Ultrasonic Effects on the Quality of Mulberry Juice

Abstract

This study was conducted to investigate the effects of ultrasonic treatments on the extraction yield and the quality of mulberry juice. The mulberry mash was treated with ultrasound at different incubation times from 30 to 120 min and different temperatures from 30 to 75 °C. The determination of the juice yield, total phenolic content, total anthocyanin content, antioxidant capacity, l-ascorbic acid content, total soluble solids, and the titratable acidity of the juice were carried out. Overall, applying ultrasound at 45 °C for 60 min resulted in the highest juice yield and antioxidant contents for the mulberry juice. The ultrasonic treatment increased the extraction yield (29.6%), the total soluble solid (8.7%), the titratable acidity (39.3%), the l-ascorbic acid content (94.3%), total phenolic content (174.1%), total anthocyanin content (156.9%) and the antioxidant capacity (40.7%) of the mulberry juice as compared to pressing only. A strong positive correlation between the total phenolic content and the antioxidant capacity indicated that phenolic compounds were the main antioxidants in the beverage.

Keywords

• mulberry juice
• ultrasound treatment
• polyphenols
• anthocyanins
• antioxidant capacity