Eugenol as active component in food packaging materials

Abstract

Eugenol (4-allyl-2-methoxyphenol) is a naturally occurring phenol present in many botanical extracts, such as clove, cinnamon, and nutmeg essential oils. The beneficial properties of this compound have been extensively investigated and reported by several authors, opening a wide range of applications in the food, pharmaceutical, cosmetic and dental care industry. Among others, antimicrobial, antioxidant, analgesic, repellent and insecticidal activities can be mentioned. In the last years, the food industry has generated new demands on packaging technology, due to the growing consumer interest on fresh or minimally processed products with extended shelf-life and controlled quality. In this sense, active packaging technology appears in the market aiming to improve food preservation, by interacting with the food product and/or the surrounding environment and making use of additives included into the packaging systems. In this context, the incorporation of natural extracts obtained from plants for active packaging development is an interesting alternative to the food packaging industry. In this chapter, the use of eugenol for the development of new active packaging material is presented, using two different technologies for two polymer matrices. First, linear low-density polyethylene (LLDPE) films were impregnated with eugenol using supercritical CO2 assisted impregnation. On a second approach, eugenol was grafted onto cellulose using a polycarboxylic acid as a linking agent for the preparation of a bioactive paper. In both cases, the effect of different process conditions on the final material properties was investigated. In the first case, the effect of pressure and depressurization rate on eugenol incorporation into LLDPE was investigated, while on the second approach, the effect of temperature, time and eugenol amount on the final properties of the bioactive paper was studied. Furthermore, the effect of the modification on the polymer mechanical properties was evaluated for both materials. Additionally, thermal properties and color were analyzed for impregnated LLDPE films and grafted paper, respectively. Finally, the antioxidant and insectifuge/insecticidal activities of the modified polymers were assessed and confirmed, showing that the modified polymers could be interesting materials for active food packaging applications.