The focus of this thesis was on vitamin C and the degradation of ascorbic acid in orange and apple juices. My research was on the effect of different temperatures on the Vitamin C content of apples and oranges during storage. For this research, I used the High-performance liquid chromatography and spectrophotometry method. This research showed that the vitamin C content in fruits decreases faster when the temperature increases. Due to the sensitive nature of Vitamin C to heat, light, and other factors, fruits are best stored at lower temperatures and for a short period of time. The best way to benefit from all the vitamin C content is to consume fresh fruits.