Abstract
The contents of tea leaves ingredients were measured by using visible and near infrared reflection spectra. Fresh tea leaves were processed by withering, rolling, fermenting and drying. At each stage in the process, the samples were collected, and the contents of amino acids (Asp, Glu, Theanine, Arg) and polyphenol compound (Catechin) in them were measured chemically. The near infrared reflection spectrum of each sample was also measured. The contents of amino acids and catechin were able to be determined by using the values of spectra over a short period of time (a few seconds) . In the process, the color of leaves changed from green into brown, and the change was measured by the visible light reflection spectrum. The spectrum showed that the peaks of blue, green and red became small as the process advanced. It is thought from the above results, that we can apply the method of the near infrared and visible light spectra to the control of the tea manufacturing process.