Abstract:

The enzymatic hydrolysis of defatted wheat germ protein using alkaline protease was optimized based on degree
of hydrolysis (DH). When the hydrolysis was carried out at 50 ℃ with an initial pH of 8 at an enzyme dose of 5.0% and a
substrate concentration of 4.0%, a DH value up to 20.08% was achieved and the hydrolysate showed 48.59%, 13.77 and
9.86 g/100 g for solubility, hygroscopicity and oil absorption, respectively. Thermal analysis indicated that the hydrolysate
was thermally stable at a temperature below 200 ℃, and its structure was analyzed as well by infrared spectroscopy.
MALDI-TOF-TOF mass spectrometry data showed that the molecular weights of its major components were below 2 000 D.
Meanwhile, this hydrolysate exhibited a strong antioxidant activity in vitro.

Key words: wheat germ protein, alkaline protease, hydrolysis, antioxidant activity