Lemon juice improved color acceptance of aronia (Aronia melanocarpa) pound cake by copigmentation

Anthocyanins can be changed into dark purplish color during pound cake preparation due to high temperature and alkaline baking soda, which lowers color acceptance by consumers. To stabilize a red color of anthocyanins in pound cake enriched with aronia (Aronia melanocarpa) powder, lemon juice was added to contain final concentrations of 0, 1, 2, and 3% (w/w) in the pound cake, which were assigned as control, PL1%, PL2%, and PL3%, respectively. As lemon juice amount increased, redness (a*) and sensory color perception as well as overall acceptance were enhanced, whereas hardness, gumminess, and chewiness decreased in texture profile analysis. In a model system, the addition of lemon juice to aronia solution caused bathochromic shift and hyperchromic effect in UV-Vis absorption spectrum, which are typical phenomena of copigmentation derived from interactions between anthocyanins and copigments. The results indicate that lemon juice improved color acceptance for aronia pound cake by copigmentation.