Extraction and quantitative determination of ascorbic acid during different maturity stages of Rosa canina L. fruit

Dog rose (Rosa canina L.) fruit in different stages of proposed was used as a source of ascorbic acid. Two sample preparation methods for extracting ascorbic acid in dog rose fruit were evaluated. These methods used high performance of liquid chromatography (HPLC) for detecting of ascorbic acid, but differed in the preparation of sample (freezing and mild-temperature-drying procedure). Under optimized conditions, the freezing procedure demonstrated better results. The method was used to compare the amount of ascorbic acid in fully ripe, half-ripe and unripe dog rose samples. The results show that dog rose has the highest amount of ascorbic acid in its fully ripe maturity stage. In addition, the intra-day stability of ascorbic acid in standard solution, fully ripe dog rose extract and fully ripe dog rose intact fruit, was investigated. The results show that ascorbic acid has highest stability in untreated dog rose fruits. As a comparative study, orange sample was also analyzed by the methodology developed in this work. The results show that the amount of ascorbic acid in dog rose fruit (417 mg per 100 g) is about 6 times higher than that in orange sample (76 mg per 100 g).