Strawberries show a large spectrum of phenolic components in which not only the anthocyanins, but also the colourless phenols (particularly ellagic acid, ellagitannins, flavanols, derivates of p-coumaric acid, kaempferol and quercetin) make a high contribution to the antioxidant capacity (Hernanz et al. 2007). The anthocyanins are subjected to intense changes during processing and storage. A considerable degradation of anthocyanins in processed strawberries is due to oxidative enzymes (Lopez-Serrano et al. 2002, Gössinger et al .2009). Anthocyanins condense also with other phenolic compounds to form oligomers and polymers. Therefore, noticeable changes of anthocyanins during processing and storage are visible to the naked eye, especially in the case of strawberry juices which are characterized by fast browning. To best preserve the valuable substances of fruits during processing, it is important to identify the processing steps which cause the highest losses. A decrease of anthocyanins and polyphenols is not only found for strawberry juices, but also for strawberry purees. The same is valid for ascorbic acid. Purees produced in an industrial scale often possess much lower vitamin C concentrations than the fresh strawberry fruits (in the range of 50-200 mg/kg compared to 300-800 mg/kg in the fruit). In the present study, the influence of main processing steps on anthocyanins, polyphenols and ascorbic acid of strawberry juice and strawberry puree was investigated.