Studies were set up during the 2003/04 harvest season to determine if the type of damage to the pods was correlated with the final level of ochratoxin A. The proportion of healthy and damaged pods and of different pod defects was determined by counting and characterizing pods from five farms at three times during the main crop harvest (December, January and February). Damaged pods were evaluated before and after pod opening to determine if they had internal damage. About 60% of the pods were healthy. Pods with only external damage represented ~25% of the total. These pods had been damaged by the machetes used when the pods were harvested or from the use of a machete to pick up harvested pods. The remaining 15% were affected by pests or were mummified or moldy; most of these pods had internal mold.
For fermentation trials, damaged pods were divided into four groups: moldy pods (black pod and other rot diseases), pods that had been left at previous collections and had dried on the tree ("mummified" pods), pods damaged by insects, and pods with external physical damage (rodent attack, machete or harvesting hook injury). For each category, an equal number of damaged and healthy pods were mixed and stored for 7 days before pod opening. The resulting pod heap was divided in two, with one half fermented by farmers' usual methods and the other by a standard practice which differed from the farmers' method as the placenta was removed and the heap was turned after 48 hours. Control samples consisting only of healthy pods also were prepared with both fermentation methods. After fermentation the beans were sun dried. The experiment was repeated four times during the harvesting period.
Higher ochratoxin A levels were found in beans from damaged pods that were stored for about one week. Beans from physically damaged pods, e.g., from machetes, rodents, etc., had the highest level of contamination, ~ 20 ng/g. Ochratoxin A levels in the moldy (~ 7 ng/g), insect damaged (~ 4 ng/g) and mummified (~ 3 ng/g) pods were substantially less than that found in the physically damaged pods, but generally greater than that found in the control un-
Figure 2. Ochratoxin A in cocoa beans stored in bags in Africa or Europe. Africa: Big bag (♦); Europe: Big bag (■), 60 kg bag, lot 1 (▲), 60 kg bag, lot 2 (x).
damaged pods (~ 2 ng/g). The two fermentation methods had no significant differential effect based on the type of damage. Due to the variation between trials and the limited number of trials, clear conclusions about the fermentation method cannot be made but the results indicate that if the pods are damaged the fermentation method has a limited effect.
Storage trials were conducted in export warehouses in Africa and in warehouses in Europe. In one trial one lot of 32 tons was split in two, with one half stored in an export warehouse in Africa and the other half shipped in bulk by container to Europe where it was stored in an open top container. Samples were taken monthly. There was considerable variation in the ochratoxin A level between samples, but there was no trend towards an increase with time (Fig. 2). The variation is probably due to nonhomogeneous distribution of the toxin in the lot since each composite sample consisted of only 16 subsamples. The results of storage of the two bean lots in 60 kg bags in Europe also showed no increase with time and less variation (Fig. 2). In these tests the composite samples were made from 100 subsamples and the effect of the nonhomogeneous distribution probably is smaller. Thus, ochratoxin A levels do not increase during storage in export warehouses in either Africa or Europe.
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