. 2021 Apr 3;7(4):e06678. doi: 10.1016/j.heliyon.2021.e06678

Table 4.

Effect of drying and storage condition on tannins, flavonoids, total polyphenols (TP), vitamin C content, ferric reducing antioxidant potential (FRAP), DPPH and ABTS radical scavenging activities of pulp of doum palm (H. thebaica) fruit. Values are expressed on dry weight basis.

Drying methods	Samples	Tannins (mg/g)	Flavonoids (mg/g)	TP (g/100g)	Vitamin C (mg/g)	FRAP (mgTE/g)	DPPH (mgTE/g)	ABTS (mgTE/g)
Sun(25–45 °C)	Swol	19.47 ± 0.18^f	13.73 ± 0.14^h	3.94 ± 0.03^g	4.32 ± 0.02^h	3.29 ± 0.09^d	28.45 ± 0.15ⁱ	32.86 ± 0.29^m
	StOL	19.33 ± 0.18^f	12.84 ± 0.10g^h	3.09 ± 0.05^l	3.72 ± 0.07^l	2.50 ± 0.12^g	26.91 ± 0.14^m	39.47 ± 0.20^h
	StOl	19.35 ± 0.19^f	12.77 ± 0.07^h	3.15 ± 0.04^k	3.92 ± 0.06^k	2.66 ± 0.07^g	27.03 ± 0.12^l	38.43 ± 0.14^k
	StoL	19.35 ± 0.21^f	13.62 ± 0.13ⁱ	3.65 ± 0.03ⁱ	4.05 ± 0.05^j	2.90 ± 0.06^f	27.04 ± 0.11^l	38.51 ± 0.16^k
	Stol	19.36 ± 0.21^f	13.71 ± 0.16^h	3.66 ± 0.03ⁱ	4.16 ± 0.02ⁱ	3.06 ± 0.03^d	27.26 ± 0.17^k	38.76 ± 0.11^k
	STOL	19.24 ± 0.13^g	13.96 ± 0.10^g	3.99 ± 0.05^g	5.50 ± 0.02^c	3.61 ± 0.06^c	28.78 ± 0.32ⁱ	39.30 ± 0.30ⁱ
	STOl	19.20 ± 0.14^g	14.04 ± 0.11^f	4.01 ± 0.02^f	5.70 ± 0.15^b	3.72 ± 0.05^c	29.39 ± 0.12^e	40.36 ± 0.28^f
	SToL	19.29 ± 0.17^g	14.03 ± 0.07^f	4.18 ± 0.04^d	5.66 ± 0.12^b	3.74 ± 0.07^c	29.41 ± 0.14^e	41.19 ± 0.12^c
	STol	19.33 ± 0.13^f	14.16 ± 0.03^e	4.23 ± 0.04^d	5.80 ± 0.06^a	3.80 ± 0.08^c	29.67 ± 0.11^d	41.81 ± 0.15^ab
Shade(25–30 °C)	swol	22.06 ± 0.22^d	13.89 ± 0.07^g	4.32 ± 0.01^c	4.58 ± 0.01^g	3.44 ± 0.04^d	30.77 ± 0.27^c	41.94 ± 0.13^a
	stOL	21.91 ± 0.15^e	13.25 ± 0.07^j	3.94 ± 0.06^g	4.07 ± 0.07^j	2.96 ± 0.06^f	29.20 ± 0.56^f	39.99 ± 0.19^g
	stOl	21.90 ± 0.24^e	13.42 ± 0.13ⁱ	4.02 ± 0.02^f	4.03 ± 0.06^j	3.15 ± 0.06^e	29.05 ± 0.13^h	39.04 ± 0.06^j
	stoL	22.16 ± 0.82^d	13.74 ± 0.04^h	4.12 ± 0.03^e	4.29 ± 0.04^h	3.27 ± 0.05^d	29.24 ± 0.13^g	39.32 ± 0.11ⁱ
	stol	21.99 ± 0.15^e	13.88 ± 0.12^g	4.13 ± 0.03^e	4.37 ± 0.04^h	3.28 ± 0.05^d	29.45 ± 0.30^e	39.60 ± 0.07^g
	sTOL	22.02 ± 0.03^d	14.17 ± 0.01^e	4.21 ± 0.03^d	5.66 ± 0.03^b	3.75 ± 0.07^c	30.93 ± 0.12^c	39.85 ± 0.12^g
	sTOl	21.97 ± 0.08^e	14.27 ± 0.11^d	4.22 ± 0.03^d	5.87 ± 0.06^a	3.83 ± 0.04^c	31.39 ± 0.09^b	40.79 ± 0.16^e
	sToL	21.81 ± 0.24^e	14.38 ± 0.06^d	4.35 ± 0.04^c	5.74 ± 0.25^ab	3.90 ± 0.08^c	31.67 ± 0.13^b	40.91 ± 0.13^e
	sTol	21.82 ± 0.18^e	14.53 ± 0.11^cd	4.38 ± 0.05^c	5.88 ± 0.13^a	3.91 ± 0.05^c	31.92 ± 0.12^a	41.27 ± 0.11^c
	Owol	17.86 ± 0.15ⁱ	12.69 ± 0.12^m	3.59 ± 0.03ⁱ	3.75 ± 0.02^l	3.26 ± 0.04^d	27.44 ± 0.18^j	41.46 ± 0.15^b
Oven (70 °C)	Otol	17.89 ± 0.16ⁱ	12.62 ± 0.13^m	3.35 ± 0.40^j	3.62 ± 0.02^lm	3.08 ± 0.06^e	26.78 ± 0.13^m	38.60 ± 0.04^k
	OTol	18.23 ± 0.07ⁱ	12.88 ± 0.06^l	3.55 ± 0.05ⁱ	4.82 ± 0.05^f	3.68 ± 0.07^c	27.91 ± 0.11^j	37.63 ± 0.23^l
	Owol	18.11 ± 0.14ⁱ	13.84 ± 0.18^g	3.66 ± 0.06ⁱ	3.64 ± 0.04^l	3.29 ± 0.02^d	27.03 ± 0.19^l	39.05 ± 0.15^j
Oven (60 °C)	Otol	17.80 ± 0.24ⁱ	13.30 ± 0.12^k	3.49 ± 0.04ⁱ	3.50 ± 0.02^m	3.10 ± 0.04^e	25.21 ± 0.18^s	39.29 ± 0.20ⁱ
	OTol	17.94 ± 0.16ⁱ	13.91 ± 0.16^g	3.61 ± 0.06ⁱ	5.12 ± 0.01^e	3.69 ± 0.05^c	26.60 ± 0.25ⁿ	38.85 ± 0.21^k
	Owol	19.85 ± 0.18^f	13.97 ± 0.14^g	4.08 ± 0.04^e	3.87 ± 0.02^k	3.31 ± 0.06^d	25.36 ± 0.30^p	39.56 ± 0.29^h
Oven (50 °C)	Otol	19.05 ± 0.17^h	13.51 ± 0.11ⁱ	3.74 ± 0.05^h	3.64 ± 0.02^l	3.09 ± 0.03^e	24.68 ± 0.21^r	43.52 ± 0.11^a
	OTol	19.33 ± 0.19^f	14.28 ± 0.22^d	4.03 ± 0.03^f	5.30 ± 0.3^d	3.87 ± 0.04^c	26.48 ± 0.19ⁿ	38.57 ± 0.25^l
	Owol	21.50 ± 0.31^e	14.32 ± 0.05^d	4.36 ± 0.03^c	3.96 ± 0.02^k	3.44 ± 0.08^d	25.64 ± 0.10^p	39.10 ± 0.20^j
Oven (40 °C)	OwOl	21.79 ± 0.09^e	14.41 ± 0.05^d	4.38 ± 0.03^c	4.06 ± 0.06^j	3.53 ± 0.09^d	25.88 ± 0.11^o	39.62 ± 0.09^h
	OwoL	22.61 ± 0.16^c	14.44 ± 0.06^d	4.49 ± 0.01^bc	4.02 ± 0.05^j	3.40 ± 0.07^d	26.35 ± 0.10ⁿ	39.78 ± 0.12^h
	Owol	23.06 ± 0.36^a	14.51 ± 0.10^c	4.57 ± 0.05^b	4.13 ± 0.01ⁱ	3.53 ± 0.05^d	26.76 ± 0.15^m	39.99 ± 0.03^g
	OtOL	22.32 ± 0.20^c	14.36 ± 0.19^d	3.99 ± 0.06^g	3.86 ± 0 .01^k	3.15 ± 0.05^e	24.95 ± 0.30^r	41.39 ± 0.22^b
	OtOl	22.32 ± 0.19^c	14.19 ± 0.09^e	4.02 ± 0.06^f	3.95 ± 0.03^k	3.20 ± 0.04^e	24.91 ± 0.05^r	39.30 ± 0.11ⁱ
	OtoL	22.71 ± 0.02^c	14.45 ± 0.08^c	4.13 ± 0.01^e	4.08 ± 0.06ⁱ	3.32 ± 0.07^d	25.19 ± 0.14^q	39.39 ± 0.17ⁱ
	Otol	22.78 ± 0.05^b	14.53 ± 0.11^c	4.16 ± 0.02^e	4.12 ± 0.02ⁱ	3.37 ± 0.07^d	25.52 ± 0.20^p	39.91 ± 0.21^g
	OTOL	22.44 ± 0.28^c	14.79 ± 0.13^b	4.53 ± 0.08^b	5.24 ± 0.03^d	4.33 ± 0.04^a	26.44 ± 0.23ⁿ	40.49 ± 0.14^e
	OTOl	22.18 ± 0.05^c	14.82 ± 0.12^ab	4.57 ± 0.04^b	5.12 ± 0.01^e	4.44 ± 0.12^a	27.29 ± 0.12^k	40.40 ± 0.24^e
	OToL	22.51 ± 0.11^b	14.88 ± 0.11^a	4.83 ± 0.07^a	5.28 ± 0.05^d	4.07 ± 0.06^b	27.30 ± 0.11^k	40.83 ± 0.16^d
	OTol	22.67 ± 0.07^b	14.92 ± 0.10^a	4.85 ± 0.27a	5.42 ± 0.02^c	4.21 ± 0.06^b	27.67 ± 0.13^j	41.22 ± 0.08^c

Values are means ± standard deviation of three repetitions (n = 3). In the same column, values followed by different superscript letters are significantly different (p < 0.01). T = pulp treated with antioxydant/antimicrobial; t = untreated pulp; O/o = pulp powder stored in the presence (O) or absence of oxygen (o); L/l = pulp powder stored in the presence (L) or absence of oxygen (l) of light. Pulps or whole fruits (w) were sun-dried (S), shade-dried (s) or oven-dried (O) at 40, 60, 50 and 70 °C.