Bioaccessibility and gut metabolism of phenolic compounds of breads added with green coffee infusion and enzymatically bioprocessed

This study aimed at investigating two strategies to enhance the bioaccessibility of phenolic compounds from whole-wheat breads: enzymatic bioprocessing and addition of green coffee infusion. Although both strategies had a significant effect on increasing the contents of total soluble phenolic compounds in breads, the addition of green coffee infusion was much more relevant (19.1-fold) than enzymatic bioprocessing (1.8-fold). The phenolic compounds present as soluble forms were completely released from all breads' matrix already at the oral phase of digestion. While gastric digestion did not promote the release of insoluble phenolic compounds, intestinal conditions led to a slight release. All bread samples showed maximum phenolic compounds bioaccessibility after 4 h of gut fermentation. Upon the end of in vitro digestion and gut fermentation, the difference between the strategies was that enzymatic bioprocessing accelerated ferulic acid release, while the addition of green coffee infusion increased 10.4-fold the overall phenolic compounds bioaccessibility.