Microencapsulated Propolis to Enhance the Antioxidant Properties of Fresh Fish Burgers

The aim of the study was to enhance the antioxidant properties of fish burgers with microencapsulated propolis. Spray-drying process was used to microencapsulate propolis (30 g in 100 mL of ethanol 70% v/v) by means of gum Arabic and Capsul in different ratios (1:6 for gum Arabic and Capsul and then 1:20 just for Capsul). Once defined the optimal microencapsulation conditions, an alcohol-free powder able to mask the strong odor of propolis was obtained, thus promoting a potential food application as source of phenolics and antioxidants. Specifically, 5% w/w of spray-dried propolis was incorporated in fish burgers. To improve their sensory properties, new ingredients such as potato flakes (3%, 5%, 7% and 10% w/w) and extra virgin olive oil (9% w/w) were tested and optimized to give a final fish product with good acceptability. Proper tests on burgers also demonstrated an effective increase of both phenolic content and antioxidant activity.