Abstract
In this work, active films based on starch and PVA (S:PVA ratio of 2:1) were developed
by incorporating neem (NO) and oregano essential oils (OEO). First, a screening of the antifungal
effectiveness of different natural extracts (echinacea, horsetail extract, liquid smoke and neem seed
oil) against two fungus (P. expansum and A. niger) was carried out. The effect of NO and OEO
incorporation on the films¿ physical and antimicrobial properties was analyzed. Only composite
films containing OEO exhibited antibacterial and antifungal activity. Antibacterial activity occurred
at low OEO concentration (6.7%), while antifungal effect required higher doses of OEO in the
films. Incorporation of oils did not notably affect the water sorption capacity and water vapor
barrier properties of S-PVA films, but reduced their transparency and gloss, especially at the highest
concentrations. The mechanical response of the S-PVA films was also negatively affected by oil
incorporation but this was only relevant at the highest oil ratio (22%). S-PVA films with 6.7% of OEO
exhibited the best physical properties, without significant differences with respect to the S-PVA matrix,
while exhibiting antibacterial activity. Thus, the use of OEO as a natural antimicrobial incorporated
into starch-PVA films represents a good and novel alternative in food packaging applications.
