Power Absorption During Microwave Heating of Emulsions and Layered Systems

Authors

  • SHERYL A. BARRINGER,

    1. Author Barringer, formerly with the Univ. of Minnesota, is now with the Dept. of Food Science & Technology, The Ohio State University, 122 Vivian Hall, 2121 Fyffe Road, Columbus, OH 43210.
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  • K. GANAPATHY AYAPPA,

    1. Author Ganapathy Ayappa, formerly with the Univ. of Minnesota, is now with the Dept. of Chemical Engineering, Indian Institute of Science, Bangalore 560012, Karnataka, India.
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  • EUGENIA A. DAVIS,

    1. Authors E.A. Davis and Gordon are affiliated with the Dept. of Food Science & Nutrition, Univ. of Minnesota, 1334 Eckles Ave., St. Paul, MN 55108.
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  • H. TED DAVIS,

    1. Author H.T. Davis is with the Dept. of Chemical Engineering & Materials Science, Univ. of Minnesota, 421 Washington Ave. SE, Minneapolis, MN 55455.
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  • JOAN GORDON

    Corresponding author
    1. Authors E.A. Davis and Gordon are affiliated with the Dept. of Food Science & Nutrition, Univ. of Minnesota, 1334 Eckles Ave., St. Paul, MN 55108.
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  • Paper No. 21125 of the contribution series of the Minnesota Agricultural Experiment Station based on research conducted under projects 18–027 and 18–063.

  • Support by the University of Minnesota Doctoral Disertation Fellowship and 1992–1994 Kraft Graduate Fellowships of the Institute of Food Technologists are gratefully acknowledged. This work was part of a Ph.D. thesis at the University of Minnesota.

Address inquiries to Dr. J. Gordon.

ABSTRACT

Microwave oven heating rates of various oil-in-water emulsions, water-in-oil emulsions, and layered systems were compared. Emulsions heated faster than corresponding layered systems, which heated faster than a calculated weighted average of individual components. Differences were attributed to increased power absorption caused by the large number of interfaces occurring in emulsions, or by a single interface in the layered system, and by resonant absorption of microwave radiation, which is determined by dielectric properties. The types and proportions of emulsions determined the number of interfaces. The dielectric properties and sample size determined in which samples resonant absorption occurred.

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