Characterization of Bioactive Compounds in Tunisian Bitter Orange (Citrus aurantium L.) Peel and Juice and Determination of Their Antioxidant Activities

Table 2

Contents (mg/g) and percentages (%) of phenolic compounds of bitter orange peel and juice^A.

Phenolic compounds	Peel		Juice
	%	Mg/g	%	Mg/L
Phenolic acids	73.80 ± 3.33^a	1.03 ± 0.02	71.25 ± 0.25^a	473.89 ± 0.30
Gallic acid	1.84 ± 0.25^b	0.03 ± 0.01	13.05 ± 0.01^a	84.53 ± 0.07
Hydroxybenzoic acid	1.13 ± 0.65^b	0.02 ± 0.01	4.05 ± 0.11^a	27.88 ± 0.05
Chlorogenic acid	8.63 ± 0.13^a	0.12 ± 0.01	—	—
Syringic acid	1.69 ± 0.46^b	0.02 ± 0.01	2.24 ± 0.00^a	13.75 ± 0.1
Vanillic acid	1.75 ± 0.57^b	0.02 ± 0.01	2.61 ± 0.04^a	17.19 ± 0.01
Rosmarinic acid	5.58 ± 0.65^a	0.08 ± 0.02	5.43 ± 0.10^a	36.84 ± 0.02
Trans-2-hydroxycinnamic acid	3.15 ± 0.28^a	0.04 ± 0.01	4.56 ± 0.05^a	30.69 ± 0.20
Trans-cinnamic acid	1.56 ± 0.65^b	0.02 ± 0.01	2.58 ± 0.01^a	15.64 ± 0.09
p-Coumaric acid	24.68 ± 2.64^a	0.34 ± 0.01	18.02 ± 0.22^b	116.13 ± 0.18
Ferulic acid	23.79 ± 3.27^a	0.33 ± 0.02	19.04 ± 0.22^b	131.24 ± 0.21
Flavonoids	23.02 ± 3.83^a	0.33 ± 0.07	23.13 ± 1.11^a	136.91 ± 0.17
Epicatechin	2.77 ± 0.83^b	0.04 ± 0.02	5.36 ± 0.15^a	36.47 ± 0.05
Catechin	3.17 ± 0.27^a	0.04 ± 0.01	3.16 ± 0.08^a	20.24 ± 0.09
Rutin	9.91 ± 1.18^a	0.14 ± 0.03	5.98 ± 0.19^b	37.21 ± 0.10
Naringin	5.23 ± 1.15^a	0.07 ± 0.02	5.59 ± 0.04^a	35.05 ± 0.12
Flavone	1.95 ± 1.98^a	0.03 ± 0.03	1.19 ± 0.01^a	7.96 ± 0.01
Phenolic monoterpenes	—		3.51 ± 0.17^a	23.54 ± 0.03
Tyrosol	—		3.51 ± 0.17^a	23.54 ± 0.03
Unknown	3.18 ± 0.50	0.04 ± 0.01	3.62	22.79 ± 0.08
Total	100	1.40 ± 0.09	100	657.13 ± 0.27

 ^AValues are given as mean ± SD (𝑛=3). Values followed by the same letter did not share significant differences at 𝑃<0.05 (Duncan’s test). —: not detected.