METHOD AND INSTRUMENT FOR NONDESTRUCTIVELY MEASURING SUGAR CONTENT OF VEGETABLE AND FRUIT

摘要

PROBLEM TO BE SOLVED: To provide a method and a small-sized instrument by which the sugar contents of vegetables and fruits can be measured nondestructively without using any diffraction grating nor multi-channel detector. SOLUTION: The small-sized instrument is provided with light sources 101a and 101b, a reflecting prism 22, and a condenser lens 21 for projecting monochromatic light rays upon a vegetable or fruit 1. The instrument is also provided with a sampling mirror 33, a condenser lens 31, and a photodetector 32 for detecting parts of the monochromatic light rays 101a and 101b. In addition, the instrument is also provided with a condenser lens 41 and a photodetector 42 for detecting parts of light rays transmitted through the vegetable or fruit 1. Moreover, the instrument is also provided with a signal processing section 230, a central control section 200, a displaying section 210, and a light control section 220. The control section 200 measures the quantities of the projected light rays and transmitted light rays from the voltage or fruit 1 detected by means of the photodetectors 32 and 42 and calculates the transmittance Ta and Tb or absorbance Abs a and Abs b from the detected voltages and the sugar content of the vegetable or fruit 1 from the values of the Ta and Tb or Abs- a and Abs- b by using formulae (1) and (2).