Efficacy of Eugenol Solutions as Seed Treatments for Controlling Escherichia coli O157:H7 and Salmonella Typhimurium in Basil (Ocimum basilicum L.) seeds under Controlled Environmental Agriculture

This thesis explores the challenges and potential solutions for improving food safety in basil (Ocimum basilicum), specifically addressing the risks posed by foodborne pathogens like Escherichia coli O157:H7 and Salmonella spp., which are frequently linked to outbreaks in raw consumption. Evaluating the use of various seed sanitation methods and achieving sufficient pathogen reduction while maintaining seed viability remains a significant challenge. The literature review highlights that eugenol, a plant-based antimicrobial agent, may offer a viable alternative due to its strong antibacterial properties, as demonstrated by its ability to disrupt bacterial membranes. However, concerns regarding eugenol’s volatility and its impact on seed germination and long-term efficacy necessitate further exploration. Also, seed disinfection was evaluated, particularly considering the limitations of chemical sanitizers, chlorine-based treatments, ultrasound, hydrogen peroxide, calcinated calcium spray, and peracetic acid and their combination with physical methods such as heat and UV-C light. 120 food microbiology papers, 50 agriculture papers, and 11 food science papers were reviewed, following the guidelines for reviewing seeds, sprouts, and microgreens sanitation treatments to reduce E. coli O157:H7 and Salmonella spp contamination. The primary objective is to optimize alternative seed decontamination strategies and develop standardized industry protocols for the safe and scalable production of sprouts and microgreens. This resulted in the conclusion that eugenol treatments effectively reduce pathogens' 4 to 5 log CFU/g reduction in the first 48 hours and regrowth later. Moreover, eugenol’s impact on seed germination was concentration-dependent, with higher doses delaying or reducing germination and biomass.