Intensification of Extraction of Antioxidant Compounds from Moringa Oleifera Leaves Using Ultrasound-Assisted Approach: BBD-RSM Design

Figures & data

Figure 1. Design of experiment for extraction yield and total phenolic/flavonoid

Table 1. Independent parameters and range of variables used in this study

Input parameters	Xi	Coded variables
		−1	0	+1
Extraction time (min)	X1	5	15	25
solvent ratio (%)	X2	60	70	80
Ultrasonic amplitude (%)	X3	20	60	100

Table 2. ANOVA results for extraction yield

Source	Sum of Squares	df	Mean Square	F-value	P-value
Model	0.047	12	4.313E-3	7.63	.0181
A: Extraction time	0.015	1	0.015	27.22	.0034
B:Solvent ratio	3.200E-3	1	3.200E-3	5.66	.0632
C: US amplitude	5.184E-3	1	5.184E-3	9.18	.0291
AB	0.013	1	0.013	22.20	.0053
AC	2.500E-5	1	2.500E-5	0.044	.8417
BC	5.476E-3	1	5.476E-3	9.69	.0265
A^2	7.504E-4	1	7.504E-4	1.33	.3012
B^2	3.035E-3	1	3.035E-3	5.37	.0682
C^2	7.504E-4	1	7.504E-4	1.33	.3012
A^2C	2.245E-3	1	2.245E-3	3.97	.1028
AC^2	4.900E-3	1	4.900E-3	8.67	.0321
Lack of Fit	2.312E-3	1	2.312E-3	18.03	.0132
Pure Error	5.128E-4	4	1.282E-4
Total	0.0475	16

Figure 2. 3-D and 2-D plots of yield against extraction time and solvent ratio

Figure 3. 3-D/2-D plots of yield against of ultrasonic amplitude and extraction time

Table 3. ANOVA results for total phenolic compounds

Source	Sum of Squares	df	Mean Square	F-value	P-value
Model	287.15	11	26.10	5.84	.0321
A-time	70.39	1	70.39	15.75	.0107
B-solvent	0.81	1	0.81	0.18	.6887
C-amplitude	12.43	1	12.43	2.78	.1563
AB	56.10	1	56.10	12.55	.0165
AC	12.43	1	12.43	2.78	.1563
BC	6.76	1	6.76	1.51	.2735
A^2	97.61	1	97.61	21.84	.0055
B^2	1.99	1	1.99	0.44	.5346
C^2	21.04	1	21.04	4.71	.0822
AC^2	21.93	1	21.93	4.91	.0776
C B^2	22.01	1	22.01	4.92	.0772
Pure Error	0.2391	4	0.0598
Lack of Fit	22.11	1	22.11	374.64	.001
Total	309.57	16

Figure 4. 3D/2D plots of total phenolics content against solvent ratio and extraction time

Figure 5. 3D/2D plots of total phenolic against of US amplitude and solvent ratio

Table 4. ANOVA results for the developed model based on RSM

Source	Sum of Squares	df	Mean Square	F-value	P-value
Model	2962.89	10	296.29	8.19	.009
A-time	210.25	1	210.25	5.81	.0525
B-solvent	1140.03	1	1140.03	31.51	.0014
C-amplitude	98	1	98	2.71	.1509
AB	400	1	400	11.05	.0159
AC	95.06	1	95.06	2.63	.1562
BC	18.06	1	18.06	0.50	.5064
A^2	108.44	1	108.44	3.00	.1341
B^2	747.60	1	747.60	20.66	.0039
C^2	97.01	1	97.01	2.68	.1527
Pure Error	53.20	4	13.30
Lack of Fit	163.91	2	81.95	6.16	.06
Total	3180.00	16

Figure 6. 3D/2D plots of total flavonoids content against of solvent ratio and extraction time

Figure 7. 3D/2D plots of total flavonoid against solvent ratio and US amplitude

Table 5. Constraints for multi-objective optimization

Variables	purpose	Maximum limit		Minimum limit	Maximum weight	Minimum weight	Significance
A: Extraction time	-	25	5.0		1.0	1.0	3.0
B: Solvent ratio	-	80	60		1.0	1.0	3.0
C: US amplitude	-	100	20		1.0	1.0	3.0
Extraction yield	Maximize	0.985	0.749		1.0	1.0	3.0
Flavonoid	Maximize	36.29	20.39		1.0	1.0	3.0
Phenolics	Maximize	50.62	29.45		1.0	1.0	3.0