Antibacterial activity of hydrolysate protein from Etawa goat milk hydrolysed by crude extract bromelain

Abstract

A study has been conducted on the potential of hydrolysate protein from Etawa goat milk protein which is hydrolysed by bromelain crude extract enzyme. The bromelain enzyme is extracted from the leaf of honey pineapple fruit. The research steps are: bromelain extraction, bromelain characterization, preparation of goat milk protein, hydrolysis of goat milk protein with bromelain and antibacterial activity test of protein hydrolysate fractions against Escherichia coli and Staphylococcus aureus bacteria by diffusion method. The bromelain crude extract enzyme has the following characteristics: optimum pH is 6, optimum temperature is 55 °C, activity is inhibited by EDTA metal chelating compound and Cu2+ and Zn2+ metal ions, whereas Ca2+ and Mg2+ metal ions increase activity. Inhibition of activity by EDTA shows that the bromelain enzyme is a metalloenzyme. Ca2+ and Mg2+ metal ions act as activators, while Cu2+ and Zn2+ metal ions are inhibitors. Protein preparation of goat milk produces two types of protein namely casein and whey. The result of hydrolysis of both protein types with characterized bromelain enzymes are hydrolysate proteins, which are then tested for their antibacterial activity. The results showed that the hydrolysate protein was able to inhibit the growth of Escherichia coli and Staphylococcus aureus bacteria.