Determinación del contenido de antioxidantes naturales en frutos secos

Nuts contain a high content of oleic acid and/or polyunsaturated acids, so their intake reduces the level of total cholesterol and LDL cholesterol in the blood, which is associated with a lower incidence of cardiovascular diseases. Besides, nuts have beneficial effects on human health due to the presence of antioxidants (polyphenols and tocopherols). In this study, lipid content, fatty acid profile and polyphenols and tocopherols content of some nuts were determined: walnuts, pecans, hazelnuts, almonds, peanuts, pistachios and cashews. The extraction of polyphenols in hazelnuts was optimized by using different mixtures of solvents as well as several conditions of temperature and extraction times. The mixture water/acetone (80:20) at 25 °C during 24 hours showed the highest content of polyphenols. The polyphenol content of the extracts obtained from the nuts showed values in the range between 427 ppm (almonds) and 8805 ppm (walnuts), while the content of tocopherols, ranges between 160 ppm (cashews) and 358 ppm (walnuts). Thus, the analyzed nuts have important antioxidant contents but in different amounts. Furthermore, the nutshell offers a barrier to slow down the oxidation processes of the oil present in the product.