Oilseeds may be processed to yield a number of potentially valuable compounds and fractions including oil, protein and small molecules. However, energy costs associated with industrial processing of oilseeds can be significant. For example, processes that use water to dissolve and separate materials are burdened with the costs associated with concentrating value-added products from dilute solutions. The ethanol industry produces large amounts of an aqueous solution called thin stillage that has little value and is used in animal feed. Thin stillage contains some of the necessary salts used in protein extraction but has a low pH. Protein extraction and protein isolate production is commonly conducted at higher pH. Waste alkali from biodiesel production has a high pH and can be used to adjust the pH of thin stillage to improve its ability to extract protein from oilseed meal. By combining the properties of the waste products of both the ethanol and the biodiesel industries, a complementary process is possible that may have greater economic potential than current practices in industry.<p> In this study, processes for protein extraction from mustard (<i>Brassica juncea</i> (L.) Czern.) meal using thin stillage from ethanol production and glycerol from biodiesel production were studied. The osmotic potential of thin stillage used in this research was lower than that of water, whereas both the density and the viscosity were higher. The pH was typically 3.7-3.8, and the total Kjeldahl nitrogen was approximately 0.080.10 %, w/w. Organic compounds identified in thin stillage were isopropanol, ethanol, lactic acid, 1,3-propanediol, acetic acid, succinic acid, glycerophosphorylcholine, betaine, glycerol and phenethyl alcohol. In addition, yeasts, bacteria and fungi were also found. Moreover, the salt types and their concentrations in thin stillage were predictable. The salt types present in thin stillage were CaCl2, NaCl, K2SO4, NaNO3, Mg(OH)2, Na2SO4 and KOH. A model thin stillage synthesized for the purposes of this research had components and chemical and physical properties comparable to those of thin stillage from ethanol production. Protein was extracted from ground, defatted meal using thin stillage at different pHs and salt concentrations. The results showed that pH and salt content affected protein extraction efficiency. However, no differences were found in the efficiency of extraction, SDS-PAGE profile, digestibility, lysine availability or amino acid composition of protein extracted with thin stillage, model thin stillage or sodium chloride solution. Moreover, extracted protein did not display significant hydrolysis. The results from peptide sequencing showed that napin and cruciferin were the most prevalent proteins in the extracted fractions. When increasing the scale of the extraction, the efficiency of protein extraction and the percentage of protein in the extracted protein were decreased. Protein recovery achieved with the complementary protocol was higher than that reported for a published protocol. Allyl isothiocyanate was found in protein extracts.

Oilseeds may be processed to yield a number of potentially valuable compounds and fractions including oil, protein and small molecules. However, energy costs associated with industrial processing of oilseeds can be significant. For example, processes that use water to dissolve and separate materials are burdened with the costs associated with concentrating value-added products from dilute solutions. The ethanol industry produces large amounts of an aqueous solution called thin stillage that has little value and is used in animal feed. Thin stillage contains some of the necessary salts used in protein extraction but has a low pH. Protein extraction and protein isolate production is commonly conducted at higher pH. Waste alkali from biodiesel production has a high pH and can be used to adjust the pH of thin stillage to improve its ability to extract protein from oilseed meal. By combining the properties of the waste products of both the ethanol and the biodiesel industries, a complementary process is possible that may have greater economic potential than current practices in industry.<p> In this study, processes for protein extraction from mustard (<i>Brassica juncea</i> (L.) Czern.) meal using thin stillage from ethanol production and glycerol from biodiesel production were studied. The osmotic potential of thin stillage used in this research was lower than that of water, whereas both the density and the viscosity were higher. The pH was typically 3.7-3.8, and the total Kjeldahl nitrogen was approximately 0.080.10 %, w/w. Organic compounds identified in thin stillage were isopropanol, ethanol, lactic acid, 1,3-propanediol, acetic acid, succinic acid, glycerophosphorylcholine, betaine, glycerol and phenethyl alcohol. In addition, yeasts, bacteria and fungi were also found. Moreover, the salt types and their concentrations in thin stillage were predictable. The salt types present in thin stillage were CaCl2, NaCl, K2SO4, NaNO3, Mg(OH)2, Na2SO4 and KOH. A model thin stillage synthesized for the purposes of this research had components and chemical and physical properties comparable to those of thin stillage from ethanol production. Protein was extracted from ground, defatted meal using thin stillage at different pHs and salt concentrations. The results showed that pH and salt content affected protein extraction efficiency. However, no differences were found in the efficiency of extraction, SDS-PAGE profile, digestibility, lysine availability or amino acid composition of protein extracted with thin stillage, model thin stillage or sodium chloride solution. Moreover, extracted protein did not display significant hydrolysis. The results from peptide sequencing showed that napin and cruciferin were the most prevalent proteins in the extracted fractions. When increasing the scale of the extraction, the efficiency of protein extraction and the percentage of protein in the extracted protein were decreased. Protein recovery achieved with the complementary protocol was higher than that reported for a published protocol. Allyl isothiocyanate was found in protein extracts.

Mass spectrometry (MS) has played a major role in the proteomic analysis of an array of biological samples. Even so, inherent limitations exist such as sample complexity and the dynamic range. In an attempt to overcome these limitations, prefractionation is typically performed followed by reversed phase liquid chromatography coupled with MS. Pre-fractionation can be performed in several formats including chromatographic or electrophoretic based methods. Solution-based isoelectric point (pI) fractionation, specifically isoelectric trapping (IET), provides an attractive alternative for pre-fractionation in bottom-up proteomic studies. A recently developed device, membrane separated wells for isoelectric focusing and trapping (MSWIFT), provides rapid separation on the basis of pI and resulting solutions are MS compatible without the need for extensive sample cleanup. Initial experiments demonstrate fractionation using MSWIFT, of peptide mixtures ranging from standards to a yeast lysate where resulting fractions are analyzed using matrixassisted laser desorption/ionization (MALDI) – MS or further separated using reversed phase liquid chromatography followed by tandem MS (MS/MS) analysis. Identified yeast proteins range in size, pI and copy number illustrating an ability to increase the depth of proteome coverage when using MSWIFT. Extensive studies were also performed using MSWIFT in a multi-stage fractionation platform to improve peptide and protein identifications for the first large-scale proteomic study of the model fungus, Neurospora crassa. A second focus of this work is the development of a new sample preparation method for proteolytic digestion and high-throughput separations using MSWIFT. Histidine is used as a neutral pH, isoelectric, sample buffer for tryptic digestion of proteins and also assists in rapid separations using MSWIFT owing to the low conductivity. Tryptic digests of individual standard proteins and a mixture of standard proteins are used to illustrate these advantages. Finally, the histidine buffer sample preparation method is incorporated into a two-dimensional separation strategy. Tryptic peptides are fractionated using MSWIFT and resulting solutions are further separated using capillary electrophoresis (CE) coupled with MALDI-MS/MS. Performing the two-dimensional strategy allows for increased confidence in peptide and protein assignment owing to experimentally determined in-solution charge states and estimated pI values.

no

Mixed solutions of β-lactoglobulin and anionic polysaccharides, specifically pectin, were formed into associative complexes through pH reduction from neutral conditions. Thermal treatment of these associative complexes was investigated as a function of biopolymer composition, heating conditions, pH, and ionic strength. Thermal treatment of β-lactoglobulin-pectin complexes at pH 4.5 – 5.0 was found to create protein-based particulates of consistent and narrow size distribution (diameter ~ 150 – 400 nm). These particulates were relatively stable to further pH adjustment and to high levels of salt (200 NaCl). Particle characteristics were maintained after re-suspending them in aqueous solutions after they have been either frozen or lyophilized. Thermal analysis of β- lactoglobulin-pectin complexes using calorimetry (DSC) and turbidity-temperature scanning indicated that the denaturation of β-lactoglobulin was unaffected by pectin, but protein aggregation was limited by the presence of pectin. Biopolymer particles formed using two different methods were compared: Type 1 – forming β-lactoglobulin nanoparticles by heating, then coating them with pectin; Type 2 – forming particles by heating β-lactoglobulin and pectin together. Type 2 particles had smaller diameters and had better pH and salt stability than Type 1 particles. It was proposed that Type 2 particles had a pectin-saturated surface that limited their aggregation, whereas Type 1 particles had “gaps” in the pectin surface coverage that led to greater aggregation. Finally, the possibility of controlling the size and concentration of biopolymer particles formed by heating β-lactoglobulin-pectin complexes by controlling preparation conditions was studied. Biopolymer particle size and concentration increased with increasing holding time (0 to 30 minutes), decreasing holding temperature (90 to 70 ºC), increasing protein concentration (0 to 2 wt%), increasing pH (4.5 to 5.0), and increasing salt concentration (0 to 50 mol/kg). The influence of these factors on biopolymer particle size was attributed to their impact on protein-polysaccharide interactions, protein denaturation, and protein aggregation kinetics. The knowledge gained from this study will facilitate the rational design of biopolymer particles with specific physicochemical and functional attributes that can be used in the food and other industries, e.g., for encapsulation, texture modification, optical properties modification.

Solid oxide fuel cell compositionally graded electrolytes could offer the advantage of improving electrical performance and efficiency compared to single-layered or bi-layered yttria stabilized zirconia and samaria doped ceria electrolytes and improving mechanical performance by reducing thermal expansion mismatch stresses compared to bi-layered electrolytes with sharp interfaces. Manufacturing of these graded structures is difficult if implementing conventional wet ceramic techniques. Suspension plasma spraying is an emerging technology that has the potential to rapidly produce thin, dense ceramic layers with no requirement for post deposition heat treatments. However, SPS requires a careful examination of the stability of the feedstock suspensions in order to produce high quality coatings. Optimum suspension formulations with excellent particle dispersion were designed based on rheological and electrostatic stability measurements. These optimized suspensions were used as feedstocks for the fabrication of suspension plasma sprayed compositionally graded YSZ/SDC layers. The feasibility of fabricating graded electrolyte structures was thus demonstrated.

Solid oxide fuel cell compositionally graded electrolytes could offer the advantage of improving electrical performance and efficiency compared to single-layered or bi-layered yttria stabilized zirconia and samaria doped ceria electrolytes and improving mechanical performance by reducing thermal expansion mismatch stresses compared to bi-layered electrolytes with sharp interfaces. Manufacturing of these graded structures is difficult if implementing conventional wet ceramic techniques. Suspension plasma spraying is an emerging technology that has the potential to rapidly produce thin, dense ceramic layers with no requirement for post deposition heat treatments. However, SPS requires a careful examination of the stability of the feedstock suspensions in order to produce high quality coatings. Optimum suspension formulations with excellent particle dispersion were designed based on rheological and electrostatic stability measurements. These optimized suspensions were used as feedstocks for the fabrication of suspension plasma sprayed compositionally graded YSZ/SDC layers. The feasibility of fabricating graded electrolyte structures was thus demonstrated.

In this work, adsorption of cadmium and lead from waste solutions by activated carbon was investigated. The activated carbons were produced from ion exchange resins and agricultural wastes in previous thesis studies under different conditions. BET surface areas of the activated carbons were given in previous studies. They were further characterized in this study. Slurry pH was measured by change in pH of water in which activated carbon was added. Methylene blue numbers were determined by adsorption of methylene blue onto activated carbons. Isoelectric points were determined by measuring zeta potential of activated carbons at different equilibrium pH. Results of the first part of sorption experiments showed a strong dependency of adsorption on pH since adsorption mechanism was exchange of heavy metal ions with H+ ions on the surface. Activated carbon produced from hazelnut shell had the highest removal efficiency with 95% Pb removal and 50% Cd removal at pH 6. However, activated carbon produced from apricot stone removed only 25% and 80% of Cd and Pb, respectively at the same pH. Initial concentration had positive effect on percent removal as shown by the second part of sorption experiments. This can be explained with saturation of available active sites as initial concentration increased. Activated carbon produced from hazelnut shell could remove 42% of Cd and 85% of Pb, but the one produced from synthetic resin couldn&amp / #8217 / t remove Cd and Pb more than 20% and 35%, respectively at initial concentration of 100 mg/l. Langmuir and Freundlich isotherms were plotted and both isotherms were in good agreement with experimental data.

The major antinutritive factor in Leucaena for ruminants is condensed tannin (CT). CT bind proteins, incurring a negative effect on protein utilisation. The two major factors affecting the ability of CT to bind protein have been purported to be CT size and the pH of the reaction environment. To test these hypotheses the protein precipitating capacities of CT extracted from four promising Leucaena genotypes, L. leucocephala (K636), L. pallida (CQ3439), L. trichandra (CPI46568), and L. collinsii (OFI52/88) were assessed. L. leucocephala had approximately half the ability to precipitate protein on a g/g basis than L. pallida or L. trichandra while L. collinsii gave no measurable ability to precipitate protein (reaction environment=pH 5.0). Increasing or decreasing the pH of the reaction solution away from pH 5.0 (the isoelectric point of the protein) reduced the ability of CT from all the species to precipitate protein; the decrease being higher a pH 2.5 than at pH 7.5. At pH 2.5 L. leucocephala CT completely lost its capacity to precipitate protein. The relatively poor ability of L. leucocephala CT to bind protein at pH’s approximating those at the abomasum suggests L. leucocephala may have the greatest potential of the four Leucaena’s tested for increasing the extent of feed protein escaping ruminant degradation for later release and digestion in the small intestine, hence increasing the total amount of protein absorbed by ruminants. CT fractions from each Leucaena were also separated into individual CT’s, by size-exclusion chromatography and examined for protein precipitating capacity. In general it was found that the larger sized CT of the accessions L. pallida and L. trichandra could precipitate more protein than the smaller sized CT. This pattern was not found for L. leucocephala.

Content: Many areas of leather production rely heavily on the manipulation of acidic and basic residues within the primary collagen structure to vary the overall charge of the substrate. For example, it is the basis which enables swelling during liming, deswelling during deliming, penetration of chromium after addition of chrome tanning salts and the fixing of chrome to carboxylate residues during basification. Manipulation of the charge on collagen is readily achieved through the addition of acids or bases into the float which may react with these residues to alter the charge. Often, the increase in anionic charge and reduction in cationic charge with increasing pH are shown to happen concurrently and linearly with the iso-electric point (IEP) given as the point at which the positive and negative charges present on the collagen are equal. However, the pH at which carboxylate/acid groups undergo protonation/deprotonation is significantly lower than that at which an amine/ammonium is protonated/deprotonated, meaning the linear model described above is not a true representation of charge of collagen at varying pH. Here we model the charge of a collagen substrate based off the amino acid profile of bovine skin, considering their relative levels within the collagen and concentrations within a water/collagen matrix, representative for collagen saturated with water. Models are presented for raw and limed bovine hides. This broader approach enables greater understanding of the influence of charge on the collagen substrate compared to IEP on its own, revealing contrasting charge profiles in acidic and alkaline regions of raw collagen, providing greater understanding of their differing behaviour during alkali swelling.