Characterization of phenolics and antioxidant abilities of red navel orange “Cara Cara” harvested from five regions of China

Figures & data

Table 1. Phenolic compounds identified by UPLC-Q-TOF-ESI-MSⁿ in red-fleshed navel orange “Cara Cara”.

Peak^a	Retention time (min)	Phenolics	λmax^b (nm)	[M-H]^–(m/z)	Fragment ions (m/z)	Identification
1	5.13	Unknown 1	248.8, 326.1	443	385, 303, 203, 111
2	5.23	Feruloyl-galactaric acid	241.7, 319.5	385	209, 191	UV, MS
3	5.55	Luteolin-6,8-di-C-glucoside	252.3, 327.3	609	519, 489, 399, 369, 293	UV, MS
4	6.02	Isorhamnetin-3-O-rutinoside-7-O-glucoside	271.3, 337.9	785	623, 315	UV, MS
5	6.34	Mixture of Ferulic acid glucoside and sinapic acid glucoside	245.2, 328.5	385, 355	223, 193, 175, 160	UV, MS
6	6.81	Apigenin-6,8-di-C-glucoside	271, 335	593	503, 473, 383, 353, 325	UV, MS
7	7.07	Flavanone-O-rutinoside 1	284.4	625	317	UV, MS
8	7.51	Narirutin-4ʹ-O-glucoside	227.5, 285.5	741	433, 271	UV, MS
9	8.02	Quercetin-3-O-rutinoside-7-O- Glucoside	273.2, 327.3	771	463, 301	UV, MS
10	8.97	Apigenin-8-C-glucoside-2ʹ’-O- xyloside	272.5, 329.7	563	443, 413, 293	UV, MS
11	9.45	Eriodictyol-7-O-rutinoside	284.4	595	475, 287	UV, MS
12	9.73	Genistein-7-O-xylosylglucoside malonylated	284.4	649	605, 433, 209	UV, MS
13	10.05	Phloretin-3ʹ5’-di-C-glucoside	254.7, 323.7	597	577, 561, 489, 477, 387, 357	UV, MS
14	10.78	Hesperetin derivative	283.2	915	843, 771, 669, 505, 463, 301	UV, MS
15	11.13	Flavanone-O-rutinoside 2	283.2	623	315	UV, MS
16	11.41	Narirutin (naringenin-7-O-rutinoside)	228.7, 283.2	579	271	Rt, UV, MS
17	12.37	Naringenin-7-O-xylosylglucoside malonylated	327.3	651	565, 403, 271	MS
18	12.71	Hesperidin (hesperetin-7-O-rutinoside)	228.7, 284.4	609	301	Rt, UV, MS
19	13.45	1,2-diferuloylgentiobiose	326.1	693		MS
20	16.44	Didymin (isosakuranetin-7-O-rutinoside)	283.2	593	285	Rt, UV, MS

^apeaks numbered according to Figure 1(a).

^bλmax (nm) in linear gradient of H₂O/acetonitrile, detected by diode array detector.

Table 1. HPLC chromatograms of phenolic compounds extracted from Fujian “Cara Cara” as recorded at 280 nm and 330 nm, and the standard mixture of narirutin, hesperidin, and didymin recorded at 280 nm (panel A); phenolic extracts and a mixture standard of narirutin and hesperidin were alkali hydrolyzed and recorded at 280 nm, with a standard mixture of caffeic acid, p-coumaric acid, ferulic acid narirutin, hesperidin, and didymin also recorded at 280 nm (panel B).

Table 2. Contents of individual phenolic compounds (mg/100 g DW) of five “Cara Cara” pulps ^a.

Compounds	Hubei	Fujian	Chongqing	Jiangxi	Hunan
Uknown	20.3 ± 0.2^ab	19 ± 2^ab	25 ± 3^a	17.3 ± 0.4^b	20 ± 2^ab
Feruloyl-galactaric acid	101 ± 5^a	104 ± 9^a	93 ± 10^a	81 ± 5^a	77 ± 5^a
Luteolin-6,8-di-C-glucoside	30 ± 5^a	25 ± 2^a	23 ± 4^a	27 ± 2^a	32 ± 4^a
Isorhamnetin-3-O-rutinoside-7-O-glucoside	19 ± 2^a	15 ± 2^a	ud	16 ± 2^a	ud
Mixture of Ferulic acid glucoside and sinapic acid glucoside	51 ± 5^a	47 ± 3^a	48 ± 5^a	44 ± 3^a	45 ± 5^a
Apigenin-6,8-di-C-glucoside	156 ± 8^a	143 ± 6^a	146 ± 8^a	133 ± 7^a	139 ± 7^a
Flavanone-O-rutinoside	39 ± 4^b	Ud	50 ± 2^a	19.5 ± 0.8c	14.2 ± 0.5c
Narirutin-4ʹ-O-glucoside	51 ± 5c	117 ± 8^a	53 ± 4c	89 ± 6^b	70 ± 6^bc
Quercetin-3-O-rutinoside-7-O-Glucoside	17.4 ± 0.7^a	14 ± 2^a	19 ± 2^a	14 ± 2^a	16.1 ± 0.7^a
Apigenin-8-C-glucoside-2ʹ’-O-xyloside	8.6 ± 0.7d	21 ± 2^a	8.4 ± 0.3^d	16.8 ± 0.6^b	12.5 ± 0.6c
Eriodictyol-7-O-rutinoside	19 ± 1^a	20 ± 2^a	18 ± 3^a	17 ± 1^a	16 ± 1^a
Genistein-7-O-xylosylgucoside malonylated	12 ± 1^a	12 ± 1^a	11 ± 1^a	11.0 ± 0.1^a	11.6 ± 0.2^a
Phloretin-3ʹ5’-di-C-glucoside	33.8 ± 0.7^bc	49 ± 3^a	35 ± 3^bc	38 ± 1^b	30 ± 3c
Hesperetin derivative	21.3 ± 0.3^a	25 ± 2^a	19 ± 1^a	25 ± 3^a	20 ± 1^a
Flavanone-O-rutinoside	ud	43 ± 2^a	32.7 ± 0.7^b	30 ± 1^b	21 ± 1^c
Narirutin	242 ± 10^b	2943 ± 13^a	200 ± 11^c	224 ± 11^bc	190 ± 10^c
Naringenin-7-O-xylosylgucoside malonylated	ud	Ud	ud	4.96 ± 0.05^b	5.3 ± 0.1^a
Hesperidin	661 ± 16^ab	691 ± 12^a	34514^d	507 ± 18^c	623 ± 17^b
1,2-diferuloylgentiobiose	12.1 ± 0.3^a	14 ± 2^a	14 ± 2^a	14.3 ± 0.5^a	13.2 ± 0.8^a
Didymin	64 ± 3^ab	78 ± 6^a	36 ± 5^c	56 ± 1^b	57 ± 4^ab
Total flavonoid index (TFI) ^b	1340 ± 41^ab	1500 ± 59^a	962 ± 56^c	1190 ± 56^b	1228 ± 54^b
Total phenolic index (TPI) ^c	1559 ± 68^ab	1732 ± 79^a	1177 ± 78^c	1384 ± 66^bc	1413 ± 70^bc

^aValues are expressed as mean ± SD, n = 3. Values followed by different letters in the same row are significantly different (p < 0.05).

^bTFI: total flavonoid index, sum of individual flavonoid contents

^cTPI: total phenolic index, sum of individual phenolic contents

“ud” represent “undetected”

Table 3. Free phenolic acid contents (mg/100 g DW) in alkali hydrolyzed samples of five “Cara Cara” pulps ^a.

Fruits	Caffeic acid	p-Coumaric acid	Ferulic acid	Total free phenolic acids
Hubei	8.48 ± 0.06a	4.9 ± 0.2b	90 ± 2a	103 ± 2 a
Fujian	7.2 ± 0.1c	5.7 ± 0.3b	94 ± 2a	107 ± 2a
Chongqing	4.4 ± 0.2d	3.33 ± 0.01 c	73 ± 2b	81 ± 2b
Jiangxi	4.73 ± 0.05d	5.0 ± 0.5b	79 ± 3b	89 ± 4 b
Hunan	7.74 ± 0.07b	7.2 ± 0.3a	93 ± 3a	108 ± 4 a

^aValues are expressed as mean ± SD, n = 3. Values followed by different letters in the same column are significantly different (p < 0.05).

Table 4. Total phenolic contents (mg/100 g DW) and antioxidant abilities of “Cara Cara” pulps. ^a

Fruits	TPC^b	DPPH^c	ORAC^d
Hubei	787 ± 21^a	14.6 ± 0.1^a	274 ± 16^a
Hunan	792 ± 28 ^a	14.3 ± 0.5^a	280 ± 19^a
Jiangxi	652 ± 26 ^b	9.2 ± 0.5^b	281 ± 21^a
Chongqing	673 ± 27 ^b	10.10 ± 0.04^b	271 ± 6^a
Fujian	725 ± 15^ab	10.5 ± 0.3^b	306 ± 12^a

^aValues are expressed as mean ± SD, n = 3. Values followed by different letters in the same column are significantly different (p < 0.05).

^bTPC: total phenolic content (gallic acid equivalent, mg GAE/100 g DW).

^cDPPH: expressed as ascorbic acid equivalent (μmol AAE/g DW).

^dORAC: expressed as Trolox equivalent (μmol TE/g DW).