Although vitamin C is essential as an antioxidant and as a cofactor in a series of enzymatic reactions, the ability for ascorbate biosynthesis was lost in humans. Thus, horticultural products and derived fruit drinks or commercial vitamin C products are considered to be important sources for the ascorbic acid intake in the human diet. These facts underline the importance of analytical methods for ascorbic acid determination in different food products. In our study two spectrophotometric and a

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... uorometric ascorbic acid determination methods have been compared with each other and with the so-called etalon HPLC method to fi nd the best for small or middle sized food analytic laboratories with a sample number of up to several hundreds. As a result of our experiments we could establish that the OPDA-fl uorometric method can be suggested for the determination of samples containing ascorbate at low concentrations. Unfortunately, the analytical properties of the OPDA method with spectrophotometric detection have been lagging far behind the others. The 2,2'-bipyridyl method could give a balanced performance for all tests. Furthermore, the results gained by this method are the closest to the results of the reference HPLC method in the case of fruit and vegetable samples.