Functional properties and bitterness of sodium caseinate hydrolysates prepared with a Bacillus proteinase

The functional and physicochemical characteristics, and bitterness were evaluated on sodium caseinate hydrolysates generated with a commercial Bacillus proteinase complex. At low degrees of hydrolysis (0.5 and 1.0% DH) the hydrolysates compared to the unhydrolyzed substrate had increased emulsion activity at pH 2 and 4. However, higher DH resulted in lower emulsion activities. At pH 8 and 10, the low DH hydrolysates displayed increased foam expansion and decreased foam drainage compared to the starting substrate. The Bacillus proteinase hydrolysetes at higher DH had similar bitterness values to tryptic hydrolyeates at equivalent DH. However, the Bacillus hydrolysate at 0.5% DH was less bitter (P<0.05) than the tryptic hydrolysate at the same DH.