Laser Light Scattering As An Alternative Method Of Investgating Coffee Quality

Abstract

The main focus of this work was to investigate particle size dependency of quality of coffee using laser light scattering. In these experiments a continuous wave frequency He-Ne (633nm) laser, lock-in amplifier, chopper were used as an apparatus. Green coffee powder was used as sample; the reason we choose green coffee as a sample is that to minimize the effect of roasting on the quality of coffee. Arranging all the apparatus as needed as the experiment was carried out and necessary data were recorded, and then analyzed to get different optical properties and particle size of coffee sample. After the determination of the optical properties of the diffusing medium (coffee) such as the absorption, scattering, reduced scattering, effective attenuation coefficients and anisotropy factor it was tried to relate with the quality of coffee. In this research also, efficient and objective discrimination of coffee quality determination method is developed by investigating particle size dependency of quality of coffee using Laser light scattering technique. The scattering coefficient has direct relation with the particle size as well as the quality; the larger the scattering coefficient is the finest the particle size and the highest the quality of coffee. Thus, since the developed method have wider economic and scientific applications; light scattering method is recommended as the most preferable for classification of coffee quality standards.