Modulating polyphenolic composition and organoleptic properties of apple juices by manipulating the pressing conditions

Initial crushing and pressing operations have a major influence on the polyphenolic composition of apple juice, therefore, we have tested the impact of variations of this step using three cider apple cultivars of contrasting polyphenolic composition: Guillevic, Kermerrien and Dous Moen. Under inert atmosphere, increased temperature (between 5 °C and 24 °C), increased the extraction of procyanidins from fruit to juice. The crushed apples were also subjected to four conditions of oxidation: preserved from oxidation as above, short contact with air, short contact with air and mixing, long contact with air and mixing. Oxidation decreased the concentrations of native polyphenols in the juices, especially for flavan-3-ols. The golden colour of the juices was initially enhanced with increases in saturation C∗ and a shift of the hue angle from yellow to orange. However, for the highest oxidation state the colour became paler and more yellow. Bitterness and astringency decreased upon oxidation, probably due to increased retention of oxidised moieties.