Análise das propriedades físicas e de fluxo de café torrado no processo de encapsulamento

Abstract

The encapsulation process is presented as a way of adding economic value to the coffee bean. It is necessary to use structures and machinery properly designed, being of fundamental importance the knowledge of t he physical properties and flow of the product. In determining the properties, the "Jenike Shear Cell", more traditional, and the "Powder Flow Tester" (PFT) a fruit of technological advancement. The objective of this work was to compare the results obtaine d by the two methods and to verify the employability of PFT in replacement of the Jenike apparatus in determining the physical and flow properties of roasted and ground coffee in the encapsulation process. For this purpose, six samples were evaluated, varying two grades of roast and three grades of grinding in both shear tests. The PFT provided the physical and flow properties, with maximum values of 35.5 ° for the internal friction angle and 46.7 ° for the effective internal friction angle. With the exception of the main consolidation stress, some samples presented statistically equal values between the PFT and Jenike tests. In the Flow Function, the results in both tests were identical and it was concluded that there are no statistical differences betw een the roasting classes, with the grinding being the variation factor. Thus, fine grinding is not indicated for the coffee encapsulation process due to the cohesive flow. In the K factor, the values obtained with the PFT were smaller when compared to those of Jenike.