Effect of baking on free and bound phenolic acids in wholegrain bakery products

Phenolic compounds, particularly ferulic acid the most abundant phenolic in wheat, are the major contributors to the in vitro antioxidant capacity. They are present in wheat in free and bound forms which affect their bioavailability. Thus the current study aims to investigate changes in free and bound phenolic acids occurred during baking in wholegrain bread, cookie and muffin. The products were also fortified with lutein due to its proved health benefits, and were previously evaluated with regard to lutein stability and bioavailability and antioxidant properties. The control and fortified wholegrain bakery products contained reasonable amounts of free and bound phenolic acids with bread products exhibiting the highest level per serving (0.6 and 11.7 mg, respectively). Ferulic acid was the principal phenolic both in the free or bound extracts of the three products followed by p-coumaric acid in the bound extracts. Baking resulted in an increase in free phenolic acids in the three products, while bound phenolic acids decreased in bread and slightly changed in cookie and muffin products. Though the effect of baking appeared to be dependent on type of baked product, type of phenolic, recipe and baking conditions, the wholegrain products should be considered good sources of phenolic antioxidants.