Strategies to enhance propolis ethanolic extract’s flavor for its use as a natural preservative in beef

Abstract

Propolis is rich in bioactive compounds like phenols and flavonoids, which make it a promising alternative as a natural preservative. However, the use of propolis in the food industry is limited due to its strong, characteristic flavor. To overcome this problem, several strategies such as the combination with other ingredients or propolis microencapsulation have been studied. In this work, the addition of honeydew (no floral honey) to, and the elimination of the ethanol from, the propolis extract solution were used to mitigate this sensorial defect. Thus, the effect of these propolis solutions on beef quality during refrigerated storage were evaluated. Throughout storage, a decrease in the pH and the a*, indicative of microbial growth and oxidation, respectively, was observed in the control samples. Both deterioration processes were slowed down in the treated samples, demonstrating the antioxidant and antibacterial properties of the propolis and the honeydew. What is more, neither ethanol evaporation nor the addition of honeydew impaired the antimicrobial activity of the solutions, with the greatest microbial reductions observed in the former. With this solution, a reduction of 0.77 and 1.45 logarithmic units were observed for the mesophiles and the Enterobacteria, respectively. Finally, the propolis and honeydew solution presented the highest scores in all the sensory attributes analyzed. In conclusion, the strategies applied in this study were effective at enhancing propolis extract flavor whilst maintaining its antimicrobial and antioxidant properties. This could be a promising starting point for a wider use of propolis as a natural preservative in the food industry.