Print version ISSN 0006-8705
On-line version ISSN 1678-4499
CARVALHO, A. et al. Occurrence of the main coffee beans deffects in several stages of ripening. Bragantia [online]. 1970, vol.29, n.unico, pp.207-220. ISSN 0006-8705. http://dx.doi.org/10.1590/S0006-87051970000100020.
The occurrence of green-coated beans, brown and black beans was studied in samples of green fruits, under-riped (plant stage) fully riped and over-riped berries, as well as in the normal and abnormal fruits which were dried on the trees and also in the fruits fallen on the ground. The samples were monthly collected during the year 1967 and 1968. The so-called abnormal dried fruits have a dull black exocarp, whereas the normal ones have bright black colored shells. The total production of three plants was harvested every month, separated according to the different ripening stages, and then, after drying, were shelled and the proportion of defective beans was scored. The data showed that the so-called green coated beans appear in significant proportions in all stages studied. The highest percentage of these was found in the unriped fruits and in the abnormal dried fruits. Its occurrence decreases as the fruits become more and more mature. The lowest percentage was found in the samples of dried fruits which had fallen on the ground. The green color is produced by the silver skin which retains the green pigment, probably chrolophyll. The brown beans appear more frequently in the fallen fruits and they also occur in a decreasing proportion in the normal and abnormal dried berries and from unriped to over-riped fruits. This type have been considered to be caused by over-fermentation, however our results indicate that it may have other causes, due to their appearance even in the unriped fruits. The high percentage of brown beans in the fruits dried on the tree indicates that the berries must be harvested in the cherry stage to have a high quality product. The black beans, characterized exclusively by the black endosperm, were more frequently found in the berries dried on the tree or in the dried fruits fallen on the ground. It seems reasonable to assume that the black beans represent a more advanced stage of deterioration of the endosperm. The initial stages would, probably, be characterized by the different shades of brown. Based on these findings it is proposed a revision on the defective beans nomenclature in Brazil. Considering the Brazilian system of coffee classification it was suggested that for the nomenclature of the defective beans more emphasis should be made in the origin of such defects rather than in the general aspect of the beans.