Phenolic Profile and Antioxidant Activity of Date-Pits of Seven Algerian Date Palm Fruit Varieties

Figures & data

Table 1  Total phenolic content (TPC), antiradical activity (AA), and hydroxyl scavenging activity (HSA) of the ethyl acetate (EA) and the methanolic (M) extracts of the different date pit varieties.*

	TPC (mg CAE/100 g FW)		AA		HSA
Date pit variety	EA	M	EA	M	EA	M
Tazizaout	26.3 ± 6.6	26.0 ± 4.0	0.11 ± 0.03	0.33 ± 0.02	0.61 ± 0.14	3.8 ± 0.3
Ougherouss	19.3 ± 0.3	31.1 ± 6.0	0.07 ± 0.01	0.30 ± 0.03	0.43 ± 0.01	3.2 ± 0.3
Deglet-Nour	48.2 ± 1.3	37.0 ± 5.3	0.25 ± 0.02	0.31 ± 0.01	1.5 ± 0.2	3.4 ± 1.0
Tantbouchte	49.1 ± 3.3	28.0 ± 0.7	0.30 ± 0.04	0.16 ± 0.01	1.6 ± 0.7	1.3 ± 0.6
Tafiziouine	19.4 ± 3.3	32.1 ± 1.7	0.10 ± 0.01	0.25 ± 0.04	0.59 ± 0.03	2.8 ± 1.1
Tazerzait	39.8 ± 3.3	29.0 ± 4.0	0.18 ± 0.02	0.22 ± 0.02	1.1 ± 0.2	2.2 ± 0.3
Akerbouche	33.5 ± 6.0	33.3 ± 1.3	0.15 ± 0.02	0.32 ± 0.04	0.93 ± 0.16	3.5 ± 0.3
*All results are means ± sd (n = 3).

Table 2  LC-DAD-MS of the phenolic compounds of the different date pit fruit varieties extracts under the ESI-ionization mode

R.T. (min)	[M - H]^− (m/z)	Fragment ion (m/z)	λ-max (nm)	Identification	Occurrence
11.70	—	290.7, 165.2, 262.7	240, 278	Catechin or epi catechin derivative	Akerbouche, Tazizaout, Deglet-Nour, Ougherouss, Tazerzait, Tantbouchte, and Tafiziouine
13.96	402.6	174.9	240, 278	Proanthocyanidin	Tazizaout
14.23	577.4	272.5, 290.1, 371.6	232, 278	Oligomer of catechin	Akerbouche, Tazizaout, Deglet-Nour, Ougherouss, Tazerzait, Tantbouchte, and Tafiziouine
15.68	371.5	174.5	248, 328	Cinnamic acid derivative	Akerbouche, Deglet-Nour, Ougherouss, and Tantbouchte
16.38	335.8	—	286	Naringenin	Tafiziouine
16.63	700.8	425.0, 399.4, 224.9	240, 286	Derivative of flavanone	Tantbouchte
18.79	378.1	349.1, 263.7	276, 320	Flavanone	Tazizaout
23.71	775.4	222.9, 316.6, 460.1	268	Unknown	Deglet-Nour, Ougherouss, and Tazerzait
24.58	316.7	—	258, 298	Unknown	Tantbouchte
24.87	318.3	141.2, 289.7, 153.8	320	Caffeoyl derivative	Tazerzait
27.99	375.2	227.1, 140.7	240, 278	Unknown.	Tazizaout
31.60	357.2	126.8, 248.9	240, 276	Proanthocyanidin	Tazizaout
38.87	351.5	—	240, 274	Proanthocyanidin	Tazizaout

Table 3  LC-DAD-MS of the phenolic compounds of the different date pit fruit varieties extracts under the ESI⁺ ionization mode

R.T. (min)	[M + H]^+ (m/z)	Fragment ion (m/z)	λ-max (nm)	Identification	Occurrence
12.03	—	224.8	240, 286, 318	Sinapic acid derivative	Akerbouche, Deglet-Nour, Ougherouss, Tantbouchte, and Tafiziouine
12.30	—	224.8	242, 320	Sinapic acid derivative	Akerbouche, Deglet-Nour, Ougherouss, Tantbouchte, and Tafiziouine
15.73	449.3	151.1	258, 268, 338	Dihydrocinnamic acid derivative	Akerbouche, Tazizaout, Deglet-Nour, Ougherouss, Tazerzait, and Tafiziouine
19.91	331.0	164.9	252	Coumaric acid derivative	Akerbouche, Deglet-Nour, Ougherouss, Tazerzait, and Tafiziouine
23.97	579.3	163, 176, 270.7, 427.3	240, 322, 398	Glycosilated esterified aurone (characterized as caffeoyl rhamnoside of 4,4′,6-trihydroxy aurone)	Tazizaout
24.40	579.3	271.1, 300.8	238, 268, 328	Glycosilated esterified apigenin (characterized as caffeoyl rhamnoside of apigenin)	Tazizaout
30.61	234.9	−	246, 290	Unknown	Tazizaout

Figure 1 UV-Vis absorption spectrum, mass spectrum, and suggestive structure of an esterified apigenin glycoside. (Color figure available online.)

Figure 2 UV-Vis absorption spectrum, mass spectrum, and tentative structure of an aurone. (Color figure available online.)