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Even though essential oils from Piper aduncum (Piperaceae) have different biological activities, little is known about their application to agricultural areas. White mold is a plant disease caused by the phytopathogen Sclerotinia sclerotiorum, which needs to be controlled by alternative measures. This study aimed at evaluating the effect of essential oils from P. aduncum leaves (PL-EO) and inflorescences (PI-EO) on the mycelial growth of S. sclerotiorum. Essential oils from P. aduncum were obtained by hydrodistillation by a Clevenger-type apparatus while their chemical composition was analyzed by GC-MS and GC-FID. Piperitone (23.4 %), myristicin (12.4 %), terpinen-4-ol (12.3 %), β-caryophyllene (7.2 %), α-humulene (6.9 %), germacrene-D (6.9 %) and dillapiol (6.3 %) were the main constituents found in oils from P. aduncum. The in vitro antifungal activity showed that PI-EO dose above 30 µL inhibited mycelial growth in 100 %, whereas PL-EO at 50 µL inhibited it in 98.74 %. This is the first report of the chemical composition of PI-EO and results suggest that the essential oils under evaluation have high potential to control the phytopathogenic fungus S. sclerotiorum.

Starch is a promising source of biopolymers and the incorporation of essential oils (EOs) into it can improve some biological properties of films. This study aimed at developing and characterizing barrier, biodegradability and optical properties of biopolymeric films made from arrowroot starch and at incorporating EOs from Piper aduncum leaves and inflorescences in order to analyze their antifungal activity against Rhizopus microsporus and Colletotrichum gloeosporioides. The casting method was used for developing arrowroot starch films and incorporating EOs into them. Resulting films exhibited satisfactory barrier properties, low water vapor permeability (WVP), transparency and good barrier property against UV-vis light, besides being 100% biodegradable. In addition, films enriched with EOs at 0.75% and 1.0% revealed promising antifungal activity. Results showed, for the first time, that arrowroot starch enriched with EOs from P. aduncum can potentially be used as an active film due to its excellent physicochemical properties and antimicrobial activity.

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The development of active packaging for food preservation is attracting increased attention due to serious environmental problems caused by synthetic and conventional materials. In the present study, the physical, chemical, optical, microstructural, and antibacterial properties of chitosan films with Citrus limonia essential oil (CEO) were investigated. The incorporation >0.75% of CEO increased the thickness of the films. The incorporation >0.25% of CEO reduced the moisture content and the water vapor permeability of the chitosan films. The biodegradability of the films over ten days ranged from 55.46–62.65% and was not affected by the addition of CEO. All films showed good UV light barrier properties, and the incorporation of the CEO caused a decrease in the visible light transmission rate values. The addition of CEO changed the color of the bioactive films significantly, remain darker and yellowish. The bioactive films showed antibacterial activity against Staphylococcus aureus, but not against Escherichia coli. The films showed a heterogeneous microstructure with oil droplets retained in the continuous polysaccharide network. The results showed that chitosan films with CEO are promising as an active packaging material for food preservation.