ABSTRACT
OBJECTIVE:To investigate the influential factors for the stability of gardenia yellow solution. METHODS:Using pigment loss rate as index,the stability of gardenia yellow solution was investigated within 12 h under different light(strong light, natural light,dark place),temperature(4,25,60,80 ℃),pH(3.0,5.0,7.0,9.0,11.0),oxidant concentration(hydrogen per-oxide solution,0,0.1%,0.2%,0.3%) conditions. The effects of 3 natural antioxidants as tea polyphenol,rosmarinic acid and grape seed extract on the stability of gardenia yellow solution were investigated within 12 h under different light(strong light,natu-ral light,dark place) and temperature (25,60,80 ℃) conditions;the effects of different concentrations of tea polyphenol (0, 0.05%,0.1%,0.2%)on the stability of gardenia yellow solution were also investigated within 12 h. RESULTS:The pigment loss rates were 20%,10% and 10% within 12 h under 3 light conditions;5%,5%,30% and 60% under 4 temperature conditions;12%,6%,6%,6% and 16% under 5 pH conditions;4%,12%,15% and 18% under 4 oxidant concentrations. After adding 3 antioxidants,pigment loss rate decreased by 10% under different light and temperature conditions except for 80 ℃,and the de-crease of tea polyphenol was most significant;among 4 concentrations of tea polyphenol,pigment loss rate was the lowest in 0.1%group. CONCLUSIONS:Gardenia yellow solution can't keep stable under strong light and high temperature;3 antioxidants can im-prove the stability of gardenia yellow solution,especially 0.1%tea polyphenol.