Variability in crude protein and mineral nutrient concentrations of almonds

Nuts are recognized as a healthy snack and a daily intake of 30-50 g is recommended as part of a healthy diet. However, their health benefits depend on their nutritional composition. The nutritional composition of nuts varies depending on their cultivar and post-harvest handling, and it is not always clear how much variation can be expected among nuts purchased from retail markets. We evaluated the variability in crude protein and mineral nutrient concentrations of four brands of almonds purchased from different commercial retailers. The mean concentrations of crude protein and minerals in almond kernels were: crude protein (22.31% weight), aluminium (3.90 mg kg-1), boron (18.50 mg kg-1), calcium (0.20% weight), copper (8.90 mg kg-1), iron (32.20 mg kg-1), magnesium (0.30% weight), manganese (25.60 mg kg-1), potassium (0.60% weight), phosphorus (0.50% weight), sodium (35.40 mg kg-1), sulphur (0.20% weight) and zinc (21.30 mg kg-1). Nutrient concentrations varied widely among almond samples from different brands, with the largest variations found in sodium and aluminium and the smallest variations found in crude protein and potassium. The following ranges were observed: crude protein (17.06-26.52% weight), aluminium (0.80-25.80 mg kg-1), boron (12.60-33.80 mg kg-1), calcium (0.12-0.33% weight), copper (3.90-13.60 mg kg-1), iron (17.60-64.50 mg kg-1), magnesium (0.16-0.36% weight), manganese (12.40-41.10 mg kg-1), potassium (0.43-0.78% weight), phosphorus (0.37-0.69% weight), sodium (0.20-134.30 mg kg-1), sulphur (0.11-0.22% weight) and zinc (12.50-30.70 mg kg-1). Aluminium, calcium, iron, magnesium, phosphorus, sodium and zinc concentrations differed significantly among brands of almond kernels but there were no significant differences in crude protein, boron, copper, manganese, potassium and sulphur concentrations. There is a need for rapid quality assessment of mineral nutrient composition of nuts before marketing and consumption. This will help in recommending quantities for consumption to meet daily health requirements