Influence of drying air temperature on coffee quality during storage

Abstract

Drying is the most important stage for maintaining coffee quality. The temperature conditions at which drying is performed can affect bean integrity. This research was developed with the aim of determining the effect of mechanical drying air temperature on the quality of coffee during storage and verifying its effect on the generation of bleached beans evaluating two air temperatures at 50 and 40 °C, and solar drying was used as a control, using an experimental design of random blocks with 10 blocks. The response variables were related to beans color and sensory quality. The analysis of repeated measures indicated that there were differences in the initial color of the coffee beans due to the effect of the treatments and the storage time. A greater magnitude of color change was obtained for coffee dried at 50 °C and that dried with solar drying. Germination was lower and different for the 50 °C treatment. This treatment also showed greater fat content since the beginning of the storage; meanwhile, the two other treatments just presented greater fat content at the end of the experiment. Regarding to sample proportion of clean cups, the multiple comparison Tukey–Kramer test was significantly different in terms of favoring solar drying at 40 °C. The effect of the drying conditions on beans has not been appreciated; however, the deterioration generated during this stage occurs during storage and manifests itself in a loss of quality, with an increase in defects.