Post-harvest practices linked with ochratoxin A contamination of coffee in three provinces of Cordillera Administrative Region, Philippines

Abstract

ABSTRACTOne of the emerging concerns in the Cordillera Administrative Region, Philippines is ochratoxin A (OTA) contamination in coffee. During 2015 to 2016, a total of 51 Arabica (Coffea arabica) coffee samples from Benguet province and 71 Robusta (Coffea canephora var. Robusta) coffee samples from the provinces of Ifugao and Kalinga were analysed for OTA contamination. The OTA-producing fungal contaminants during drying and storage of Arabica and Robusta coffee were Aspergillus niger and Aspergillus ochraceus. Ochratoxin A was more commonly detected in Robusta coffee (36.6%) than in Arabica coffee (21.6%). Among the contaminated samples, Robusta coffee cherries in the drying yard had the highest mean OTA level (120.2 μg kg−1, n = 10) while roasted Robusta coffee beans had the lowest mean level (4.8 μg kg−1, n = 9). The onset of contamination of Arabica coffee occurred during storage, with a mean OTA level of 46.7 μg kg−1 (n = 9). Roasted coffee had lower OTA content although five samples had levels >5.0 μg kg−1. Pearson Chi-square analysis (χ2) and Fisher’s exact test revealed that several post-harvest practices involving non-removal of the husk or hull and mixing of defective coffee were significantly associated with the occurrence of OTA during drying and storage (p < 0.05). No significant associations, however, were identified during roasting. This study suggests that the post-harvest practices in Cordillera Administrative Region should focus on the removal of defective coffee in all stages of post-harvest and rapid reduction of moisture content particularly during drying.