Review of Factors Affecting Development of Sensory Attributes of Coffee

ABSTRACT The typical pleasant coffee aroma, which attracts millions of people on a daily basis, is prepared during roasting. This heat treatment is a complex physical and chemical process with several contributing factors. The number of volatile compounds is more than double (2.83 times) in roasted coffee compared to that of green beans. These compounds are primarily products of acids (organic and chlorogenic) and carbohydrates from the Maillard reaction in roasting. Up to 74% of the volatile compounds are formed in the Maillard reaction or linked to it by thermal decomposition, and Strecker degradation. As a result, roasting is considered the most important process determining coffee flavor and aroma. There are several options to adjust the roasting profile: isothermal, dynamically changing rate of rise, and the use of gas, electricity, microwave, or infrared heating. The kinetics and effect of the roasting profile on sensory attributes are discussed in detail, especially focusing on the chemical compounds and developed flavor. The role of advanced measurement techniques, like electronic nose and tongue, will change, and they will be commonly applied to provide information by mimicking human perception. Cultural heritage and regional traditions also affect the acceptance and evaluation of certain sensory characteristics, even in the case of trained panelists. Understanding the development of sensory profile and how factors contribute to it is facilitating the optimization of processing technology. Tailored processing considering the cultivar, geography, and climate, as well as targeted customers, can achieve the best quality and increase profitability.