Chitosan based edible film obtained with extracts obtained from different Prunella L. species, characterization and their antioxidant properties

Production, characterization, antioxidant capacity and antibacterial activity of chitosan-based edible and biodegradable films, prepared with the help of the extracts of Prunella L. species those are Prunella grandiflora (PG), Prunella laciniata (PL), Prunella orientalis (PO) and Prunella vulgaris (PV), were examined in this study. As an extraction, Prunella plants were put into 70% ethanol solution and left for extraction to happen in agitator. For the production of films, 1 mL, 5 mL and 10 mL of extracts were mixed with 1% (w/v) chitosan solution incorporating 1% (v/v) glacial acetic acid solution and after the addition of glycerol, solutions were waited to dry and form the films. Some of the physical and chemical properties of the films (solubility, water vapor permeability, swelling ratio, moisture ratio, thickness, SEM analysis) were determined and each one of them was consistent with the literature. HLPC-DAD had proved that the phenolic compounds (rosmarinik acid, cathequic acid, caffeic acid, rutin and chlorogenic acid) exist in the films; and ABTS method showed that the films containing Prunella extracts have higher antioxidant activities than the films without extract. With the increasing extract amount in the films, total phenolic content and antioxidant property increased. Antibacterial activity results showed that there is an optimum extract amount between 1.0 mL and 5.0 mL that prevents bacteria reproductivity and kills them with minumum extract amount.