RESIDENCE TIME DISTRIBUTION OF CARROT CUBES IN STARCH SOLUTIONS IN A PILOT-SCALE ASEPTIC PROCESSING SYSTEM

Residence time distribution (RTD) of carrot cubes flowing in starch solutions was evaluated in a commercial pilot-scale aseptic processing system using a full factorial design of experiments employing flow rate (15 and 20 kg/min), temperature (80 and 100-degrees-C), holding tube length (0, 60 and 100%), particle size (6 and 13 mm) and starch concentration (3 and 5% w/w) as factors. All factors were found to be significant (p < 0.05) in influencing the fastest particle residence time (FPRT), mean particle residence time (MPRT), particle residence time variance (PRTV) and their normalized versions. While particle size, holding tube length and starch concentration increased the FPRT, fluid flow rate and temperature had the opposite effect. The FPRT was lower than the average fluid retention time under all testing conditions.