Title
Effects of Ultrasonic and Microwave Processing on Avidin Assay and Secondary Structures of Egg White Protein
Author
Yao Zhu, Sai Kranthi Vanga, Jin Wang, Vijaya Raghavan
Year
2018
Journal
Food and Bioprocess Technology
Abstract
The effect of microwave and ultrasonic processing on the secondary structure of egg white protein was evaluated using Fourier-transform infrared spectroscopy and circular dichroism spectroscopy. The influence of these methods on avidin activity was also evaluated. Microwave treatment was performed at 60 °C, 70 °C, and 80 °C for 1, 3, and 5 min. Avidin activity was found to decrease in all the processed samples. However, the reduction in its activity was higher when treated at 80 °C. The secondary structure analysis revealed that the β-sheets increased at temperatures 60 °C and 70 °C as the processing time rose while became almost constant at 80 °C. α-helices were found to decrease with time at each of the temperatures at which microwave was applied. Turns and unordered structures remained constant. Ultrasonic processing was carried out for 1, 4, 8, 12, and 16 min. α-helices declined significantly with remarkable increase of β-sheets when samples were treated for 1 min compared to control. However, the secondary structure content did not change significantly when the duration of ultrasonication was increased, showing minimal processing capabilities of ultrasound.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Food science, Biochemistry