Determination of Essential Elements in Selected Nuts Produced in Kenya

Nuts, when eaten regularly, have been shown to reduce the risk of developing obesity, diabetes, and cardiovascular disease. They contain healthy fats such as monounsaturated fatty acids and are high in protein, vitamins, fiber, phenolics, phytosterols, and essential minerals. Essential minerals are important in preserving good health and body immunity against infections. They are categorized as macro minerals or micro minerals. This study intends to determine the essential elements present in macadamia nuts and peanuts and explain the importance of these nuts to human health and the intake suitable for consumption. The two nuts were collected in triplets from each study area and transported to the University of Nairobi, Department of Chemistry laboratory. The moisture content of the nuts was determined by the gravimetric method. The samples were then wet digested followed by determination of the essential elements using atomic absorption spectroscopy (AAS). Moisture content results were as follows: Macadamia nuts recorded an average moisture content of 15.68% while that of peanuts was 3.89%. The spectrum of correlation coefficients extends from +1 to 0.9036. The results indicated that macadamia nuts from Magumoni had the highest levels of Ca (15.25 ± 0.35 mg/kg), Na (10.99 ± 0.17 mg/kg), Fe (6.96 ± 0.18 mg/kg), Mn (0.465 ± 0.276 mg/kg) and Cu (1.01 ± 0.45 mg/kg). Peanuts from the Kangemi market had the highest levels of Mg (49.45 ± 4.71 mg/kg), K (46.95 ± 0.35 mg/kg), and Zn (0.49 ± 0.01 mg/kg). Mg was the most abundant essential element in both nut samples. Comparing the results with WHO/FAO permissible limits for essential elements in food, the concentration of Fe, Zn, and Cu were within the recommended limits. The levels of K, Na, Mn, Ca, and Mg were below the recommended limits by WHO.