Effect of Grinding and Sieving on the Coffee Properties: A Systematic Review

Authors

Justiniano, Nayhsa Karolyne

Velásquez, María Laura

Zenteno, Fabiola Gabriela

Rojas, Meliza Lindsay

Abstract

The coffee bean is widely used in industries in order to transform it into a product apt for human consumption. The processing of coffee requires unitary operations such as harvesting, conditioning, roasting, grinding, sifting, and packaging, which determine the final quality of the coffee. While roasting is known to confer sensory characteristics, grinding and sieving will influence how the flavor and color compounds are extracted. However, to date there are no systematic reviews in this regard. The objective of this review is to describe and analyze information regarding the application of grinding and sieving in coffee, and to explain their effects on the properties of coffee. The systematic review was conducted under the PRISMA model, the search was conducted in recognized databases, and in a range of 7 years (2015-2021). Thirty-one articles were finally selected to perform the systematic review. As results it was found that grinding is performed to reduce the coffee beans by dividing and/or fractioning, which implies only a physical transformation that should preserve the characteristics of the initial raw material; while sieving retains the larger particles above a certain size, leaving the small particles to pass according to the requirements for the types of coffee. The granulometry of roasted and ground aged coffee is around 610 ± 13.2 μm and for roasted and ground untreated coffee is 590 ± 14.8 μm. Among the general properties of coffee that will be altered by grinding and sieving are aroma and flavor. If the conditions are adequate, a coffee with an ideal aroma and flavor will be obtained; on the contrary, if the grinding is coarse the coffee will be watery, without aroma or cream, and if it has a floury consistency, it will have less aroma and more bitterness. However, it is important to mention that the properties of coffee also depend on the origin, variety picked, drying and roasting of the coffee. Therefore, it can be concluded that there should be adequate conditions of grinding and sieving so that the coffee particles during its use present positive effects, providing and intensifying its aroma and flavor of the final beverage.