Ascorbic Acid Determination in Vegetables and Fruits: Comparison of Colorimetry with High Performance Liquid Chromatography

Ascorbic Acid (AsA) is included in various fruits and vegetables and its quantity correlates with quality after harvest. The quantity of AsA is usually evaluated by colorimetry but as this technique uses reduction of iron, it is easy for colorimetry to be influenced by reducing agents such as AsA. In this study, we compare colorimetry with high performance liquid chromatography (HPLC) in measurement of AsA in fruits and vegetables. We also evaluated the correlation between colorimetry and antioxidant and iron reduction ability. As a result, the quantity of AsA measured by colorimetry was higher than that with HPLC for reduction materials except for AsA. There was poor correlation between colorimetry and antioxidant ability but good correlation between colorimetry and iron reduction ability. We conclude that colorimetry is not suitable for accurate evaluation of the quantity of AsA in vegetables and fruits but it is suitable for evaluation of iron reduction.