Effect of high intensity ultrasound on carbohydrate metabolism of bifidobacteria in milk fermentation

► Four bifidobacteria were examined in milk fermentation under high intensity ultrasound. ► Lactose hydrolysis and trans-galactosylation reaction were accelerated. ► Ultrasonication stimulated major organic acid production. ► Ultrasonication decreased the ratio of acetic acid to lactic acid in BB-12 samples. ► Ultrasonication decreased (acetic + propionic acids)/(lactic acid) in BB-46 samples.