Author(s): Marques, João Manuel Simões da Silva
Date: 2011
Persistent ID: http://hdl.handle.net/10400.5/4034
Origin: Repositório da UTL
Subject(s): roasted coffee; shelf-life; sensory analysis; physical-chemical analysis; aging
Author(s): Marques, João Manuel Simões da Silva
Date: 2011
Persistent ID: http://hdl.handle.net/10400.5/4034
Origin: Repositório da UTL
Subject(s): roasted coffee; shelf-life; sensory analysis; physical-chemical analysis; aging
Mestrado em Engenharia Alimentar - Qualidade e Segurança Alimentar - Instituto Superior de Agronomia
The aging process of commercial roasted coffee, throughout its shelf-life, is little known. In this work we studied a commercial blend of roasted coffee beans during their shelf-life, in order to understand the changes that occur at the sensory and physico-chemical composition, and to identify possible indices of aging. Samples with 0, 6, 12, 18 and 24 months of storage were subjected to descriptive sensory analysis and physical-chemical (moisture content, aqueous extract, fat, fatty acids, color, titratable acidity, pH, peroxide, caffeine and trigonelline). It was concluded that aging was developed in two main phases. In the first (up to 12-18 months), the characteristic flavor, color, body and bitterness intensity decreased but acidity, peroxides, the metallic flavor, color, and trigonelline increased, mainly due to the hydrolysis reactions fat. In the second phase (18-24 months) continued to increase the humidity and the rancid flavor, the bitterness seems to have diminished. The fat changes have evolved in relation to the previous phase, being particularly evident the effects of oxidation reactions, which determined, sensory, the end of life of the blend studied.