MECHANISMS OF DETERIORATION AND FORMULATION OF SPACE DIETS
Abstract
Model systems similar in composition to three types of freeze-dried foods were developed and used in studies on the effects of composition on the rates of deteriorative reactions at 55C. Oxidation of lipids was found to proceed most rapidly at low water contents, while non-enzymatic browning and oxidation of proteins was more rapid at elevated water contents. Antioxidants and chelating agents had only a limited effectiveness which was also dependent on moisture content. During studies on dehydrated systems it was observed that hydrolysis of sucrose can occur even at low water contents and that the reducing sugars produced in the hydrolysis undergo considerable browning. Moisture contents corresponding to monolayer coverage by water were generally optimal in minimizing deteriorative changes. Studies on actual foods were limited to a 3- week storage study at 55C. At this relatively high temperature non-enzymatic browning was found to be the cause of deterioration. Under these conditions none of the foods were found to be satisfactory after storage, and oxidative changes were less important than browning. Consequently the over-all quality of materials packaged under vacuum showed no improvement over that of materials packaged in air. Moisture content did have a significant effect, with high water contents resulting in more extensive deterioration.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 15, 1967
- Accession Number
- AD0663210
Entities
People
- Marcus Karel
- Theodore P. Labuza
Organizations
- Massachusetts Institute of Technology