Edible Coatings with Essential Oils

Five stocks of edible coating solutions and their emulsions with essential oils were produced. chitosan solution was made at a final concentration of 1% by dissolving 1 g of chitosan of medium molecular weight obtained from crab shells (48165, Sigma Aldrich, St. Louis, MO, USA) in 100 mL of 1% glacial acetic acid (100056, Merck KGaA, Darmstadt, Germany) and stirring overnight at room temperature. Alginate solution was produced at a final concentration of 1.5% by dissolving 1.5 g of sodium alginate obtained from brown algae (alginic acid sodium salt BioChemica, A3249, AppliChem GmBh, Darmstadt, Germany) in 100 mL of deionized water and stirring overnight at room temperature. chitosan and alginate emulsions with oregano oil were made at a final concentration of 0.1% by dissolving 0.1 mL of oregano oil (W282812, Sigma Aldrich, Burlington, MA, USA) in 100 mL of the stocks of chitosan or alginate solutions and mixing until fully incorporated at room temperature. Alginate emulsion with olive oil was produced at a final concentration of 2% by dissolving 2 mL of olive oil (of extra virgin grade, procured bottled from a local convenience store) in 100 mL of the stock of alginate solution and mixing until well combined at room temperature. All stocks were finally sterilized at 121 °C for 15 min.