蔗糖对绿茶饮料理化成分及其风味稳定性的影响

绿茶饮料的风味稳定性一直是制约高品质绿茶饮料货架期的技术瓶颈。为了提高绿茶饮料的风味稳定性,分析比较了绿茶加工过程中不同蔗糖添加量(0,1%,2%,4%和8%)对绿茶饮料灭菌(135℃,15 s)、贮藏(4,25,38℃;0~60 d)过程中感官品质以及理化成分的影响。结果表明,与对照(未加蔗糖处理)相比,添加蔗糖使绿茶饮料滋味更鲜爽甜醇,香气浓度增加;灭菌后,添加蔗糖使得绿茶饮料的香气和滋味品质提高,总儿茶素和表型儿茶素含量增加,非表型儿茶素下降;在不同贮藏条件下,相比对照,添加蔗糖后的绿茶饮料风味品质有明显改善,包括汤色亮度增加,香气和滋味增强,茶多酚、氨基酸、咖啡碱以及儿茶素含量均有所增加,在贮藏42 d内添加蔗糖对绿茶饮料风味品质稳定性的提高更为明显,且2%和4%蔗糖添加量对绿茶饮料的风味品质有更好的改善作用。研究结果表明在一定的贮藏条件下,绿茶加工过程中添加蔗糖可以较好地改善绿茶饮料的风味品质并保持其稳定性。     

茶饮料色泽劣变及护色技术研究进展

茶饮料滋味独特、文化底蕴深厚且营养成分丰富,广受消费者的青睐,是世界上仅次于水的第二大饮料。汤色是评价茶饮料品质好坏的重要指标。不同类型的茶饮料呈现出不同的色泽,茶汤色泽的呈现是茶汤中各种物质综合作用的结果,这些物质主要包括儿茶素类、黄酮醇及其苷类以及花青素等,除此之外还有一些脂溶性色素。茶汤色泽劣变主要是由于这些物质易受茶饮料加工与贮藏条件的影响,从而发生一系列反应生成有色物质,致使茶汤变黄、变红、变褐。茶饮料色泽的劣变是制约该产业发展的主要瓶颈之一。本文从茶饮料中主要呈色物质及其在加工贮藏过程中的变化规律入手,对茶饮料色泽劣变机理和护色技术进行概括总结,旨在为茶饮料护色技术研发提供理论参考。     

茶饮料色泽劣变及护色技术研究进展

茶饮料滋味独特、文化底蕴深厚且营养成分丰富,广受消费者的青睐,是世界上仅次于水的第二大饮料。汤色是评价茶饮料品质好坏的重要指标。不同类型的茶饮料呈现出不同的色泽,茶汤色泽的呈现是茶汤中各种物质综合作用的结果,这些物质主要包括儿茶素类、黄酮醇及其苷类以及花青素等,除此之外还有一些脂溶性色素。茶汤色泽劣变主要是由于这些物质易受茶饮料加工与贮藏条件的影响,从而发生一系列反应生成有色物质,致使茶汤变黄、变红、变褐。茶饮料色泽的劣变是制约该产业发展的主要瓶颈之一。本文从茶饮料中主要呈色物质及其在加工贮藏过程中的变化规律入手,对茶饮料色泽劣变机理和护色技术进行概括总结,旨在为茶饮料护色技术研发提供理论参考。     

转生产方式 调产品结构 走中国特色茶饮料创新发展之路

中国大陆茶饮料一直以来呈快速增长趋势,已成为国际上最大的茶饮料生产地区,然而进入2012年以后茶饮料增长趋势明显放缓,茶饮料的增长首次受到明显抑制。我国经济社会发展达到一定的高度,人民生活水平不断提高,消费者对茶饮料的要求越来越高。虽然中国大陆茶饮料产业已形成较为稳定的产销格局,但是产品同质化程度较高,天然、原味的高端产品少,结构亟待完善。因此,国内茶饮料企业应积极借鉴他人的成功经验,利用好国内主要的技术研发平台和中国特有的自然资源,有机整合传统消费文化和饮料时尚特性,拓展产品开发思路,积极应用各类食品高新技术支撑新产品开发,从技术创新、材料创新、产品开发思路创新上走出一条中国特色的茶饮料创新发展之路。     

Crude fibre as a parameter in the quality evaluation of tea

Tea is one of the oldest beverages known to mankind. Its quality is determined, among other things, by aroma and taste properties. We have paid attention herein to the fact that crude fibre is an important parameter in the quality evaluation of tea and influences its sensory properties. The elucidation of role and meaning of crude fibre in tea is attempted in this paper; therefore its content in tea from various places of origin has been determined. A significant correlation between crude fibre content and tannins content of tea samples was found (R² = 0.72).     

不同产地无糖绿茶饮料滋味特征差异分析

对市售不同产地无糖绿茶饮料滋味品质及其化学成分进行分析比较,以期明确无糖绿茶饮料中的主要滋味物质,探究不同产地绿茶饮料间滋味特征的差异性。结果表明,不同产地绿茶饮料的滋味因子和色差差异不明显,其中日本绿茶饮料的整体滋味品质较优。日本和中国台湾绿茶饮料中茶多酚、咖啡碱、黄酮、可溶性糖质量浓度和儿茶素总量、黄酮苷总量、阳离子总量都明显高于中国大陆绿茶饮料。有13 种化学组分与感官评分相关性较高,其中茶多酚（0.910）、黄酮（0.917）、Mn2＋（0.912）质量浓度与绿茶饮料滋味浓度呈极显著正相关（P＜0.01）;咖啡碱（0.830）质量浓度与绿茶饮料滋味苦度呈极显著正相关（P＜0.01）;牡荆素-2’’-O-鼠李糖苷（Vit-rha）（0.862）、Al3＋（0.811）质量浓度与绿茶饮料滋味涩度呈极显著正相关（P＜0.01）。滋味贡献度（dove-over-threshold,Dot）分析发现黄酮及其苷元对无糖绿茶饮料涩味起主要贡献,包括槲皮素-3-O-芸香糖苷（Que-rut）、山柰酚-3-O-芸香糖苷、槲皮素-3-O-半乳糖苷、槲皮素-3-O-葡萄糖苷、杨梅素-3-O-半乳糖苷、Vit-rha,其中Que-rut的Dot值最高;咖啡碱对无糖绿茶饮料苦味起主要贡献。     

四种茶饮料中茶多酚、游离氨基酸及维生素C含量分析及稳定性评价

本文检测了四种代表性市售茶饮料中的茶多酚、游离氨基酸和维生素C的含量,并研究茶饮料在室温未拆封持续贮藏5个月稳定性和拆封后室温下96 h内各指标变化。结果表明,除原叶绿茶中茶多酚略低于标准GB/T 21733-2008外,其他受试茶饮料各品质成分均符合相关标准,同时在室温未拆封存储条件下,各种茶饮料随储存时间的延长,茶多酚、游离氨基酸和维生素C含量明显下降;其中各样品中茶多酚在存储第3个月(即9月份)含量下降最明显,维生素C含量在存储第1~3个月(即7~9月份)下降较快,存储5个月后,只有调味绿茶中有维生素C检出,而调味红茶、原叶绿茶及原液红茶均未有维生素C检出。茶饮料开封后96 h内茶多酚、游离氨基酸和维生素C含量均明显下降,红茶饮料中维生素C在开封后72 h时只有微量检出,96 h后未有检出。以上结果表明茶饮料不宜长期室温存放,开封后不宜长时间放置。对茶饮料中主要品质成分茶多酚、游离氨基酸和维生素C含量及稳定性进行分析,能够为茶饮料生产、存储及消费提供参考。     

姜汁茶生产工艺条件的研究

采用微孔滤膜技术，以姜和绿茶为主原料，研制出一种保健姜汁茶。探讨了姜汁与绿茶混合口味及色泽的最佳比例，以及解决瓶装姜汁茶饮料沉淀的最佳工艺条件，如：pH值、杀菌温度、抗氧化剂、精滤工艺等。     

以膜浓缩茶汁调制纯茶饮料的品质研究

以膜浓缩茶汁为原料制备了纯茶饮料 ,并就其风味、澄清性及过滤方面的特性进行了对比实验 ,得出膜浓缩茶汁将是生产茶饮料的最佳选择的结论。     

Determination of essential and non-essential elements in various tea leaves and tea infusions consumed in Turkey

Tea is one of the most popular beverages in the world. Thus, the chemical components in tea are of great interest, especially in relation to health. In this study, 12 tea samples (10 black, 1 white and 1 green) and 5 herbal tea samples were purchased from supermarkets in Izmir, Turkey. Sample preparation has been performed using wet and microwave digestion procedures. The elemental content (Fe, Zn, Cu, Mn, Ni, Na and K) in the digests and infusions has been analysed. Generally, elemental contents in tea leaves were found to be higher than those in tea infusions. The accuracy of the method was checked and confirmed by standard reference material analyses. The comparison of wet and microwave digestion has not shown significantly different results. Therefore, the microwave digestion procedure was preferred because it is less laborious. The elemental intake related to tea consumption has also been studied.     

罗汉果叶饮料的可行性研究

采用化学方法定性、UV及HPLC法测定罗汉果叶中氨基酸、茶多酚、黄酮含量．实验结果表明罗汉果叶含氨基酸5.82%、茶多酚1．61％、黄酮1．62％，具有较高的饮用价值，适用于饮料。     

Aluminium content in tea leaves and in differently prepared tea infusions

Aluminium content of tea leaves has been engaging the attention during recent years because of its uptake in the form of beverages such as tea. Hence, data were generated on the Al content in tea and its infusions, using an inductively coupled plasma spectrometer. The average values of Al in fresh tea leaves and commercial tea powders were 250 and 325 μg/g dry wt, respectively. Tea infusions contained 20–80 μg/g of Al. Al complexes with tea components like tannic acid and theoflavins were studied and stability characteristics as well as the nature of the complexes were computed.     

提高绿茶饮料风味的途径

从栽培中的处理、采且处理、杀青技术、原料及烘焙、灭菌技术、酶技术、添加食品添加剂和调香技术等方面深入探讨了提高绿茶饮料风味的途径。绿茶饮料成为茶饮料发展的主流,而开发具有名优绿茶风味的茶饮料则是绿茶饮料的发展方向。     

茶多酚提取与纯化方法及其功能活性研究进展

茶是世界上三大无酒精饮料之一,已有上千年的饮用历史。茶叶中富含茶多酚,具有良好的食用价值和药用价值,开发前景广阔。本文简要介绍了茶多酚的组成结构及性质,并综述了茶多酚的提取与纯化方法及特点,以及茶多酚在抗氧化、抗肿瘤、抗辐射、抗动脉粥样硬化等方面的研究进展,最后对茶多酚的研究前景进行展望,以期为茶多酚的研究和应用提供一定的理论参考。     

LC/MS characterization of phenolic constituents of mate (Ilex paraguariensis,St. Hil.) and its antioxidant activity compared to commonly consumed beverages

Mate is a tea-like beverage widely consumed in South America, prepared from the dried leaves of Ilex paraguariensis, St Hil. The total polyphenols (PP) and antioxidant activity of mate infusions and acid–methanol/acetone extracts were determined in three commercial brands, and compared to commonly consumed beverages like green and black teas, red, rosé and white wines, and orange juice. Mate had a PP content comparable to tea and orange juice, and, when normalized for the PP content of beverages, mate had an antioxidant activity slightly higher than wines, orange juice and black tea, but lower than green tea. LC/MS analysis of mate extracts showed that caffeoylquinic and dicaffeoylquinic acid isomers were the major components of the phenolic fraction of mate. Mixed mono-, di- and tri-esters of quinic acid and other hydroxycinnamates were also detected. Several quercetin and kaempferol glycosides were identified. Consumption of mate infusions would significantly contribute to the overall antioxidant intake, providing high amounts of caffeoylquinic acid derivatives, with biological effects potentially beneficial for human health.     

不同茶饮料贮藏过程中品质的变化

本文从色泽、浊度及活性成分含量三个方面分析不同茶饮料的品质变化特征，分别对高酸绿茶饮料、低酸绿茶饮料、高酸红茶饮料及低酸红茶饮料在不同贮藏条件下的可溶性固形物含量、透光率、浊度、色差、茶多酚含量、表没食子儿茶素没食子酸酯（Epigallocatechin gallate，EGCG）含量等指标进行测定，探究不同茶饮料在不同贮藏条件（温度、时间）下品质变化的情况。结果表明:不同茶饮料在贮藏过程中，透光率无显著变化；高酸绿茶饮料在4 ℃及25 ℃条件下贮藏，随贮藏时间的延长，浊度显著增加，贮藏至第180 d，分别增加了52.04%、34.12%，红茶饮料浊度无显著变化；不同茶饮料在贮藏过程中，随贮藏时间的延长，L*值降低，a*值及b*值增加，25 ℃条件下贮藏至180 d，高酸绿茶饮料、低酸绿茶饮料、高酸红茶饮料及低酸红茶饮料的L*值分别降低了31.86%、39.98%、30.22%及37.73%；茶饮料中的茶多酚及EGCG含量随着贮藏时间的延长而降低，EGCG降解程度较茶多酚高，在55 ℃条件下贮藏15 d，高酸绿茶饮料、低酸绿茶饮料、高酸红茶饮料及低酸红茶饮料的茶多酚含量分别降低9.08%、10.28%、13.39%及18.63%，EGCG含量分别下降了35.32%、42.18%、47.22%及49.03%。     

A review of recent studies in China on the possible beneficial health effects of tea

Tea is one of the most heavily consumed beverages in the world. The relationship between tea drinking and human health is becoming a subject of intense study by scientists throughout the world. In this paper, we first provide a comprehensive analysis of the medical literature on tea published in China during the past 20 years, and then highlight some recent studies in China on the relationship between tea and several human diseases. During the period 1982–2002, 691 research papers related to tea and health have been published in 290 Chinese journals. These studies showed that tea and tea constituents have various biological activities and suggested that tea drinking might be beneficial to human health. Tea has potential in the prevention or adjuvant treatment of several diseases including cancer, cardiovascular diseases and obesity. The trend and future direction in medical research on tea in China are also briefly discussed.     

茶叶中挥发性香气物质研究进展

茶是3大非酒精饮料之一,具有降血糖、抗氧化和抗炎等健康功能。近年来,大量研究报道了茶叶的生物活性和健康功能,而作为感官审评的重要指标,茶叶的香气同样值得深入研究。按照香气物质的生源途径分类,茶叶中香气物质可以分为类胡萝卜素、脂肪酸、糖苷类源香气前体物质以及加工过程中产生的美拉德反应产物。本综述对茶叶中香气物质的研究进展进行了归纳总结,以期为茶叶风味品质化学的研究提供借鉴。     

鱼蛋白水解液系列饮料的制作

利用鱼蛋白水解液和乌龙茶叶及各种水果原汁配制风味(茶)果汁复合饮料．添加不同的遮蔽剂以藏少鱼蛋白水解液的不良风味和口感，加入一定量的稳定剂保持饮料的均匀、稳定．以饮料的风味、澄清度、稳定性等为指标选取适宜的工艺配方．结果表明用菠萝原汁调配的菠萝、鱼蛋白水解液复合饮料．风味和口感最佳。     

不同产地绿茶饮料香气特征及差异分析

利用顶空固相微萃取与气相色谱-质谱联用法并结合相关性与气味活度值分析研究了不同产地绿茶饮料挥发性风味成分物质含量及构成差异。结果表明：低糖型绿茶饮料的香气总量要远高于无糖型,且不同产地绿茶饮料主要香气物质组成不同,主要共性成分是芳樟醇和柠檬烯;其中中国大陆饮料中含量较高的有酯类、酮类和烯类,日本饮料以醇类、烯类和醛类为主,中国台湾饮料中醇类、酯类的含量较高,而烯类含量很低。其中有10 个香气组分与香气评分相关性较高,主要是反-氧化芳樟醇（0.93**）与花香呈显著正相关,顺-3-己烯醇（0.90*）和β-环柠檬醛（0.92**）与清香呈显著正相关,β-紫罗酮（－0.92**）与果香呈显著负相关,β-大马烯酮（0.95**）与甜香呈显著正相关,1-乙基吡咯（0.87*）与烘焙香呈显著正相关;6 个气味活度值较高的组分分别是β-大马烯酮、β-紫罗酮、芳樟醇、大马酮、癸醛和柠檬烯,它们对整体香气贡献较大。