Purpose: The purpose of this research was to develop cost model estimates for competitive exclusion microbes (CEM) of Pseudomonas strains (non-plant pathogenic and non-human pathogens) as biocontrol of S. enterica on tomatoes. Published research on process-based models for biocontrol of foodborne pathogens on produce at post-harvest is limited.
Methods: Cost-estimates of competitive exclusion process were based on material inputs, equipment and facilities for application of biocontrol microbes, and projected processing conditions of post-harvest packaging of tomatoes or vegetables. The microbiological data for inactivation of S. enterica was based on published data from biocontrol experiments. Cost estimates of small and large scale applications of biocontrol and processing of tomatoes were compared.
Results: Initial capital investment costs for small-scale (assumed to have processing capacity of 2,000 Kg of tomatoes/h, 16 h/day, 6 days/week and 3 month/year) was US$ 391,000. For a large-scale facility, operating at 100,000 Kg of tomatoes/h for operational period, cost estimates were US$ 2.1 million. Application of CEM for biocontrol of S. enterica on tomatoes was estimated at US$ 0.058-0.073 kg of tomatoes. This cost can exceed other technologies such as chlorine dioxide.
Significance: Cost estimate for CEM was developed. CEM applied against S. enterica on tomatoes may be attributed to microbial competition for space /nutrients, antagonism and antimicrobial compounds. For high value produce, CEM may complement existing post-harvest technologies, increase food safety, reduce loses and extend shelf life of produce if efficacy and delivery systems can be optimized.