Identification of some physicochemical and microbiological variables related to aged coffee Identificación de algunas variables fisicoquímicas y microbiológicas asociadas con el defecto reposo en el café

In order to identify the relation among some physicochemical and microbiological characteristics associated to aged coffee, this research was carried out in three stages: I) The physical, chemical, microbiological and sensory variables of dry coffee with defect (CD) and without defect (SD) were evaluated. II) The relation of such characteristics to the CD samples were analyzed, and III) The storage effect on dry coffee regarding the aged defect over time was verified. With respect to the sensory quality evaluated with the SCA scale, the CD samples showed lower percentage values in the variables taste, residual taste, acidity, body and balance. CD coffee showed lower percentage values of healthy green beans and moisture, and higher threshing yield factor. The content of total lipids and stearic acid in CD was 11.9% and 7.9%, respectively. Linoleic acid predominated in SD (37.43%). The microbiological evaluation did not indicate variations in the two types of coffee. In stage II, the aged coffee defect was more frequent in coffee with less than 71% of healthy green coffee. After 60 days of storage, dry coffee showed an increase (not meaningful) of stearic acid content in the stored samples, and after 120 days there were statistically significant changes in the score of the sensory analysis associated with the appearance of the aged coffee defect. The percentage of healthy green coffee, the content of stearic acid and the activity of polyphenoloxidase (PFO) were identified as possible indicators of aged coffee.