FOOD SCIENCE ›› 2019, Vol. 40 ›› Issue (7): 114-119.doi: 10.7506/spkx1002-6630-20171129-361

• Food Engineering • Previous Articles     Next Articles

Effect of Ultrasonic Pulping Process on the Preparation and Quality of Freeze-Dried Tofu

LIU Baohua, TONG Xiaohong, WU Changling, QI Yuman, LIU Zongzheng, ZHANG Wankun, LI Yang, JIANG Lianzhou, CHEN Fusheng, MA Chuanguo, WANG Zhongjiang   

  1. 1. School of Food Science, Northeast Agricultural University, Harbin 150030, China; 2. College of Cereal and Food, Henan University of Technology, Zhengzhou 450052, China
  • Online:2019-04-15 Published:2019-05-05

Abstract: Ultrasonic treatments at different powers (0, 100, 200, 300, 400 and 500 W) were applied on soybean milk to evaluate their effects on the preparation and quality of freeze-dried tofu. The particle size distribution results showed that the average particle size of soybean milk gradually decreased with increasing ultrasonic power up to 300 W and then increased, which indicated that appropriate ultrasonic treatment could reduce the aggregation of soybean milk. Texture profile analysis showed that hardness, springiness, cohesiveness and chewiness of freeze-dried tofu after rehydration were significantly increased when compared with fresh tofu (P < 0.05), which indicated that protein denaturation occurred during the freezing process. Scanning electron microscope and rehydration rate demonstrated that appropriate ultrasonic treatment could result in uniform hole distribution of freeze-dried tofu with a simultaneous reduction in aperture. Therefore, freeze-dried tofu with good texture characteristics and high rehydration rate could be prepared by 10 min ultrasonic treatment at 300 W.

Key words: ultrasound, tofu, soybean milk, texture

CLC Number: