Penicillium air mycoflora in postharvest fruit handling environments associated with the pear export chain

Abstract

Penicillium is a well-known airborne fungal contaminant that is prevalent in indoor air. In this study, the total air mycoflora was determined in postharvest fruit handling environments. The study included eleven indoor environments from the packhouse to the final retail outlet. Standard active and passive air sampling methods were used over a period of three years to obtain a profile of air quality. A total of 6047 and 5849 Penicillium colonies were counted of which 1123 and 508 isolates were obtained using active and passive sampling methods respectively. Ultimately, 25 dominant Penicillium spp. were identified from active air samples. The five most prevalent species isolated were: P. glabrum (31.88%); P. expansum (14.18%); P. crustosum (13.42%); P. chrysogenum (10.35%) and P. brevicompactum (10.25%). Furthermore, a total of 22 Penicililum spp. were isolated from passive air samples with P. glabrum (23.72%); P. italicum (16.45%); P. brevicompactum (14.22%); P. crustosum (13.80%) and P. chrysogenum (11.76%) being most prevalent. The presence of pathogenic Penicillium spp. in the air of fruit handling environments was profiled. Counts of total air mycoflora were significantly higher in the re-pack facilities than in all other environments sampled and are significantly higher than the proposed baseline threshold value. This study clearly shows the importance of air quality in facilities that regularly handle different fruit types. Re-pack and retail facilities should therefore be cleaned more effectively to reduce the potential air inoculum that can induce decay of fruit at the market-end. Finally we propose an air quality standard for fresh produce environments.