Chlorogenic acid induced colored reactions and their effect on carbonyls, phenolic content, and antioxidant capacity in sunflower butter cookies

The high chlorogenic acid (CGA) content of sunflower seeds causes a greening reaction in sunflower butter baked products which can deter application of sunflower butter as an allergen-free alternative to other plant and dairy based butters. This study focused on how greening intensity of sunflower butter cookies made with different sweeteners (maple, agave, corn syrups, honey and xylitol) affected greening, protein oxidation products, Folin and ABTS(center dot)+ radical scavenging ability. Cookies made with maple syrup and xylitol had higher pH and resulted in more greening. The dough made with agave syrup had highest total carbonyls caused by its highest reducing sugar content resulting in more Maillard reaction during dough preparation, while after baking cookies with highest greening (maple syrup) and highest reducing sugar (agave syrup) had higher carbonyls than other sweetener treatments. Cookies made with maple syrup and xylitol also had lower folin-ciocalteau reagent reducing capacity and tryptophan fluorescence. The greening reaction did not affect Schiff bases from oxidation and antioxidant capacity in cookies made with different sweeteners. Higher pH sweeteners thus enhanced greening intensity, tryptophan loss and lowered the total phenolic content after baking and storage, but did not influence the ABTS(center dot)+ capacity of sunflower butter cookies. (C) 2017 Elsevier Ltd. All rights reserved.