.

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In Anlehnung an Koloman Beneze: Veränderungen von Fettsäuren in Anwesenheit insecticider Chlorkohlenwasserstoffe. Diss. TU München in Weihenstephan 1973     

Changes in taste and flavor in aging

This study aims at understanding the role of mixtures (mutual quality suppression) in the evaluation of impact of the human aging process on the perception of taste.

Heretofore, the effect of aging on taste has been directed at threshold and suprathreshold magnitudes of single chemicals (e.g., NaCl, sucrose, citric acid) in aqueous solution. Although absolute thresholds typically rise in advanced age (2 to 9 times, depending on the study), suprathreshold magnitude assessed by magnitude matching seems (except for bitter) to resist change in the way presbycusis spares suprathreshold loudness, fostering the impression that aging may handicap the aged little in the perception of food.

Asked, however, to discriminate the presence‐absence of the prescribed salt flavoring (nominally suprathreshold) in tomato soup, the young outperformed the middle‐aged who, in turn, outperformed the elderly. Moreover, NaCl thresholds in the presence of tomato measured several times higher than in water, but the difference between the young and the elderly continued to hold. Elevation of threshold to much higher levels by mixture suppression leaves the young‐elderly difference unchanged, implying that the elderly may fail to detect salt levels that really count in their diet.

To examine the relation between age and taste mixtures, we measured detection thresholds: (1) for NaCl in citric acid, from zero to strong; (2) for sucrose in citric acid, from zero to strong; and (3) for citric acid in sucrose, from zero to strong. Whether in water alone or in a weak or strong suppressor, the elderly subjects’ threshold was consistently 2 or 3 times higher than that of the young. Moreover, the way in which threshold for one quality rises with concentration of a suppressor is the same, except for constant upward displacement of the elderly peoples’ threshold. In general, both young and elderly confuse salty and sour (show large suppression at all concentrations of the suppressor) much more than they confuse sweet and sour (seen mainly at high concentrations of the suppressor). Study of other mixtures is planned.