Non-destructive sugar content measuring apparatus

Abstract

A non-destructive sugar content measuring apparatus for determining the sugar content of a vegetable or fruit by measuring absorption of light in sugar when near infrared light is made incident on the vegetable or fruit; comprising at least one light source that emits light rays having three kinds of wavelengths within a wavelength range of from 860 nm to 960 nm, and a detector that detects the absorption of light. The detector is disposed at a position except the position on an extended line of a straight line that connects i) the center of a light-incident area formed on the surface of the vegetable or fruit by the light emitted from the light source and incident on the vegetable or fruit and ii) the center of the vegetable or fruit, and at the same time at a position where the light-incident area formed on the surface of the vegetable or fruit by the incident light and the detection area formed on the surface of the vegetable or fruit by the light emergent from the vegetable or fruit and to be received by the detector do not overlap each other. This apparatus effectively enables non-destructive measurement of sugar content of vegetables and fruits in an accuracy of about plus-minus 1.0.degree.Brix, which is a resolving limit of sugar content that can be perceived by humans.