. 2019 Mar 20;56(5):2458–2466. doi: 10.1007/s13197-019-03722-9

Table 2.

Effect of drying (tray, vacuum and freeze) on color and phytochemical analysis of kinnow peel

	Fresh peel	Tray dried peel	Vacuum dried peel	Freeze dried peel
L*	57.75 ± 0.21^a	37.14 ± 0.90^b	57.64 ± 0.30^a	59.75 ± 0.05^a
a*	16.31 ± 0.04^b	19.63 ± 0.20^a	15.63 ± 0.10^c	15.31 ± 0.06^d
b*	65.18 ± 0.10^a	54.05 ± 0.56^d	56.21 ± 0.21^c	59.18 ± 0.11^b
Hue	75.95 ± 1.0^a	69.86 ± 0.20^b	74.41 ± 0.06^a	75.65 ± 0.16^a
Chroma	67.15 ± 0.15^a	58.13 ± 0.26^b	58.14 ± 0.10^b	64.393 ± 1.89^a
Browning index	290.59 ± 2.21^a	265.47 ± 2.57^b	222.00 ± 1.59^c	216.76 ± 2.07^d
Whitening index	14.63 ± 0.28^b	20.18 ± 0.04^ab	26.81 ± 0.12^a	27.9 ± 0.40^a
Total phenolic content (mg GAE/g)	24.51 ± 0.08^a	16.84 ± 0.05^d	17.94 ± 0.03^c	21.96 ± 0.12^b
Total flavonoid content (mg QE/g)	19.12 ± 0.09^a	11.11 ± 0.09^d	13.36 ± 0.08^c	15.32 ± 0.05^b
DPPH assay (IC₅₀ value) μg/mL	66.5 ± 0.50^d	73.15 ± 0.06^a	72.18 ± 0.10^b	68.15 ± 0.09^c
Scavenging activity (%)	86.55 ± 0.53^b	83.28 ± 0.04^d	89.07 ± 0.06^a	84.77 ± 0.60^c
TEAC µmolTE/g	51.77 ± 0.05^b	44.17 ± 0.10^d	47.2 ± 0.12^c	51.21 ± 0.05^a
Β-carotene bleaching assay (%)	33.88 ± 0.07^a	23.19 ± 0.09^d	24.12 ± 0.10^c	29.05 ± 0.03^b
Ascorbic acid (mg/100 g)	46.87 ± 0.10^a	29.92 ± 0.07^d	31.08 ± 0.08^c	41.24 ± 0.20^b
Extraction yield (%)	5.19 ± 0.20^a	14.95 ± 0.01^d	15.56 ± 0.07^c	22.04 ± 0.16^b

All values are mean ± standard deviation of triplicate analysis and values in the same row bearing different superscript lowercase letters are significant difference (p ≤ 0.05) by Duncan’s test