Application of natural-based nanocoatings for extending the shelf life of green bell pepper fruit.

Pectobacterium carotovorum is a phytopathogenic bacteria that causes significant economic loses in food crops, such as bell pepper, which is of special significance in the value of production and trade in Mexico. Therefore, a solution for fruit conservation must be sought. Due to environmental concerns, it is necessary the use of environmentally-friendly active packaging. In this article, chitosan and chitosan-thyme essential oil nanocoatings were used for the preservation of green bell pepper. Different formulations based on chitosan nanoparticles (CSNPs) and chitosan-thyme essential oil nanoparticles (15, 30, and 45%) were prepared. For uncoated and coated bell peppers, the quality and physiological variables of inoculated and uninoculated fruit with P. carotovorum during 12-day storage period were assessed. According to the results, the weight loss of the fruit remained almost constant over the storage days for the different formulations. A decrease in fruit firmness and an increase in the respiration rate and ascorbic acid content until day 8 with a decrease at the end of the storage period were observed. Of all the evaluated nanocoatings, the fruit treated with the formulation containing 15% CSNPs showed the lowest colony-forming units and disease incidence. Also, the coated bell peppers with this formulation had lower CO production compared to the remaining treatments, and the weight loss and firmness were maintained. Therefore, the use of CSNP coatings could represent a good alternative for the protection of bell pepper against the pathogenic bacteria P. carotovorum. PRACTICAL APPLICATION: The results of the application of nanocoatings based on chitosan and chitosan-thyme essential oil as an antibacterial agent against P. carotovorum on green bell pepper during 12-day storage period suggest that nanoparticle-based coatings can be a natural option for the preservation of fruit quality during ripening.