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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Functional Properties and Utilization of High pH Beef

Garcia, Lyda G. 2009 August 1900 (has links)
Two Texas fed beef and cow/bull packing plants were surveyed for high pH beef carcasses as well as the evaluation of functional properties of high pH beef in whole muscle beef jerky, frankfurters, and snack stick production. An estimated 42% of cow carcasses were of 6.0 muscle pH or greater as well as exhibiting darker, less red colored lean. Jerky high in pH from cow inside rounds resulted in the greatest percent moisture and least percent protein compared to other treatments. High pH cooked jerky were higher in (P < 0.05) pH and water activity and lower in percent fat and shear force values. In cooked jerky slices, fed-high resulted in the highest percent MPR and cook yield, but was the most tender. In contrast, fed-normal resulted in the least water activity, MPR and toughest jerky slices. In frankfurter production, emulsion stability and hydration values was highest for C (1.98mL) followed by 100H (3.37mL) that decreased as percent high pH decreased. As storage day increased, frankfurter pH decreased, especially by day 56 (5.67) where LAB and APC counts had reached a log of 6.0 indicative of spoilage by day 28 and became lighter and less red in color with minimal lipid oxidation. 100H was harder and less cohesive with trained panelists reported containing at least 50% high pH meat was harder. The pH and internal color of cooked snack sticks significantly increased and became lighter and redder as percent high pH meat increased. Even though water activity compared to a whole muscle dry product or an emulsified, water added product ranged from 0.85 to 0.86 (P > 0.05), minimal (P greater than 0.05) lipid oxidation occurred. 100N resulted in the least percentage of fat but 3% more (P less than 0.05) protein and highest shear force values. Overall, beef raw materials high in pH may be better suited in a semi-dry fermented product.
2

Using Lipase to Improve the Functional Properties of Yolk-Contaminated Egg Whites

Macherey, Laura Nicole 17 December 2007 (has links)
Egg yolk contamination of egg whites continues to be a serious problem in the egg industry. The ability of egg whites to form stable and voluminous foams is greatly inhibited by accidental yolk contamination, even at extremely small levels. Experiments were conducted to determine if lipase can regenerate the functional properties of yolk-contaminated egg whites. Treatments included control, 0.2% yolk-contamination, and 0.2% yolk-contamination that was treated with lipase and colipase and heated at 37°C for 1 hour. Lipase from Mucor meihei and colipase from porcine pancreas were added to yolk-contaminated egg white samples to target and hydrolyze the triglycerides from egg yolk. Enzymatic hydrolysis was confirmed using thin-layer chromatography. Treatment of yolk-contaminated samples with lipase, colipase and heat yielded a drastic improvement in a number of the functional properties, including the final foam volume, foam capacity, and foaming power. These functional properties showed complete restoration to control levels. However, foam stability and foam drainage levels were not statistically different from yolk-contaminated samples that had not been enzymatically treated. Enzyme treated yolk-contaminated egg whites were also tested in an angel food cake system. There were three treatments, including an uncontaminated control, a contaminated control, and a lipase and colipase treated yolk-contaminated sample. Comparison between treatments was performed by volume analysis. The enzyme treated yolk-contaminated egg whites performed similarly to uncontaminated control angel food cakes. / Master of Science
3

Effects of Starch-based Anti-caking Agents on the Functional Properties of Shredded Mozzarella Cheese

Akins, Maureen Lynch 06 December 2002 (has links)
Mozzarella cheese production has been gaining market share due in part to increasing market for pizza and ready to eat food items. Anti-caking agents are utilized in the production of shredded cheese for reducing clumping and increasing the appearance of separate cheese shreds. Six anti-caking agents were applied to low moisture part skim Mozzarella cheese and examined for effects on three major functional properties of Mozzarella cheese; meltability, stretchability, and free oil formation. Meltability determination utilizing a fabricated UW Meltmeter resulted in no significant differences between untreated samples (control) and samples treated with anti-caking agents containing cellulose, potato starch or mixtures including dextrose. Stretchability measurements taken using a modified helical viscometry procedure also resulted in no significant differences between control and treated samples. Significant differences were found when comparing free oil percentages obtained from varying treatments of anti-caking agents. A mixture of potato starch and cellulose resulted in the lowest level of free oil among all samples tested. Because potato starch treated samples performed equally to cellulose treated samples in both meltability and stretchability testing, anti-caking agents containing potato starch could be considered as an alternative to cellulose-based anti-caking agents. In addition, the use of potato starch alone and in conjunction with powdered cellulose has been shown to be more effective for free oil control. By treating with potato starch, functional properties of shredded Mozzarella cheese have been positively altered in a way which may increase acceptability by consumers. / Master of Science
4

Functional Properties of Concrete Roads - Development of an Optimisation Model and Studies on Road Lighting Design and Joint Performance

Löfsjögård, Malin January 2003 (has links)
The roads constitute a major part of the nation’sinfrastructure. For the society and the individuals it isimportant with a well functioning road network. To sustain theimpact from traffic intensity and heavy loads durable pavementsare demanded. Concrete pavements for roads with high trafficintensity and heavy loads are common in the USA and in severalEuropean countries. In Sweden, less than 1 % of the roadnetwork consists of concrete roads. The research about concrete road pavements has been focusingon development of design methods and studies of surfaceproperties like friction, longitudinal evenness, wearresistance and noise. To increase the knowledge and use ofconcrete roads there is a need to optimise the differentfunctional properties with regard to each other and to socialfactors. The objective of this doctoral thesis is to survey, analyseand quantify relationships between functional properties ofconcrete roads and social factors such as environmental impact,traffic and user safety, riding comfort and economicconsiderations (costs). The goal is to develop a model that canbe used as an instrument for optimising the concrete roaddesign. This thesis describes a thorough literature investigation,special studies on road lighting design of concrete pavements,laboratory investigations about saw-cutting times for jointsand bonding properties of dowels and development of anoptimisation model. The literature investigation has resultedin compiled knowledge on functional properties of concreteroads and their relationships with social factors. A compiledanalysis has also been performed from follow-ups of the fourconcrete roads constructed in Sweden in the 1990s. From thespecial study on road lighting design, proposals are made forusing new values for brightness and specularity and changingthe classification of wet concrete pavements. Theinvestigations of joint performance have given recommendationsfor the earliest saw-cutting time for joints in concrete roads.An optimisation model is proposed, and presently parts of themodel can be used for economic comparisons between differentalternatives. The proposed model needs further research regardingvaluation of the relationships before the model can be used asa total model. Other areas interesting for further researchare: road lighting design and especially wet pavements, upperbound of sawcutting time for joints and further analysis ofdowel performance.
5

Evaluation of micronized lentil and its utilization in low-fat beef burgers

Der, Tanya J. 13 September 2010
Dehulled seed from four lentil market classes (large- and small-sized green and red types) were tempered to15% moisture and micronized to a surface temperature of 135 °C, and their compositional, physical, and functional properties were investigated. Micronization of lentil modified starch- and protein-related properties. Approximately 2.5 to 5.6% of the starch was gelatinized following micronization. Differential scanning calorimetry (DSC) results showed a 13 to 40% decrease in heat enthalpy, and viscosity analysis (Rapid Visco Analyzer) showed a 21 to 55% increase in peak viscosity and a 1 to 3 °C reduction in pasting temperature. Nitrogen solubility decreased across the pH range of 2 to 9, and lipoxygenase activity was reduced by 100-fold. There was a 25 to 43% increase in water holding capacity with no change in oil absorption capacity. The colour intensity of the pigments in the green and red lentil were reduced upon micronization of seed, and the particle size of flour was lowered with 7 to 13% more flour passing into the finest (<75 um) sieve. Flours from dehulled green and red lentil (large type) were incorporated as a binder into low-fat (<10%) beef burgers at levels of 6 and 12%. Cooking properties, colour, texture, oxidative status, and sensory properties of these burgers were analyzed. Overall, increasing binder addition to low-fat beef burgers increased cooking yield up to 86% and minimized dimensional shrinkage upon cooking. Storage of raw, fresh burgers for 7 days under simulated retail display (4 °C) resulted in gradual reductions in HunterLab a* values, with those containing micronized lentil flour generally displaying significantly greater retention of redness from days 1 to 5 of storage. Thiobarbituric acid reacting substances (TBARS) of burgers containing micronized lentil flour were significantly lower compared with those containing non-micronized lentil after 9 to 11 weeks of frozen storage. A trained sensory panel (n=13) reported increasing burger juiciness and tenderness with the incorporation of up to 6% and 12% of lentil flour, respectively. Although off-flavour increased in burgers with non-micronized lentil flour addition, it was significantly reduced when seed was micronized. Consumer panel analysis (n=107) showed higher acceptability for burgers containing 6% micronized lentil flour or toasted wheat crumb compared with those containing non-micronized lentil flour or no binder. These results demonstrate that the conditions used to micronize lentil altered the functional properties of the flours, and when used as a meat binder at an optimal level improved cooking properties, texture, and flavour profiles in low-fat beef burgers.
6

Evaluation of micronized lentil and its utilization in low-fat beef burgers

Der, Tanya J. 13 September 2010 (has links)
Dehulled seed from four lentil market classes (large- and small-sized green and red types) were tempered to15% moisture and micronized to a surface temperature of 135 °C, and their compositional, physical, and functional properties were investigated. Micronization of lentil modified starch- and protein-related properties. Approximately 2.5 to 5.6% of the starch was gelatinized following micronization. Differential scanning calorimetry (DSC) results showed a 13 to 40% decrease in heat enthalpy, and viscosity analysis (Rapid Visco Analyzer) showed a 21 to 55% increase in peak viscosity and a 1 to 3 °C reduction in pasting temperature. Nitrogen solubility decreased across the pH range of 2 to 9, and lipoxygenase activity was reduced by 100-fold. There was a 25 to 43% increase in water holding capacity with no change in oil absorption capacity. The colour intensity of the pigments in the green and red lentil were reduced upon micronization of seed, and the particle size of flour was lowered with 7 to 13% more flour passing into the finest (<75 um) sieve. Flours from dehulled green and red lentil (large type) were incorporated as a binder into low-fat (<10%) beef burgers at levels of 6 and 12%. Cooking properties, colour, texture, oxidative status, and sensory properties of these burgers were analyzed. Overall, increasing binder addition to low-fat beef burgers increased cooking yield up to 86% and minimized dimensional shrinkage upon cooking. Storage of raw, fresh burgers for 7 days under simulated retail display (4 °C) resulted in gradual reductions in HunterLab a* values, with those containing micronized lentil flour generally displaying significantly greater retention of redness from days 1 to 5 of storage. Thiobarbituric acid reacting substances (TBARS) of burgers containing micronized lentil flour were significantly lower compared with those containing non-micronized lentil after 9 to 11 weeks of frozen storage. A trained sensory panel (n=13) reported increasing burger juiciness and tenderness with the incorporation of up to 6% and 12% of lentil flour, respectively. Although off-flavour increased in burgers with non-micronized lentil flour addition, it was significantly reduced when seed was micronized. Consumer panel analysis (n=107) showed higher acceptability for burgers containing 6% micronized lentil flour or toasted wheat crumb compared with those containing non-micronized lentil flour or no binder. These results demonstrate that the conditions used to micronize lentil altered the functional properties of the flours, and when used as a meat binder at an optimal level improved cooking properties, texture, and flavour profiles in low-fat beef burgers.
7

Functional Properties of Concrete Roads - Development of an Optimisation Model and Studies on Road Lighting Design and Joint Performance

Löfsjögård, Malin January 2003 (has links)
<p>The roads constitute a major part of the nation’sinfrastructure. For the society and the individuals it isimportant with a well functioning road network. To sustain theimpact from traffic intensity and heavy loads durable pavementsare demanded. Concrete pavements for roads with high trafficintensity and heavy loads are common in the USA and in severalEuropean countries. In Sweden, less than 1 % of the roadnetwork consists of concrete roads.</p><p>The research about concrete road pavements has been focusingon development of design methods and studies of surfaceproperties like friction, longitudinal evenness, wearresistance and noise. To increase the knowledge and use ofconcrete roads there is a need to optimise the differentfunctional properties with regard to each other and to socialfactors.</p><p>The objective of this doctoral thesis is to survey, analyseand quantify relationships between functional properties ofconcrete roads and social factors such as environmental impact,traffic and user safety, riding comfort and economicconsiderations (costs). The goal is to develop a model that canbe used as an instrument for optimising the concrete roaddesign.</p><p>This thesis describes a thorough literature investigation,special studies on road lighting design of concrete pavements,laboratory investigations about saw-cutting times for jointsand bonding properties of dowels and development of anoptimisation model. The literature investigation has resultedin compiled knowledge on functional properties of concreteroads and their relationships with social factors. A compiledanalysis has also been performed from follow-ups of the fourconcrete roads constructed in Sweden in the 1990s. From thespecial study on road lighting design, proposals are made forusing new values for brightness and specularity and changingthe classification of wet concrete pavements. Theinvestigations of joint performance have given recommendationsfor the earliest saw-cutting time for joints in concrete roads.An optimisation model is proposed, and presently parts of themodel can be used for economic comparisons between differentalternatives.</p><p>The proposed model needs further research regardingvaluation of the relationships before the model can be used asa total model. Other areas interesting for further researchare: road lighting design and especially wet pavements, upperbound of sawcutting time for joints and further analysis ofdowel performance.</p>
8

THE EFFECT OF GENOTYPE AND THE ENVIRONMENT ON THE PHYSICOCHEMICAL AND FUNCTIONAL ATTRIBUTES OF FABA BEAN PROTEIN ISOLATES

2015 May 1900 (has links)
The overarching goal of this research was to investigate the differences in the physicochemical and functional properties of protein isolates produced from seven different faba bean genotypes (CDC Fatima, Taboar, SSNS-1, FB9-4, FB18-20, Snowbird and CDC Snowdrop) grown at different locations in Canada (Saskatchewan, Alberta and Manitoba) in 2011 and 2012. The protein isolates were prepared by alkaline extraction (pH 9.5) followed by isoelectric precipitation at pH 4.5. The isolates had an average protein content of ~94% and average protein and isolate yields of ~77% and ~25%, respectively. The physicochemical properties assessed in this study included surface charge/zeta potential (ZP), surface hydrophobicity (SH), and surface and interfacial tension (ST and IT). The functional properties tested included foaming capacity (FC) and foam stability (FS), emulsion capacity (EC) and creaming stability (CS), emulsion activity index (EAI) and emulsion stability index (ESI), oil holding capacity (OHC), and protein solubility. The findings indicated that all physicochemical properties for all isolates were independent of genotype. Overall, an average ZP of + 22.1 mV, SH of 47.2 arbitrary units, and ST and IT of 65.0 mN/m and 10.7 mN/m, respectively, were observed. However, with the exception of ZP considerable differences were observed due to the effect of environment. The ratio of the major globulin protein fractions [legumin:vicilin (L/V)] was found to shift during processing, from 3.8 (range: 3.4-4.6) in the flour to 4.5 (range 4.0-4.9) in the isolates. The L/V ratio for faba bean flour and isolate samples was also found to be independent of genotype. For all genotypes, with the exception of the zero-tannin varieties (Snowbird and CDC Snowdrop), the L/V ratio was affected by the environment. Similar to the physicochemical properties, all functional attributes were found to be independent of genotype. However, environmental effects were observed for all functional properties with the exception of EAI and ESI. Average values for FC of 162.0%, for FS of 65.0%, for EC of 184.0 g/g, for CS of 94.0%, for OHC of 5.7 g/g, for EAI of 13.0 m2/g, for ESI of 10.7 min and for solubility of 81.0% were reported. Zeta potential was observed to be positively correlated with CS (r = 0.46; p<0.05) and FS (r = 0.54; p<0.01), whereas SH and L/V ratio were not. The L/V ratio in the isolate, however, was correlated positively with SH (r = 0.40; p<0.05) and negatively with ZP (r = -0.39; p<0.05). Moreover, the solubility of faba bean isolates was found to be positively correlated with ZP (r = 0.44; p<0.05) and negatively correlated with both IT (r = -0.38; p<0.05) and OHC (r = -0.38; p<0.05). The functional properties of some commercial protein isolates (soy, pea, whey, egg and wheat) were evaluated for comparative purposes. The OHC of the faba bean isolate was found to be higher than that of any of the commercial isolates. With the exception of CS (soy and pea) and FC (egg), all of the emulsifying (EC, EAI and ESI) and foaming (FC and FS) properties of the faba bean protein isolates were comparable to those of soy, pea and egg isolates. In contrast, values for most of the other functional properties were greater for faba bean isolates than for the pea and wheat isolates, but lower than for the whey isolate. For example, the solubility of the protein isolates was observed to decrease in the following order: whey (89.0%) = egg (88.1%) > faba bean (81.0%) > soybean (30.5%) > pea (20.1%) > wheat (10.7%).
9

The Production of Protein Isolates from the Aqueous Extraction of De-hulled Yellow Mustard Flour and Determination of their Functional Properties

Hijar, Benjamin 12 July 2013 (has links)
Two types of protein isolates were prepared from de-hulled yellow mustard flour by aqueous extraction, membrane processing and acid precipitation of proteins at the isoelectric point (IEP 5.5). Their electrophoretic, main functional properties and protein composition were determined. The precipitated and acid soluble protein isolates had 83.0 and 96.0% protein content on a moisture and oil free basis, respectively. The acid soluble protein isolate had comparable functional properties to those of commercially available soybean and other protein isolates. The precipitated protein isolate exhibited less desirable functionality than the soluble isolate, due to its high lipid content (~25%); however, it was still comparable to soybean isolates. Storage temperature had limited effect on lipid oxidation, and hence the stability of the precipitated protein isolate at 25-45ºC. Taste and texture of wieners and bologna prepared with 1-2% of this isolate as binder were comparable to those prepared with soy protein isolates.
10

The Production of Protein Isolates from the Aqueous Extraction of De-hulled Yellow Mustard Flour and Determination of their Functional Properties

Hijar, Benjamin 12 July 2013 (has links)
Two types of protein isolates were prepared from de-hulled yellow mustard flour by aqueous extraction, membrane processing and acid precipitation of proteins at the isoelectric point (IEP 5.5). Their electrophoretic, main functional properties and protein composition were determined. The precipitated and acid soluble protein isolates had 83.0 and 96.0% protein content on a moisture and oil free basis, respectively. The acid soluble protein isolate had comparable functional properties to those of commercially available soybean and other protein isolates. The precipitated protein isolate exhibited less desirable functionality than the soluble isolate, due to its high lipid content (~25%); however, it was still comparable to soybean isolates. Storage temperature had limited effect on lipid oxidation, and hence the stability of the precipitated protein isolate at 25-45ºC. Taste and texture of wieners and bologna prepared with 1-2% of this isolate as binder were comparable to those prepared with soy protein isolates.

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