In vitro bioaccessibility of phenolic compounds in fruits: effect of the gastrointestinal digestion on the phenolic compound composition and on the scavenging capacity against reactive oxygen and nitrogen species

• Grant number: 13/03127-1
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: August 01, 2013
• End date: October 31, 2013
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Science
• Principal Investigator: Adriana Zerlotti Mercadante
• Grantee: Eliseu Rodrigues
• Host Institution: Faculdade de Engenharia de Alimentos (FEA). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The consumption of food rich in phenolic compounds has been related to the decreased risk of development of some chronic-degenerative diseases. This effect is attributed, by hypothesis, to the capacity of these compounds to minimize oxidative and/or nitrosative reactions induced by reactive oxygen (ROS) and nitrogen (RNS) species related to the pathogenesis of such diseases. In order to scavenge ROS and RNS in the human body, the phenolic compounds must be bioaccessible, i.e., they need to be released from the food matrix and become available to intestinal absorption. Despite being important, there are few studies on the bioaccessibility of phenolic compounds. Moreover, in these studies, the existence of two recurrent method limitations can be observed, (1st) the evaluation of the antioxidant capacity using methods based on non-biological radicals (ABTS*+ and DPPH*) and (2nd) the lack of the identification of the compounds formed after in vitro gastrointestinal digestion. The non-biological radicals present very different chemical properties, such as reactivity and stability, from those presented by the ROS and RNS generated in the human body. Thus, the results obtained with these methods generate limited information on the antioxidant capacity of the phenolic compounds and of the compounds formed after gastrointestinal digestion. The identification of the phenolic compounds formed after in vitro gastrointestinal digestion can indicate if the ingested phenolic compounds will be bioaccessible in their original form or as derivatives. The aim of this work is to determine the in vitro bioaccessibility of the phenolic compounds of three fruits (mana-cubiu, murici and umari) and of phenolic compound standards in a food mimetic system (emulsion). In addition, the effect of each phase of the in vitro gastrointestinal digestion (gastric and intestinal phases) on the phenolic compound composition (determined by HPLC-DAD-MSn) and its scavenging capacity against reactive species of biological relevance, namely peroxyl radical (ROO*), hydroxyl radical (HO*), hydrogen peroxide (H2O2), hypochlorous acid (HOCl), peroxynitrite anion (ONOO-) and nitric oxide radical (*NO), will be evaluated.