Functionality assessment of Scolymus hispanicus (golden thistle) for its daily-basis incorporation in the Mediterranean diet Artigo de Conferência uri icon

resumo

  • Golden thistle (Scolymus hispanicus L.) is naturally distributed in the Mediterranean region. Its roots and fresh rosettes are traditionally consumed in soups and special meals, and have been reintroduced in some European countries since the consumption of native species is an integral and crucial part of the so-called Mediterranean diet; long associated with several beneficial health effects against diseases spread worldwide1. Although most of these native species are traditionally collected in the wild by the local communities, the increasing demand for such edible plants has created a market niche for the commercial exploitation of Wild Edible Plants (WEPs). This practice may fulfill consumer demands for product availability throughout the year, as well it prevents the risk for genetic erosion due to irrational gathering. There are reports, available in the literature, for cultivation practices of native species and how these practices may affect its nutritional profile, chemical composition, and bioactive compounds content2. The aim of the present study was to evaluate the effect of fertilization with nutrient solutions that contained different ratios of nitrogen (N), phosphorus (P), and potassium (K) on the nutritional profile (AOAC methods) of S. hispanicus edible plant parts. The mineral content was determined by atomic absorption spectrophotometry. Energy was calculated according to the equation: energy (kcal per 100 g) = 4 x (g protein + g carbohydrate) + 2 x (g total dietary fiber) + 9 x (g fat). The sample fertilized with 200:200:200 ppm of N:P:K (S222) stood out for its fiber content (40.7±0.2 g/100 g dry weight), followed by the sample S211 (fertilized with 200:100:100 ppm of N:P:K) that also showed promising crude protein values (10.8±0.3 g/100 g of dw); however, the crude protein content showed no significant differences between this sample (S211) and samples fertilized with 100:100:100 N:P:K (S111) and S222, respectively. The total dietary fiber content was different among the seven experimental treatments, which suggests the influence of the nutrient solution on this parameter. Sample S111 showed similar fat content to the control sample. The control sample (without fertilization) showed the highest levels in the majority of the studied parameters, except for fiber content, carbohydrates, and energy. The sample fertilized with 300 ppm of nitrogen had the lowest values in relation to fat, crude protein, and fiber contents. The energy calculation ranged from 301 to 285 kcal/100g of dry weight, while the sample with the highest energy value had the highest carbohydrate content. Mineral composition was affected by fertilization treatments for most of the minerals evaluated in the present study. Sample S311 (fertilized with 300:100:100 ppm of N:P:K) showed the highest amount of sodium, calcium, and magnesium and the lowest content of potassium and zinc. On the other hand, the control sample had the lowest amounts of sodium, magnesium, manganese and copper and the highest levels of potassium, iron, and zinc. Iron and other micro minerals are an essential part of many compounds in the oxygen transport and storage system and function as cofactors for enzymes3. It was possible to verify that the concentration of nitrogen, phosphorus and potassium in nutrient solution may directly affect the nutritional value and mineral content of the plant under study, with high concentrations of nitrogen presenting a negative impact on the protein content, indicating the low response of the species to increasing nitrogen fertilization rates. With the results obtained, it is possible to select the appropriate nutrient solution to obtain golden thistle with a promising nutritional profile and high mineral contents, as well as to promote its incorporation into commercial farming systems and the exploitation in a more sustainable manner through tailor-made fertilization regimes.

data de publicação

  • outubro 2022