Ultrasound-Assisted Quality Enhancement of Iranian Honey: Impact on Key Biochemical Markers and Microbial Safety during Long-Term Storage

Crystallization, the formation of structured solid crystals within a uniform solution, is a primary cause of quality deterioration in honey. This study investigated the effects of ultrasound treatment on the biochemical, antioxidant, and microbial properties of natural Iranian honey. Key parameters assessed included 5-hydroxymethylfurfural (HMF), pH, acidity, proline content, diastase activity, moisture content, sucrose, fructose, glucose, fructose-to-glucose ratio, ABTS radical scavenging activity, total phenolic content, reducing sugars, and total sugars. Honey samples were subjected to ultrasound at frequencies of 30 kHz and 42 kHz, temperatures of 20 °C and 45 °C, and treatment durations of 1, 5, and 10 minutes. Changes in these parameters were monitored after storage periods of 1, 30, 90, and 180 days. The findings demonstrated that ultrasound treatment at 42 kHz significantly reduced the total counts of aerobic mesophilic bacteria, molds, and osmophilic microorganisms. Compared to both the untreated control and the 30 kHz treatment group, the 42 kHz-treated samples exhibited higher levels of diastase activity, proline, and total phenolic content, alongside lower HMF, ABTS values, moisture content, pH, and acidity. These changes were associated with enhanced antimicrobial and antioxidant properties, likely linked to the reductions in moisture, pH, and acidity. The results suggest that 42 kHz ultrasound processing offers potential benefits for improving and preserving the quality of natural honey in the food industry.