Influence of different processing conditions on phenolic profile, antioxidant, and anti-cholinesterase activities of spinach, and mustard leaves

Figures & data

Table 1. Effects of cooking techniques on the phenolic composition (mg/100 g) of spinach leaves.

Peak	Rt.(min)	Identity	λmax (nm)	Raw	Boiled	Fried	Microwaved	Freezing
1	1	p-Hydroxybenzoic acid	256	249.4 ± 1.5^a	176.6 ± 1.2^b	1282.5 ± 6.0^c	4076.1 ± 3.3^d	156.1 ± 1.5^e
2	14.7	Isorhamnetin-3-(caffeoyl-diglucoside)-7-rhamnoside	333, 270	68.0 ± 0.3^a	7.3 ± 0.1^b	2.6 ± 0.0^c	1127.4 ± 2.0^d	14.7 ± 0.2^e
3	15.4	Apigenin	338, 271	90.8 ± 0.3^a	39.9 ± 0.3^b	143.6 ± 3.2^c	1634.8 ± 1.6^d	22.8 ± 0.2^e
4	17.1	Kaempferol	333, 268	16.0 ± 0.2^a	63.6 ± 0.5^b	13.9 ± 0.1^a	1376.7 ± 1.7^d	30.2 ± 0.5^e
5	17.9	Kaempferol-3-coumaroyl sinapoyl diglucoside	338, 268	20.3 ± 0.3^a	14.4 ± 0.1^b	70.8 ± 0.3^c	429.1 ± 1.4^d	67.7 ± 0.2^e
6	19.5	Apigenin-2-pentoxide-8-hexoside	338, 270	160.1 ± 0.4^a	44.9 ± 0.1^b	152.1 ± 1.3^c	1840.7 ± 1.3^d	22.5 ± 0.3^e
7	21.6	Quercetin-3-(sinapoyldiglucoside)-7-glucoside	338, 268, 247	146.2 ± 0.5^a	67.1 ± 0.7^b	42.5 ± 1.4^c	508.0 ± 0.4^d	0.0 ± 0.0^e
8	24.6	Diometin-7-rutionside	342, 270	10.5 ± 0.2^a	7.6 ± 0.1^b	32.7 ± 0.8^c	135.5 ± 2.3^d	0.0 ± 0.0^e
9	26.6	Quercetin-3-(p-coumaroyl-diglucoside)-7-glucoside	316, 234	9.1 ± 0.1^a	9.1 ± 0.1^a	212.5 ± 3.1^c	10.1 ± 0.2^d	5.5 ± 0.1^e
10	30.2	Kaemferol-3-(p-coumaroyl-diglucoside)-7-glucoside	315, 268, 233	108.1 ± 0.2^a	81.2 ± 0.7^b	247.0 ± 2.4^c	36.3 ± 3.7^d	100.0 ± 0.8^e
11	31.9	Quercetin-3-sinapolysophoroside-7-glucoside	328, 272	87.6 ± 0.7^a	55.1 ± 0.2^b	95.1 ± 3.2^c	44.6 ± 0.3^d	78.8 ± 0.2^e
12	32.6	Quercetin-3,4-diglucoside-3-(6-feruloy-glucoside)	326, 272	91.9 ± 0.4^a	294.0 ± 0.7^b	67.9 ± 3.4^c	13.5 ± 0.6^d	32.4 ± 0.3^e

Different letters (a-e) represent significant differences with respect to the Raw sample using Dunnett’s multiple comparisons test at a < 0.05.

Table 2. Effects of cooking techniques on the phenolic composition (mg/100 g) of mustard leaves.

Peak	Rt.(min)	Identity	λmax (nm)	Raw	Boiled	Fried	Microwaved	Freezing
1	1	p-Hydroxybenzoic acid	256	325.8 ± 1.0^a	1471.1 ± 24.1^b	6155.1 ± 6.5^c	3899.1 ± 1.8^d	604.5 ± 1.2^e
2	2.1	Caffeic acid	323	0.0^a	2.0 ± 0.0^a	226.7 ± 2.6^c	150.1 ± 0.3^d	7.0 ± 0.1^e
3	3.6	Caffeoylferuloylquinic acid	324, 236	0.0^a	0.0^a	0.0^a	235.0 ± 0.4^b	0.0^a
4	5.1	Apigenin-7-glucoside	365, 267	0.0^a	0.0^a	0.0^a	460.0 ± 3.7^d	12.6 ± 0.2^e
5	6.1	Quercetin −3,7-diglucoside	332, 266	13.3 ± 0.4^a	0.0 ± 0.5^b	0.0^c	1217.2 ± 4.3^d	0.0^e
6	6.9	Kaempferol-3-sinapoylsophotrioside	336, 268	0.0^a	0.0^a	0.0^a	408.9 ± 5.1^d	0.0^a
7	7.7	Kaemferol-3-p-coumaroylsinapoyldiglucoside	333, 268	0.0^a	0.0^a	0.0^a	833.8 ± 7.4^d	6.1 ± 0.1^e
8	9.6	Kaempferol-feruloylglucoside diglucoside	332, 268	5.3 ± 0.3^a	15.0 ± 0.5^b	34.8 ± 0.5^c	587.1 ± 8.2^d	91.4 ± 0.9^e
9	15.2	Isorhamnetin-3-caffeoyl-7-rhamnoside	337, 254	20.4 ± 0.3^a	0.0 ± 0.3^b	0.0^c	320.8 ± 6.0^d	0.0^e
10	16.1	Kaempferol 3-(caffeoyldiglucoside)-7-rhamnoside	330, 244	11.0 ± 0.3^a	9.1 ± 0.1^a	6.2 ± 0.1^a	377.2 ± 8.8^d	0.0^e
11	21.2	Luteolin-3-glucoside	350, 247	0.0^a	0.0^a	0.0^a	134.9 ± 4.9^d	0.0^a
12	23	Isorhamnetin-3,7-diglucoside	352, 254	125.5 ± 0.6^a	16.1 ± 0.1^b	233.6 ± 1.8^c	18.0 ± 0.1^d	0.0^e
13	27.3	Quercetin-3-(sinapoyldiglucoside)-7-glucoside	340, 248	589.1 ± 2.3^a	38.0 ± 0.4^b	23.5 ± 0.1^c	68.1 ± 1.2^d	0.0^e

Different letters (a-e) represent significant differences with respect to the Raw sample using Dunnett’s multiple comparisons test at a < 0.05.

Figure 1. Effects of cooking techniques on nitric-oxide inhibition activity. *** = 0.002, **** = < 0.0001, versus raw samples.

Figure 2. Effects of cooking techniques on superoxide anion inhibition activity. * = 0.01, **** = < 0.0001, versus raw samples.

Figure 3. Effects of cooking techniques on anti-choline esterase activity. **** = < 0.0001, versus raw samples.

Figure 4. The biplot of principal component analysis (PCA) of phenolic compounds of spinach leaves represents the loadings (cooking treatments) and scores (phenolic compounds) in the dimensional spaces determined by the principal components.

Figure 5. The biplot of principal component analysis (PCA) of phenolic compounds of mustard leaves represents the loadings (cooking treatments) and scores (phenolic compounds) in the dimensional spaces determined by the principal components.

Data availability statement

The manuscript contains all the data created during the study.