Benzaldehyde Use to Protect Seeds from Foodborne Fungal Pathogens

Contamination of food/crops by fungi is a recurring food safety and security issue. There is a limited efficacy with conventional seed sanitation methods, directly affecting food safety. For instance, the insufficient elimination of mycotoxin-producing fungi contaminating seed surfaces can result in high mycotoxin contamination. In 2020, peanut seeds in southeast United States exhibited significantly low germination rate during crop season, which was preceded by a high frequency of aflatoxin (AF) contamination in 2019. The prevalence of the Aspergillus flavus fungicide-resistant strains was the root cause of the high AF contamination and poor seed quality. Heat treatment (pasteurization/blanching) is one of the strategies preventing microbial contamination in agricultural/food production. However, excessive heat treatment can negatively affect the quality of the crops/food products. Hurdle technology is an approach where co-application of different types of preservation method at reduced individual intensities achieves increases in the effectiveness of antimicrobial treatments. In this study, a new seed sanitation formula was investigated by examining Generally Regarded As Safe (GRAS) molecules such as natural compounds/structural derivatives or redox-active molecules repurposed from FDA-approved food additives as active ingredients. Selected benzo derivatives, previously shown to inhibit mycotoxin production, could function as heat-sensitizing agents, enhancing the efficacy of sanitation against fungi. When benzo derivatives and mild heat (57.5 ^oC) were co-administered for 90 seconds (in vitro), the co-application achieved > 99.999% microbial elimination, while independent application of either agent alone allowed pathogen survival. For seed treatments, co-application of a benzo derivative (3 mM) and mild heat (50 ^oC) (20 to 30 minutes) completely inhibited the germination of aflatoxin-producing A. flavus contaminated on Brassica rapa Pekinensis (Chinese cabbage hybrid) seeds, whereas seed germination rate was unaffected. In summary, benzo derivative-based heat sensitization developed could be a promising tool to achieve safe and cost-effective pathogen control in agriculture/food production.