Release of resin-bound ferulic acid during an in vitro digestion simulation and antioxidant activity evaluation

• Autor(a) principal: Martins, Gonçalo Nuno Gouveia
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.13/1917
• topic: Ferulic acid; Resin; Immobilization; Digestion; Antioxidant; Ácido ferúlico; Resina; Imobilização; Digestão; Antioxidante; Applied Biochemistry; .; Faculdade de Ciências Exatas e da Engenharia; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Química

Ferulic acid is one of the most abundant hydroxycinnamic acids in Nature, with impact in human health whereas an antioxidant protection might be implicated. It has uses in cosmetics and food industry. It can be found in various foodstuffs, but mostly present etherified to lignins or esterified to carbohydrates or sterols, which hinders its absorption by the organism during the digestive process. The free form of ferulic acid is rapidly absorbed from the stomach, jejunum and, in a much lesser extent, from the ileum, in a pH dependent process. Since the ileum is particularly susceptible to inflammation and oxidative stress it is important to ensure that ferulic acid is able to exert its action in that part of the body without being absorbed from the stomach. A possible way to increase ferulic acid’s bioavailability to the ileum is by immobilization in solid matrixes resistant to low pH but not neutral or basic conditions. In the present work, the adsorption of ferulic acid onto the polystyrene adsorbent resin Lewatit® VP OC 1064 MD PH was studied, and a loading of 144 mg/g dry resin was obtained. To evaluate the release of the resin-bound ferulic acid, an in vitro “digestion” was performed with simulated gastrointestinal juices. The intestinal step was the most relevant with a release of 13-35 % of FA from the loaded resin. After each step of the in vitro digestion simulation, the antioxidant activity of ferulic acid was evaluated using the DPPH radical scavenging assay and all samples successfully maintained antioxidant activity throughout the digestive process. The confirmation of the incorporation of ferulic acid onto the resin was made by ATRFTIR spectroscopy and morphological analysis was made by SEM. The quantification of ferulic acid in solution was performed by HPLC-DAD throughout the entire work. This work showed that the free form of ferulic acid can be delivered in the intestine, after immobilization of solid matrixes, maintaining its antioxidant activity. This study is probably the first on this subject with these materials and methods.