Effect of Robusta (<i>Coffea canephora P.</i>) Coffee Cherries Storage after Harvest before Putting Out for Sun Drying on Development of Toxigenic Fungi and the Variation of the Physicochemical Components

Abstract

In this study, the effects of the storage duration of coffee cherries after harvest before putting out for sun drying on the kinetics of drying, fungi development and the variation of physicochemical content were evaluated. The results showed that the longer coffee cherries were stored after harvest before putting out for sun drying, the quicker they dried. Indeed, the drying durations were 19, 16, 12, 10, 7 days respectively for coffee cherries put out for sun drying at the day of harvest, the second, the fourth, the sixth and the eighth day after harvest. However, this storage of the cherries after harvest before putting out for sun drying led to the increasing to the infection of cherries by fungi. Indeed, samples of more contaminated inside were those from the lots of cherries stored 8 days after harvest before putting out for sun drying with 55.55% of the samples infected with a percentage of infected beans between 10% and 50%, and 44.45% of the samples were infected with a percentage of infected beans between 50% and 100%. Furthermore, those put out for sun drying at the day of harvest were free inside by fungi. Among the fungi isolated, toxigenic species was found. However, no relationship between the frequencies of ochratoxin A producing strains isolated and the storage duration of the cherries after harvest before putting out for sun drying was noted. This storage of the cherries after harvest before putting out for sun drying also led to the acidification of the cherries (pH = 5.27 - 3.6) and the degradation of their chlorogenic acids content (12.58% - 10.30%) while for their caffeine content (2.53% - 2.55%). No significant difference was observed about the storage duration of the cherries after harvest before putting out for sun drying.