5. Evolution of the solids content Brix) in the concentrated and ice fraction function of the cryoconcentration cycle from a fruit juice. (o-fresh juice. 1, 2, 3: fractions obtained at the first, second and third cryoconcentration cycles, respectively) a: Blueberry juice: b: pineapple juice. water content of this fruit. By increasing the number of cycles, solids content in the concentrated fraction increased quasi-linearly with a correlation coefficient R 0.9966, and reached values of about 20, 26 and 33 "Brix at the first, second and third cryoconcentration cycles, re- spectively reach after the third cycle an increase of approximately 2.5 times the initial concentrations of solids. Amount of solutes entrapped the separated ice fraction has been estimated at 2 and 12 Brix at the first and second cryoconcentration cycles, respectively. In the third cycle, overall process efficiency decreased, and the solutes in the ice fraction increased up to 15 Brix (Fig. 5a). In the cryoconcentration from a pineapple juice (Fig. 5b) a similar behavior is observed, and solute content in the concentrated fraction increased quasi-linearly with a correlation coefficient R 0.9975, and reached values of about 32 Brix at the third cryoconcentration cycle. This value is lower than that achieved by Bonilla-Zavaleta et al. (2006), which was close 41 °Brix from 12 °Brix pineapple juice, frozen at -20 °C and centri- fuge by cycles using centrifuge tubes much wider (8 cm long x 8 cm wide) than the present study, so possible that under these conditions frozen concentrate radial stratification occurs, causing a better separa- tion of the solutes by centrifugation because the ice would be more concentrated toward the surface of the centrifuge tubes (Bakal & Hayakawa, 1973). The evolution over the cryoconcentration cycles from both fruit juices was expected, because similar behavior was