Abstract
The compressive mechanical properties of freeze-dried green beans show a pronounced decrease in rigidity when moisture content and/or temperature are increased. There exist several temperature and moisture combinations which give common values for mechanical properties. These combinations also give a common compressive behavior. Using this information on mechanical properties, it is possible to predict a stress-strain relationship, if given either a temperature, a moisture content, or the value of a pertinent mechanical property.
It is shown that the moisture contents and temperatures that exist in the dry layer during freeze-drying result in mechanical properties that are suitable for compression of the dry layer. From studies on compression behavior during freeze-drying, it is shown that applied compressive pressure is the main determinant of final degree of compression. Increasing the compressive pressure gave a higher compression effect and gave a more rapid drying, presumably due to improved heat transfer in the compressed dry layer.
From the above information, a simple method to predict compression behavior during freeze-drying was developed.
This work was conducted while the authors were associated with the Department of Nutrition and Food Science, Massachusetts Institute of Technology, Cambridge, MA 02139 USA.
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References
S-H. Emami, Mechanical compression of food products during freezedrying through force produced by springs, M.Sc. Thesis, MIT, Cambridge, MA (1976).
G. Beke, The effect of sublimation temperature on the rate of freeze-drying process and upon the volumetric change in meat muscle tissue, in: “Proceedings XII International Congress Refrigeration,” Vol. 3, Madrid (1969).
J.D. Hatcher, The use of gamma radiation to measure moisture distribution during drying processes, M.S. Thesis, Georgia Institute of Technology (1964).
J.D. Hatcher, D.W. Lyons, and J.E. Sunderland, An experimental study of moisture and temperature distributions during freeze-drying, J. Food Sci. 36:33 (1971).
A. Margaritis and C.J. King, Factors governing the terminal rates of freeze-drying of poultry meat, Chem. Eng. Prog. Symp. Ser. No. 108 67:112 (1971).
J.M. Aguilera and J.M. Flink, Determination of moisture profiles from temperature measurements during freeze-drying, J. Fd. Technol. 9:391 (1974).
A.M. Brajnikov, A.I. Vassiliev, V.A. Voskoboinikov, and E.I. Kantchechivili, Transfer de chaleur et de masse dans les materiaux poreaux pendant le lyophilisation sous vide, Bull. Int. Inst. Refrig. Annex 1969 4:11 (1969).
S.H. Emami, Compression of foods during vacuum freeze dehydration, Ph.D. Thesis, Massachusetts Institute of Technology (1979).
M. Karel, Freeze-dehydration of foods, in: “Principles of Food Science, Part II, Physical Principles of Food Preservation,” O.R. Fennema, ed., Vol. 4, Marcel Dekker, New York (1975).
J.M. Aguilera and J.M. Flink, A combined experiment-computer technique for determining heating programs for batch and continuous freeze dryers, J. Fd. Technol. 9:329 (1974).
C.J. King, “Freeze Drying of Foods,” CRC Press, Cleveland (1971).
O.C. Sandall, C.J. King, and C.R. Wilke, The relationship between transport properties and rates of freeze drying of poultry meat, AIChE J. 13:428 (1967).
G.L. Gentzler and F.W. Schmidt, Thermodynamic properties of various water phases relative to freeze drying, Trans. ASAE 16:179 (1973).
G.W. Oetjen, Continuous freeze drying of granulates with drying times in the 5–10 minutes range, in: “Proceedings of XII International Congress of Refrigeration,” Vol. 3, AVI, Washington, DC (1973).
J.G. Kapsalis, J.E. Walker, Jr., and M. Wolf, A physico-chemical study of mechanical properties of low and intermediate moisture foods, J. Text. Stud. 1:464 (1970).
A.P. MacKenzie and B.J. Luyet, Recovery of compressed dehydrated foods, Phase II., Technical Report 72-33-FL, U.S. Army Natick Laboratories, Natick, MA (1971).
I. Sakata, and R. Senjue, Thermoplastic behavior of lignin with various synthetic plasticizers, J. Appl. Poly. Sci. 19:2799 (1975).
C. Emami and J.M. Flink, Continual hydraulic compression of food during freeze drying, submitted for publication.
S.H. Emami, J.M. Flink, and A.R. Rahman, Compression of foods during freeze drying, J. Fd. Proc. Preserv. 2:285 (1979).
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© 1991 Springer Science+Business Media New York
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Emami, C., Flink, J.M. (1991). Compression of Foods during Freeze-Drying: Water Plasticization at the Ice-Dry Layer Interface. In: Levine, H., Slade, L. (eds) Water Relationships in Foods. Advances in Experimental Medicine and Biology, vol 302. Springer, Boston, MA. https://doi.org/10.1007/978-1-4899-0664-9_40
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DOI: https://doi.org/10.1007/978-1-4899-0664-9_40
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