Scientific evidence shows that dietary intake of the omega-3 polyunsaturated fatty acids is beneficial to human health. Fish oil is a rich source of omega-3 fatty acids. However, fish oil with high levels of omega-3 PUFA is very susceptible to oxidative deterioration during storage. The objective of this study was to investigate the effect of xanthan gum (XG)-locust bean gum (LBG) mixtures on the physicochemical properties of whey protein isolate (WPI) stabilized oil-in-water (O/W) emulsions containing 20% v/v menhaden oil. The O/W emulsions containing XG/LBG mixtures were compared to emulsions with either XG or LBG alone. The emulsions were prepared using a sonicator by first mixing menhaden oil into the WPI solution and then either XG, LBG or XG/LBG mixtures were added. WPI solution (2 wt%) and gum solutions (0.0,0.05, 0.1, 0.15, 0.2 and 0.5 wt%) were prepared separately by dissolving measured quantities of WPI in distilled water. XG and LBG gums were blended in a synergistic ratios of 50:50 for the mixture. The emulsions were evaluated for apparent viscosity, microstructure, creaming stability and oxidative stability. Addition of 0.15, 0.2 and 0.5 wt% XG/LBG mixtures greatly decreased the creaming of the emulsion. The emulsion with 0.15, 0.2 and 0.5 wt% XG/LBG mixtures showed no visible serum separation during 15 d of storage. The apparent viscosity of the emulsions containing XG/LBG mixtures was significantly higher (p < 0.05) than the emulsions containing either XG or LBG alone. The viscosity was sharply enhanced at higher concentrations of XG/LBG mixtures. Microstructure images showed depletion flocculation for LBG (0.05-0.5 wt%), XG (0.05- 0.2 wt%) and XG/LBG mixtures (0.05 and 0.1 wt%) emulsions. Flocculation was decreased with the increased biopolymer concentration in the emulsion. The decrease in flocculation was much pronounced for the emulsion containing XG/LBG mixtures. The rate of lipid oxidation for 8 week storage was significantly (p < 0.05) lower in emulsions containing XG/LBG mixtures than in emulsions containing either of the biopolymer alone. The results suggested that the addition of XG/LBG mixtures greatly enhanced the creaming and oxidative stability of the WPI-stabilized menhaden O/W emulsion as compared to either XG or LBG alone.

Diets formulated to contain varying ratios of omega 6 to omega 3 fatty acids were fed to exercising yearlings to evaluate bone activity and inflammatory response. Nine Quarter Horse yearlings were arranged within a triplicated 3 X 3 Latin Square experimental design and fed one of three diets. Exercise protocol was designed to stimulate sub-clinical inflammation and normal bone response. Body weight and physical growth measurements were not different between groups (P > 0.05), and feed intake was similar between groups (P > 0.05). Horses consuming soybean oil (SBO) diet had lower fatty acid profiles (% by weight) of C16:0 and C16:1 (P < 0.05) when compared to horses consuming either corn oil (CO) or menhaden/corn oil (MCO) diets. Though numerically different, percentage changes in C16:0 and C16:1 were not different between diets (P < 0.05). Horses consuming MCO had significantly higher measurements of C20:4, C20:5 and C22:6 over the 28 day period when compared to horses consuming SBO or CO. Percent change in mean concentrations of C20:5 were significantly different between the MCO group and the SBO group (P < 0.05) with no observed difference between MCO and CO treatment groups. Overall mean carboxyterminal telopeptide of type I collagen (ICTP) concentrations did not differ between diets (P > 0.05) nor was there a significant change from baseline values when compared to day 28 of the period. Mean Osteocalcin (OC) concentrations did not differ between treatments (P > 0.05). Numerically, OC levels were lower after 14 days, with subsequent increases occurring from day 14 to day 28; however, there was no significant day effect (P > 0.05). Mean measurements of PGE2 and fibrinogen, the two inflammation markers evaluated, did not differ among groups (P > 0.05). However, when fibrinogen data were normalized, horses consuming SBO had a significantly lower change in baseline values of fibrinogen compared to horses fed CO or MCO diets (P< 0.05). In general, horses fed SBO exhibited reduced levels of the inflammatory marker fibrinogen (P< 0.05). No other variable evaluated was influenced by the supplementation of varying ratios of polyunsaturated fatty acids into the equine diet.

Preventing oxidative deterioration of fish oil is a significant challenge for the food industry. Natural antioxidants are widely incorporated into foods and oils to prevent oxidation and extend shelf life. The goal of the study is to investigate the activity of novel antioxidants in menhaden oil and to develop optimum formulations containing mixed tocopherols to control oxidation of menhaden oil. Alpha tocopherol, gamma tocopherol, and delta tocopherol in menhaden oil were found at 0.18mg/g, 0.37mg/g, and 0.14mg/g, respectively, using HPLC analysis. Teng Cha extract effectively delayed oxidation of menhaden oil (MO) when stored at 40°C for eight days by measuring primary oxidation products and secondary oxidation products. The combinations of Teng Cha extract and rosemary extract and combinations of ascorbyl palmitate, citric acid, Teng Cha extract and rosemary extract more effectively improved stability of MO containing mixed tocopherols than Teng Cha extract alone at 40°C storage for eight days by measuring primary oxidation products and secondary oxidation products. From this study, Teng Cha extract can be used as a potential natural antioxidant in food industry, especially in combinations with rosemary extract and tocopherols, extending shelf life of menhaden oil. / Master of Science in Life Sciences