Table 2.

Concentrations of essential in mussels from different types of conservation in the Spanish market. Results are expressed in ng/g.

	Preserved Mussels (n = 88)			Frozen Mussels (n = 80)			Fresh Mussels (n = 20)			p Value a
Element	Mean ± SD	Median	P25–P75	Mean ± SD	Median	P25–P75	Mean ± SD	Median	P25–P75	Preserved vs. Frozen	Preserved vs. Fresh	Frozen vs. Fresh
Fe	34,945.1 ± 11,496.8	33,376.0	25,848.3–41,727.6	45,965.2 ± 44,720.5	32,310.0	26,713.1–50,700.1	24,427.6 ± 5553.9	22,924.9	20,137.1–26,850.9	n.s.	<0.01	<0.01
Zn	46,011.4 ± 24,034.8	38,961.6	33,105.8–48,439.9	47,141.4 ± 17,788.6	46,231.2	37,356.5–58,914.3	56,624.1 ± 14,019.9	54,712.7	45,823.5–70,423.9	<0.01	<0.005	<0.05
Cu	1332.5 ± 383.1	1268.8	1028.4–1492.1	1564.6 ± 340.9	1529.7	1349.5–1831.3	1235.9 ± 195.5	1313.7	1035.5–1405.7	<0.05	n.s.	<0.01
Se	646.0 ± 200.8	599.6	538.3–683.3	1075.9 ± 187.9	1085.6	949.0–1229.2	1223.8 ± 125.1	1274.6	1129.5–1315.2	<0.005	<0.005	n.s.
Mn	1251.0 ± 261.8	1227.7	1057.9–1407.0	1726.8 ± 812.5	1424.4	1170.0–2079.5	1479.8 ± 298.8	1569.1	1249.4–1702.4	<0.05	<0.01	<0.05
Mo	271.4 ± 279.9	151.3	120.3–288.1	187.6 ± 113.6	142.4	106.7–208.5	187.4 ± 45.7	201.9	183.4–216.0	n.s.	n.s.	n.s.
Co	40.8 ± 11.0	40.6	33.6–46.5	66.4 ± 67.2	50.2	42.2–75.1	74.2 ± 16.5	74.1	58.9–91.0	<0.01	<0.005	<0.005

^a Mann–Whitney U test; n.s. non-significant.