Conservação de cafés especiais em ambiente refrigerado: estudo técnico e econômico

Abstract

The coffee trade depends on coffee quality; value varies significantly along with improvement in coffee qualitative attributes. Quality has become an increasingly important factor, which has led to the emergence of the specialty coffee market and the value attributed to it. It has been shown that the low air temperatures in storage and maintaining the exocarp (natural coffee, in coconut) and endocarp (in parchment, depulped) not only decrease the incidence and development of microorganisms but are also effective in conservation of the qualitative traits of the coffee beans. Thus, the aim of this study was to investigate the technical and economic feasibility of storing specialty coffees, with different scores and from different growing regions, in an environment under controlled temperature and under non-controlled ambient conditions. Natural coffee and pulped natural coffee or demucilaged coffee in whole form or in hulled form from three important coffee growing regions were stored under refrigerated air at 15°C or under non-controlled conditions with a mean temperature of 25°C. The coffees were evaluated through sensory analysis and electrical conductivity tests throughout the storage period at 0, 3, 6, 9, and 12 months. In addition to the technical study, an operational cost analysis of the refrigeration technology was carried out during storage. The financial gain obtained from maintaining the quality of coffee stored at low temperatures was compared with the operational cost of refrigeration. Results showed reduction in the quality of specialty coffees with a score above 84 points in sensory analysis, according to the SCA protocol, when stored in the environment without temperature control; they can lose classification as specialty coffee. Refrigerated storage allows quality to be maintained, especially for the specialty coffees with the highest scores. The quality of specialty coffees is best conserved when the beans are stored in whole form, without hulling, both in the controlled temperature environment and in the noncontrolled environment. Refrigerated storage is economically advantageous over a period of six and twelve months for natural coffee, and for CD or demucilaged coffees, both stored in the hulled form. For wet processed specialty coffees stored in whole form (parchment or dry cherry), without hulling, refrigeration is efficient in maintaining sensory quality, ensuring classification as specialty coffees, but the operational cost of the technology should be assessed.