Classification of Coffee Beans Quality using Gas Sensors

The coffee industry has experienced significant expansion in recent years, driven by increasing demand for high-quality coffee. The quality of coffee beans is conventionally evaluated using extraction procedures that emphasize sensory characteristics such as crema, body, and heart. This paper proposes a novel approach to evaluate coffee beans quality by utilizing gas sensors to measure the degassing process of coffee beans. The proposed technique provides the classification coffee beans quality without extraction process. The example of coffee beans in our experiment includes three distinct groups of coffee beans: (1) freshly roasted beans, (2) roasted beans that allowed to rest within an optimal degassing period, and (3) roasted beans that had been roasted for over one month. Our experimental results demonstrate that the gas release profile during degassing successfully differentiated the quality of the beans across the various groups. Each batch of coffee beans has distinct gas release patterns that indicate their quality, whether poor or high. These results confirm that the measuring degassing behavior of coffee beans can evaluate the coffee beans quality. Moreover, the proposed approach has the potential to improve quality of control in coffee production, streamlining the assessment process without the need for traditional extraction methods.