Optimization of edible coating with essential oils in blueberries

Abstract

The application of edible coatings containing natural antimicrobials is a postharvest conservation technology in fruits that have generated interest. This research aimed the determination of the edible coating composition and the concentration of essential oil that allows optimizing the physical-mechanical characteristics for its application in the conservation of blueberries. The antimicrobial activity of the essential oils of cinnamon and lemon was determined, resulting in a minimum inhibitory concentration of 0.3% in both cases. After applying the Box Behnken design of the Response Surface Methodology (RSM), the optimal treatment for edible coating with cinnamon essential oil 0.3% was determined: aloe vera gel 18.40%, gelatin 2%, and glycerol 0.055% obtaining values of 27.95% solubility, 0.90 mm of deformation and 3.34 N of breaking strength. Likewise, the same procedure was followed for the coating with lemon essential oil 0.3%, determining as optimal 23.94% aloe vera gel, 2% gelatin, and 0.05% glycerol, getting values of 28.06% solubility, 0.45 mm deformation, and 4.53 N of breaking strength. Finally, their applications in Biloxi blueberries were validated, preserving the main physicochemical and microbiological quality attributes during 28 days of storage at 2 °C, compared, to a control sample.