江安夏橙原汁中维生素C稳定性分析

Study on the Stability of Vitamin C in Jiang'an Summer Orange Juice

以新鲜江安夏橙为原料,研究不同温度、加热时间、接触空气、光照、蔗糖浓度及p H条件对江安夏橙原汁中维生素C稳定性的影响.结果表明：橙子原汁中维生素C随着加热温度（30-100℃）升高和加热时间（2-12 min）延长,其维生素C呈现大幅度下降趋势;橙子原汁中维生素C暴露在空气时,暴露30 min时橙子原汁中的维生素C被快速氧化,30 min后橙汁中维生素C的分解速度开始减缓;光照条件下,橙子原汁中维生素C随着光照时间的延长和光照强度的增加,维生素C分解速度有所增加;随着橙子原汁中p H值的升高,维生素C的保存率呈现明显下降趋势,pH值为9时,其保存率仅有24.72%;在橙子原汁中加入浓度为6%的蔗糖,能提高维生素C的保存率,保持橙汁的营养价值.研究结果对橙子原汁的贮藏、加工等具有实际意义.

Using fresh Jiang＇an summer orange as material, the changes of the stability of vitamin C in orange juice at dif-ferent processing and preserving conditions were studied. The vitamin C in orange juice decreases significantly with theheat treatment temperature（30-100℃） heightened and heating time（2-12 min） prolonged. Vitamin C in orange juice israpidly oxidized when exposed in air for 30 mins, with the decomposition rate of vitamin C in orange juice beginning toslow down after 30 mins. The decomposition rate of vitamin C in orange juice increase with the light intensity heightenedand illumination time prolonged; the vitamin C retention rate in orange juice decrease evidently with the increase of p Hvalues. When the value of pH is 9, its preservation rate is only 24.72%. 6% of added sugar can improve the rate of preser-vation of vitamin C. The study has practical significance for storage and processing.