Life Sciences Commons^™

Antioxidant Synergism Between Α-Tocopherol And A High Phosphatidylserine Modified Lecithin, Harshika Arora

Masters Theses

Phospholipids, such as phosphatidylserine (PS) have been shown to work synergistically with tocopherols to extend the shelf life of oil-in-water emulsions. However, the high cost of PS prevents it from being used as a food additive. This work investigated the potential use of a high PS enzyme-modified lecithin to be used along with α-tocopherol to extend the lag phase of oil-in-water emulsions stabilized using Tween 20. Phospholipase D from Streptomyces sp. and L-serine were used to modify lecithin to increase PS concentration. Enzyme activity was optimized as a function of pH and temperature using a high PC soybean lecithin. The …

Antioxidant Combination Of High Phosphatidylserine (Ps) Lecithin With Mixed Tocopherol In Soybean Oil-In-Water Emulsion: Effect Of Ph And Salt, Princy Agnihotri

Masters Theses

Lipid oxidation is one of the major challenges faced by the food industry as it contributes to the loss of nutritional quality and loss of flavor in food products. Studies have shown that naturally occurring phospholipids like phosphatidylserine (PS) and phosphatidylethanolamine (PE) can regenerate oxidized tocopherols and help delay the lipid oxidation in bulk oils and oil-in-water emulsions. Since consumers desire simpler and cleaner labels, without chemically synthesized antioxidants, this research is of great interest. The combination of PS and PE with tocopherols has already been studied. However, PS was a better antioxidant in combination with tocopherols in the oil-in-water …

Application Of Flow Cytometry As Novel Technology In Studying Lipid Oxidation In Oil-In-Water Emulsions, Peilong Li

Masters Theses

The body of literature on the impact of emulsion particle size on oxidation rates is unclear. This could be because emulsions are typically polydisperse and the oxidation rate of individual droplets is impossible to discern. Flow cytometry is a technique for studying individual cells and their subpopulations using fluorescence technologies. It is possible that individual emulsion droplets could also be characterized by flow cytometry as a novel approach for studying lipid oxidation. Typical emulsion droplets are too small to be visualized by flow cytometer, so emulsions were prepared to have droplets > 2 μm; weighting agent and xanthan gum were added …

Reactive Carbonyl Compounds: Their Control And Consequences In Foods, Michael Freund

Masters Theses

Polyunsaturated omega-3 fatty acids (n-3 PUFAs) have been suggested to reduce risk for multiple diseases but animal studies on the beneficial effects of n-3 PUFAs are conflicting, possibly due to the presence of toxic lipid oxidation products in the oils used in these studies. In order to provide guidance for future research in n-3 PUFA supplementation, this study researched lipid oxidation and its inhibition in an animal feed system enriched with fish oil. Different storage conditions were tested, and it was found that samples stored at room temperature or above were at significant risk for oxidation with lag phases of …

Tocopherol Regeneration By Phospholipids In Soybean Oil-In-Water Emulsions: Effect Of Tocopherol Homologue And Emulsifier Type, Gautam Samdani

Masters Theses

Phospholipids can regenerate oxidized tocopherols and help delay lipid oxidation. The impact of emulsifier type, tocopherol homologue and phospholipid head group on tocopherol-phospholipid interaction was investigated in this study.

Three µmol tocopherol/kg emulsion and 15.0µmol/kg emulsion of PE or PS were dissolved in oil and emulsions were prepared. Tween 20 or bovine serum albumin(BSA) was used as emulsifier and the continuous phase contained 10mM imidazole/acetate buffer at pH 7. Lipid hydroperoxides and hexanal were measured as lipid oxidation products and the lag phase was determined. With Tween 20 as the emulsifier, α and δ-tocopherol had a hexanal lag phase of …

Utilizing Nutritive Sweeteners To Control Lipid Oxidation In Low Moisture Baked Goods, Samantha Vieira

Masters Theses

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 …