Study on the extractions and physical and chemical properties of yellow pigments from Wisteria sinensis sweet calyx with different processing

The raw materials of fresh calyx, dried calyx and frozen calyx of the folk edible wisteria ( Wisteria sinensis Sweet) were studied for the extracting procedure, physical and chemical properties of yellow pigments.The results revealed that fresh calyx, dried calyx and frozen calyx were suitable for microwave-assisted extraction, heating reflux extraction and ultrasonic-assisted extraction respectively, all the three kinds of yellow pigments were stable under acidic conditions and freely soluble in polar solvent such as ethanol, strong heat resistance, more sensitive to light, poorer oxidative resistance.The coexisting components of common food such as NaCl, Vc, sodium benzoate, sucrose, and metal iron such as Mg2 +, Ca2 +, Fe3 +, Cu2 +had greater effects, with significant differences, on the stability of three yellow pigments and.Therefore, the wisteria kept with dried calyx was optimal.