Multiple indicators metrological analysis for 5 kinds of tea produced in Yunnan, China

Abstract

Five kinds of tea, including camphor-scented palace tea, fossil glutinous rice tea, old tree white tea, Brown Mountain ancient tree tea, and pure Banzhang tea, from Yunnan Province, China, were selected as the samples for analysis. The combustion heat, differential thermal-thermogravimetric, fat content, crude fiber content, ash content, and trace element content data of the teas we selected were determined, and quality evaluation and classification were carried out by the stoichiometric method from the perspective of food nutrition. In this paper, according to the combustion heat, differential thermal-thermogravimetric, fat content, crude fiber, ash content, and trace element content data of the teas we selected, systematic multi-index comprehensive evaluation systems were constructed through gray pattern recognition, factor analysis, the entropy method and entropy cluster analysis. The multi-index comprehensive evaluation system established in this study provides a new concept for the quantitative control of the quality of tea, a powerful method for research on the large-scale development and classification of tea and basic support for the selection of raw tea materials and the application of a quantitative control mode for assessing the contributions of multi-index ingredients to tea quality.

Keywords:
tea; entropy method; thermogravimetric analysis; ICP–OES; trace elements