栽培土壤对“中国苦水玫瑰花”香气构成的影响

采用顶空固相微萃取气相色谱质谱联用技术和离子色谱技术分析\     

烤烟类胡萝卜素含量与香气质量的关系

以2007年我国13个烤烟主产区63个产烟县的中橘三(C3F)烟叶为材料,采用高效液相色谱法测定了烟叶中的类胡萝卜素含量,并进行感官质量评吸。结果表明:①相同品种在不同生态条件下栽培的烟叶中类胡萝卜素含量差异明显。云南、贵州和四川等西南烟区烟叶的类胡萝卜素含量显著高于湖南、河南和辽宁等产区,在全国范围内,烟叶类胡萝卜素含量随产区纬度上升呈下降趋势;②通过聚类分析与方差分析发现,随类胡萝卜素含量的提高,烟叶香气质分值呈上升趋势,且含量最高的类别香气质分值显著高于最低的类别,香气量分值则以类胡萝卜素含量中等的类别最高。     

“玉金香”甜瓜常温贮藏期间香气构成变化分析

采用顶空固相微萃取-气相色谱-质谱联用技术,分析“玉金香”甜瓜常温贮藏过程中香气构成的变化。结果表明：贮藏过程中,样品中共检出香气成分71 种,其中酯类最多29 种,其次为醛酮类15 种,醇类12 种。醇醛类化合物是贮藏前期的主体香气成分,相对含量41.9%,清香感突出;以清香感为主的正己醛、顺-3-己烯醇、2-己烯醛、（E,Z）-2,6-壬二烯醛、（E,Z）-3,6-壬二烯-1-醇、（Z）-6-壬烯醛相对含量较高。随贮藏时间的延长,酯类化合物相对含量增加,成为主体香气成分,其中果香感突出的乙酸乙酯和乙酸苯甲酯释放量显著增加。贮藏第10天酯类化合物相对含量增加至91.57%,成为主体香气成分,此时果香突出。“玉金香”甜瓜常温贮藏不同时期,香气构成差异显著。     

小米中类胡萝卜素含量与食味品质的相关性分析

本试验选取46种小米测定其米色、类胡萝卜素含量及食味品质指标,并通过相关性及聚类分析研究了小米中类胡萝卜素含量与食味品质的关系。结果表明：食味品质、类胡萝卜素含量和b*值的相关性达到极显著水平;第二类谷子品种类胡萝卜素含量较高及食味品质较好,第四类(九谷25)类胡萝卜素含量较低、食味品质较差;小米中类胡萝卜素含量对于食味品质的影响比米色b*值大,两者与食味品质皆呈正相关线性关系。小米中类胡萝卜素含量直接影响其食味品质,类胡萝卜素含量越高,小米食味品质越好,两者具有显著相关性。     

遮光处理对转色至完熟期间“赤霞珠”和“蛇龙珠”葡萄果实品质的影响

以酿酒葡萄"赤霞珠"和"蛇龙珠"为材料,在转色-完熟期间通过套袋对其果实进行遮光处理,以常规管理果实为对照,分析遮光处理对酿酒葡萄果实理化及香气品质的影响。结果表明:遮光处理完熟"蛇龙珠"和"赤霞珠"果实百粒质量较对照分别高出7.43%和8.74%,平均粒径较对照分别高出1.57%和2.60%,可溶性固形物含量较对照分别高出7.50%和2.76%,pH值较对照分别高出4.16%和1.04%,可滴定酸含量较对照分别低出25.37%和14.71%。香气成分分析显示,遮光处理可抑制样品酿酒葡萄果实醇类物质的释放,促进醛类物质释放。     

玫瑰花桃红葡萄酒与桃红葡萄酒基酒的香气成分研究

为了分析玫瑰花桃红葡萄酒及桃红葡萄酒基酒香气成分的差异,采用大孔吸附树脂萃取方法提取玫瑰花桃红葡萄酒及桃红葡萄酒基酒的香气成分,再经气相色谱-质谱联用（GC-MS）技术鉴定其香气成分。结果表明,玫瑰花桃红葡萄酒中共检测到香气成分48种,桃红葡萄酒基酒中共检测到香气成分41种,主要为酯类物质、有机酸、醇类、莽草酸衍生物、羰基类、烷烃类和萜烯类物质,其中检测到的酯类物质含量最多,玫瑰花桃红葡萄酒及桃红葡萄基酒中酯类物质分别占总香气成分的60.22%、64.89%。玫瑰花桃红葡萄酒的香气成分与桃红葡萄酒基酒相比,增加了3种酯类物质、1种有机酸、2种莽草酸衍生物和2种烷烃类化合物。     

吹扫捕集-气相色谱/质谱联用分析玫瑰花水香气成分

采用吹扫捕集-气相色谱/质谱联用技术首次分析了玫瑰花水的香气组成成分,并对苦水和大马士革两种玫瑰花水香气成分进行比较。结果表明,吹扫捕集最优实验参数为:样品量7.0 mL;吹扫温度40℃;吹扫时间13 min,此时苦水和大马士革玫瑰花水共鉴定出香气成分71种,其中苦水玫瑰花水69种,大马士革玫瑰花水61种;苦水、大马士革共有成分59种,苦水玫瑰花水特有成分10种(相对含量之和为4.15%),大马士革玫瑰花水特有成分2种,相对含量之和为0.54%。吹扫捕集法分析玫瑰花水香气成分操作简单,浓缩富集效率高,重现性好,绿色环保,真实全面地反映了玫瑰花水香气成分的构成,为玫瑰花水香气特征研究提供技术支撑,为其开发利用和产品质量控制提供理论依据。     

‘龙眼’葡萄酒微生物变化及与挥发性香气的相关性分析

以‘龙眼’葡萄为原料,通过高通量测序和顶空固相微萃取-气相色谱-质谱联用技术,对干白葡萄酒发酵过程中的微生物演替和挥发性香气变化进行了监测。得到相对含量>1%的优势细菌20种、真菌6种;鉴定出挥发性香气28种。利用正交偏最小二乘(R²>0.5,Q²>0.5)和Spearman(|R|>0.7)对优势微生物与挥发性香气化合物进行相关性分析。结果表明,‘龙眼’干白葡萄酒发酵过程中VIP>1的细菌11种,真菌2种;其中4种细菌和1种真菌与发酵过程中产生的挥发性香气呈显著正相关,特别是地芽孢杆菌属(Geobacillus)、乳酸杆菌属(Lactobacillus)和嗜热厌氧杆菌属(Thermoanaerobacterium)与乙酸癸酯、乙酸苯乙酯、4-萜烯醇、β-大马士革酮、乙酸苯乙酯和癸酸异戊酯等呈极显著正相关。     

特异茶树品种“紫娟”不同茶产品主要化学成分及其抗氧化活性分析

目的:采用不同的加工工艺,分别制备"紫娟"绿茶(炒青、烘青、蒸青和晒青)、红茶和乌龙茶产品,从感官品质、化学成分以及抗氧化活性角度出发,尝试提出"紫娟"茶的最佳加工方式,为其更为合理的开发应用提供科学基础和理论借鉴。方法:分析比较了不同"紫娟"茶产品茶汤中的主要品质化学成分含量、抗氧化活性和感官品质等;此外,采用顶空固相微萃取—气相色谱—质谱联用技术分析了"紫娟"不同茶产品的香气成分组成。结果:"紫娟"茶产品的总抗氧化活性与其茶多酚和儿茶素含量呈显著的正相关性关系,而清除1,1-二苯基-2-三硝基苯肼自由基活性与其花青素含量呈显著正相关;感官审评结果表明,烘青绿茶及红茶的感官品质较好。结论:从主要品质化学成分含量、抗氧化活性以及感官品质等多方面考虑,"紫娟"茶产品的制作以采用烘青或炒青绿茶的制作工艺为宜。     

茶树鲜叶采前诱导和采后加工对类胡萝卜素及其衍生香气的影响

类胡萝卜素是茶叶中重要的脂溶性色素成分,也是多种关键香气物质形成的前体。利用靶标代谢组学分析方法,对茶树鲜叶中类胡萝卜素含量进行绝对定量,其总含量为（859.98±60.20）μg/g,其中叶黄素含量最高为（405.06±17.71）μg/g。制作的成品红茶中类胡萝卜素总量为（406.17±32.21）μg/g,成品绿茶中为（433.95±36.21）μg/g,与鲜叶中的含量相比,下降幅度超过50%。外源茉莉酸甲酯诱导茶树鲜叶后,鲜叶中的类胡萝卜素含量发生显著变化。利用诱导12 h后的茶鲜叶加工得到的成品红茶中的类胡萝卜素总量为（439.70±31.35）μg/g,而绿茶中类胡萝卜素总量达到（682.69±46.12）μg/g。诱导24 h后鲜叶加工制得的红茶与绿茶中14种类胡萝卜素衍生香气成分显著增加,尤其是β-大马酮,β-紫罗兰酮、香叶基丙酮以及二氢猕猴桃内酯相对含量增加>2倍。结论：利用外源茉莉酸甲酯诱导提高茶树鲜叶中类胡萝卜素含量,研究采后茶树鲜叶中类胡萝卜素在红茶和绿茶加工过程中的动态变化规律,明确诱导12 h和24 h的鲜叶制作的成品茶香气品质显著提升,类胡萝卜素含量...     

不同保藏条件下大马士革玫瑰颜色和香气变化研究

针对产精油玫瑰花期集中、不利于周年加工的难题,本文以大马士革玫瑰作为材料,采用热脱附-气相色谱/质谱联用仪研究不同温度不同时间保存条件下玫瑰花瓣的色泽、香气种类及其含量的变化。结果表明:花瓣的色泽在-80℃下能够保藏70d之后颜色如同刚采摘的花瓣,花瓣的香气成分则是在-20℃下保藏70d左右的花瓣香气成分损失较少。通过本文研究得到了大马士革玫瑰花瓣的最佳保藏条件为-20℃。      

中间香型烟叶特色彰显度与主要化学成分的相关及通径分析

为了解中间香型烟叶特色彰显度与烟叶主要化学成分的关系,对国内不同中间香型产区烟叶主要化学成分及派生值与中间香型特色彰显度进行了简单相关和通径分析.结果表明,烟碱和钾氯比与中间香型特色彰显度呈极显著或显著正相关;两糖比、蛋白质、氮碱比、氯、总氮和糖碱比与中间香型特色彰显度呈极显著或显著负相关.通径分析表明,烟碱、总氮、氯、蛋白质和糖碱比直接影响中间香型特色彰显度,两糖比主要间接影响中间香型特色彰显度,氮碱比和钾氯比对中间香型特色彰显度的影响间接效应大于直接效应.     

An in vitro evaluation of various Rosa damascena flower extracts as a natural antisolar agent

The aim of this work was to evaluate ultraviolet (UV) absorption ability of various extracts of Rosa damascena flowers as an antisolar agent. Extracts were prepared using the following solvent mixtures: water:ethanol (50 : 50), ethyl acetate:ethanol (80 : 20) and ether. The hydroalcoholic and ethyl acetate:ethanol extracts were prepared by maceration, and ether extract was prepared by soxhletion. Preliminary studies on the extracts prepared confirmed the presence of flavonoids as the major components of all extracts. Next, the UV absorption spectra (in the range of 200-400 nm) of all extracts were obtained. Results show that all three extracts can effectively absorb UV radiation in the range of 200-400 nm. However, the range giving maximum absorption for the hydroalcoholic, ethyl acetate:ethanol and ether extracts were 200-320, 250-360 and 230-370 nm, respectively. In the next stage, extracts prepared were incorporated into an oil in water cream base (prepared based on preliminary studies), at two concentrations of 5 and 8%. The sun protection factor (SPF) of these creams were determined. Based on the findings, the hydroalcoholic extract seems to give the highest SPF among the three extracts evaluated, when incorporated to the cream base. On the other hand, by performing a few physicochemical tests on the prepared creams, cream containing 5% ether extract showed the most desirable appearance and stability among the creams investigated. The UV absorption ability of these extracts is suggested to be because of the presence of flavonoid compounds within the extracts. However, it should be noted that in order to obtain an effective suncare product with high SPF values, these extracts could be used along with other synthetic antisolar agents.     

Volatile oil composition of Turkish rose (Rosa damascena)

A series of trials was conducted to determine the effectiveness and limitations associated with the use of partially hydrogenated triglycerides as a protective coating to enhance amino acid escape from the rumen. Commercially prepared prills and laboratory-synthesized prills containing either lysine or methionine were incubated from 0–24 h in situ, in a fistula Ted cow fed hay and grain (1:1, w/w DM). Multiple factors were found to affect the ability of fat to protect amino acids. Examination of prill size where prills were separated by sieves into sizes ranging from 703 μm to 2.5 mm indicated that, overall, larger prills provided greater protection than smaller prills. Differences in protection exist between amino acid source, as methionine recovery was consistently greater than lysine. Reduction of lysine particle size improved its protection, but was still not protected as well as methionine. Prills with iodine values (IV) of < 1, 17 and 40 were also examined. Differences in protection between IV levels was not great, however, IV < 1 and 17 provided greater protection than IV 40. Utilizing results from the various trials, maximal protection level was achieved (approximately 90%) for methionine in prills made from IV 17 which ranged in size from 2 to 2.5 mm.     

Effect of harvesting hour on some physical and mechanical properties of Rosa damascena Mill

BACKGROUND: Mechanization of Rosa damascena flower harvest is limited because of the asynchronous flowering period, the necessity for the harvest operation to take place in the early hour of the morning, and a lack of knowledge regarding the physical–mechanical properties of R. damascena. This study investigated the effect of harvesting hour on some physical–mechanical properties of R. damascena. RESULTS: The terminal velocity of the rose flower ranged from 4.00 to 2.38 m s^?1. The highest picking force was found to be 6.29 N for the harvesting hour of 06:00 am. Tear forces of petal changed from 1.54 to 0.97 N for the harvesting hour of 06:00 am and 12:00 pm, respectively. The tension force of pedicel varied between 8.25 and 7.76 N. The weight of the rose flower was measured as an average of 1.61 and 1.50 g at 06:00 am and 12:00 pm, respectively. Horizontal and vertical projection areas of rose flowers were positively correlated with harvesting hour, with an R² of 0.97 and 0.75, respectively. Results showed that there was a minor loss in colour for both inner and outer surfaces of petals. CONCLUSION: The results of physical–mechanical properties of R. damascena obtained from this study should be considered for the operation of flower harvest mechanization. Copyright © 2011 Society of Chemical Industry     

刺梨皮渣和籽仁中游离态和键合态香气物质的比较

采用顶空-固相微萃取法提取刺梨皮渣、籽仁中游离态香气物质和酶法释放刺梨皮渣、籽仁中键合态香气物质,结合气相色谱-质谱法分析技术对刺梨皮渣和籽仁中的游离态和键合态香气物质进行定性和定量研究。结果表明,检出的刺梨皮渣中游离态香气物质有21 种,萜烯类物质最丰富,其次是酯类物质和酮类物质;检出的键合态香气物质有23 种,其中酸类物质最为丰富,其次是酚类物质和醇类物质。皮渣中游离态和键合态香气物质有很大差异,只有辛酸1 种物质都以游离态和键合态的形式存在。刺梨籽仁中检出游离态香气物质有9 种,萜烯类物质最为丰富,其次是醇类物质和酚类物质;检出的键合态香气物质有18 种,包括酸类8 种、酚类3 种、醇类3 种、羟基醛类2 种,羟基酯类和羟基酮类各1 种。籽仁中被释放出来的香兰素（3-甲氧基-4-羟基苯甲醛）和异香草醛（3-羟基-4-甲氧基苯甲醛）2 种羟基醛是重要的键合态香气物质。     

玫瑰精油β-环糊精包合物的制备与表征

目的：为提高玫瑰精油水溶性与稳定性,以β- 环糊精为包合材料,制备并表征玫瑰精油的包合物。方法：采用饱和水溶液法制备玫瑰精油包合物,薄层色谱(TLC)、气相色谱- 质谱(GC-MS)分析包合前后精油的化学成分,并利用红外(IR)、差示扫描量热法(DSC)对包合物与包合作用进行表征与分析。结果：以包合率为指标确定包合最佳条件为：m 玫瑰精油:mβ- 环糊精=1:10,反应温度60℃,反应时间2h,在此条件下,玫瑰精油包合率达到80% 以上。结论：玫瑰精油包合物能够保留玫瑰精油的主要特征成分,提高精油的溶解度和稳定性,为开发口服玫瑰精油功能食品提供了固体粉末中间体。     

不同基因型烤烟化学成分和致香物质间的相关和通径分析

通过对不同基因型烤烟品种烤后烟叶常规化学成分和香气物质含量的相关分析,发现总糖与类胡萝卜素类呈显著正相关,总氮与类胡萝卜素类呈显著负相关,烟碱与类胡萝卜素类呈极显著负相关;钾与棕色化产物类呈极显著正相关,总氮和烟碱与棕色化产物类呈极显著负相关;总氮和钾与茄酮呈显著正相关,烟碱与茄酮呈极显著负相关.通径分析结果表明,烟碱、总糖和钾对类胡萝卜素类、棕色化产物类和茄酮的直接影响最大;常规化学成分经蛋白质对类胡萝卜素类的间接影响最大,烟碱对棕色化产物类和茄酮的间接影响最大.协调好化学成分,有利于提高香气物质的含量.     

5种黑茶香气成分的比较分析

本研究采用感官审评法和顶空固相微萃取法,结合气相色谱-质谱仪联用技术,对5种黑茶样品挥发性成分进行了分析鉴定。结果表明,5种黑茶共检出83种香气化合物,共有成分30种,主要包括醇类、醛类、酮类、芳香烃类、烯类和酯类等;不同产区黑茶香气特征及组成存在明显差异:青砖茶陈香纯正,以醛类和酮类化合物为主,包括(E,E)-2,4-庚二烯醛、β-紫罗酮、己醛;茯砖茶\     

微波辅助酸解释放刺梨汁键合态香气物质的效果

以野生刺梨汁为研究对象,采用微波辅助酸解,结合Amberlite XAD-2树脂吸附和GC-MS分析技术,研究其释放键合态香气物质的最佳微波辅助酸解条件,并与单一酸解比较其释放键合态香气物质的效果。结果表明：pH1.0含糖苷类物质的刺梨汁水相经800W功率的微波能辅助酸解3min后,再在40℃酸解36h,释放的键合态香气物质的种类最多;其中含量最高的是辛酸,其次为棕榈酸、4-(3-羟基-1-丁烯基)-3,5,5-三甲基-2-环己烯-1-酮、4-(5-羟基-2,6,6-三甲基-1-环己烯基)-3-丁烯-2-酮、2,4-二叔丁基苯酚等;微波辅助酸解释放刺梨汁键合态香气物质效果明显优于同pH值和同温度下酸解时间更长的单一酸解效果。