食品科学 ›› 2020, Vol. 41 ›› Issue (19): 25-30.doi: 10.7506/spkx1002-6630-20190930-367

• 基础研究 • 上一篇    下一篇

颗粒形绿茶的物理特性与外形品质关联性

郭丽,余方林,赵锋,张悦,朱荫,戴伟东,董春旺,林智   

  1. (1.中国农业科学院茶叶研究所,浙江?杭州 310008;2.福建农林大学园艺学院,福建?福州 350002;3.浙江工商大学食品与生物工程学院,浙江?杭州 310018)
  • 出版日期:2020-10-15 发布日期:2020-10-23
  • 基金资助:
    “十三五”国家重点研发计划重点专项(2018YFD0700500);现代农业产业技术体系建设专项(CARS-19); 浙江省科技计划项目(2013C32098);中国农业科学院科技创新工程项目(CAAS-ASTIP-2014-TRICAAS)

Correlation of Physical Properties of Granular Green Tea with Its Appearance Quality

GUO Li, YU Fanglin, ZHAO Feng, ZHANG Yue, ZHU Yin, DAI Weidong, DONG Chunwang, LIN Zhi   

  1. (1. Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China;2. College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China;3. School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China)
  • Online:2020-10-15 Published:2020-10-23

摘要: 颗粒形是绿茶机械化采制的优选造型,揭示颗粒形绿茶的物理特性与外形品质因子的相关性,对于绿茶机械化加工与品质调控具有重要的意义。本研究以8 份颗粒形绿茶和1 份卷曲形绿茶为材料,采用人工感官审评筛选出具有代表性的颗粒形绿茶,进而利用计算机视觉技术、量筒法、质构仪法分析茶样的颜色和形状特征以及容重、百粒质量、弹性和塑性等物理特性,运用多元逐步回归分析(multiple stepwise regression analysis,MSRA)法分析各参数与外形品质因子的关联性。结果表明,‘勾青’茶的外形品质因子得分在85 分以上,具有较好的形状品质与整齐度,可作为颗粒形绿茶的典型代表。随原料成熟度的增加,‘勾青’茶的红色通道值、绿色通道值、蓝色通道值、亮度与饱和度减小,色调值增大,叶色由黄绿转为深绿;圆形度和形状指数增大,容重下降,百粒质量升高,且最高达33.1 g;塑性减弱,其与弹性的比值达1.5。不同物性指数与颗粒形绿茶的外形品质的相关性存在差异,MSRA结果显示蓝色通道值、色调值、弹性、塑性和圆形度对颗粒形绿茶外形品质的影响较明显;色调值、弹性对其形状品质、色泽品质起负作用,蓝色通道值、圆形度只与整齐度有相关性。细化颗粒形绿茶的外形品质因子,针对性地研究单项品质子的主导因素,更有利于体现不同物性指标的贡献。

关键词: 绿茶;颗粒形绿茶;外形品质;物理特性;形状品质;整齐度;色泽品质

Abstract: Granular shape is a preferable appearance for green tea manufactured by a machine. Uncovering the correlation between the physical characteristics of granular green tea and its appearance quality factors is great significance for the mechanical processing and quality control of green tea. Therefore, in this study, 8 kinds of granular green tea and 1 type of curly green tea were chosen for sensory evaluation, and representative samples were selected for analysis of their color and shape features by computer vision technology, and their physical properties such as bulk density, hundred-grain mass, elasticity and plasticity by graduated cylinder and texture analyzer, respectively. The correlation of the physical parameters with the appearance quality factors were explored by multiple stepwise regression analysis (MSRA). The results showed that ‘Gouqing’ tea had a good appearance quality and uniformity, and its appearance quality score was above 85. Accordingly, it could be considered as a typical representative of granular green tea. As the maturity of the raw material increased, the color parameters red channel value, green channel value, blue channel value, lightness value and saturation value decreased, while Hue value increased, and the color changed from yellow green to dark green. The circular degree and shape index of ‘Gouqing’ tea increased whereas the bulk density decreased. Furthermore, the hundred-grain mass increased up to 33.1 g. Meanwhile, the plasticity was weakened, and thus its ratio to elasticity increased up to 1.5. However, there were different correlations of each physical property with the appearance quality of granular green tea. The results of MSRA showed that the effects of blue channel value, hue value, elasticity, plasticity and circularity on the appearance quality of granular green tea were more obvious than those of the other factors. Hue value and elasticity had negative effects on the shape and color. Blue channel value and circular degree were associated with the uniformity. Therefore, scrutinizing the appearance quality factors of granular green tea and evaluating the dominant factors responsible for individual quality attributes will be helpful to reveal the contribution of each physical property to the appearance quality of granular green tea.

Key words: green tea; granular green tea; appearance quality; physical properties; shape quality; uniformity; color quality

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