Purpose: This study validated microbial risk factors which may cause cross-contamination of food poisoning pathogens on the harvesting steps in perilla leaf farms.
Methods: Samples were collected from cultivation environments and utensils (soil and irrigation water), plants (perilla leaf and stem), personnel hygiene (hand, glove, cloth) and airborne bacteria at three farms (A, B, C) of perilla leaf on the harvesting steps. The collected samples were assessed for sanitary indications, fungi, and foodborne pathogens (Staphylococcus aureus, Escherichia coli O157, Listeria monocytogenes, Bacillus cereus, and Salmonella ssp.).
Results: Total bacteria and coliform in perilla leaf were detected at the level of 4.4~5.2 and 3.4~4.3 log CFU/g, respectively. Meantime, E. coli was not detected in all samples. In case of pathogenic bacteria, B. cereus was detected at levels of 0.7 ~ 5.0 log CFU/g (or ml, hand, and 100 cm2), and S. aureus was detected in worker’s hand of farm A at levels of 3.4 log CFU/hand. Other pathogenic bacteria (E. coli O157, L. monocytogenes and Salmonella spp.) were not detected in either of the samples from all farms.
Significance: This study demonstrates that perilla leaf after harvesting was contaminated with various microbial risk factors. To minimize food poisoning outbreaks associated with perilla leaf, GAP system should be applied for ensuring the safety of perilla leaf.