Nutritional quality of natural and processed nuts

Total fat and salt contents are crucial factors for the nutritional quality of nuts. In the last years, several studies have reported the importance of nuts consumption to promote health benefits, especially those related with the prevention of cardiovascular diseases. The overall objective of this study was to compare the total fat and salt contents of 21 samples of natural and processed nuts (walnuts, pistachios, broad beans, corn, hazelnuts, cashews, almonds, peanuts and mixtures of different nuts). Natural nuts have nothing added, while processed have honey, salt and/or other ingredients. The selected nuts were analysed regarding their moisture, fat and salt contents. Moisture content was determined by gravimetric method. For total fat, acid hydrolysis followed by Soxhlet extraction with petroleum ether was used, while for salt determination Charpentier-Volhard’s titration was performed. The results are expressed in g/100 g of edible portion. Total fat content varied between 12.3 ± 0.3 and 72.9 ± 0.3 g/100 g, for corn and walnuts, respectively. With respect to salt content a range from 0.0291 ± 0.0 (natural walnuts) to 2.65 ± 0.0 g/100 g (pistachio) was obtained. The analysed natural nuts presented the lowest salt content (0.0291 – 0.105 g/100 g). World Health Organization recommends a daily salt intake below 5 g. Therefore, it is of utmost importance to increase the variety of natural nuts available in the market, since these have much lower contents of salt than the processed nuts, and at the same time provide significant amounts of unsaturated fatty acids.This work was funded by National Institute of Health Dr. Ricardo Jorge, I.P., under the project “PTRANSALT - Evaluation of trans fatty acids, saturated fat and salt in processed foods: current situation in Portugal - (2012DAN828)”. Tânia Gonçalves Albuquerque is grateful for research grant (BRJ/DAN-2012) funded by National Institute of Health Dr. Ricardo Jorge, I.P