Lipid and fatty acid profiles of Castanea sativa Mill. Chestnuts of 17 native Portuguese cultivars

Abstract

In recent years, chestnuts have increasingly become important in human nutrition because of their nutrient contents and potential beneficial health effects. In Portugal, Trás-os-Montes e Alto Douro is the most important region for chestnut production, generating 85% of the total national output. In 1994, three chestnut protected designation of origin (PDO) areas were created: Terra Fria, Soutos da Lapa, and Padrela within the jurisdiction area of the Regional Agricultural Services of Trás-os-Montes Region. Seventeen cultivars were selected from these PDO to evaluate crude fat content and fatty acid (FA) composition over a period of 2 years. Total fat extraction was performed according to AOAC methodology, using a Soxhlet apparatus for 16 h. Petroleum ether was used for extraction and FAs were identified and quantified by gas chromatography. The cultivars studied confirm that chestnuts have low crude fat content, low saturated fatty acids (SFA) (17%) and high unsaturated fatty acids (USFA) (83%). The major FAs are linoleic, oleic and palmitic; these accounted for more than 85% of the total FA content. From the results two potentially health-beneficial cultivars were identified: cv. Lada, with high linoleic acid content, and cv. Aveleira, with higher USFA content. With respect to FA profiles of chestnuts from the three PDO regions, Padrela chestnuts consistently contained the highest level of linoleic acid. The variation detected among cultivars and PDO areas may reflect differences in genotype and are influenced by environmental and growing conditions. The Longal chestnuts, the only traditional cv. growing on two different PDO areas, had better nutritional qualities in PDO Terra Fria, which confirm that the ecological conditions where chestnut orchards are established influences nut quality.