Table 3.

Effect of solvent type and extraction time on astaxanthin content and antioxidant properties of shrimp shell extract.

Solvent type	Extraction time	Astaxanthin content	DPPHsc	FRAP
	(h)	(µg/g)	(%)	(µmol Fe²⁺/g)
Petroleum ether	2	10.40 ^m*	23.73 ^h	959.60^f
	4	12.32 ^l	26.42 g	985.15^f
	6	14.24 ^k	29.41^f	1038.61^e
Hexane	2	18.95 ^h	18.88 ^k	1122.95^d
	4	24.32 ^g	26.53 ^g	1230.47^c
	6	31.89 ^d	38.90 ^e	1291.05^c
Ethanol	2	16.48 ⁱ	19.17 ^k	1058.80^e
	4	20.86 ^h	21.33 ⁱ	1070.09^e
	6	26.96^f	29.67^f	1087.21^e
Acetone	2	28.16 ^e	43.62 ^d	1175.82^d
	4	35.76^c	48.64^c	1263.14^c
	6	45.79^b	64.88^b	1424.11^b
Petroleum ether/acetone/water (5:45:50)	2	5.18^p	15.32 ^l	915.65^f
	4	6.13 ^op	18.46 ^k	956.04^f
	6	6.70^o	21.47 ⁱ	1022.57^e
Petroleum ether/acetone/water (15:50:35)	2	5.91^p	15.00 ^l	906.14^f
	4	6.11 ^op	22.56 ⁱ	947.13^f
	6	9.18ⁿ	29.62^f	1011.28^e
Petroleum ether/acetone/water (15:75:10)	2	32.14 ^d	44.69 ^d	1166.91^d
	4	36.27^c	48.64^c	1295.21^c
	6	48.47 ^a	67.64 ^a	1504.90^a

*: Means within a column with the same lowercase letters are not significantly different at p < 0.05.

FRAP: Ferric Reducing Antioxidant Power

DPPHsc: scavenging activity of DPPH