Table 3.

Antioxidant activity and ACE inhibition activity of peptides obtained by enzymatic hydrolysis of food proteins pre-treated by combined ultrasound (US) and microwave (MW).

Food protein source [reference]	US-MW pretreatment	Antioxidant capacitya	ACE inhibition activityc
		DPPHa	ABTSa	FRAPa
Milk protein concentrates[72] Chinese sturgeon (Acipenser sinensis) protein[75] Golden threadfin bream (Nemipterus virgatus) myofibrillar protein[73]	US for 10 min (20 kHz, power not reported) and MW for 10 min at 800 WUS 40 kHz-50 W and MW power 50 W at 55 °C for 8 minUS100-MW100 b Pepsin Alcalase US200–MW100 b Pepsin Alcalase US300–MW100 b Pepsin Alcalase US400–MW100 b Pepsin Alcalase	0.77 (0.62) 3.01 ± 0.04 (3.78 ± 0.04) 5.1 ± 0.3 4.9 ± 0.6 4.5 ± 0.3 2.8 ± 0.1 4.1 ± 0.8 2.3 ± 0.2 4.7 ± 0.8 4.1 ± 0.8	1.85 ± 0.03 (2.69 ± 0.04)	0.32 (0.30)	6.7 ± 0.7 6.2 ± 0.5 4.9 ± 0.3 5.2 ± 0.6 4.6 ± 0.4 3.5 ± 0.1 7.5 ± 0.5 5.3 ± 0.4
Sweet potato protein [74]	US 40 kHz-MW10-800 at 50 °C for 180 min ALC FLA ALC + FLA	OHd 67.11 ± 0.38 (42.69 ± 1.27) 57.04 ± 0.82 (37.10 ± 0.6) 60.06 ± 0.09 (52.18 ± 0.09)	ORAC (µg TE/mL) e 110.32 ± 1.42 (102.59 ± 5.24) 121.80 ± 12.34 (89.97 ± 4.31) 106.32 ± 3.59 (96.74 ± 3.36)

^aIC₅₀ in mg/mL (control);

^bControl hydrolysates by pepsin = 10.60 ± 0.6 and alcalase = 10.1 ± 0.4;

^cControl 16.9 ± 0.3;

^d% of hydroxyl radical scavenging (control) and

^eOxyradical Antioxidant Capacity and TE is Trolox Equivalent.