Bioaccessibility of polyphenols and cinnamaldehyde in cinnamon beverages subjected to in vitro gastro-pancreatic digestion

The present study was undertaken to investigate the in vitro bioaccessibility of polyphenols and cinnamaldehyde in cinnamon beverage and formulations during simulated gastro-pancreatic digestion. Cinnamon polyphenols post-pancreatic bioaccessibility was 79.8%. The decline in total polyphenols was caused by the precipitation of proanthocyanidins by pepsin. The addition of sweeteners increased the polyphenols bioaccessibility decreasing the interaction between pepsin and tannins. The addition of bovine milk had no effect on polyphenols post-pancreatic bioaccessibility. Quercetin-3-rhamnoside, syringic and coumaric acids were found to be poor bioaccessible whereas kaempferol and cinnamaldehyde were stable during digestion. The addition of sweeteners did not affect the bioaccessibility of these compounds. The final bioaccessibility was affected by milk only for cinnamaldehyde. The present study demonstrates that cinnamon beverage provides a significant source of dietary bioaccessible polyphenols and that the modality of consuming cinnamon could represent a crucial factor since the addition of sweeteners improve their bioaccessibility whereas milk has no effect on their bioaccessibility.