目的:为探究不同足火热传递方式对工夫红茶品质的影响,本实验以’翠峰’品种为原料制作工夫红茶,设定3类、共5种足火热传递方式:热辐射(远红外足火、微波足火)、热对流(箱式热风足火)、热传导(理条足火、六角辉锅足火),检测干茶外形亮...目的:为探究不同足火热传递方式对工夫红茶品质的影响,本实验以’翠峰’品种为原料制作工夫红茶,设定3类、共5种足火热传递方式:热辐射(远红外足火、微波足火)、热对流(箱式热风足火)、热传导(理条足火、六角辉锅足火),检测干茶外形亮度(L值)、红度(a值)、黄度(b值),汤色透亮度(LL值)、红度(La值)、黄度(Lb值)等指标,及茶多酚、儿茶素、茶黄素、茶红素、茶褐素、黄酮苷、可溶性糖等60余种品质成分,比较不同方式下各指标差异,结合感官审评及电子舌技术评价所制成品茶的品质优劣,通过偏最小二乘法(partial least squares,PLS)分析及显著性分析探明各方式对"高亮"汤色、"甜醇"滋味、"乌润"外形等的影响,并获得标志性差异物质。结果表明:热传导足火有利于儿茶素组分(除表没食子儿茶素没食子酸酯)、茶黄素组分、茶红素、茶褐素,除牡荆素葡萄糖苷(vitexin-glucoside,Vit-Glc)外的黄酮苷组分、氨基酸组分、可溶性总糖等成分的保留和浸出,六角辉锅足火整体上较理条足火低,热辐射次之,热对流最低。外形L值和b值、汤色La值和Lb值均以热传导显著最优,外形a值以微波足火最优,汤色LL值以热对流最优。电子舌分析可看出3类方式雷达相应轮廓图显著不同,热辐射、热传导、热对流方式分别对茶汤酸味和鲜味、苦味和咸味、甜味和综合属性响应强烈。感官审评角度热传导方式下汤色红亮,但外形色泽易带灰,滋味较浓带涩,热辐射则获得香气高甜,滋味浓爽,汤色橙红。PLS分析模型将3类方式下工夫红茶在汤色和滋味分属性明显区分,外形属性则热传导明显区分于热辐射和热对流,通过显著性分析获得不同足火热传递方式工夫红茶分属性的关键差异物:汤色差异成分为茶黄素、茶黄素-3,3’-双没食子酸酯(theaflavin-3,3’-gallate,TF-D-G)、茶黄素-3-没食子酸酯、可溶性糖、精展开更多
For quality control purpose, an approach of fingerprinting and simultaneous quantification of five major bioactive constituents of Rhizoma Coptidis was established via a high-performance liquid chromatograph coupled w...For quality control purpose, an approach of fingerprinting and simultaneous quantification of five major bioactive constituents of Rhizoma Coptidis was established via a high-performance liquid chromatograph coupled with a photodiode array UV detector（HPLC-DAD） and an electrospray ionization mass spectrometer（HPLC-ESI/MS） The compounds were identified on the basis of the comparison of their mass spectra with literature data and those of standard samples and quantified by the HPLC-DAD method. Baseline separation was achieved on an XTerra C18 column（5 μm, 250 mm×4.6 mm i. d.） with linear gradient elution of formate buffer（consisting of 0.5% formic acid, adjusted to pH=4.5 with ammonia） and acetonitrile（consisting of 0.2% formic acid and 0.2% triethylamine）. The me- thod was validated for linearity（r^2〉0.9995）, repeatability（RSD〈3.1%）, intra- and inter-day precision（RSD〈1.8%） with recovery（99.9%-105.1%）, limits of detection（0.15-0.35 μg/mL）, and limits of quantification（0.53-0.82 μg/mL）. The similarities of 32 batches of Rhizoma Coptidis and their classification according to their manufacturers were based on the retention time and peak areas of the characteristic compounds. The five compounds were selected for quality assessment ofRhizoma coptidis via partial least squares analysis（PLS）.展开更多
文摘目的:为探究不同足火热传递方式对工夫红茶品质的影响,本实验以’翠峰’品种为原料制作工夫红茶,设定3类、共5种足火热传递方式:热辐射(远红外足火、微波足火)、热对流(箱式热风足火)、热传导(理条足火、六角辉锅足火),检测干茶外形亮度(L值)、红度(a值)、黄度(b值),汤色透亮度(LL值)、红度(La值)、黄度(Lb值)等指标,及茶多酚、儿茶素、茶黄素、茶红素、茶褐素、黄酮苷、可溶性糖等60余种品质成分,比较不同方式下各指标差异,结合感官审评及电子舌技术评价所制成品茶的品质优劣,通过偏最小二乘法(partial least squares,PLS)分析及显著性分析探明各方式对"高亮"汤色、"甜醇"滋味、"乌润"外形等的影响,并获得标志性差异物质。结果表明:热传导足火有利于儿茶素组分(除表没食子儿茶素没食子酸酯)、茶黄素组分、茶红素、茶褐素,除牡荆素葡萄糖苷(vitexin-glucoside,Vit-Glc)外的黄酮苷组分、氨基酸组分、可溶性总糖等成分的保留和浸出,六角辉锅足火整体上较理条足火低,热辐射次之,热对流最低。外形L值和b值、汤色La值和Lb值均以热传导显著最优,外形a值以微波足火最优,汤色LL值以热对流最优。电子舌分析可看出3类方式雷达相应轮廓图显著不同,热辐射、热传导、热对流方式分别对茶汤酸味和鲜味、苦味和咸味、甜味和综合属性响应强烈。感官审评角度热传导方式下汤色红亮,但外形色泽易带灰,滋味较浓带涩,热辐射则获得香气高甜,滋味浓爽,汤色橙红。PLS分析模型将3类方式下工夫红茶在汤色和滋味分属性明显区分,外形属性则热传导明显区分于热辐射和热对流,通过显著性分析获得不同足火热传递方式工夫红茶分属性的关键差异物:汤色差异成分为茶黄素、茶黄素-3,3’-双没食子酸酯(theaflavin-3,3’-gallate,TF-D-G)、茶黄素-3-没食子酸酯、可溶性糖、精
基金Supported by the National Natural Science Foundation of China(No.30725045)Shanghai Leading Academic Discipline Project (No.B906)in part by the Scientific Foundation of Shanghai China(Nos.07DZ19728, 06DZ19717 and 06DZ19005)
文摘For quality control purpose, an approach of fingerprinting and simultaneous quantification of five major bioactive constituents of Rhizoma Coptidis was established via a high-performance liquid chromatograph coupled with a photodiode array UV detector（HPLC-DAD） and an electrospray ionization mass spectrometer（HPLC-ESI/MS） The compounds were identified on the basis of the comparison of their mass spectra with literature data and those of standard samples and quantified by the HPLC-DAD method. Baseline separation was achieved on an XTerra C18 column（5 μm, 250 mm×4.6 mm i. d.） with linear gradient elution of formate buffer（consisting of 0.5% formic acid, adjusted to pH=4.5 with ammonia） and acetonitrile（consisting of 0.2% formic acid and 0.2% triethylamine）. The me- thod was validated for linearity（r^2〉0.9995）, repeatability（RSD〈3.1%）, intra- and inter-day precision（RSD〈1.8%） with recovery（99.9%-105.1%）, limits of detection（0.15-0.35 μg/mL）, and limits of quantification（0.53-0.82 μg/mL）. The similarities of 32 batches of Rhizoma Coptidis and their classification according to their manufacturers were based on the retention time and peak areas of the characteristic compounds. The five compounds were selected for quality assessment ofRhizoma coptidis via partial least squares analysis（PLS）.
