Characterization and functional properties of oils extracted from nuts and walnuts

Abstract

Epidemiological studies have proved an inverse relationship between the  intake of nuts and the development of  chronic illnesses such  as cardiovascular  disease and cancers. Nuts have phenolic  acids and flavonoids, in addition to being  rich in tocopherols, phytosterols and squalene.  They are sources of carbohydrates,  essential fatty acids and minerals. The possible beneficial effects of these  compounds are due to their antioxidant and anti-proliferative activity. This study had  as its objective to characterize the oils ex tracted from nuts to identify the beneficial  bioactive compounds to the application of these oils in foods. Tests were conducted  to determine the centesimal  composition of Brazil nuts ( Bertholletia excelsa ),  Sapucaia nuts ( Lecythis pisonis ), Cotia nuts ( Couepia edulis ) Gurguéia nuts  ( Dipteryx lacunifera ), Pecan nuts ( Carya illinoensis ) and Walnuts ( Juglans regia ). The  oils extracted from the nuts were analyzed to determine their physical-chemical  characterization (content of free fatty a cids, acid value, peroxide value, iodine value,  refractive index, saponification value, unsaponi fiable matter and oxidative stability),  their composition of fatty  acids, tocopherols, and total phenolic compound content.  The results were submitted to analysis o f variance and Turkey’s range test for  averages of 5% using the ESTAT prog ram version 2.0. From the results, it was  verified that the nuts studied had distinct  centesimal compositions, but all constituted  significant sources of lipids (35.74-68.89%), t hese oils being an alternative source of  edible vegetable oils. The physical-chemical properties of the oils extracted from the  nuts were comparable to the conventional oi ls of good quality; in addition they also  have in their composition the majority of thei r fatty acids as palmitic, stearic, oleic and  linoleic, amounting to 87-99% of  the total. With regard to th e content of phenolic and  tocopherol compounds, the oil from Cotia nu ts stands out with 2.02 mg GAE/g and  484.50 mg/kg respectively. However, in gene ral, the oleaginous showed significant  amounts of total phenolic compounds and tocopherols.