Fig. 2.

Ultraviolet–visible absorption spectra of FVP, U-FVP1 and U-FVP2 reaction with I₂-KI (a); Maximum absorption wavelength of Congo red and Congo red with FVPs at various concentrations of NaOH (b); CD curve of FVP and its ultrasonic modified fractions (c); The effects of calcium ion and Congo red on the CD curve of FVP (d), U-FVP1 (e) and U-FVP2 (f). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)