Chlorogenic acid oxidation-induced greening of sunflower butter cookies as a function of different sweeteners and storage conditions

- Sweeteners with higher moisture and/or pH enhanced greening in cookies.
- Storage at higher relative humidity resulted in higher surface greening.
- Chlorogenic acid-lysine adduct content was inversely correlated to greening reactants.
- Lowering the pH, moisture and aw would inhibit greening when it is not desired.

Sunflower butter use as an allergen-free alternative to tree and legume nut butter in baking is limited by chlorogenic acid induced greening that occurs at alkaline pH. Limited information is available on controlling this greening in a food matrix. This study examined how different liquid sweeteners and relative humidity influenced greening of sunflower butter cookies. Doughs had similar initial pH (7.52-7.66) which increased to 8.44-9.13 after baking as ranked: xylitol > maple syrup > corn syrup > honey > agave syrup. Cookies made with maple syrup had the highest moisture and greening corresponding with lowest free chlorogenic acid. The % greening followed the same trend as greening intensity, and was positively correlated (r = 0.9101) with chlorogenic-lysine adduct content. Our findings provide an ingredient solution to controlling greening, as results demonstrate that greening can be promoted with high relative humidity storage, and use of high moisture and pH ingredients. Unwanted greening can be inhibited by simply changing the liquid sweetener.