Date of Award
Doctor of Philosophy
Food Science and Technology
John R. Mount, Federico M. Harte, Dean A. Kopsell
Food quality is often times measured by the way one perceives the food, particularly with respect to color and texture. Color quality often pre-determines expectation making it an important parameter to understand. The same can be said for textural properties of food. Maintaining color and texture are just two ways in which the shelf-life of food can be measured. One particular product that has experienced problems in this area is processed cheese spread in which the US military uses as part of the Meal, Ready-to-Eat (MRE) rations. The cheese spread is one of the most highly accepted products in the MRE’s; therefore, research was necessary to determine formulary changes that could be made in order to improve product quality and increase the parameters of its shelf life. Studies were done to determine the cheese-age effect and ingredient effects for the addition of vitamins, colorants, emulsifiers, and stabilizers. The greatest improvement for the problems of hardening and darkening over time was observed when vitamins were removed from the product. Colorants were studied in the cheese spread, as well as in model systems. Carotenoid pigments were selected to determine stability against the effects of light and oxygen, and to measure antioxidant capacity after exposure to ozone. These compounds are responsible for the yellow, orange, and reds observed in fruits, vegetables, and some algal species. Extraction from the natural source has made carotenoid pigments commercially available to the food industry. Environmental influences such as atmosphere and lighting do affect the stability of carotenogenic compounds by causing structural degradation which in turn causes changes in antioxidant abilities.
Craig, Ann Marie Doneski, "The Stability of Carotenogenic Food Colorants and Strategies to Prolong the Shelf Life in Process Cheese Spread. " PhD diss., University of Tennessee, 2007.