Properties and Antioxidant Capacity of Anchovy (Engraulis encrasicholus) By-Product Protein Films Containing Thyme Essential Oil

Abstract

In this study, some properties and antioxidant capacity of anchovy (Engraulis encrasicholus) by-product protein films with added 0.5, 1.0 and 1.5 % of thyme essential oil were investigated. The films with thyme essential oil had higher elongation at break, water vapour permeability and oxygen permeability, lower solubility and tensile strength than control film (p<0.05). The incorporation of thyme essential oil affected transparency values of the films, but only the addition of 1.5 % of thyme essential oil significantly reduced the transparency (p<0.05). In the film matrix, molecular organisation and intermolecular interaction were changed by thyme essential oil addition. The films with thyme essential oil had a heterogeneous surface and a relatively smooth cross-section structure. Slightly higher phase transition and lower glass transition temperatures were observed in films with thyme essential oil. The antioxidant capacity of the films was improved by incorporating thyme essential oil depending on its volume fraction.