Date of Award
Master of Science (MS)
Food, Nutrition, and Culinary Science
Dr. Feng Chen
Dr. Jun Luo
Dr. Kurt Young
Thiamine degradation occurs during storage and transportation for short and long periods due to the exposure to several factors, such as heat, oxidation-reduction reactions, and alkali. In this study, the effects of four metal ions (i.e., Cu+, Cu2+, Fe2+, and Fe3+) on thiamine stability in aqueous solutions at three temperatures (i.e., 25, 40, and 55°C) for the storage time of 7 days were discussed. Thiamine degradation was found to follow the first-order kinetic reaction, and the degradation rate could also be estimated. The factors in influencing thiamine stability included pH values, temperatures, and chemical properties of metal chlorides.
High-performance liquid chromatography (HPLC) equipped with an Eclipse XDB C18 column (4.6 mm x 150 mm, 5μm) was used to analyze thiamine contents. The method was operated in a gradient elution program, which comprised solvents A (0.1M ammonium acetate was adjusted to pH = 5.8 by 0.1% acetic acid) and solvent B (acetonitrile in HPLC grade) at the flow rate of 1 mL min-1 up to 5 mins. The column was maintained at 30°C, and the UV detector was set at a wavelength of 254 nm. The pH values of the samples were also monitored during the entire storage time.
At 25°C, the highest loss of thiamine (64.00%) was in 50 mg L-1 of CuCl solution, while the lowest loss of thiamine (78.34%) was in 50 mg L-1 of FeCl3 solution. At 40°C, the highest loss of thiamine (59.76%) was in 50 mg L-1 of FeCl2 solution, while the lowest loss of thiamine (91.48%) was in 50 mg L-1 of FeCl3 solution. At 55°C, the highest loss of thiamine (61.94%) was in 50 mg L-1 of CuCl solution, while the lowest loss of thiamine (95.98%) was in 50 mg L-1 of FeCl3 solution.
Huang, Jhong Huei, "Effect of Metal Ions and Temperature on Stability of Thiamine Determined by HPLC" (2022). All Theses. 3936.