Composition of clear and cloudy juices from French and Polish apples in relation to processing technology

- Quality of apple juice strongly depends on processing technology.
- Selection of cultivars is a key factor for the production of juices rich in phenolic compounds.
- Sedimentation rather than centrifugation preserves antioxidants in juice.

Four technologies of clear and cloudy juice production according to typical Polish and French procedures were investigated with six apple cultivars. Clear juices were produced using technologies similar to those used by the processing industry, while cloudy juices were processed according to simple protocols used in small-scale processing. In order to best evaluate the effects of the processing technology and cultivar on juice quality, the production of juices was carried out both in Poland and France on the same raw material. The technology, unlike the cultivar, did not affect the soluble solids content of the juice, or the levels of most of the sugars, malic acid or potassium. However, the antioxidant activity measured by the ABTS+ method and the levels of monomeric phenolics and procyanidins strongly depended on the apple cultivar and production technology. For cloudy juices, the selection of appropriate cultivars and production without centrifugation are the key to substantially increasing the amounts of healthy compounds in apple juice.