FOOD SCIENCE ›› 2014, Vol. 35 ›› Issue (4): 39-43.doi: 10.7506/spkx1002-6630-201404009

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Optimization of Ultrasonic Sterilization Process of Sika Deer Placenta Polypeptides by Response Surface Methodology

PI Yu-zhen, GUAN Chu-yu, SUN Wen-hua, YUE Xi-qing   

  1. College of Food Science, Shenyang Agricultural University, Shenyang 110086, China
  • Received:2013-06-17 Revised:2014-02-17 Online:2014-02-25 Published:2014-03-17
  • Contact: PI Yu-zhen E-mail:1014436061@qq.com

Abstract:

In this experiment, polypeptides obtained from enzymatic hydrolysis of sika deer placenta were sterilized by
ultrasonic radiation. The effects of ultrasonic intensity, treatment time and impulse time on sterilization efficiency were
investigated. The optimal parameters were determined by response surface methodology as follows: 850 W of ultrasonic
intensity, 4.6 min of ultrasonic treatment time and 7 s of ultrasonic impulse time. The results showed that the polypeptide
loss rate was 20.2% and the sterilization efficiency was 87.5% under these conditions. In addition, the total bacterial count
was 68 CFU/mL and the most probable number (MPN) of Escherichia coli was zero. All these parameters complied with the
national standards. The free radical scavenging activity of sterilized sika deer placenta polypeptides against superoxide anion,
hydrolxyl and DPPH radicals was decreased by only 3.3%, 1.1% and 1.7% as compared to the unsterilized counterpart.
These results indicate that sterilized sika deer placenta polypeptides reach the requirements of commercial sterilization while
maintaining their bioactivity.

Key words: sika deer placenta polypeptides, ultrasonic sterilization, sterilization efficiency

CLC Number: