April 21/Beijing/Journal of Farming -- According to recent research from Beijing, People's Republic of China, "Removal of salts from protein hydrolysate mixtures on a large scale is very difficult and relatively inefficient. Selecting practical proteinase system and hydrolysis conditions for the production of whey protein isolate (WPI) enzymatic hydrolysates with high angiotensin I-converting enzyme (ACE) inhibitory activity and low ash content is very useful."

"The effect of alcalase, neutrase, trypsin and their combined system, i.e. alcalase-neutrase and trypsin-neutrase, under two different hydrolysis conditions, i.e. pH-controlled and pH-spontaneous drop, on the formation of ACE-inhibitory peptides and the characteristics of WPI hydrolysate was investigated. The ACE-inhibitory activity of WPI hydrolysate obtained with alcalase was significantly higher than that of its trypsin or neutrase hydrolysate obtained at the same hydrolysis time by both pH-controlled and pH-spontaneous drop method (P<0.05). The WPI hydrolysate obtained after three hours incubation with alcalase plus two hours with neutrase under pH-spontaneous drop condition possessed the highest ACE-inhibitory activity of 54.30% and the lowest ash content of 2.95%," wrote L. Wang and colleagues, China Agricultural University.

The researchers concluded, "This is practical as a functional ingredient in the food industry because of its high ACE-inhibitory capability, commercial availability in large supply of alcalase and neutrase and no needing for additional desalting process."

Wang and colleagues published their study in International Journal of Food Science and Technology ("Effect of Enzyme Type and Hydrolysis Conditions on the In Vitro Angiotensin I-converting Enzyme Inhibitory Activity and Ash Content of Hydrolyzed Whey Protein Isolate." International Journal of Food Science and Technology</i>, 2010;45(4):807-812).

For additional information, contact X.Y. Mao, China Agricultural University, Chinese Minist Educ, Key Lab Funct Dairy, Coll Food Sci & Nutr Eng, Beijing 100083, People's Republic of China.

From the April 26, 2010, Prepared Foods E-dition