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Thesis
Generation of oxidative species from UV (254 nm) light induced photolysis of food ingredients
Master of Science (M.S.), Drexel University
Jun 2013
DOI:
https://doi.org/10.17918/etd-4462
Abstract
Ultraviolet light (UV) processing of juices has emerged as an attractive alternative to heat pasteurization due to its effectiveness in inactivating bacteria and enhanced retention of flavor and nutritional attributes. It also has effects on nutritional compounds within solution. Fructose has shown a significant reactivity during ultraviolet light (UV, 254 nm) processing of fruit juices that can adversely affect product quality. Present study demonstrates that this reactivity of fructose is due to the oxidative nature of products formed from UV induced photolysis of fructose. This was accomplished using fluorescein, a fluorescent dye that loses fluorescence intensity upon reaction with oxidative species. Fructose caused a concentration dependent decay of fluorescence from fluorescein only in presence of UV, indicating oxidative nature of photolysis products of fructose. The transient oxidative species including free radicals and not one of the final photolysis products, furan, were responsible for fluorescence decay. Addition of an antioxidant and removal of oxygen from solution lowered the rate of fluorescence decay, suggesting strategies that can be employed to lower the deleterious effects of fructose on product. Furthermore, it these radicals appear to transverse layers of a model system of a solid food surface, approximated by 1% agarose gels. In addition, riboflavin or vitamin B2 undergoes photolysis under UV exposure, and caused a concentration dependant decay of fluorescence from fluorescein only in the presence of UV, indicating oxidative nature of the photolysis products. The understanding developed can be used to optimize UV processing of juices and potentially solid food systems.
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Details
- Title
- Generation of oxidative species from UV (254 nm) light induced photolysis of food ingredients
- Creators
- Aachen Elsinghorst - DU
- Contributors
- Rohan Tikekar (Advisor) - Drexel University (1970-)
- Awarding Institution
- Drexel University
- Degree Awarded
- Master of Science (M.S.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Resource Type
- Thesis
- Language
- English
- Academic Unit
- Nutrition Sciences; College of Nursing and Health Professions; Drexel University
- Other Identifier
- 4462; 991014632050304721