Regression Models for Description of Roasted Ground Coffee Powder Color Change during Secondary Shelf-Life as Related to Storage Conditions and Packaging Material

Besides sensory attributes, color is a parameter affecting consumers’ perception of the powdered coffee product or brew. The aim of this study was to develop and compare non-linear and linear regression models for the description of experimentally determined color changes during 6 months of storage in two different packaging materials. Model parameters were estimated using two software packages: Eureqa Formulize (Nutonian, Inc., Boston, MA, USA) and Statistica 10.0 (StatSoft, Palo Alto, CA, USA) and compared based on their R2 goodness of fit. Both non-linear and linear models used in this study pointed to a significant influence of intrinsic (sample moisture content) and external (relative humidity (RH) and temperature) factors on ground roasted coffee color change. Non-linear model was the most suitable for description of color changes during storage. Based on lower moisture sorption of the sample packed in triplex bag, triplex packaging is proposed as the more suitable one