Effects of Thermal Treatment, Ultrasonication, and Sunlight Exposure on Antioxidant Properties of Honey.

OBJECTIVES

This study aimed to determine effects of controlled heating, ultrasonication, and sunlight on antioxidant capacity, total phenolic content (TPC), and total flavonoid content (TFC) of honey.

MATERIALS AND

METHODS

Honey was subjected to thermal treatment (for 5-20 min at 30-80°C), ultrasonication (for 5-20 min at 37 kHz frequency), and sunlight (for 1-10 days), and the impact of these treatments on antioxidant capacity, TPC, and flavonoid contents was evaluated. One-Way ANOVA, followed by Tukey's post-hoc test, was performed to compare the differences between experimental results.

RESULTS

Antioxidant quality of samples heated at 60°C and 80°C were negatively affected when compared to untreated samples (p<0.05); however, there were no statistically significant differences between untreated samples and samples heated at 30°C and 45°C. On the other hand, ultrasonication of honey samples for 60 min enhanced the antioxidant properties when compared to untreated samples (p<0.05). In addition, while exposure to sunlight for 10 days decreased the TPC, the TFC and antioxidant capacity began to decrease after 6 days (p<0.05).

CONCLUSION

The results suggest that producers and consumers should consider the adverse effects of sunlight and temperature on antioxidative quality of honey. Additionally, ultrasonication technique has the advantage of preserving the antioxidant properties of honey.