Effect of Fermentation of Arabica Coffee on Physicochemical Characteristics and Sensory Analysis

Abstract

This work studied the physicochemical characteristics and final sensory quality of the Yellow Catuai IAC 62 fermented with Saccharomyces cerevisiae. An experimental design was done by a Composite Central Rotational Design (CCRD) to evaluate the fermentation time and temperature. The responses were: fermentative mass pH, fruit moisture (just as processes were conducted), sugars, organic acids content (HPLC), and sensory quality by Specialty Coffee Association (SCA) methodology on two different roasts levels (light-medium roast and medium roast). It was observed that coffees, even in extreme time and temperature, behave similarly related to final scores (in general from 81 to 85 in SCA score), all classified as specialty coffees. Fructose content varies only with fermentation time regardless of temperature, decreasing its levels as time increases, from 12g/L to near 5g/L. In contrast, sucrose content decreased while time and temperature advanced, from 4g/L to 2g/L in lowers time or temperature for sucrose, similar behavior for glucose from 7g/L to zero, however it shows some concentration increase on lowers time or temperature. Glycerol was formed depending on both time and temperature, and its content increased with time and temperature increase, showing optimum formation conditions between 24°C and 32°C and 35 to 45 hours. pH behaved just as described by literature, decreasing with time advance and more intensely as temperature increases, beginning from around 5 and getting to lower than 4 in extreme cases. Organic acids such as acetic, propionic, succinic, and lactic were measured at final fermentation and presented in different concentrations.