metals) and hydroperoxides, phase transition, mobilization of pro- and antioxidants, and diffusion-related phenomena (Fritsch, 1994).

In the case of the EFP, oxidative changes in the lipid phase would be of concern when unsaturated lipids and minerals are present in significant amounts, for not only could they lead to adverse changes in flavor and acceptability, but also to production of toxic by-products and destruction of fat-soluble vitamins (Gregory, 1996). Therefore, although products at an intermediate moisture range may be more appealing in sensory quality, they may also be more prone to spoilage, browning, and other reactions. On the other hand, lowering the water content of the product to a dry state (< 5 percent moisture) may promote lipid oxidation. A solution to this dilemma would be to develop a dry product (< 5 percent moisture) in which lipids and pro-oxidants are kept separate by means of physical barriers, such as in encapsulation. Use of antioxidants also may be necessary depending on the level of saturation of the lipids. Additionally, the packaging method and materials used would play an important role in the oxidative stability of the EFP (Burke, 1990). The advantages of a dry product must be weighed against the fact that, for a thirsty recipient, eating it may be an unpleasant experience.

It should be noted that in the event the product is amenable to hydration before consumption, its microbiological safety should be evaluated. Potential growth of pathogenic microorganisms after rehydration—particularly if the product is not immediately consumed—could pose serious health risks, especially for recipients having impaired immune systems and vulnerable subgroups such as young children and the elderly.

Because of the above considerations, it is advisable that the lipids and pro-oxidants (e.g,. added mineral ingredients) in the EFP be kept physically separated within the product during manufacturing and subsequent storage by encapsulation of the minerals. Careful design of the encapsulation materials will be required so that they cover the intended ingredients efficiently, hold their integrity under the selected processing conditions, and disintegrate upon consumption so that nutrients are made physiologically available. Further protection against oxidation of unsaturated fats and vitamins in the EFP may be accomplished through a combination of microencapsulation, use of suitable antioxidants, development of stable emulsion prior to drying, and appropriate packaging.

Experimental data on vitamin stability and degradation kinetics have been extensively reviewed (Karmas and Harris, 1988; Kirk, 1981; Villota and Hawkes, 1992). The nutritional quality of dehydrated foods is a function of temperature, light, oxygen, moisture, and the physicochemical state of the water (Bluestein and Labuza, 1988). The various chemical forms of added nutrients

Front Matter (R1-R12)

Executive Summary (1-8)

1 Introduction (9-16)

2 Nutrient Content and Special Considerations (17-96)

3 Processing and Packaging of the Emergency Food Product (97-128)

4 Performance Specifications (129-140)

Appendix Biographical Sketches of Subcommittee Members (141-143)