微波浸提乌龙茶浓缩液中试研究

以乌龙茶为材料,采用自主研制的50L微波萃取罐,通过超滤与反渗透制取乌龙茶浓缩液,以水浴浸提为对照,研究微波与水浴浸提乌龙茶浓缩汁的效果。结果表明,在1:35的相同茶水比下,微波(2kW)浸提液的主要内含物成分、超滤液内含物保留率以及浓缩液得率等均高于水浴浸提液及其浓缩液,且浸提时间由水浸提过程的30min缩短为微波浸提过程的8min,而能耗仅为水浴的40%;正交试验获得的微波浸提优化方案为:茶水比1:15,微波功率2kW,浸提8min。      

微波辅助浸提鱼鳞卵磷脂的工艺研究

通过单因素试验,研究了乙醇体积分数、乙醇用量、提取时间、微波功率对鱼鳞卵磷脂提取量的影响规律,采用正交试验,得出了鱼鳞卵磷脂提取工艺的最佳参数组合为:乙醇体积分数95%、乙醇用量50mL/g、提取时间4min、功率240W。在此条件下每克鱼鳞中可提取卵磷脂23.87mg。     

乌龙茶粉的研究

以乌龙茶为原料，进行茶粉的研制．经过实验找出最佳的浸提条件，回收浓缩过程中散发的香味物质，兑制回浓缩液中，经过喷雾干燥得到速溶茶粉．并对茶渣进行处理以减少污染。     

微波辅助浸提杜仲叶中绿原酸的工艺研究

为了给工业化提取杜仲叶中的绿原酸提供参考,研究了微波醇提杜仲叶中绿原酸的最佳工艺条件。通过单因素实验研究各因素对提取率的影响,采用正交试验优化工艺条件。微波辅助乙醇浸提法提取杜仲叶中绿原酸的最佳工艺条件：提取温度为60℃,乙醇浓度为70%,pH值为6,料液比为1∶30,浸提时间为25min,在此条件下,绿原酸的提取率为4.8568mg/g。     

大蒜微波浸提液对亚硝酸盐的清除效果研究

主要研究了大蒜微波浸提液对亚硝酸盐的清除效果。采用盐酸萘乙二胺分光光度法对影响亚硝酸盐清除率的因素进行了分析。结果表明,微波功率460 W,微波作用时间90 s,大蒜微波浸提液用量3 mL,反应液pH为4.0时对亚硝酸盐的清除率最高,可达到99.26%。将研究结果直接用于肉制品中,对亚硝酸盐的清除效果也非常显著。     

燕麦麸皮β-葡聚糖的微波辅助浸提技术研究

以微波辅助提取技术,分别考查了微波、微波时间、功率料水比、浸提温度等因素对提取燕麦麸皮β-葡聚糖得率的影响,并与热水浸提法进行比较,确定了微波辅助提取工艺的最佳工艺参数为:料水比为1∶15、微波时间为4min、微波的功率为640W、温度为80℃,β-葡聚糖的得率可达5.1%。该工艺与传统浸提方法相比较,提取率提高,节省了水和时间。      

茶饮料浸提工艺的微波辅助萃取(MAE)应用研究

浸提工艺是茶饮料生产过程一个关键生产工艺。本文比较了传统热水浸提工艺和微波辅助萃取工艺之间的最优工艺参数，并利用高效液相色谱分析方法研究了微波萃取对茶多酚浸出得率和单体组成的影响，表明微波萃取技术（Microwave-assisted extraction，MAE）可应用在茶饮料生产中，而且比传统热水浸提工艺省时节能。结果表明：传统热水浸提工艺的最优浸提温度90℃、时间43min、液固比20：1，茶多酚的得率为19．76％；微波辅助萃取工艺的最优浸提功率360W、时间3、5min、液固比25：1，茶多酚的得率为20．63％。微波短时处理茶叶不会对茶多酚的结构和单体组戍产生破坏性影响。     

微波浸提——酸碱滴定法测定果品中的总酸度

介绍了一例微波新技术，在密闭容器内，对果品进行微波浸提，快速测定其总酸度的新方法，并探讨了微波功率，微波时间等因素对测定结果的影响，与标准方法相对照，经Ｆ－检验法及ｔ－检验法检验，没有明显差异，大大加快了测定速度，缩短了测定的周期，提高了测定的效率，该法具有操作简便，省时，宜于批量样品的测定，便于推广等优点，为果品中总酸度的测定，提供了一个快速，准确、简便易行的分析方法，亦可借鉴于其它食品的浸提测     

微波辅助萃取(MAE)绿茶的浸提动态过程研究

以绿茶作为材料,采用微波辅助萃取(MAE)技术,变化微波功率、浸提时间、浸提溶剂量、浸提溶剂4个变量因子,对浸提过程中茶汤的有效成分——茶多酚、氨基酸和咖啡碱等动态变化进行研究。比较绿茶中不同有效成分在不同条件下进行MAE过程的萃取效率,并利用SPSS软件把动态过程归结为各种模型,得到的模型分别是:Y=-10.877 0.40055×X-0.00196×X2 3.324×10-6×X3(360W);Y=-2.472 0.27910×X-0.001167×X2 1.4345×10-6×X3(540W);Y=-16.492 0.72497×X-0.00463×X2 9.061×10-6×X3(720W)。     

水溶性大豆多糖的微波浸提工艺优化

采用响应面分析法(response surface analysis,RSA)优化了微波浸提低温豆粕水溶性多糖的工艺条件。在单因素实验结果基础上,选取pH值、时间、料水比及微波功率4个因素进行中心组合旋转实验设计(central composite rotatable design,CCRD),并通过RSA对微波浸提水溶性大豆多糖工艺参数进行了优化组合。结果表明:在pH 8.0,料水比(g∶mL)1∶6,提取时间2.6 min,功率380W条件下,水溶性大豆多糖的得率可达5.86%,与验证实验相对误差为0.44%,证明响应面法优化结果是真实有效的。     

乌龙茶多糖提取工艺及抗氧化作用研究

以乌龙茶为原料,研究不同因素对乌龙茶多糖得率的影响,初步探讨了乌龙茶多糖的抗氧化活性.结果表明,各因素对茶多糖得率的影响为:提取次数＞提取温度＞提取时间＞料液比;最佳提取工艺为提取时间80min,提取温度80℃,提取次数3次,料液比1∶35.在此条件下,茶多糖得率为15.73％.体外抗氧化试验表明,乌龙茶多糖对羟自由基、超氧阴离子自由基、1,1-苯基-2-苦基肼自由基均具有一定的清除效果,且清除率随浓度的增大而增加.     

新型乌龙茶酸奶的研制

以乌龙茶为原料研制出新型乌龙茶酸奶。通过对乌龙茶汁提取方法及发酵工艺的研究,最终确定乌龙茶汁提取的最佳工艺参数为:冲泡温度90℃、冲泡时间20min、茶水比1∶10;乌龙茶酸奶的最佳配方为:乌龙茶汁3%、接种量2%、蔗糖6%、稳定剂0.05%。制成的乌龙茶酸奶色泽乳白微黄,乌龙茶香与酸奶香味融合较好,风味最佳。     

Study of aroma compound formations and transformations during Jinxuan and Qingxin oolong tea processing

We characterised the formation and dynamic changes in the main aroma compounds produced during the manufacturing process of Jinxuan and Qingxin oolong tea. Thirty-five aroma compounds were investigated. Subsequent principal component and cluster analyses showed that the fresh leaves, spread leaves and rocked leaves of the two varieties of tea were distinguished from each other. Particularly, the aldehyde and ‘other’ compounds showed the highest correlation coefficients (0.71 and −0.70) among the principal. The heat map showed that the proportions of acetic acid, 3-methylbutanal and 2-methylbutanal significantly changed during the manufacturing process of the two tea varieties. The key amino acids (isoleucine, leucine, valine and aspartic acid) and enzymes (branched-chain amino acid aminotransferase, aspartate aminotransferase and acetaldehyde dehydrogenase) involved in the synthesis of 3-methylbutanal and 2-methylbutanal differed between the two varieties during manufacture. Our study reveals the characteristics of different varieties of oolong tea and their aroma formation after manufacture using the same process.     

正交试验法优选绿茶绿色素的微波提取工艺

应用微波技术进行正交试验设计,优选绿茶中绿色素提取的最佳工艺条件。以绿色素的乙醇浸提液在可见光区665nm处的吸光度为指标,应用正交试验法对提取过程中乙醇浓度(A)、微波功率(B)、料液比(C)、提取时间(D)4个因素进行优选研究。结果表明,乙醇浓度对茶叶中绿色素提取率的影响最为显著,最佳工艺条件为乙醇浓度90%、料液比为1/30、提取时间90s、微波功率480W。在此工艺下茶叶中绿色素提取率达36.77%。     

Comparison of the relative dissipation rates of endosulfan pesticide residues between oolong and green tea

The dissipation behaviour of endosulfan in dry made-tea leaves of oolong and green tea was compared to establish whether there was any difference in dissipation rates between the two teas. The dissipation of endosulfan in oolong and green tea corresponded with a first-order kinetics curve. The average half-life of endosulfan (n = 12) was 1.60 ± 0.44 days in green tea and 2.01 ± 0.55 days in oolong tea, showing a statistically significant difference, and indicating that the dissipation of the pesticide was significantly slower in oolong tea than that in green tea. Although the initial levels of residual endosulfan were lower in oolong tea, due to the slower dissipation rate, the residues 5–7 days after application were higher in oolong than in green tea. It is suggested that the minimum interval between endosulfan application and tea leaf harvesting is 7 days for green tea and 10 days for oolong tea in the case where the maximum residue limit of endosulfan in made-tea is fixed as 10 mg kg^?1.     

龙井绿茶茶多酚提取工艺研究

为了提高茶多酚的得率和纯度,以龙井绿茶为原料,对茶多酚进行乙醇溶液提取、超声波和微波辅助提取。醇提的最佳条件为乙醇浓度50％,浸提4次,每次45min,温度为70℃,液固比为20：1,最大浸提率为24．45％。微波辅助提取最佳条件为预浸30min,乙醇浓度40％,微波解冻档浸提4min,浸提2次,液固比为40：1,最大浸提率为24．70％。超声波辅助浸提最佳条件为乙醇浓度80％,浸提温度50℃,浸提时间25min,浸提2次,液固比为14：1,最大浸提率为24．72％。结果表明：微波与超声波提取率稍高于醇提,但三者差别不大。     

Comparison of the relative dissipation rates of endosulfan pesticide residues between oolong and green tea

The dissipation behaviour of endosulfan in dry made-tea leaves of oolong and green tea was compared to establish whether there was any difference in dissipation rates between the two teas. The dissipation of endosulfan in oolong and green tea corresponded with a first-order kinetics curve. The average half-life of endosulfan (n = 12) was 1.60 ± 0.44 days in green tea and 2.01 ± 0.55 days in oolong tea, showing a statistically significant difference, and indicating that the dissipation of the pesticide was significantly slower in oolong tea than that in green tea. Although the initial levels of residual endosulfan were lower in oolong tea, due to the slower dissipation rate, the residues 5-7 days after application were higher in oolong than in green tea. It is suggested that the minimum interval between endosulfan application and tea leaf harvesting is 7 days for green tea and 10 days for oolong tea in the case where the maximum residue limit of endosulfan in made-tea is fixed as 10 mg kg^-1.     

微波萃取技术

对微波萃取技术的研究近况作了总结 ,着重说明了微波萃取技术的原理、优点、设备影响因素及其应用     

从残次茶中制备茶多酚的关键技术研究

现今对残次茶的利用和茶多酚的提取工艺不完善,以至于造成残次茶的浪费。因此,研究从残次茶中提取茶多酚的关键技术是很有必要也很有意义的。试验以黑毛茶为原料,乙醇为提取溶剂,采用超声辅助提取的方法提取茶多酚,并通过响应面分析得到最佳工艺条件：超声功率70 W,乙醇体积分数70%,浸提温度65 ℃,浸提时间30 min,料液比1∶25（g∶mL）。在此条件下,茶多酚提取率为7.44%。 关键词：中图分类号：TS202.3 文献标识码：A 文章编号：0254-5071（20１5）06-0094-05 doi: