Effects of natural copigment sources in combination with sweeteners on the stability of anthocyanins in sour cherry nectars.

• Sweeteners and copigment sources had significant effects on color of sour cherry nectar. • Addition of gallic acid and pomegranate rind extract increased anthocyanin stability. • Rose leaf extract increased stability of color density by up to 117%. • Pomegranate rind extract resulted in the lowest turbidity and turbidity formation rate. • Pomegranate rind extract is recommended for enrichment and stability of colour. Effects of various co-pigment sources [gallic acid (GA), rose leaf extract (RLE), cherry stem extract (CSE), pomegranate rind extract (PRE) and green tea extract (GTE)] on anthocyanin content, colour, and turbidity in sour cherry nectar (SCN), sweetened with sucrose (SCNS), maltose syrup (SCNM) or honey (SCNH), were investigated during storage at 20 °C. Co-pigment sources were associated with increases in λ max (up to 4.1 nm), colour density (up to 22%), and polymeric colour (up to 1.7 times). Among the co-pigment sources, GA and PRE were associated with the greater anthocyanin stabilities in SCNS and SCNH. Moreover, the lowest turbidity, at the beginning of storage, and turbidity formation rate, throughout storage, were observed in SCNS, SCNM and SCNH containing PRE. When the changes in A max , λ max , polymeric colour, colour density, and turbidity were considered together, PRE was the best co-pigment source, regardless of the sweetener used. [ABSTRACT FROM AUTHOR]