[Hydrolysis method for whey protein and the hypoglycemic activity of its peptides in diabetic KKAy mice]

To explore the hydrolysis method for whey protein with alkaline proteinase, and to investigate the hypoglycemic activity of the peptides in diabetic KKAy mice.

Whey protein was hydrolyzed with alkaline proteinase, and the degree of hydrolysis, nitrogen and amino acid content, mass spectrographic analysis of the peptides were determined. Changes of fasting blood glucose, random blood glucose, glucose tolerance and insulin levels in diabetic KKAy mice were measured after the peptides were given by gavage.

The degree of hydrolysis of whey protein was 14.8%, the nitrogen in the peptides was 68.2%, and the molecular weight of the peptides was 900 - 1900 Dal, mostly was 1800 - 1900 Dal. Blood glucose of KKAy mice was decreased at 0.5 and 1 h after oral injection of the peptides, and insulin level was increased at 0.5 h after ingestion of the peptides.

Fasting blood glucose and random blood glucose levels of type 2 diabetic KKAy mice could be significantly decreased, and the glucose tolerance and insulin secretion of mice could be improved by whey protein peptides.