Ultrasonic-Assisted Extraction of Natural Yellow Pigment from Physalis pubescens L. and Its Antioxidant Activities

Table 2

Response surface design.

	Ultrasonic power (%)	Ultrasonic time (min)	Ultrasonic interval time
	A	B	C
1	35	18	15 s (on 15 s, off 15 s)
0	30	15	10 s (on 10 s, off 10 s)
−1	25	12	5 s (on 5 s, off 5 s)