Effect of Robusta (Coffea canephora P.) coffee cherries quantity put out for sun drying on contamination by fungi and Ochratoxin A (OTA) under tropical humid zone (Côte d‘Ivoire)

The effect of coffee cherries quantity put out for sun drying on the kinetics of the drying, chemical components variation, fungal growth and ochratoxin A production was evaluated. The results showed that the more coffee cherries quantity on the drying area was important, the slower they dried. Indeed, the drying durations were 12, 17, 21, 26, 31 and 32 days respectively for the lots of 10 kg, 20 kg, 30 kg, 40 kg, 50 kg and 60 kg of cherries by square meter of drying area. The slowness of the drying led to the increasing of fungal development and ochratoxin A production in the cherries. Indeed, samples more contaminated were those from the lots of 50 kg and 60 kg of cherries by square meter of drying area with between 10% and 100% of infected beans and with levels of ochratoxin A ranging from 0.92 to 118.47 and 1.4 to 131.33 μg kg−1 respectively. The slowness of the drying led also to the acidification of the cherries (pH = 5.55–4.54) and the degradation of their chlorogenic acids content (13.03–11.69) while for their caffeine content (2.52–2.54), any significant difference was observed whatever the drying duration.