IN VITRO BIOACESSIBILITY AND BIOACTIVITY OF PHENOLIC COMPOUNDS FROM HALOPHYTE PLANTS

• Autor(a) principal: Sousa, João Henrique Gonçalves
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/145155
• topic: Halophyte plants; in vitro digestion; Salicornia ramosissima; Sarcocornia fruticosa; Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias

Halophyte plants have a high content of minerals (e.g. sodium, potassium and manganese) and phytochemicals with antioxidant properties (e.g. phenolic compounds). For this reason, there is a growing interest in the use of these plants as food. However, the bioactivity of these plants is dependent on the bioaccessibility of their bioactive compounds, namely phenolic compounds. The main objective of this thesis is to evaluate the impact of the in vitro gastrointestinal digestion process on the phenolic composition and bioactivity of halophyte plants. To achieve this objective, two halophyte plants were selected and submitted to an in vitro digestion process, in order to assess the bioaccessibility and antioxidant activity of phenolic compounds throughout the phases of the digestive process. In the first part, the phenolic composition of seven halophyte plants were determined by HPLCDAD-ESI-MS/MS, and further quantified by HPLC-DAD and the colorimetric method - Folin-Ciocalteu method. Two plants (Salicornia ramosissima and Sarcocornia fruticosa) were selected for the in vitro digestion studies due to their high content and variety of phenolic compounds. The analysis of digestive fractions revealed that there was an increase in total phenolic compounds from oral to gastric phase and a consequent decrease in intestinal phase. The % of bioaccessible phenolics of S. ramosissima were 6.8%,18.4% and 7.4% and for S. fruticosa were 32.3%, 67.5% and 51.5%, for oral, gastric and intestinal fractions, respectively. The same trend was observed in the antioxidant activity assays (ORAC and HOSC values). HPLC-DAD analysis demonstrated that gallocatechin, caffeoylquinic acids and caffeoylquinic acid derivatives were identified as the major phenolics found in both plants. Most of these compounds proved to be poorly bioaccessible as they were not detected in the intestinal fraction.