Thermal Analysis of Coffee Hulls and their Effect on the Drying Process in Conventional Ovens

Correa Rodrigo,Mu�Oz Neira Milton Javier,Roa Manuel

doi:10.17485/ijst/2018/v11i36/131682

Abstract

Background/Objectives: This article includes some of the most relevant experimental results related to the thermal properties of coffee hulls taken from samples of a Colombian coffee variety Castilla. Methods: Coffee hull samples were analyzed using IR, DSC, TGA and DTGA. Analytical thermal experiments described its thermal behavior when it was heated at 5°C/min from room temperature to about 900°C. Furthermore, we include some drying curves and analyze the observed delay effect of the hull presence on the coffee drying process. Findings: Some of the main thermal transitions where observed in the range of 50-300°C. The IR test showed that its main composition was cellulose. Such delay was related to the hull composition. The diffusion coefficients of water in coffee grains with hull, without its hull, and of hull alone, are also reported. Applications: This work provides important information to understand in a better form some thermal characteristics and inference in drying process of coffee grains hull of variety Castilla, original from Colombia northeast region. Keywords: Coffee Grains Drying, Coffee Hull, Thermal Analysis, DSC, TGA, IR

Highlights

Coffee is one of the most representative products of agriculture in Colombia
Some of the IR and thermograms obtained for samples of coffee hull of the variety Castilla are shown
Vol 11 (36) | September 2018 | www.indjst.org cm-1 signals of CO and C-O-C. These signals allow concluding that the coffee hull is composed mainly of cellulose derivatives

Summary

Introduction

Coffee is one of the most representative products of agriculture in Colombia. Data from the Ministry of Agriculture show that, on average, over the past five years, coffee has contributed 12.74% to the gross domestic p roduct of the agricultural sector. The Ministry of Finance of Colombia estimated for 2017, a production of 14.19 million bags of coffee of 60 kg each, which ranked the country as the third largest producer in the world. This large production represents, on the other hand, a high generation of solid waste, among which, those associated with the natural envelope of the grain are the most representative. In1 refer for this case that for each ton of coffee treated in the benefit, 0.18 tons of solid waste associated with its wrapping are generated, of which approximately 12% correspond to its shell (mixture of skin, pulp and grain hullor parchment)

Methods

Results

Conclusion