Effect of Low-Frequency Ultrasonic-Assisted Enzymolysis on the Physicochemical and Antioxidant Properties of Corn Protein Hydrolysates

Table 1

Factors and levels of the orthogonal design L₉ (3⁴) of ultrasound pretreatment process and experimental results for corn protein hydrolysis (, mean ± SD); number 10 represents traditional hydrolysis.

Test number	Factors (levels)				Experimental results
	(); Ultrasound powers (W)	(); Ultrasound on/off time	(); Ultrasound temperature (°C)	(); Ultrasound time (min)	DPPH IC50 (mg/ml)	Degree hydrolysis (%)	Conversion rate of protein (%)
1	45	2/2	30	15	3.125 ± 0.078	19.528 ± 0.402	51.451 ± 3.065
2	45	3/2	40	20	2.495 ± 0.092	20.720 ± 1.065	54.288 ± 2.539
3	45	4/2	50	25	2.643 ± 0.118	21.497 ± 2.102	56.615 ± 2.457
4	52	2/2	40	25	2.322 ± 0.045	22.266 ± 1.402	56.304 ± 4.258
5	52	3/2	50	15	2.647 ± 0.035	23.713 ± 0.645	58.067 ± 4.831
6	52	4/2	30	20	2.581 ± 0.184	20.755 ± 0.056	56.985 ± 3.112
7	65	2/2	50	20	2.035 ± 0.113	24.704 ± 0.495	62.85 ± 0.491
8	65	3/2	30	25	2.289 ± 0.045	21.640 ± 0.112	56.768 ± 0.328
9	65	4/2	40	15	2.354 ± 0.168	23.502 ± 0.682	60.288 ± 2.539
10	—	—	—	—	2.402 ± 0.098	19.275 ± 0.608	51.581 ± 2.654