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

ABSTRACT

BACKGROUND: 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. RESULTS: 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 pH 7.14 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. CONCLUSION: 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.