Golden Delicious apples were obtained from a local supermarket,
and processed in a domestic juice extractor. Ascorbic and citric
acid (800 mg/L and 325 mg/L respectively) were added to the juice
to prevent oxidation and colour change and clarifying enzymes
donated by ENMEX S.A. de C.V. (Mexico, DF,Mexico) were added for
12 h at 4 C. The juice was filtered with cheesecloth before HPP
treatment. Samples of 90 mL of clarified juice were packed in lowdensity
polyethylene bags minimising as possible the air into the
bags before sealing. Samples were transferred to a 5 L pressure
treatment chamber of a High Pressure Processing Unit ACIP 6500/5/
12VB (ACB pressure systems, Nantes, France) equipped with temperature
and pressure regulators. Water was used as the pressure
transmitting medium.