Optimisation of edible chitosan coatings formulations incorporating Myrcia ovata Cambessedes essential oil with antimicrobial potential against foodborne bacteria and natural microflora of mangaba fruits

- Edible coatings incorporating Myrcia ovata essential oil were obtained.
- The composition of the coatings was optimised by response surface methodology.
- Mathematical models for B. cereus, B. subtilis and S. marcescens inhibition were obtained.
- The edible coatings inhibited native microorganisms of mangaba fruits.

Various edible coating formulations were prepared from cassava starch, chitosan and Myrcia ovata Cambessedes essential oils (MYRO-174 or -175) according to a 23 experimental design including six factorial points and three central points. The antimicrobial activity of the coatings was evaluated against eight foodborne bacteria using the disc diffusion method. The coatings containing MYRO-175 essential oil were the most effective. Mathematical models describing Bacillus cereus, B. subtilis and Serratia marcescens inhibition were developed using response surface methodology. The edible coatings containing 0.5% cassava starch-0.5% chitosan-1.25% MYRO-174 or -175 essential oil were applied to mangabas and their microbiological quality was evaluated during storage at 10 °C for 12 days. The total aerobic mesophilic bacteria, mould and yeast counts were reduced by ∼3 log from day 4-12. For coated mangabas inoculated with B. cereus, the counts were <1.0 log from day 2-12 of storage. These innovative coatings show potential for controlling foodborne bacteria and natural microorganism growth during the storage of fruit, particularly, mangabas.