Mineral Composition of Lettuce (Lactuca sativa L.) Grown in Soil and Hydroponics Consumed in Salvador City, Brazil

In the present paper, the mineral composition of lettuce (Lactuca sativa L.) grown in soil and hydroponics consumed in Salvador City, Brazil was determinate. In the sampling process 30 lettuce samples were collected, 12 samples were hydroponics grown and 18 samples were soil grown. The analytical technique used was Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES). The evaluation and interpretation of the achieved experimental results was carried out using the Student Newman Keuls (SNK) test. The results regarding on wet weight, demonstrated that medium content of soil grown lettuce is: calcium (48.52 mg/100 g), magnesium (20.46 mg/100g), iron (0.8667 mg/100g), manganese (0.1998 mg/100g), copper (0.1295 mg/100g) and zinc (0.2933 mg/100g). The mineral content of hydroponics grown lettuce is: calcium (51.58 mg/100g), magnesium (19.21 mg/100g), iron (0.3145 mg/100g), manganese (0.2117 mg/100g), copper (0.1755 mg/100g) and zinc (0.1489 mg/100g). Lettuce soil grown has statistically content higher of zinc and iron and lettuce hydroponics grown of calcium, copper, magnesium and manganese. The interpretation of results based on the SNK test, demonstrated also that the content of zinc, iron and calcium in lettuce is affected by seasonal conditions, while magnesium, manganese and copper are not.