Optimization of Ultrasonic-Assisted Osmotic Dehydration and the Influence on the Quality of Frozen Broccoli

Abstract:

According to the measurement of water loss and hardness of frozen broccoli，the processing parameters of ultrasound-assisted osmotic dehydration on broccoli with trehalose solution before freezing were optimized by single factor and orthogonal experiments. The results showed that the optimal osmotic conditions were as followed，ultrasonic power of 240 W，osmotic time of 30 min，and osmotic concentration of 50%. Under these conditions，the water loss of broccoli was 1.26，and the hardness of frozen broccoli was 39.59 N. The results also indicated that ultrasound-assisted osmotic dehydration improved the efficiency of freezing，reduced the drop loss，and prevented the loss of ascorbic acid and the change in color of broccoli during frozen storage.