壳聚糖在绿茶汁澄清中的应用研究

本研究了壳聚糖对绿茶汁的澄清作用，表明壳聚糖是一种良好的澄清剂，能提高绿茶汁的透光度与稳定性，而不影响绿茶汁的主要风味物质。     

Green Tea and Bone Marrow Transplantation: From Antioxidant Activity to Enzymatic and Multidrug-resistance Modulation

Epigallocatechin-3-gallate (EGCG), the main flavonoid of green tea (GT), could play an active role in the prevention of oxidative-stress-related diseases, such as hematologic malignancies. Some effects of EGCG are not imputable to antioxidant activity, but involve modulation of antioxidant enzymes and uric acid (UA) levels. The latter is the major factor responsible of the plasma non-enzymatic antioxidant capacity (NEAC). However, hyperuricemia is a frequent clinical feature caused by tumor lysis syndrome or cyclosporine side effects, both before and after bone marrow transplantation (BMT). Besides this, food–drug interactions could be associated with GT consumption and could have clinical implications.

The molecular mechanisms involved in the redox and drug metabolizing/transporting pathways were discussed, with particular reference to the potential role of GT and EGCG in BMT. Moreover, on reviewing data on NEAC, isoprostanes, uric acid, and various enzymes from human studies on GT, its extract, or EGCG, an increase in NEAC, without effect on isoprostanes, and contrasting results on UA and enzymes were observed.

Currently, few and contrasting available evidences suggest caution for GT consumption in BMT patients and more studies are needed to better understand the potential impact of EGCG on oxidative stress and metabolizing/transporting systems.     

Quantitative and Qualitative Portrait of Green Tea Catechins (Gtc) Through Hplc

Green tea (Camellia sinensis) is a prosperous source of polyphenols, especially catechins. In the current research, an effort was made to optimize the extraction conditions for maximum yield of catechins from the local green tea Qi-Men. For the purpose, three different solvents were used, i.e., aqueous ethanol (50%), aqueous methanol (50%), and water at different time intervals (20, 40, and 60 min). Green tea catechins were quantified through HPLC using a C18 column and UV detector. The antioxidant activity of green tea catechins was measured through in vitro tests including DPPH radical scavenging ability and antioxidant activity. Results showed that extraction through aqueous ethanol resulted in maximum yield of green tea catechins (17400 ± 0.19 mg/100 g green tea leaves. Moreover, epigallocatechin, epigallocatechin gallate, epicatechin gallate, and epicatechin ranged from 4.26 ± 0.09 to 6.4 ± 0.2, 12.1 ± 0.123 to 17.7 ± 0.3, 1.32 ± 0.03 to 1.81 ± 0.02, 5.48 ± 0.099 to 8.6 ± 0.2 g/100 g of dry-extract, respectively. Furthermore, highest antiradical (80.65 ± 3.69%) and antioxidant activity (67.12 ± 3.08%) were observed in catechins extracted through aqueous ethanol.     

浅述云南磨锅绿茶加工技术

云南磨锅绿茶是在传统炒青绿茶制作工艺基础上,依据大叶群体种鲜叶特性经生产总结定型生产的一种绿茶,经过特定的加工工艺,形成了云南磨锅绿茶特有的干茶条索紧结、色泽绿润、茶条附有茶霜、带板栗香及汤色绿亮、滋味浓强鲜的品质特征,通过对云南磨锅绿茶从鲜叶采摘要求、加工制作工艺和加工技术的浅述,阐明其工艺技术要点,提高云南磨锅绿茶品质,促进云南磨锅绿茶健康可持续发展。     

常熟“沙家浜”绿茶多糖的纯化

以"沙家浜"粗绿茶为原料制取茶多糖,并对茶多糖进行脱蛋白和脱色纯化研究。结果表明:聚酰胺吸附柱层析法作为茶多糖纯化(脱蛋白、脱色)的最佳方法,其脱色的适宜工艺条件为,聚酰胺用量为粗多糖质量的6倍,聚酰胺柱用1.5倍柱体积的去离子水以1.5mL/min的流速进行洗脱,在此工艺条件下,蛋白质脱除率达到95.8%。     

茶叶中茶多酚提取及含量测定的研究

探讨茶多酚的提取条件。采用均匀设计法,以茶多酚提取率为指标,考察乙醇浓度、液固比、提取时间对茶多酚提取率的影响。结果表明,茶叶中茶多酚最佳提取条件为：采用索氏提取法,以60%的乙醇为溶剂,液固比为8∶1（mL∶g）,提取时间为180 min。验证试验结果表明提取物收率为46.19%。     

绿茶儿茶素抗癌作用机理的研究进展

绿茶儿茶素是绿茶中主要的一类活性物质，现有资料表明其具有一定的肿瘤预防及治疗作用。有关其作用的机理，研究者们主要从绿茶儿茶素的抗氧化能力(包括其结构、对自由基的作用、对抗化酶系统的作用等)、免疫调节功能、抗突变作用，诱导细胞凋亡等不同的角度进行了探讨。     

醒发过程中绿茶馒头面团品质变化研究初探

本文主要研究绿茶馒头面团在醒发过程中茶多酚、游离氨基酸和叶绿素以及物性指标的变化规律。实验结果表明,随着醒发时间的增加,面团中功能成分呈递减趋势,面团的硬度、粘聚性、胶着性和咀嚼性越来越小,而粘着性、弹性和回复性越来越大;醒发时间一定的条件下,随绿茶粉添加量的增加,功能成分减少速率呈递减趋势,面团的硬度、粘着性、粘聚性、胶着性及咀嚼性增大,而弹性及回复性逐渐减小。     

绿豆、绿茶冰淇淋的研制

以绿豆、绿茶、鲜鸡蛋、无水奶油等为主要原料，利用L9(3^4)正交试验方法，得出绿豆、绿茶冰淇淋主要成分的最佳含量为乳脂肪质量分数8％，甜味剂质量分数16％，总固形物质量分数32％。该产品风味独特、口感细腻、色泽均匀、质地坚实、营养丰富、清爽解暑，是值得开发的冰淇淋新品。     

绿茶粉对月饼饼皮挥发性风味物质的影响

本文基于固相微萃取和气质联用分析技术,定量分析了高温烘焙环境下,绿茶粉对月饼饼皮挥发性风味物质的影响试验结果表明:构成月饼饼皮风味物质在绿茶粉的添加前后发生了显著变化,主体风味物质由甲苯、己醛转变为3-羟基-2-丁酮、β-庚烯醛、戊醇以及3甲基丁醛;其中β-庚烯醛为绿茶风味成分。     

焙烤茶薯片研制及产品评价

以马铃薯全粉、面粉、糖、植物黄油等为原料,添加绿茶粉,通过焙烤方式得到绿茶薯片。确定了产品的配方和加工工艺条件,并对产品品质作出评价。     

绿茶多酚化合物的精制和抗氧化试验

应用高压液相色谱法和葡聚糖凝胶柱层析技术 ,从绿茶多酚化合物中分离纯化精制EGCG(表没食子儿茶素没食子酸酯 ) ,EGC(表没食子儿茶素 )和ECG(表儿茶素没食子酸酯 )等单体化合物 ,并用油脂氧化稳定测定仪 (Rancimat)对其抗氧化性能进行了试验。结果表明 ,抗氧化性能依次排列为 :EGCG >EGC >ECG >BHT(BHT为商品油脂抗氧化剂 )     

茶叶儿茶素组分HPLC测定中的提取方法研究

以蒸青绿茶为材料,利用单因素试验和正交实验研究了不同提取时间、不同提取温度以及不同提取料液比例等对茶叶中儿茶素组分的影响。结果表明:当提取料液比例为1:125(g:mL)、提取温度为70℃、提取时间为30 min时,蒸馏水一次提取可以达到相对理想的提取效果,适用于常规分析实验。     

冠突散囊菌发酵型茶饮料的研究

对分离自四川自然发酵砖茶中的冠突散囊菌发酵粗老的绿毛茶茶汁的单个优化条件进行了研究,并用正交设计优化了条件组合。结果表明,茶水比为1:30、时间180～216 h、接种量0.8%～1.0%、温度28～30℃为较优的工艺参数;液体发酵过程中茶多酚氧化率影响的主次顺序为接种量>温度>时间>茶水比;试验中各因素水平的优化组合为:接种量1%(孢子悬液浓度为1.6×10~7～2.0×10~7个/mL)、温度为26℃、时间为216 h、茶水比1:30。     

黄瓜绿茶保键饮料的研制

以黄瓜、绿茶为主要原料,配以适当的白砂糖、柠檬酸和食盐,研制出口感清爽、风味独特、清凉降火、营养丰富的黄瓜绿茶保健饮料.通过三因素三水平的正交试验确定了黄瓜绿茶保健饮料的最佳配方,并通过单因素试验探讨饮料稳定剂的选择.结果表明:黄瓜绿茶饮料的最佳配方为黄瓜汁25％、绿茶汁45％、白砂糖8％、柠檬酸0.2％、食盐0.1％,稳定剂选用0.2％的海藻酸钠、CMC-Na、黄原胶的复合溶液(1∶1∶1).     

鸠坑毛尖茶机械加工技术

鸠坑毛尖茶历史悠久,文化底蕴深厚,本文介绍了历史名茶鸠坑毛尖的恢复创制过程。重点叙述了新创制的鸠坑毛尖茶机械加工工艺流程和技术参数。鸠坑毛尖的主要工艺为:鲜叶采摘与摊放、杀青、理条、揉捻、初烘、整形、复烘,本文对各工序技术要点和所用机械进行了总结,并提出了加工过程中应注意的问题。     

向日葵叶绿茶复合饮料的开发研究

以超纯水为溶剂,以向日葵叶中绿原酸提取率为考察指标,从新鲜向日葵叶中提取绿原酸,研究颗粒度、料液比、浸提时间、提取温度对向日葵叶中绿原酸提取率的影响。试验结果表明:绿原酸最佳提取工艺:物料粒度100目、料液比1∶50、提取温度70℃、浸提时间20min。以最佳工艺提取得到的富含绿原酸向日葵叶汁和绿茶汁为主要原料,添加白砂糖、柠檬酸和食用香精等制备复合饮料,通过正交试验确定绿原酸复合饮料的最佳配方:富含绿原酸向日葵叶汁与绿茶汁的体积比为1∶2、白砂糖添加量为4%,柠檬酸添加量0.2%,食用香精添加量0.03%,此时,效果最佳,口感良好。     

柑橘绿茶复合饮料的研制

以柑橘、绿茶为原料研制柑橘绿茶复合饮料,探讨各因素对酶解及调配效果的影响。结果表明:柑橘汁的最佳酶解工艺为0.12 mL/L果胶酶、pH 3.5、温度45℃、时间2.0 h;以柑橘清汁为原料,复合饮料最佳调配工艺为柑橘汁8%、绿茶汁30%、白砂糖10%、苹果酸0.05%、蜂蜜0.005%,在此试验条件下,可得到感官、理化性质最佳的柑橘绿茶复合饮料。     

Isolation of Green Tea Catechins and Their Utilization in the Food Industry

Tea is a rich source of catechins, which are well-known antioxidants. Tea consumption has been found to promote human health; however, only drinking tea may not provide a sufficient level of catechins to achieve health benefits. Thus, the utilization of catechins in foods is an alternative way to supplement catechin consumption. Furthermore, catechins can prevent lipid oxidation and improve color and flavour of foods; hence, addition of catechins can also prolong the shelflife of foods. Therefore, catechins have recently been isolated from green tea for utilization in food products to enhance their shelflife and health benefits. This article outlines several methods for the isolation of catechins from green tea, discusses the challenges involved, and reviews the utilisation of catechins in the food industry.