Table 4.

ACE-inhibitory activities in vitro of five modified casein hydrolysates subjected to Neutrase- catalyzed plastein reaction

Samplea	Decreased amount of free amino groups (μmol⋅g−1 peptides)	ICb50 (μg⋅mL−1)
CH	0	40.4 ± 2.0 A
MCH 1	89.8	31.1 ± 1.5 B
MCH 2	102.1	22.0 ± 0.5 C
MCH 3	137.1	18.2 ± 0.7 D
MCH 4	176.4	16.0 ± 1.0 DE
MCH 5	210.0	14.7 ± 0.2 E

^aCH, casein hydrolysate; MCH 1–5, modified casein hydrolysate prepared with reaction time of 2, 3, 4, 5 and 6.3 h, respectively

^bThe values represent the solution concentration of the sample needed to inhibit ACE by 50% under assaying conditions. Different capital letters after the values indicate that one-way ANOVA of the means is significantly different (P <0.05)