In this study, we determined the effect of nutritive sweeteners at 0 to 0.50 moles/kg on lipid oxidation in a model cookie system. Confocal microscopy using Bodipy 493 as a fat soluble dye showed that the fat formed a continuous phase surrounding the starch granules regardless of sugar type. The impact of glucose concentration on lipid oxidation was monitored by lipid hydroperoxides and headspace hexanal during storage at 55°C. Low concentrations of glucose (0.09) were strong inhibitors. At equal molar concentrations, reducing sugars (glucose and fructose) inhibited lipid oxidation, greater than a two months increase in lag phase compared to the control. Sucrose inhibited lipid oxidation, but to a much lesser extent than reducing sugars. The inhibition of lipid oxidation is potentially due to sugar’s ability to bind water. Additionally, reducing sugars may exhibit this effect due to their ability to act as a hydrogen donor which could inactivate free radicals or due to the production of Maillard reaction products (MRPs). For example, the l-values were lower and b-values were higher for cookies with non-reducing sugars compared to cookies with sucrose indicating that there were more MRPs. The addition of cysteine, sulfites, and ascorbic acid acted as a strong browning inhibitors however cysteine was showed to be antioxidative. When compared to synthetic antioxidants, glucose proved to be a strong natural alternative. These results could be utilized to develop effective means of controlling water activity and extending shelf-life of low moisture baked goods.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:masters_theses_2-1432 |
| Date | 07 November 2016 |
| Creators | Vieira, Samantha |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Masters Theses |
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