Antimicrobial protection and antioxidant enhancement of wheat gluten films treated with thyme essential oil: in vitro studies

FRANCISCO ZUBELDÍA; NORMA E. MARCOVICH; MARÍA ROBERTA ANSORENA

Concordia, Entre Ríos

Conferencia; International Conference on Food Innovation (FoodInnova 2014); 2014

The objective of this work is to use wheat gluten (WG) to develop active, edible and suitable films for food packaging, prepared by intensive mixing and compression moulding; a thermoplastic process involving high temperature and high pressure. Thyme essential oil (TEO), which has very interesting antioxidant and antimicrobial properties although intense aromas that could limit the organoleptic acceptability of the final product was selected as the active ingredient. Therefore, two methods of film preparation are compared: directly adding the oil in the mixture of wheat gluten and glycerol, but also microencapsulating it in β-cyclodextrins (β-CDs). The high temperature needed to process WG may oxidize and degrade TEO. We hope that microencapsulation of TEO is a viable alternative to trap the active constituents of the oil, masking its smell and taste, while preserving its antioxidant and antimicrobial capacity during the processing stage. This work compares and analyzes, initially, the antimicrobial and antioxidant properties of films based on plasticized wheat gluten at different TEO concentrations (0-15 wt%).