Antioxidant and antimicrobial properties of thyme essential oil encapsulated in zein particles

Zein has been used successfully for encapsulation of functional foods. Thyme essential oil was encapsulated in zein particles by liquid-liquid dispersion method. Functional properties of thyme essential oil can be enhanced by encapsulation technology. Based on the SEM images, size of the particles was in micron scale. A centrifugation step was applied to separate encapsulated particles during production. This treatment caused some differences in structural and functional properties. The highest encapsulation efficiency value of 97.02 % was achieved at 503xg for 10min centrifugation. Interaction time between samples and DPPH radicals was extended by encapsulation. Advantage of encapsulation in terms of antioxidant actions was highlighted by Rancimat test. A fast release rate of thyme essential oil encapsulated in zein was observed in triacylglycerols media. Antimicrobial activity of encapsulated thyme essential oil was lower than that of free form in 24h incubation. A better encapsulation efficiency rate was obtained compared to reported values. Rancimat test can be effectively used to measure antioxidant activity when essential oils are used as antioxidants in encapsulated form. A fast release rate of thyme essential oil encapsulated in zein was observed in TAGs media. Copyright (c) 2015 John Wiley & Sons, Ltd.