Biofortificação agronômica da rúcula (Eruca sativa) com selênio : impacto nos compostos fenólicos totais e atividade antioxidante

Abstract

Arugula and other vegetables from the Brásicas family are prominent in human food due to their bioactive content such as phenolic compounds or glycosinolates and also for their ability to accumulate selenium. Selenium is an important mineral in the prevention of chronic non-communicable diseases, maintenance of the immune system. Desiring the variability in selenium content in soils and especially reduced levels in most of Brazil, a biofortification of brassicas with selenium has been explored as a strategy to increase the intake of selenium by humans. However, the impact of the biofortification of brassicas with selenium on the content of secondary metabolites such as phenolic compounds is still a scientific gap that needs to be explored. In addition to the impact on the content of phenolic compounds, an important factor is their bioaccessibility, as not all ingested content is actually absorbed by the body. In addition to biofortification, intrinsic factors of the plant such as the growth stage can also be determinant in the content of phenolic compounds in brassicas. Thus, this work aimed to analyze the phenolic compounds at different stages of maturation of the arugula; measure the influence of biofortification with selenite or selenate on the content of phenolic antioxidants, nutritional value, content and accessibility of phenolic compounds; and to assess the impact of selenium biofortification on phenolic compounds through a systematic review and meta-analysis. The results demonstrate that biofortification did not alter the nutritional content of the arugula, it only increased the mineral content due to the concentration of additional selenium, with emphasis on the biofortified arugula with selenate, which obtained about 98% higher content of Se than the arugula with selenite . The content of phenolic compounds was reduced with biofortification (11% for selenate and 18% for selenite), but the accessibility of the compounds evaluated through simulated in vitro digestion increased by 15% in biofortified with selenate. In the systematic review, seven studies were included, and these studies four were included in the meta-analysis. The results of the meta-analysis demonstrated that a biofortification can increase the content of phenolic compounds, and several factors such as type of application, dose of selenium, type of selenium and species of the plant can interfere. The development phase of the arugula interfered with the content of phenolic compounds and antioxidant activity, with the peak of accumulation on the 29th day, when the plant presented 20% higher content compared to the arugula in the commercial size. According to the results of the systematic review, biofortification can increase the content of phenolic compounds, but in some species, as in the case of arugula in this study, it can reduce. However, according to this study, the hypothesis is that biofortification with Se can increase the accessibility of these compounds. In addition, the immature arugula had a higher content of phenolic compounds compared to the adult size, so the consumption of immature plants should be encouraged to increase the consumption of compounds and because they are produced in reduced spaces and with less waste.