Oxidation products of unsaturated fatty acids in foods cause rancid flavor and limit the storage stability of food products. Even though many synthetic antioxidants are used, increasing interest has been directed towards the utilization of normal food constituents having antioxidative properties. / In aqueous lysine-sucrose model systems, the effects of reaction time, pH and molar ratio were studied on the formation of non-enzymatic browning reaction (NBR) products. The extent of sucrose hydrolysis was measured and the antioxidant effect of NBR products on linoleic acid emulsions was examined. Nuclear magnetic resonance (NMR) spectra were obtained at various stages of browning. / Sucrose produced NMR products with lysine in an aqueous system at 100(DEGREES)C. The C-13 NMR spectra indicated that the NBR started when sucrose and lysine were dissolved in water. The C-13 NMR spectra also showed that heating did not have an effect on the gross composition of polymeric species. The absorbance at 480 nm of 0.75 M lysine-sucrose solution heated up to 6 hours increased with reaction times. The pH values of heated lysine-sucrose solution gradually decreased with reaction time. When 0.75 M sucrose or lysine solution was heated separately up to 6 hours, there were no changes in absorbance in pH. In the pH range of 3.52 - 6.35, higher absorbance was obtained from heated lysine-sucrose solution at acidic pH levels than at neutral pH levels. / As the concentration of lysine and sucrose solution was increased, the absorbance increased. At longer reaction times or acidic pH levels, enhanced hydrolysis of sucrose to reducing sugars resulted in more NBR products. NBR products obtained at a longer reaction time, an acidic pH, and higher concentration of reactants showed a darker brown color and were effective in preventing the formation of peroxides. The oxygen uptake of linoleic acid emulsion having NBR products was smaller than that of linoleic acid emulsion without NBR products. Based on these results, it was concluded that sucrose may act as an antioxidant in processed foods containing both amino acids and lipids. / Source: Dissertation Abstracts International, Volume: 48-02, Section: B, page: 0312. / Thesis (Ph.D.)--The Florida State University, 1987.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_76051 |
| Contributors | KIM, NAN-SOOK KOO., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 117 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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