May 12/Xian, China/Food Weekly Focus -- According to recent research from Xian, People's Republic of China, "Six different proteases (Flavourzyme(A), Neutrase(A), Protamex(A), Alcalase(A) 2.4L, Proleather(A) FG-F, and papain) were employed to hydrolyze apricot kernel protein (AKP). Alcalase(A) is an inexpensive and non-specific protease that has been shown to be useful for the generation of bioactive peptides from AKP."

"Alcalase(A) 2.4L was selected for further study on enzymatic preparation of ACE inhibitory peptide from AKP. After 60 minutes of hydrolysis, the highest ACE inhibition was 82 +/- A 0.14%. Results of molecular weight distribution revealed that most of ACE inhibition activity was probably attributed to low-molecular weight peptide fraction ranging from 200-900Da. Ultrafiltration on membranes with several molecular weight cutoffs (MWCFs) demonstrated that most of the ACE inhibitory activity was due to peptides with a less than 1,000Da molecular weight: the IC50 value of the 1-kDa ultrafiltrate was 0.15 +/- A 0.007mg mL(-1), while it was 0.378 +/- A 0.015mg mL(-1) before ultrafiltration. Additionally, further separation and purification of the ACE inhibitory peptides were carried out using gel filtration and C-18 RP-HPLC," wrote Z.B. Zhu and colleagues, Shaanxi Normal University.

The researchers concluded, "The result of research can be used to optimize AKP enzymatic hydrolysis for producing ACE inhibitory peptides which could be used for food industry and nutraceuticals."

Zhu and colleagues published their study in European Food Research and Technology ("Production and Characterization of Angiotensin Converting Enzyme (ACE) Inhibitory Peptides from Apricot (Prunus Armeniaca L.) Kernel Protein Hydrolysate." European Food Research and Technology, 2010;231(1):13-19).

For additional information, contact N.X. Qiu, Shaanxi Normal University, College Life Science, Xian 710062, People's Republic of China.

From the June 7, 2010, Prepared Foods E-dition