Effect of sweeteners on anthocyanin stability and colour properties of sour cherry and strawberry nectars during storage.

Effects of various sweeteners (sucrose, maltose syrup and honey) on individual anthocyanins, colour and turbidity in sour cherry (SCN) and strawberry nectars (SN) were investigated during 168 and 42 days of storage at 20 °C, respectively. In SCN, major anthocyanin was cyanidin-3-glucosylrutinoside (cyd-3-glu-rut), followed by cyanidin-3-rutinoside (cyd-3-rut), cyanidin-3-glucoside (cyd-3-glu) and cyanidin-3-sophoroside (cyd-3-soph). Maltose syrup increased stabilities of cyd-3-glu-rut (8%) and cyd-3-rut (4%), while honey reduced stabilities of all anthocyanins in SCN. Due to higher anthocyanin stability, maltose syrup for SCN was recommended. In SN, the major anthocyanin was pelargonidin-3-glucoside (pg-3-glu), followed by pelargonidin-3-rutinoside (pg-3-rut) and cyd-3-glu. Stabilities of anthocyanins (46-51%) and colour density (6-7%) in SN sweetened with honey were higher than that sweetened with sucrose and maltose syrup. Considering maximum wavelength (λmax), absorbance value at λmax (Amax), polymeric colour and colour density values together, copigmentation of anthocyanins occurred in SN sweetened with honey. This study is the first study showing copigmentation of anthocyanins with honey.