Microbiological Safety of Ornamental Edible Flowers

The present work focuses on the microbial characterisation of edible flowers intended solely for aesthetic purposes. This market segment is especially critical. In fact, due to the limited resilience to mechanical shocks, edible flowers are rather difficult to wash. All analysed samples exhibited substantial microbial loads, dominated by Enterobacteriaceae, Pseudomonadaceae, coliforms, yeasts, and moulds. Refrigerated storage (5 days at 4 °C) resulted in a marked and consistent increase in microbial populations, as confirmed by multivariate analysis, which identified storage as the primary driver of microbial dynamics. Primary foodborne pathogens were not detected; however, several bacterial species with opportunistic pathogenic potential, including Pseudomonas juntendi, Enterobacter asburiae, Ralstonia mannitolilytica, and Pantoea agglomerans, were identified in pansies, while Pseudomonas aeruginosa was detected in snapdragon. Multivariate analyses further revealed that in addition to storage, flower type and production source contributed to variability in microbial composition. Moreover, colour-based analysis indicated that corolla colour may influence microbial profiles, with differences becoming more pronounced after storage in pansies and already detectable at purchase in snapdragons. Overall, these findings demonstrate that ornamental edible flowers can have high and dynamic microbial populations, with storage conditions representing the dominant factor influencing microbial proliferation.