The Journal of Biological Physics and Chemistry



Volume 21, Number 2, pp. 43-46




Discrimination between defective and non-defective coffee beans using a laser prism spectrometer

A. Belay and B. Kebede

Department of Applied Physics, School of Applied Natural Sciences, Adama Science and Technology University, P.O.Box 1888, Adama, Ethiopia

The concentration- and temperature-dependent refractive indices of solutions extracted from defective and non-defective coffee beans have been investigated using a He-Ne laser. The refractive index has a linear relationship with the presumed concentration of the coffee solutions in the range of 0.5-3%. Higher and lower values of refractive index were obtained for immature and non-defective coffee beans, respectively. Refractive index of bean extracts can be successfully used to separate defective from non-defective beans.

Keywords: coffee extract, refractive index, temperature dependence


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