Milk is one of the eight major food allergens. Cow's milk allergy is the most common allergy in children under 2 years of age. About 1.6 to 2.8 percent of children under this age are reported to have cow's milk allergy. Casein, β-lactoglobulin and α-lactalbumin are major milk protein allergens. Nonthermal treatments like high intensity ultrasound, ultraviolet (UV) light and nonthermal plasma treatments have been reported in the literature to be effective in reducing the allergenicity of different food proteins. Hence it was expected for these treatments to reduce cow milk allergenicity. The objective of this study was to investigate the effect of high intensity ultrasound, nonthermal atmospheric plasma and UV-C light treatments in reducing the allergenicity of isolated major milk proteins. Sonics Vibracell VC 505 ultrasonic liquid processor was used to perform high intensity ultrasound treatments. UV light treatments were performed using a DDK Scientific Corporation UV tunnel. A nonthermal atmospheric plasma setup assembled in Department of Microbiology lab was used to perform plasma treatments. Samples were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to estimate the change in protein concentration and enzyme linked immuno sorbent assays (ELISA) to observe the change in IgE binding. A one-way analysis of variance was conducted to evaluate the relationship between treatment time and percent IgE binding at 95% confidence level. Further investigation was conducted with nuclear magnetic resonance (NMR) spectroscopy on treated casein to assess any change in the structure of protein. SDS-PAGE results for ultrasound and plasma treatments didn't show any change in gel band intensities for casein, β-lactoglobulin and α-lactalbumin indicating no significant change in protein concentration. Ci-ELISA analysis showed that there was no significant difference (p>0.05) in IgE binding values for control and treated samples in ultrasound and plasma treatment conditions tested in this study. The intensities of all the three protein bands in SDS-PAGE gel were reduced by UV-C light treatment at 15 min treatment time. In Ci-ELISA, there was a significant difference (p< 0.05) in IgE binding values for control and treated samples and a reduction in allergenicity of proteins (25% reduction for casein and 28% reduction for whey protein fractions) was observed. Further investigations using in vivo clinical trials need to be conducted to confirm this result. NMR results didn't show any noticeable changes in the structures of casein with all three different treatments. In conclusion, UV-C light treatment can reduce the allergenicity of isolated major milk proteins to some extent. High intensity ultrasound and nonthermal atmospheric plasma treatments failed to generate effective results for reducing allergenicity at the conditions tested in this study. Higher intensity and longer treatment conditions might yield better results with ultrasound treatment. Different power and gas flow rates used to generate plasma with direct exposure of proteins might yield better results towards reducing the allergenicity of major milk allergens.

Understanding the composition of camel milk coupled with studying the effects of thermal and non-thermal treatments on its components and bacterial inactivation were the general objectives of this dissertation. In the first study (Chapter 2), the gross composition of camel milk including milk protein, fat, casein, total solids, lactose, ash, and mineral content were analyzed. In addition, fatty acid profile, amino acid profile, protein fractions, and volatile compounds were evaluated as well. Our results revealed that camel milk has its unique nutrients profile. These findings make it easier for the researchers and consumers to understand some of the nutritional attributes of camel milk.The impact of non-thermal ultrasound treatment (900 W, 20 kHz, 100% power level) on some milk-borne microorganisms and the components of camel milk was studied in Chapter3. We reported that continuous ultrasound processing was efficient in inactivating Escherichia coli (E.coli) O157: H7 and Salmonella Typhimurium (S. Typhimurium) in camel milk without detrimental effects on milk fatty acids profile, lipid peroxides, and protein fractions except for some changes in milk volatile compounds (VC). In Chapter 4, another non-thermal technique, ultraviolet-C (UV-C) light, was applied to camel milk to study the effects of different UV-C light doses on the viability of E. coli O157:H7 and S. Typhimurium and the chemical changes to milk components. The main findings of this study were: (i) UV-C treatment at a dose of 12.45 mJ/cm2 resulted in only 3.9-log10 for both bacterial strains which did not meet the Food and Drug Administration (FDA) requirements for the 5-log pathogen reduction; (ii) the UV-C treatment at the above dose, had limited effects on camel milk components. Thermal pasteurization of milk was first introduced to prevent milk-borne infectious diseases, however, its effects on camel milk components and quality are still unknown. Therefore, in Chapter 5, we investigated the efficacy of three previously reported thermal methods: PAST-1 (65ºC/30 min), PAST-2 (72ºC/5 min), and PAST-3 (80ºC/5 min) on bacterial inactivation and some camel milk components such as the fatty acid profile, lipid peroxidation, VC, and milk protein fractions. Complete elimination (6 log10 CFU/ml reduction) of E. coli O157: H7 was achieved using all pasteurization methods, however, only 3.4 log10 CFU/ml reduction of the total viable counts was reported using PAST-1 and PAST-3 methods. We also reported that the PAST-1 and PAST-3 methods did not affect the chemical composition of camel milk. In conclusion, we assessed the main components of camel milk along with the amino fatty acid profile, acid profile, volatile compounds, and protein fractions. Thermal methods were more effective than the non-thermal methods in terms of microbial inactivation and most camel milk components were not significantly influenced by thermal and non-thermal methods.