Protease from Aspergillus oryzae: Biochemical Characterization and Application as a Potential Biocatalyst for Production of Protein Hydrolysates with Antioxidant Activities

Table 5

Antioxidant activities from the DPPH and ORAC assays and linearity ranges for the ORAC assay (net AUC versus concentration) performed on the control and hydrolysate samples produced by the protease from A. oryzae LBA 01.

Protein source	Protease (U·mL^−1)	DPPH		ORAC
		Trolox EQ mol·g^−1	Radical scavenging (%)	Trolox EQ mol·g^−1	Sample concentration range (mg·mL^−1)	Slope	Intercept
SPI	Control	0.88 ± 0.14^a	30.77 ± 1.53^a	186.11 ± 48.45^a	0.25–1.00	0.11	−0.07	0.94
	20	4.61 ± 0.12^b	69.18 ± 1.54^b	574.35 ± 46.15^b	0.25–1.00	0.04	−0.08	0.99
	40	4.25 ± 0.08^c	66.43 ± 0.95^c	645.20 ± 104.78^b	0.30–1.20	0.04	−0.22	0.99
WHEY	Control	2.44 ± 0.11^a	40.67 ± 0.28^a	18.51 ± 7.20^a	1.15–4.60	0.61	0.25	0.99
	20	4.92 ± 0.09^b	73.62 ± 0.07^b	132.61 ± 6.43^b	1.00–4.00	0.14	−0.15	0.99
	40	4.53 ± 0.01^c	69.53 ± 0.07^c	172.11 ± 17.32^c	1.20–4.80	0.13	−0.59	0.99
EGG	Control	4.42 ± 0.11^a	63.03 ± 1.56^a	47.18 ± 7.45^a	1.05–4.20	0.34	−0.04	0.99
	20	1.89 ± 0.30^b	45.93 ± 3.17^b	423.43 ± 56.80^b	0.50–2.00	0.06	−0.32	0.99
	40	Undetected	33.99 ± 1.41^c	469.65 ± 47.80^b	0.50–2.00	0.05	−0.24	0.99

 ^a,b,cResults are presented as the mean () ± SD, and those with different letters are significantly different, with . Comparisons were made between the values of each protein source (not between different protein sources). The DPPH assay was carried out using sample concentration of 5 mg·mL⁻¹.