In vitro gastrointestinal digestion model to monitor the antioxidant properties and bioaccessbility of phenolic extracts from elderberry ( Sambucus nigra L.)

This study performed an in vitro gastrointestinal digestion model to monitor the antioxidant properties of phenolic extracts derived from the elderberry (Sambucus nigra L.). The stability and antioxidant qualities of phenolic compounds from elderberry were assessed by an in vitro gastrointestinal digestion model involving pepsin digestion (to simulate gastric digestion) and pancreatin digestion (to simulate small i22ntestine conditions). Digested and undigested elderberry were subject to antioxidant assays including total phenolic content (TPC) assay, DPPH radical scavenging assay, and oxygen radical absorbance capacity (ORAC) assay. Our result showed that digestion process significantly reduced DPPH radical scavenging activity but had no significant effect on TPC and ORAC of elderberry. This indicates a need to investigate phenolic compounds in digestion that mimic biological gastrointestinal environments and to monitor these compounds for changes individually if possible.