Typescript (photocopy). / Digitized by Kansas Correctional Industries

Shrimp waste samples were extracted with a variety of organic solvents. Each fraction was measured for antioxidant activity by determining the rate of oxidation of β-carotene-linoleic acid in an emulsion system. An ethanol extract exhibited the highest antioxidant activity. Purification of the most active fraction was accomplished by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). Antioxidant activity was not significantly effected by heating at 100°C for 4 hr or 30 days storage at 4°C. Purified antioxidant samples were further analyzed by several spectroscopy methods such as Fourier transformed-infrared spectroscopy (FT-IR), mass spectrometry and nuclear magnetic resonance (NMR). The antioxidant was characterized as an ortho-disubstituted benzene. The content of antioxidant in shrimp waste was estimated to be 1.80 ppm. Antioxidant from shrimp waste was extracted and partially purified by silica gel glass column chromatography. Two species of rockfish (Sebastolobus alascanus, Sebastes ruberriumus) were treated with crude antioxidant solution respectively, while rockfish fillets (Sebastes alutus) were treated with different concentrations of antioxidant solutions from the column chromatography. Higher a* values were found in rockfish samples treated with antioxidants compared to the control without antioxidant during iced storage. Furthermore, rockfish fillets treated with 0.20%, and 0.50% (w/v) antioxidant had lower 2-thiobarbituric acid (TBA) values compared to the control group of rockfish fillets (Sebastes alutus). Crude extract (0.50% w/w), and purified antioxidant (0.10%, 0.20%, and 0.50% w/w) from shrimp waste were applied to sablefish mince and evaluated for their effectiveness to inhibit oxidative and hydrolytic rancidity of mince samples. Treatments with crude extract (0.5%), partially purified antioxidant (0.2%, 0.5%) had a significantly lower TBA, and peroxide value (PV) compared to the control group during refrigerated (4°C) and frozen storage (-20°C). The results from free fatty acid values suggested that antioxidant from shrimp waste had no effect on hydrolytic rancidity in sablefish mince. / Graduation date: 1995

The distribution of anthocyanin pigments and polyphenolics of sweet (Prunus avium) and sour cherries (Prunus cerasus) were determined by Ultraviolet- Visible (UV-Visible) spectrophotometry and High Performance Liquid Chromatography with photodiode array detector (HPLC-DAD). Their antioxidant properties were determined by Oxygen Radical Absorbance Capacity (ORAC) and Ferric Reducing Antioxidant Power (FRAP). The effect of frozen storage, canning, and brining on those properties was measured. Experiments were conducted on three sweet cherry cultivars; Bing, Rainier, Royal Ann and one sour cherry cultivar; Montmorency. Cherries were separated into skins, flesh, pits, and pitted cherries for subsequent analyses. Bing had the highest anthocyanin pigments (60.6 mg/lOOg fw) while Montmorency had both the highest total phenolic content (5.6 mg GAE/g fw) and the highest antioxidant activities (ORAC 51.02 μmoles Trolox equivalent (TE) /g fw, FRAP 47.96 μmoles TE/g fw). Hydroxycinnamates predominated in sweet cherries (70-80%) while flavanols were the major class of polyphenolics in sour cherries (70%). The major anthocyanins in sweet and sour cherries were cyanidin-3-rutinoside and cyanidin-3- glucosylrutinoside, respectively. Skins contained the highest amount of anthocyanins, polyphenolics, and antioxidant activities. Anthocyanins and flavonol glycosides predominated in cherry skins. Bing cherries were different from the others in that it had substantial anthocyanins in flesh and pits. The proportion of flavanols increased from skins to pits. Pitted Bing cherries were frozen and stored at -23 and -70°C for 3 and 6 months. Pitted Bing cherries were also canned in light syrup and stored at 2 and 22°C for 5 months. Both Bing and Royal Ann cherries were brined in bisulfite for one year. In all processing experiments, polyphenolics were more stable than anthocyanins. Degradation of hydroxycinnamates occurred during frozen storage and canning while flavonol glycosides were relatively stable. With both canning and brining, anthocyanins and polyphenolics leached into syrup and brine. With brining, hydroxycinnamates and flavonol glycosides disappeared, and unidentified compounds with UV-Visible spectra similar to flavanols were formed. Unidentified compounds possessed antioxidant activity. Cherry skins are high in anthocyanins, polyphenolics and antioxidant properties. Cherry pits and spent brine solution may be a potential source for natural colorants, nutraceuticals, and natural antioxidants. / Graduation date: 2004

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The use of natural antioxidants to improve the oxidative stability of food lipids has received special attention because of the worldwide trend to avoid the use of synthetic food additives. A wide range of natural sources has been shown to contain antioxidant properties, these include plant extracts, herbs and spices, citrus fruits, oilseeds and legumes. Some antioxidants have been found to be fonned during the heat processing of foods, including the Maillard reaction products that are formed by the reaction of amino acids, peptides and proteins with reducing carbohydrates. A study was undertaken to investigate the antioxidant activity of Maillard reaction products fonned during extrusion of soyabeans. A preliminary oxidation study carried out to identify a suitable substrate revealed that sunflower oil stripped of antioxidants was a suitable substrate with a low induction period of 15 minutes via the Rancimat Method and 4.5 hours via the method of Ross and de Muelenaere. Methyllinoleate was found to be sensitive to oxidation, but not readily available and costly. Storage test of antioxidant stripped sunflower oil under various headspace conditions showed that the substrate stability was best at 4°C under nitrogen or vacuum. Under such conditions the product could be stored for a period of 136 days. Nitrogen was chosen as the most suitable for this exercise as it was not easy to remove all residual air from the samples by vacuum. Furthermore with nitrogen headspace residual 02 could be measured based on Ni02 ratio changes. Hexane solvent was found to be able to remove all lipids from soyabeans. Under the experimental conditions practised it was found that the induction periods for extruded and unextruded soya flour hexane extracted lipids were very similar. Addition of glucose or fructose to the extrusion mixture increased induction period of hexane extracted lipids by 37.5% and 1.5% respectively as measured by the Ross and de Muelenaere method and by 50% and 6.5% respectively as measured by the Rancimat Method. Available lysine of glucose containing extrudate was reduced by 69% while that of the fructose containing extrudate was reduced by 23%. Residual glucose and fructose analysis of extrudates showed that 66% of glucose was utilized in the formation of the Maillard reaction products while only 21% of fructose was utilized during extrusion processing. Comparison of induction periods of soya glucose and soya fructose extrudates to induction period of TBHQ antioxidants (200ppm) in antioxidant stripped sunflower oil gave antioxidant activity of 86ppm and 9ppm for soya glucose extrudates and soya fructose extrudates respectively. The observed antioxidant activity of Maillard reaction products could be utilized with success in different types of processed foods without the need for extensive testing as required for synthetic antioxidants but supplementation of lysine may be required to maintain nutritional balance. / Thesis (M.Sc.)-University of Natal, 1994.

Exercise-induced muscle soreness and damage have been investigated for almost a century, and yet it appears that there is little that can be done to avoid these consequences of over-exertion, except train on a regular basis. It is likely that freeradicals are involved at a number of stages in the muscle damage process, and therefore the provision of appropriate antioxidants may theoretically offer some protection. One such antioxidant is vitamin C, although the literature available in support of this notion is scarce. The aim of these studies, therefore, was to assess whether different nutritional interventions using vitamin C would offer any benefit to exercise-induced muscle damage and soreness. In the past, investigators have often used exercise protocols designed to maximise the extent of injury. The studies reported in this thesis, however, used an exercise protocol (Loughborough Intermittent Shuttle Test: LIST) based on the multiple-sprint sports (e.g. football). Participation in such sports is very high, although frequently on an irregular basis, and therefore exercise of this nature may have the capacity to cause muscle damage and soreness. The LIST provided a suitable exercise model, and in different studies led to increases in soreness, markers of muscle damage, lipid peroxidation, and inflammation. It also led to poorer muscle function up to 72 h after exercise in some muscle groups. Short-term supplementation with vitamin C 2 hours before exercise successfully increased plasma and cellular concentrations, although failed to have any beneficial outcomes in terms of muscle damage or soreness. Supplementation in the hours and days (up to three days) after exercise also produced no beneficial effects, and it may be that supplementation occurred at an inappropriate time. Prolonged supplementation with vitamin C proved more promising (14 days), and was associated with reduced plasma concentrations of interleukin-6 and malondialdehyde. Furthermore, there were modest benefits to certain' aspects of muscle soreness and function, although these were not always statistically significant. However, tliere was no effect on circulating markers of muscle damage (creatine kinase and myoglobin). These findings suggest that the regular ingestion of vitamin C may be associated with some favourable changes following damaging exercise. However, the consumption of large amounts of vitamin C immediately before or after exercise offer no appreciable benefits, despite large changes in plasma concentrations of this vitamin.

Background: Increasing evidence indicates that oxidative injury exists in schizophrenia. Although it may not be the main cause, oxidative damage has been suggested to contribute to the pathophysiology and may account for deteriorating course and poor outcome in schizophrenia. There is increasing interest in the neuroprotective efficacy of antioxidants in modulating such processes with at least one polyphenolic being tested as a prophylactic in Alzheimer's disease. Beneficial effects of adjunctive ω-3 (n-3 series) polyunsaturated fatty acids with combined intakes of vitamin C and E on both the positive and negative symptoms of schizophrenia have been reported. Robust in vitro systems are desirable, enabling a mechanistic investigation of the molecular mechanisms underpinning such effects and identification of further potentially efficacious nutraceuticals. Materials and Method: Comparative studies employing a lymphoblastoid cell line of schizophrenic origin, a neuroblastoma IMR-32 cell line and the lymphoma U937 cell line was undertaken. The cytoprotective effects of phenolic antioxidants and essential fatty acids in affording protection to cellular DNA, protein and lipids from an oxidative challenge were assessed in the three cell lines. In addition, two human studies were undertaken. The first study utilised the non-invasive technique of breath hydrocarbon analysis and the lipid peroxidation products in a population of schizophrenic patients were compared to a population of apparently healthy aged-matched control subjects, while the second study investigated possible differences in biomarkers of DNA, lipid and protein oxidation in schizophrenic and control subjects. Plasma vitamin C levels were also compared in both groups. Results and Conclusion: Cell Culture Studies: Pre-treatment of peripheral and neuronal cells with antioxidant or ω-3 fatty acids followed by an oxidative challenge significantly reduced the levels of DNA damage. Treatment with H₂O₂ alone and following pre-treatment with EPA or DHA had no effect on the levels of protein carbonyls in U937 cells, however, DHA supplementation did appear to reduce endogenous and H2O2-induced protein carbonylation. Marked differences in the uptake of fatty acids by the cell types were found and the IMR-32 cell line was most susceptible to the oxidant challenge. Hydroxytyrosol gave significant cytoprotection in all three cell lines and this possible neuroprotective efficacy warrants further investigation, both in vitro and in vivo. Treatment of the three cell lines with a high concentration of H2O2 for 30min or 4 hours did not induce a significant increase in MDA. U937 cells were supplemented for 24 hours with fatty acids followed by a 4 hour oxidative stress. Both EPA and DHA treatment appeared to reduce LOOH levels in the U937 cells but not significantly. Cytoplasmic PLA2 activity in the three human cell lines was examined and the basal level of cPLA2 activity was found to be comparable in the lymphoblastoid and IMR-32 cells but significantly lower than that measured in the U937 cells. Supplementation of the U937 cell line with EPA caused a significant decrease (p<0.05) in cPLA2 activity relative to the vehicle treated control but neither EPA nor DHA supplementation appeared to have any significant effect on either total PLA2 or cPLA2 activity in IMR-32 or lymphoblastoid cell lines. Abstract v Human Studies: No significant difference was found between the levels of ethane and pentane in the breath from the schizophrenic patients and control samples. In addition, no significant difference in the levels of plasma MDA between the two groups was detected. Ethane levels and MDA levels were higher in the male schizophrenic samples than in the female schizophrenic samples but the results were not statistically significant. The pentane levels were higher in the female schizophrenic samples when compared to the male schizophrenia samples but again, these were not significantly greater. Finally, results of study 2 revealed that cellular DNA damage and plasma protein carbonyl levels were increased in the schizophrenic group compared to control subjects but not significantly. However, DNA damage in lymphocytes from the male schizophrenic group was significantly higher than the female group. Biomarkers of lipid peroxidation and plasma vitamin C levels also revealed no significant difference between the two groups under investigation, although a significant elevation in plasma vitamin C was observed in the female control group when compared to the male groups. Treatment of cells with EPA, DHA and hydroxytyrosol to reduce levels of oxidative damage warrants further investigation. Ultimately, it is important to investigate a range of biomarkers to determine whether the measurement of oxidative damage to lipids, proteins and DNA has clinical significance. This will enable better understanding of the disease of interest and allow these biomarkers to become potentially useful clinical tools.