Integrated effects of ascorbic acid,flavonoids and sugars on thermal degradation of anthocyanins in blood orange juice

This study aimed to elucidate how the major intrinsic factors, such as ascorbic acid (AA), flavonoids and sugars affected the thermal degradation of blood orange anthocyanins. The results in our study indicated that AA and sugars significantly accelerated anthocyanins degradation while flavonoids had a protective effect on degradation of anthocyanins. Flavonoids and AA could reduce the influence of temperature on anthocyanins degradation rate. However, the promoting effects of sugars on anthocyanins degradation correlated with the temperature. Moreover, the degradation of anthocyanins in the presence of sugars followed complex reaction kinetics when temperature was above 70 °C, and the promoting effects of sugars on anthocyanins degradation were glucose < sucrose < fructose. The results also indicated that flavonoids had a protective effect against either AA or sugars accelerated the degradation of anthocyanins, and this protective effect played a more important role in the degradation of anthocyanins comparing to the negative effect of AA or sugars. In addition, AA and sugars showed a synergistic effect on the degradation of anthocyanins at all our investigation temperatures except 90 °C.