Rate of Deterioration of Freeze-Dried Salmon as a Function of Relative Humidity

Authors


  • This manuscript is Contribution No. 1062 from the Department of Nutrition and Food Science, Massachusetts Institute of Technology, Cambridge, Massachusetts. It was taken from part of an M.S. thesis completed by one of the authors (F. M.).

  • The study was supported in part by U. S. Public Health Service Research Grant EF-00376-04 from the Division of Environmental Engineering and Food Protection and by Project No. AF 41(609)-2981, Aerospace Medical Division, Air Force Systems Command, United States Air Force. One of the authors (F. M.) was supported by an A. I. D. fellowship from the Department of State, U. S. A. Presented at the annual meeting of the Institute of Food Technologists, Minneapolis, Minnesota, May,1967.

  • Presented at the annual meeting of the Institute of Food Technologists, Minneapolis, Minnesota, May, 1967.

Abstract

SUMMARY— The rates of several deteriorative reactions, including lipid oxidation, astacene pigment loss, carbon dioxide production, and production of non-enzymatic browning pigments, were studied in freeze-dried salmon at 37°C and at several relative humidities. Results previously obtained in cellulosic model systems containing methyl linoleate were confirmed by data on oxygen absorption as a function of moisture content. Both the rate of the initial peroxide mono-molecular decomposition and the peroxide value decreased as the water content was increased. Astacene pigment loss was reduced significantly by the higher moisture contents; non-enzymatic browning was increased. The significance of the reactivity of water at low moisture contents was demonstrated by its effect on the various reactions.

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