Antimicrobial activity assessment of an innovative powdered honey production approach: a comparative study

Working with honey in laboratory or applied settings presents practical challenges that extend beyond its well-known antimicrobial properties. Honey is viscous and sticky, tends to harden into crystals over time, and can make it tedious to apply the same amount repeatedly. These everyday issues have led researchers to seek powdered alternatives, though many published approaches involve heating steps or require so much carrier material that parts of honey’s natural properties may be altered unintentionally. In this study, a powdered honey (P.H.) mixture supported with water-insoluble microcrystalline cellulose (MCC) was evaluated alongside liquid honey, ensuring that the actual amount of honey applied in each experiment was equivalent. Two commercially available honeys with different declared botanical origins (chestnut and polyfloral) were included to assess the applicability of the approach across market-available samples. Antimicrobial activity was assessed against Gram-positive Staphylococcus aureus and Gram-negative Salmonella typhimurium using both disc and well diffusion assays. Before testing, powdered samples were rehydrated so that each application delivered a quantity of honey equivalent to that present in 10 µL of the liquid form. The resulting inhibition zones were measured using calibrated digital image analysis. Under matched-dosing conditions, antimicrobial activity was preserved in both liquid and powdered honey, with inhibition patterns varying depending on the microorganism and experimental conditions. Overall, the findings suggest that this non-thermal, MCC-assisted powdering strategy can preserve antimicrobial performance while improving handling, storage, and dose reproducibility, and that inhibition outcomes may be shaped by physical form–dependent diffusion behavior under equivalent honey content.