Bioactivities of Peptides from Sumbawa Horse Milk Hydrolyzed by Bromelain

Abstract

Sumbawa horse milk is used traditionally to cure several diseases such as hypertension, diabetes, asthma and hypercholesterolemia. However, research on enzymatic hydrolysis of Sumbawa horse milk and exploration of their potential bioactive peptide have not yet been reported. The aim of this study was to evaluate the bioactivities of the peptides from Sumbawa horse milk hydrolyzed by bromelain. Sumbawa horse milk was hydrolyzed by bromelain extract at various pH and time of hydrolysis and fractionated by membrane molecular weight cut off (MWCO) 10 KDa. The peptic hydrolysates and fractions obtained were then assayed for antibacterial and antioxidant activities. The results showed that peptide from Sumbawa horse milk hydrolyzed at pH 6 for 60 min has the highest antibacterial and antioxidant activities. The peptide inhibited Escherichia coli, Salmonella Typhimurium and Listeria monocytogenes, and scavenged 2,2’ -azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical up to 100 % per 0.1 mg protein/mL. Fractionation using 10 KDa membrane showed that peptide < 10 kDa has higher antibacterial and antioxidant activities compared to both before fractionation and fraction > 10 kDa. Hemolytic assays using hydrolysate and its fractions did not cause lysis of red blood cells, indicating that they are safe for consumption.