Feasibility study on detecting different types of sugar solutions using a dielectric resonator sensor

Abstract

One of the most important ingredients of most foods is sugar, so it is important to detect the type of sugar in foods. In this study, a cylindrical dielectric sensor using a function generator and a spectrum analyzer was used to measure dielectric spectra in the range of 0-150 MHz to detect different sugars in water-sugar solutions. Dielectric spectra were investigated by preparing a variety of water-sugar solutions including glucose, sucrose, fructose, invert, high fructose corn syrup and malt extract (dominantly maltose sugar) in four brix levels ranged within 3-12. Moreover, samples were tested with mixing the sugars in a solution. The statistical method of principal component analysis (PCA) was evaluated for detecting and discriminating different types of sugars from dielectric spectral data. PCA with two principal components PC1 and PC2, showed a distinct separation of sugars in three visual groups of sucrose and high fructose corn syrup, fructose and invert and glucose and malt. Irrespective of glucose, the mixed sugar solutions were discriminated from single sugar solutions in two groups. The results of this study showed a promising potential of dielectric method for detecting different sugars, however, the cumulative dielectric effect of the mixed sugars was not discriminable which is expected to be detected with greater range of frequency.

Keywords

• sugar
• cylindrical sensor
• dielectric power spectroscopy