Acidulant effect on greening, reducing capacity, and tryptophan fluorescence of sunflower butter cookie dough during refrigerated storage.

Abstract

Sunflower seed derived butter can be a source of protein and phenolic antioxidants in refrigerated dough. Chlorogenic quinone-amino acid induced greening can however occur at alkaline pH, which could result in less bioavailable conjugated phenol-amino acids. Acidulants were tested as potential anti-greening ingredients in refrigerated chemically leavened cookie dough. Effect of refrigerated storage time, leavening agents and acidulants on tryptophan fluorescence (λex=280 nm, λem=300-500 nm), color (hunter L*, a*, b* color scale), reducing capacity [1,1'-diphenyl-2-picryl-hydrazyl (DPPH) and Folin-Ciocalteu reducing capacity (FCRC)], and hydroxycinnamic acids were measured. The pH range of acidified doughs was 4.83-6.98 compared to 7.65-9.18 in non-acidified leavened doughs after 24 days. Greening was higher in baking soda dough control (a*=-0.54) than baking powder dough control (a*=2.98) after 24 days, attributed to higher pH (9.18) of the former compared to pH7.14 in the later. Tryptophan fluorescence intensity in baking soda dough decreased in the order: control>glucono-delta lactone≈citric acid after 24 days. The DPPH and FCRC of acidified doughs were greater than corresponding control doughs. The use of acidulants would prevent greening in sunflower dough without lowering its phenolic concentration, making use of sunflower butter in refrigerated dough for baked goods feasible. © 2018 Society of Chemical Industry.