Evaluation of Antioxidant and Microbial Property Changes in Honey Supplemented with Propolis

The mixture of honey and propolis has become increasingly popular due to its potential functional and antimicrobial properties, generating interest in its stability and quality during storage. This study aimed to evaluate the evolution of physico-chemical and microbiological parameters of honey enriched with different propolis concentrations (0.1%, 0.2%, and 0.3%, w/w) over a 30-day period under controlled storage conditions. Honey samples with and without propolis were stored at 20 °C in the absence of light, and physico-chemical parameters (moisture content, electrical conductivity, pH, and acidity), antioxidant-related indicators (total phenolic content, total flavonoid content, and DPPH radical scavenging activity), and microbiological parameters (the total aerobic viable count, yeast and mold counts, and coliform bacteria counts) were analyzed at defined intervals. The results showed that the monitored physico-chemical parameters remained stable throughout the storage period, indicating good product stability. Antioxidant-related parameters increased proportionally with the concentration of propolis added, reflecting the contribution of phenolic compounds and flavonoids present in propolis. Microbiological analysis confirmed the absence of coliform bacteria in all samples, while a gradual increase in total viable count and in yeast and mold counts was observed in propolis-enriched honey samples during storage. Overall, the findings indicate that honey–propolis mixtures maintain physico-chemical stability, comply with microbiological safety requirements, and exhibit enhanced antioxidant potential during short-term storage. These conclusions are limited to the 30-day storage period investigated and should not be extrapolated to long-term storage stability.