Journal of Flow Injection Analysis
Online ISSN : 2433-7374
Print ISSN : 0911-775X
Simple Lab-on-chip with Light Scattering Measurement for Determination of Sweetness in Grape Juices
Original Paper
Sujitra ThaithetWasin WongwilaiSupaporn HartwellKate GrudpanSomchai Lapanantnoppakhun
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2015 Volume 32 Issue 1 Pages 9-

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Abstract

A simple lab-on-chip with reflective optical fiber system was developed for determination of sweetness in grape juice samples. The detection principle is based on the measurement of light scattering due to Schlieren effect that occurs when a sample solution containing sugar merges with another liquid (DI water) of different refractive indices. The degree of Schlieren effect and thus, the intensity of scattered light, relates to the concentration of sugar in the sample. The angle of the LOC at 65 with respect to the horizontal plane was found to be suitable to provide a well-defined response peak shape for easy peak area integration. The system was evaluated at detection wavelengths 700, 750, and 800 nm. The linear range of the sugar contents of 7-20 degree Brix (°Bx), and RSD of less than 5% (n=5), were achieved for the three detection wavelengths. The results obtained from the red and white grape juice samples agree well with the reading from the refractometer.

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© 2015 Japanese Association for Flow Injection Analysis
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