Assessment of the long-term stability of retort pouch foods to support extended duration spaceflight

To determine the suitability of retort processed foods to support long-duration spaceflight, a series of 36-mo accelerated shelf life studies were performed on 13 representative retort pouch products. Combined sensory evaluations, physical properties assessments, and nutritional analyses were employed to determine shelf life endpoints for these foods, which were either observed during the analysis or extrapolated via mathematical projection. Data obtained through analysis of these 13 products were later used to estimate the shelf life values of all retort-processed spaceflight foods. In general, the major determinants of shelf life appear to be the development of off-flavor and off-color in products over time. These changes were assumed to be the result of Maillard and oxidation reactions, which can be initiated or accelerated as a result of the retort process and product formulation. Meat products and other vegetable entrées are projected to maintain their quality the longest, between 2 and 8 y, without refrigeration. Fruit and dessert products (1.5 to 5 y), dairy products (2.5 to 3.25 y), and starches, vegetable, and soup products (1 to 4 y) follow. Aside from considerable losses in B and C vitamin content, nutritional value of most products was maintained throughout shelf life. Fortification of storage-labile vitamins was proposed as a countermeasure to ensure long-term nutritive value of these products. The use of nonthermal sterilization technologies was also recommended, as a means to improve initial quality of these products and extend their shelf life for use in long-duration missions. Data obtained also emphasize the importance of low temperature storage in maintaining product quality.

Retort sterilized pouch products are garnering increased commercial acceptance, largely due to their improved convenience and quality over metal-canned products. Assessment of the long-term stability of these products with ambient storage can identify potential areas for improvement, and ultimately increase consumer satisfaction with these technologies.