Antimicrobial activity of chitosan enriched with lemongrass oil against anthracnose of bell pepper

• Lemongrass essential oil (EO) and chitosan (CH) tested to control anthracnose of bell pepper.
• EO was effective for in vitro control of anthracnose but activity declined in vivo.
• Combination of CH with EO maintained fruit quality and minimised disease.
• Better extension of bell pepper shelf life achieved using 1.0% CH.

Essential oils have been investigated as potential additives for polysaccharide based coatings. In this study the effectiveness of combining lemongrass essential oil with chitosan as an edible coating for bell pepper was examined. Lemongrass essential oil at concentrations of 0.5% and 1.0% was incorporated into 0.5% and 1.0% chitosan solution and evaluated as a means of controlling anthracnose of bell pepper in vitro and in vivo. Fungal growth was effectively controlled by 0.5% and 1.0% EO in vitro. The application of 1.0% chitosan was determined as an effective concentration, and was used in subsequent in vivo analysis as a base coating for maintaining the safety and quality of fresh bell peppers stored at room temperature for 21 days. EO was found to be less effective in vivo, however the combination of EO with CH did enhance the antimicrobial activity of the coating. Quality of the fruits, as determined by weight loss, firmness, colour, SSC and TA, was maintained throughout the storage by the chitosan coating solely and in combination with EO. The in vivo results demonstrated that, as an edible coating, the application of 1.0CH + 0.5 EO was significantly better at maintaining the fruit quality, however, with the anthracnose disease incidence results in consideration, chitosan individually was more effective in the extension of fruit shelf life.