Configuration of a combined active packaging system with modified atmospheres and antimicrobial control to preserve fresh strawberry fruits

Abstract

The strawberry is a fruit widely consumed worldwide but very perishable and susceptible to spoilage caused by microorganisms such as Botrytis cinerea. This study proposes an integrated packaging solution combining different preservation techniques to extend the shelf life of strawberry fruits. Initially, the respiration rates of the fruits were determined. Then, a perforation-mediated modified atmosphere packaging (MAP) was adjusted using heat-sealed polylactic acid (PLA) trays with a perforation on the upper cover. Subsequently, tests were carried out to incorporate menthol, cinnamaldehyde, and clove essential oil (eugenol), first in pure form and then absorbed into a powdered bentonite matrix arranged in porous sachets. The tests were conducted at 4 and 20 °C, determining the effect of the type and amount of antimicrobial present in the packages on the fruit deterioration. At 4 °C, steady O2 and CO2 levels of 14-18% and 5-10% (mole fraction) were achieved in the MAP. At this temperature, the trays with 50mg of menthol absorbed in 2g of bentonite slowed microbial spoilage up to 25 days at 4 °C compared to 7 days for samples in open packages. At 20 °C, high CO2 levels (> 20%) were reached, and there were no differences between the different antimicrobials evaluated, obtaining 5-6 days of shelf life. The sensory acceptability of the fruits limited the maximum amount of preservative substances used. The proposed system can be implemented as a practical and sustainable solution for preserving strawberries.