Antibacterial activity of biopolymer composite materials obtained from pumpkin oil cake and winter savory or basil essential oil against various pathogenic bacteria

摘要

Pumpkin oil cake, a by-product obtained after oil extraction from pumpkin seed, possesses good film-forming properties, as well as the ability to be used as a matrix for various compounds in order to obtain active biopolymer materials. Use of essential oils, as active components with a pronounced activity, can be a good alternative to synthetic chemical compounds. In the present work, composite pumpkin oil cake-based films with winter savory or basil essential oil were developed and their antibacterial activity against two Gram-negative bacteria (E. coli, S. Enteritidis) and three Gram-positive bacteria (L. monocytogenes, Staph. aureus and B. cereus) was analysed. Gas chromatographic-mass spectromet-ric analysis confirmed the main phenolic compounds to be carvacrol in winter savory essential oil and linalool in basil essential oil. Pumpkin oil cake film without essential oils did not show antibacterial activity against any of the tested bacteria, while films with basil essential oil showed some antibacterial activity against L. monocytogenes and B. cereus. However, films with winter savory essential oil showed antibacterial activity in all added concentrations against all 5 bacteria. Addition of winter savory and basil essential oils into pumpkin oil cake-based film enhanced its antibacterial activity, demonstrating its possible application as an active composite material.