Shape and Size Variability of Roasted Arabica Coffee Beans

Abstract

Quantification and evaluation of selected Arabica (Coffea arabica L.) coffee beans' shape and size was performed. Twenty different coffee types originating from 13 different countries were analyzed. The main dimensions for individual coffee types were quantified. Sphericity, as a useful parameter for the calculation of processing and handling operations, was also quantified and ranged from 0.006536 to 0.009452. Calculation of shape variability using elliptic Fourier descriptors showed relevant differences among individual coffee samples. A dominant importance and the relevance of length-to-width ratio were quantitatively confirmed. A simple mathematical formula describing coffee grain contour was used with a satisfying correlation coefficient. Applicability of the approach was shown on the calculation of curvature radius.

Keywords:

• Image analysis
• Coffee beans
• Shape variation
• Sphericity
• Fourier descriptors

ACKNOWLEDGMENT

The research has been supported by the Grant Agency of the Czech Academy of Sciences under Contract No. IAA201990701.