Study on the use of various concentration of acetic acid and different precipitation duration on casein characteristics

Abstract

Casein can be precipitated from skim milk using acetic acid. The effectiveness of the casein formed during precipitation was determined by precipitation duration. The purpose of this study was to determine the characteristics of casein (water content, the amount of isolated casein and/or yield and the amount of dissolved protein) with various concentrations of acetic acid and precipitation duration. This study used a completely randomized design (CRD) factorial pattern with three replications. Factor A was the various concentration of acetic acid (6%, 9%, and 12%) and factor B was the different precipitation duration (30 minutes, 60 minutes, and 90 minutes). The parameters measured are casein yield, water content and dissolved protein. The results showed that the concentration of acetic acid and the precipitation duration significantly affected the characteristics of casein yield, water content and dissolved protein. The casein yield values ranged from 20.16 to 26.49%, the water content ranged from 71.55 to 76.63% and dissolved protein ranged from 1.17 to 1.98%. The use of 6% acetic acid and the 60-minute precipitation duration produced casein with low water content and a less amount of dissolved protein. The casein yield produced was in line with the casein water content.