Designing antimicrobial polypropylene films with grape pomace extract for food packaging

Grape pomace (mixture of skins and seeds) is a residual by-product of the winemaking process, rich in polyphenolic compounds that have antioxidant and antimicrobial properties and can be recycled to manufacture fruit extracts to be used in new technological products. The use of non-toxic substances is exciting for developing packagings that are in direct contact with food, as components present in the polymer might migrate to the food. Moreover, the gradual release of these non-toxic bioactive components confers long-term antimicrobial activity to these PP films enriched with grape pomace extract. In addition, the use of raw materials from natural and renewable origins to manufacture antimicrobial packaging contributes to a more sustainable and eco-friendly industrial production and to mitigate environmental impacts. In this research, bactericidal isotactic polypropylene (PP) was developed using grape pomace extract as an antimicrobial additive and presents low water vapor permeability and antimicrobial activity against Gram-negative ( Escherichia coli ) and Gram-positive ( Bacillus subtilis ) bacteria, showing potential to function as an active and safer polymeric food packaging. • Multifunctional polypropylene films for packaging. • Flexible and transparent polypropylene films prepared with grape pomace extract. • Grape biomass residue was applied as an antimicrobial additive for polymer packaging. • Polypropylene films with low water vapor permeability. • Rheological behavior of polypropylene melts with grape pomace extract.