Aspectos sensoriais, fisiológicos e bioquímicos de grãos de café armazenados em ambiente refrigerado

Abstract

The grain storage is one of the steps in the coffee production process but the use of improper methods may provide a reduction in quality. Various physical, physiological and biochemical changes may occur in the grains, influencing negatively on the coffee beverage quality. Traditionally, the coffee grains are benefited before being stored in uncontrolled environment being packed in jute sacks. In these conditions, the grains are exposed to changes in environmental conditions can accelerate the deteriorating process. Thus, there is a need to investigate alternatives to the secure storage of coffee grains. Considering that the cooling air provides the grains’ deterioration reduction of several species, in this work aimed to investigate the effects of processing and storage in air cooled on the sensory quality and on physical, chemical, physiological and biochemical features of the depulped natural coffee. For these studies, experiments were conducted in two crops, where the coffee cherry fruits were harvested at maturity stage and were dried until they reach 11% water content after being processed by dry method (natural coffee, in coconut) and wet method (in parchment, depulped). After drying, part of the coffee were processed and other kept unprocessed during storage under controlled conditions of cooled air (10 °C and 50% relative humidity) and environment at 25 °C without relative humidity control. In the first harvest, color parameters of coffee grains stored for eight months were evaluated. In the second crop, the coffees were evaluated at 0, 3, 6 and 12 months of storage, through the sensory evaluation and electrical conductivity, potassium leaching, total acidity, total sugars, germination, tetrazolium, color analysis and enzyme activity of the antioxidant process. To investigate the effects of cooling and processing in the conservation of the quality coffee grains, it was applied to optimization of simultaneous responses of sensory variables, physiological and chemical. In all experiments and studies conducted it was concluded that reduction of the air temperature and the intact grain storage without processing, contribute to the maintenance of the sensory quality, chemical, physical, physiological and biochemical of the coffee grains, as an alternative technically feasible for storage. The beneficial effects of these factors are evidenced by the enzyme activity of the antioxidant process and are also confirmed by optimization studies of the response variables.