Ultrasonic pretreatment of corn gluten meal proteins and neutrase: Effect on protein conformation and preparation of ACE (angiotensin converting enzyme) inhibitory peptides

Abstract

The impact of ultrasound pretreatment of corn gluten meal (CGM) protein and neutrase on the ACE (angiotensin converting enzyme) inhibitory activity of hydrolysate was studied. The UV–vis differential spectra and fluorescence spectra of the CGM protein and neutrase were determined. The neutrase activity and the ACE inhibitory activity of the CGM protein hydrolysates were analyzed. The highest ACE inhibitory activity was obtained at 10min hydrolysis when the CGM protein was pretreated at 20kHz for 10–30min and at a power of 1000W. The neutrase activity and ACE inhibitory activity were at their maxima at sonication of 250W and sonication time of 15min. The fluorescence and UV differential spectra of the proteins of CGM and neutrase reflected molecular unfolding due to sonication. Sonication of the protein substrate and the enzyme before hydrolysis may be an effective way to enhance the ACE inhibition attributes of the hydrolysate.