POD, CAT and SOD enzyme activity of corn kernels as affected by low plasma pretreatment

Figures & data

Table 1. Levels of response surface design.

Factor	Level
	−1	0	+1
Plasma pretreatment power X1 (W)	300	400	500
Plasma pretreatment time X2 (s)	30	40	50
Air flow rate X3 (mL·min^−1)	100	150	200

Table 2. Response experimental results of enzyme activity.

Factor				Response
Exp	X1	X2	X3	Y1		Y2		Y3
	Plasma pretreatment power (W)	Plasma pretreatment time (s)	Air flow rate (mL·min^−1)	POD enzyme activity(U·g^−1)		CAT enzyme activity(U·g^−1)		SOD enzyme activity(U·g^−1)
				Actual	Predicted	Actual	Predicted	Actual	Predicted
1	300	50	150	279.300	275.900	42.926	43.660	351.029	354.250
2	400	40	150	293.700	293.320	63.983	66.570	410.818	411.050
3	400	50	200	259.200	258.390	42.520	40.850	417.128	415.590
4	500	50	150	289.100	291.180	41.788	41.710	332.847	331.180
5	500	30	150	310.500	313.900	51.382	50.650	397.234	394.010
6	400	30	100	276.100	276.910	60.243	61.910	439.589	441.130
7	400	30	200	273.300	271.160	59.430	58.410	452.102	452.120
8	300	40	100	247.200	248.460	59.105	57.360	375.201	371.990
9	400	50	100	263.700	265.840	44.471	45.490	414.347	414.330
10	400	40	150	297.400	293.320	69.430	66.570	406.673	411.050
11	400	40	150	293.800	293.320	66.585	66.570	415.237	411.050
12	400	40	150	289.800	293.320	63.008	66.570	411.704	411.050
13	300	40	200	239.600	243.810	51.300	52.240	386.218	384.530
14	500	40	100	280.700	276.490	47.235	46.300	384.827	386.510
15	500	40	200	269.200	267.940	41.544	43.290	383.009	386.220
16	400	40	150	291.900	293.320	69.837	66.570	410.818	331.180
17	300	30	150	279.100	277.020	68.617	68.700	353.061	354.730

Table 3. Regression models and ANOVA results.

Response	Regression models	R^2	Adj R^2	Pred R^2	RMSE
POD enzyme activity	Y1 = 293.32 + 13.04X1-5.96X2-3.30X3-5.40X1X2 -0.97X1X3-0.42X2X3-6.36X1^2 + 2.54X2^2-27.78X3^2	0.9795	0.9531	0.7547	2.5701
CAT enzyme activity	Y2 = 66.57–5.00X1-8.50X2-2.03X3 + 4.02X1X2 +0.53X1X3-0.28X2X3-8.63X1^2-6.7X2^2-8.14X3^2	0.9697	0.9307	0.8203	1.7962
SOD enzyme activity	Y3 = 411.05 + 4.05X1-15.83X2 + 3.06X3-15.59X1X2 -3.21X1X3-2.43X2X3-50.49X1^2-2.01X2^2 + 21.76X3^2	0.9940	0.9862	0.9377	2.3587

Figure 1. Predicted values versus actual values of POD enzyme activity.

Figure 2. Response surface of the independent variables on POD enzyme activity.

Figure 3. Predicted values versus actual values of CAT enzyme activity.

Figure 4. Response surface of the independent variables on CAT enzyme activity.

Figure 5. Predicted values versus actual values of SOD enzyme activity.

Figure 6. Response surface of the independent variables on SOD enzyme activity.

Table 4. Optimal combination verification test of POD enzyme activity.

Factor						Response (Y1)
Exp	Plasma pretreatment power (W)		Plasma pretreatment time (s)	Air flow rate (mL·min^−1)		POD enzyme activity (U·g^−1)
1	500		30	150		311.575
2	500		30	150		312.389
3	500		30	150		310.506
Average value						311.157
Predicted value						313.900
1	350	30			150	69.943
2	350	30			150	69.841
3	350	30			150	70.655
Average value						70.146
Predicted value						71.061

Table 5. Optimal combination verification test of CAT enzyme activity.

Factor				Response (Y2)
Exp	Plasma pretreatment power (W)	Plasma pretreatment time (s)	Air flow rate (mL·min^−1)	CAT enzyme activity (U·g^−1)
1	350	30	150	69.943
2	350	30	150	69.841
3	350	30	150	70.655
Average value				70.146
Predicted value				71.061

Table 6. Optimal combination verification test of SOD enzyme activity.

Factor				Response (Y3)
Exp	Plasma pretreatment power (W)	Plasma pretreatment time (s)	Air flow rate (mL·min^−1)	SOD enzyme activity (U·g^−1)
1	400	30	200	450.711
2	400	30	200	451.205
3	400	30	200	453.108
Average value				451.675
Predicted value				452.172