Pulsed Ultra High Pressure Treatments for Pasteurization of Pineapple Juice |
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Authors: | GIOVANNA D. ALEMÁ N,MARCIA WALKER,DANIEL F. FARKAS,J. ANTONIO TORRES,EDMUND Y. TING,SIGURD C. MORDRE,ADRIAN C.O. HAWES |
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Affiliation: | Authors Alemán, Walker, Farkas, and Torres are with the Food Process Engineering Group, Dept. of Food Science &Technology, Oregon State Univ., Corvallis, OR 97331-6602. Authors Ting, Mordre, and Hawes are with Flow International Corporation, Kent, WA 98032. Address inquiries to Dr. J. Antonio Torres. |
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Abstract: | Sinusoidal and step-pressure pulses were compared with static pressure treatments for the inactivation of Saccharomyces cerevisiae 2407-1a in pineapple juice. No inactivation was observed after 40–4,000 fast sinusoidal pulses (10 cycles/s) at 4–400 sec in the 235–270 MPa range. Static 270 MPa treatments at 40 and 400 sec resulted in 0.7 and 5.1 decimal reductions, respectively. Slower 0–270 MPa step pulses at 0.1 (10 pulses), 1 (100 pulses), and 2 (200 pulses) cycles/s with 100 sec total on-pressure time resulted in 3.3, 3.5, and 3.3 decimal reductions, respectively. A comparable static pressure treatment resulted in 2.5 decimal reductions. Changing the on-pressure/off-pressure time ratio (3:1, 3:3 and 1:3) showed that treatments with longer on-pressure time, e.g., 0.6 sec on-pressure and 0.2 sec off-pressure were significantly more effective showing nearly a 4 decimal reduction in 100 sec. |
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Keywords: | ultra high pressure pineapple juice preservation yeasts |
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