Abstract:To protect plant essential oil aroma and control its release, cocoa essential oil was used as the raw material, and its components were analyzed using headspace solid-phase microextraction-mass spectrometry (HS-SPME-GC-MS). Next, a Pickering emulsion of cocoa essential oil was prepared using OSA starch following the ultrasonic shearing method, and its antioxidant and bacteriostatic properties were examined. Terpenes and esters accounted for 23.81% and 20.41% of all components of the essential oil, respectively. Other components with high relative content were acetic acid (6.64%), 2,3-butanediol (5.27%), and ethyl acetate (4.64%). Particle size of the Pickering emulsion was 0.47 μm at an essential oil concentration of 5%, indicating that the preparation of a Pickering emulsion could effectively slow down the aroma release of essential oils. The antioxidant activity of the Pickering emulsion of cocoa essential oil encapsulated in OSA starch was improved. The DPPH scavenging ability of the Pickering emulsion at 24 h was significantly higher than that at 30 min. The ABTS+ scavenging ability of the Pickering emulsion peaked at 12 h and was significantly higher than that of the essential oil. In addition, Cocoa essential oil and Pickering emulsion exhibited potent bacteriostatic effects on food-borne pathogens. Therefore, preparation of a Pickering emulsion of cocoa essential oil is a reliable method to reduce the aroma release of essential oil during processing as well as to improve its storage stability, antioxidant activity, and antibacterial activity. The present study provides a theoretical basis for further expanding the application scope of cocoa essential oil.
