Effects of Ultrasound Treatment on the Physicochemical, Biochemical, Antioxidant, and Microbiological Properties of Natural Iranian Honey During Storage

Ultrasonic processing presents a viable alternative to thermal techniques for honey processing. The objective of this study was to evaluate the effects of ultrasound frequency (30 and 42 kHz), treatment temperature (20 and 45 °C), and treatment duration (1, 5, and 10 min) on selected physicochemical, biochemical, antioxidant, and microbiological characteristics of natural Iranian honey during 180 days of storage. Changes in 5-hydroxymethylfurfural (HMF), pH, acidity, proline, diastase, moisture, sucrose, fructose, glucose, fructose-to-glucose ratio, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), total phenolic content, reducing sugars, total sugars, and microbiological indicators were assessed after 1, 30, 90, and 180 days. Treatment with 42 kHz ultrasound reduced the total viable count of aerobic mesophilic bacteria, as well as mold and osmophilic organisms, under several treatment conditions. Compared with the untreated control and, where indicated, the 30 kHz treatment, 42 kHz ultrasound was associated with higher diastase, proline, and phenolic content and lower HMF, ABTS values, and moisture content. The effects on pH were temperature-dependent, with increases observed under some treatments at 20 °C and decreases under selected treatments at 45 °C. The findings demonstrate that ultrasound treatment can modify physicochemical, biochemical, antioxidant-related, and microbiological characteristics of natural Iranian honey during storage.