Formulation and Evaluation of Biopesticides Derived from Local Biological Resources for the Sustainable Post-harvest Preservation of Fresh Fruits and Vegetables

Background: Post-harvest deterioration of fruits and vegetables poses a major challenge for food preservation, particularly in Côte d’Ivoire. The development of biological solutions using local biological resources represents a promising approach to limiting these losses. Aims: The overall objective of this study was to formulate and evaluate biopesticides designed to ensure the long-term preservation of fresh fruit and vegetables after harvest. The overall objective of this study was to formulate and evaluate biopesticides to explore their potential for extending the shelf life of fresh fruit and vegetables after harvest. Methods: Three formulations were investigated: BS, based on metabolites produced by Bacillus subtilis in a filtrate of ageing papaya pulp; BS/T, combining these metabolites with tomato filtrate; and PS/T, prepared from papaya seeds and tomato filtrate. The estimated production of lipopeptides was monitored during fermentation. The antifungal activity, pH and sedimentation of the formulations were assessed over a four-week period at 4 °C and at approximately 33 °C. Their preservative potential was also examined in bananas, tomatoes, aubergines, mangoes, papayas and cucumbers by monitoring changes in weight and spoilage scores. Results: The results showed antifungal activity for all three formulations, to varying degrees. BS/T exhibited lower activity than BS under the conditions assessed, while PS/T stood out for producing the largest inhibition zone at approximately 33 °C (27.00 ± 0.58 mm in the first week) and lower sedimentation after four weeks at this temperature. The effects on the storage life of fruit and vegetables varied between products, with no consistent efficacy across all formulations. All three formulations exhibited antifungal activity of varying intensity. The PS/T formulation showed the largest zone of inhibition during the first week (27.00 ± 0.58 mm; mean ± standard deviation, n = 3). During stability testing at 4 °C and approximately 33 °C, this formulation exhibited less sedimentation after four weeks at approximately 33 °C, while the other formulations showed better stability at 4 °C. Preservation tests, conducted over 14 days on six types of fruits and vegetables, revealed varying effects depending on the produce and the formulations. Conclusion: These results indicate that the PS/T formulation showed the most promising antifungal potential under the conditions studied, but further trials under real-world conditions are needed to confirm its post-harvest efficacy. The PS/T formulation shows promising antifungal potential and good stability at approximately 33 °C. However, the variable effects observed on different fruits and vegetables do not allow for a conclusion regarding uniform efficacy for postharvest storage. Additional trials under real-world conditions are needed to confirm its potential for application.