Food chemical stability as affected by iron and ultraviolet light exposure: Rebaudioside A degradation as a case study

摘要

Chemical stability is critical for maintaining the shelf life of foods, and strategies for controlling chemical deterioration should be investigated. This project evaluated the effects of iron and ultraviolet (UV) light on chemical stability using rebaudioside A degradation as a model reaction. Iron, citrate, and UV light exposure negatively affected the storage stability of rebaudioside A. Storage of pH 3 solutions in darkness for 2 months at 30 degrees C caused no observable loss of rebaudioside A. Degradation rate constants increased significantly (p < .05) when solutions were exposed to UV light. Increasing concentrations of iron enhanced photodegradation rates. The presence of iron in combination with citrate further increased rebaudioside A degradation. Manufacturers of beverages and other liquid products need to be aware that photodegradation of food ingredients, such as rebaudioside A, is enhanced in the presence of iron and citrate buffer. Practical applications This research demonstrates the large effect of iron and citrate on the chemical stability of beverages and other liquid products stored in packaging permeable to UV light. Photodegradation of food ingredients, such as rebaudioside A, reduces food quality and potentially nutritional value. Thus, strategies should be implemented to minimize these reactions. The use of packaging materials that block UV light will prevent photodegradation reactions. Monitoring and removing iron contamination from water or other food ingredients is another strategy. Both approaches will promote a longer shelf life.