In vitro bioaccessibility of carotenoids and phenolic compounds in emulsions: compounds formed and influence on the antioxidant capacity

Abstract

Carotenoids and phenolic compounds have important physic-chemical properties related to the decreased risk of chronic-degenerative diseases. Their action is partially related to the reduction or inhibition of deleterious oxidation reactions by scavenging reactive oxygen (ROS) and nitrogen (RNS) species produced during the oxidative/nitrosative stress. The identification of the compounds formed after digestion and the alterations in the antioxidant capacity against reactive species of biological relevance were investigated in only a few studies on the bioaccessibility of carotenoids and phenolic compounds in food. However, this type of information is essential, since the content of the bioactive compounds in food, as well as the antioxidant capacity, should be overestimated when compared to the bioaccessible fraction. In this sense, this project aims to answer the following questions: (i) Does the in vitro digestion have negative or positive impact on the ROS and RSN scavenging capacity of carotenoids and phenolic compounds?; (ii) What are the bioaccessible compounds available as antioxidants after the in vitro digestion?; (iii) What is the effect of the simultaneous presence of carotenoids and phenolic compounds on the in vitro bioaccessibility and on the antioxidant capacity? In order to answer these questions, emulsions containing lipophilic and hydrophilic extracts from fruits or standards of carotenoids and phenolic compounds will be prepared and the in vitro digestion will be evaluated by a static method, the ROS and RNS scavenging capacity will be evaluated by specific methods for each reactive species and the compounds formed after the digestion will be characterized by high performance liquid chromatograph coupled to a diode array and a mass spectrometer detectors (HPLC-DAD-MSn). (AU)