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 Properties And Anti-Cancer Effects Of Polyphenols In Sweetpotato Leaves, Josue Bolanos

Graduate Theses and Dissertations

Although the root is widely consumed, sweetpotato leaves (SPL) are often discarded and are only consumed in a few countries. In the United States, SPL consumption is limited to private gardens, particularly in the Southeastern United States. Not only are SPL a good source of nutrients such as vitamins and minerals, but they also contain polyphenol compounds including the caffeoylquinic acid derivatives and carotenoids such as lutein. Several studies have shown the polyphenol contents and antioxidant capacities of SPL, which vary based on year and variety, while few studies have shown anti-colon cancer effects of SPL. Therefore, this study investigated …

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 …

Understanding The Impact Of Oxygen Concentration And Active Packaging On Controlling Lipid Oxidation In Oil-In-Water Emulsions, David Johnson

Doctoral Dissertations

Consumer concern over synthetic food antioxidants have led researchers to seek alternative natural, or ‘clean’ label, solutions to prevent lipid oxidation. Unfortunately, natural antioxidants are often not as effective as their synthetic counterparts. As a result, there remains a need to develop active packaging strategies and maximize current antioxidant strategies in food applications. Active packaging, or packaging that has a function beyond being an inert barrier, is an attractive strategy to limit lipid oxidation in foods. Active packaging performs the work of an antioxidant without appearing on the package label. The work presented here builds upon active packaging development as …

Impact Of Microwave-Assisted Heating And Enzymatic Treatment On Functional And Antioxidant Properties Of Rainbow Trout (Oncorhynchus Mykiss) By-Product Hydrolysates, Elizabeth Bich Hang Nguyen

Open Access Theses

Fish protein hydrolysates (FPH) have been widely used as a mean to better utilize fishery by-products through the use of proteolytic enzymes to produce a wide range of functional peptides that can be used as food ingredients. Studies have shown that these functional peptides have enhanced interface-stabilizing properties (e.g. functionality) and antioxidant activity. FPH production can be accelerated by using rapid heating methods (e.g. microwave) compared to slower conventional heating (CH). The objective of this study was to investigate the effects of microwave heating (MW) during enzymatic hydrolysis on functionality and antioxidant properties of FPH. Treatments consisted of adding Alcalase™ …

Synthesis And Applications Of Non-Migratory Metal Chelating Active Packaging, Maxine J. Roman

Doctoral Dissertations

Many packaged foods use synthetic chelators (e.g. ethylenediaminetetraacetic acid, EDTA) to inhibit metal promoted oxidation and/or microbial growth that may cause food spoilage. Consumer demand for foods without synthetic additives has prompted growing interest in alternative preservation methods. Our research group has previously developed non-migratory metal chelating active packaging materials by surface immobilization of polymeric chelators and demonstrated their ability to inhibit lipid oxidation in model food emulsions. The work presented in this dissertation investigates the synthesis, performance stability, and practical application of metal chelating surface modifications to optimize design of non-migratory metal chelating active packaging materials. Metal chelating active …

In Vitro Gastrointestinal Digestion Model To Monitor The Antioxidant Properties And Bioaccessbility Of Phenolic Extracts From Elderberry (Sambucus Nigra L.), Ninghui Zhou

Wayne State University Theses

This study performed an in vitro gastrointestinal digestion model to monitor the antioxidant properties of phenolic extracts derived from the elderberry (Sambucus nigra L.). The stability and antioxidant qualities of phenolic compounds from elderberry were assessed by an in vitro gastrointestinal digestion model involving pepsin digestion (to simulate gastric digestion) and pancreatin digestion (to simulate small i22ntestine conditions). Digested and undigested elderberry were subject to antioxidant assays including total phenolic content (TPC) assay, DPPH radical scavenging assay, and oxygen radical absorbance capacity (ORAC) assay. Our result showed that digestion process significantly reduced DPPH radical scavenging activity but had no significant …

Impact Of Algae Supplemented Diets Combined With Antioxidants On The Nutritional Profile, Quality Attributes, And Storage Stability Of Chicken Breast Meat, Rebecca G. Norcross

Theses and Dissertations--Animal and Food Sciences

Consumers’ demands for ω-3 polyunsaturated fatty acids (PUFAs) are at all-time high. Algae, a common source of PUFAs, and antioxidants are both used as supplements in livestock feeds, are known to affect the overall quality of meat. To implement PUFA deposits into broiler meat, this study evaluated combining antioxidants and algae in broiler feed to enhance the breast meat quality. Broilers were fed diets supplemented with 50 IU Vitamin E or 200 g/ton EconomasE (EcoE, an antioxidant pack) plus 10 IU Vitamin E, with or without 0.5% algae extract (SP-1). The feed oil was partially oxidized soybean oil (POV: 86 …

Antioxidant Effect Of Peach Skin Extracts From 13 Varieties Of South Carolina Grown Peaches, Yueyuan Zhang

All Theses

South Carolina is the second largest peach producing state in the United States. Every year, large quantities of peaches do not meet the fresh peach standard and are discarded or used for further processing. The waste stream from discarded and processed peaches includes the skin and this could be recovered as a rich source of antioxidants. The objective of this research was to determine the antioxidant (phenolic) content and antioxidant capacity of peach skin from various peach varieties grown in South Carolina. Chapter 1 is a literature review which covers topics of oxidation in foods, mechanism of lipid oxidation, antioxidants …

The Protective Effect Of Antioxidants On Vitamin A Stability In Nonfat Dry Milk During Thermally Accelerated Storage, Amalie Brown Kurzer

Theses and Dissertations

Two studies were conducted to determine the relative effect of various combinations of antioxidants on vitamin A oxidation and isomerization in nonfat dry milk (NDM). In the first study, one lot of pasteurized unfortified skim milk was divided, fortified with vitamins A and D and one of 11 antioxidant treatments, and spray dried. A control batch from the same lot was also fortified with vitamins A and D and spray dried. Samples were analyzed for total vitamin A bioactivity after zero, one, and two weeks of storage. After two weeks at 50°C, the only NDM samples that did not experience …

Selenium Supplementation Increases Antioxidant Response In Vitro, Yasmin Fakhereddin

Wayne State University Theses

Reactive oxygen species and free radicals are associated with the negative effects of aging. Enzymatic and non-enzymatic mechanisms can defend cell structures from free radical damage. Selenium is an essential trace element necessary for cellular functions in the human body. A positive correlation between low serum selenium levels with the morbidity and mortality of a range of cancers has been illustrated in numerous studies. Glutathione Peroxidase catalyzes a reaction in which H2O2 oxidizes the reduced form of GSH and forms H2O. NADPH further reduces GSSG, the oxidized structure of glutathione, in a reaction catalyzed by glutathione reductase. Tissue culture was …

Effects Of Common Culinary Cooking Techniques On The Antioxidants In Collard Greens, Alexander Clifford

All Theses

This thesis explores the effects of different cooking techniques on the antioxidant activity in collard greens. Chapter 1 is a literature review covering the topics of antioxidants, nutrition, cooking techniques and the effect of thermal treatment on antioxidants. Chapter 2 is a research manuscript evaluating collard greens from a local South Carolina farm exposed to seven different thermal treatments along with an untreated raw group. The thermal treatments utilized were sautŽ, both long and short simmer, the sautŽ treatment applied to both a long and short simmer treated group and the reserved cooking water from both a long and short …

Almond Skins As A Natural Antioxidant, Heather Johnson

All Theses

In this thesis, the potential for almond skins in their native state as a natural antioxidant in foods was explored. A literature review of general information on almonds, research done on almond skins, and general information on antioxidants is presented. The almond skins used in this study required an additional heat treatment step to improve their microbiological quality before further treatments and analysis could be performed. A descriptive analysis sensory panel was utilized to identify potential flavor and aroma descriptors and their intensities. The aroma descriptors identified were toasted, bran, and toasted; nutty. The flavor descriptors identified were toasted, bran, …