Freeze Desiccation. A New Method of Food Preservation

Abstract

Freeze desiccation of foods is based on the use of a solid desiccant for the adsorption of water vapor which sublimes from the frozen food at a reduced pressure. Desorption isotherms of the food and adsorption isotherms of the desiccant were used for the calculation of the quantities of desiccant necessary to obtain different pre-determined residual moisture contents of the food. An equation and a curve were developed for this purpose. The new method compares favorably with conventional freeze dehydration. It offers the specific advantages of accurate control of the end point residual moisture in the food. For moisture contents above about 5%, the use of silica gel as a desiccant was found to be very suitable. For moisture contents below this limit, substitution of molecular sieves for the silica gel in a two-stage desiccation process was necessary in order to desorb the more firmly bound water.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1968
Accession Number
AD0837172

Entities

People

  • J. W. Giffee
  • John G. Kapsalis
  • Jurgen Strasser

Organizations

  • United States Army Soldier Systems Center

Tags

DTIC Thesaurus Topics

  • Adsorption
  • Dehydrated Foods
  • Dehydration
  • Desiccants
  • Desorption
  • Equations
  • Food
  • Freeze Dried Foods
  • Freeze Drying
  • Frozen Foods
  • Heat Energy
  • Isotherms
  • Mass Transfer
  • Moisture
  • Moisture Content
  • Molecular Sieves
  • Silica Gels
  • Sorption
  • Water Vapor

Readers

  • Agricultural Chemistry/Soil Science
  • Industrial Economics
  • Thermal Physics or Thermal Science.