Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 23 of 23

Full-Text Articles in Life Sciences

College And University Administrators' Attitudes Concerning Contract-Managed And Self-Operated Food Service, Thomas F. Gaddis Nov 1992

College And University Administrators' Attitudes Concerning Contract-Managed And Self-Operated Food Service, Thomas F. Gaddis

Masters Theses

The purpose of this research was to ascertain factors which influence college and university administrators' decisions to change the management format of their food service operation. Specifically this included 1) developing a list of potential factors which could influence an administrator's decision in this area, 2) determining administrators perceived importance of the factors, 3) determining the attitudes of administrators toward contract companies and the services provided, and 4) determining if significant differences existed between attitudes toward contract companies as they related to size and type of institution (public or private).

A list of potential decisional factors was developed by ...


The Effect Of Nutrition Education In The Form Of Cafeteria Posters On Knowledge, Attitudes, And Plate Waste Of Sixth Graders, Camille L. Ivey Aug 1992

The Effect Of Nutrition Education In The Form Of Cafeteria Posters On Knowledge, Attitudes, And Plate Waste Of Sixth Graders, Camille L. Ivey

Masters Theses

The purpose of this research was to determine whether there was a difference in nutrition knowledge scores, nutrition attitude scores, and plate waste of 6th graders who received nutrition education in the form of cafeteria posters for a period of 19 days and 6th graders who received no nutrition education. In addition, the effects of gender, weight control action, and source of lunch on these scores were assessed.

Nutrition knowledge and attitudes regarding dietary fat were assessed in 6th grade students in 3 middle schools using pretest and posttest questionnaires. Nutrition education in 2 of the middle schools consisted of ...


A New Method For Measuring Macroparticulate Systems Applied To Measuring Syneresis Of Renneted Milk Gels, Jonathan R. Maynes May 1992

A New Method For Measuring Macroparticulate Systems Applied To Measuring Syneresis Of Renneted Milk Gels, Jonathan R. Maynes

All Graduate Theses and Dissertations

Syneresis is an integral part of cheese manufacture. The rate and extent of syneresis affect the properties of cheese. There are many factors that affect syneresis, but measured results vary because of inaccuracies in measuring techniques. To better control syneresis, an accurate mathematical description must be developed. Current mathematical models describing syneresis are limited because of inherent error in measuring techniques used to develop them. Developing an accurate model requires an accurate way to measure syneresis.

The curd becomes a particle in a whey suspension when the coagulum is cut. The most effective technique to measure particle size, without interference ...


The Role Of Lactose In The Age Gelation Of Ultra-High-Temperature Processed Concentrated Skim Milk, Venkatachalam Narayanaswamy May 1992

The Role Of Lactose In The Age Gelation Of Ultra-High-Temperature Processed Concentrated Skim Milk, Venkatachalam Narayanaswamy

All Graduate Theses and Dissertations

The purpose of this research was to relate lactose reactivity and age gelation of UHT processed concentrated milk. Skim milk was pasteurized, diafiltered batchwise to reduce lactose concentration to less than 0.05%, and UF concentrated to 3X (one-third volume reduction). Lactose and sucrose were then each added at 3% or 6% w/v to part of the concentrate. The five samples, control ( < 0.05% lactose), 3% w/v lactose, 6% w/v lactose, 3% w/v sucrose, and 6% w/v sucrose, were UHT processed at 140°C for 4 s using the indirect heating method. Samples were collected aseptically in presterilized plastic containers and stored at 4°C, 20°C, and 35°C for periodic analysis.

All samples stored at 4°C and 20°C gelled after 21 weeks of storage. The viscosity changed slightly during the first 19 weeks of storage but increased suddenly (> 100 cPs) just before gelation. Samples stored at ...


Estimation Of Selected Milk Protein Genetic Variants By Multi-Component Analysis Of Amino Acid Profiles, Carol M. Hollar May 1992

Estimation Of Selected Milk Protein Genetic Variants By Multi-Component Analysis Of Amino Acid Profiles, Carol M. Hollar

All Graduate Theses and Dissertations

Cation-exchange fast protein liquid chromatography separated whole casein into β-casein A2, A1, and B, K-casein, αs1-casein, and αs2-casein fractions as well as γ-caseins and several unidentified peaks using a urea-acetate buffer at pH 5 and a NaCl gradient. The whole casein fractions eluted in the following order: breakdown products of β-casein and unidentified peaks; β-casein A2, Al, and B; additional breakdown products of β-casein and unidentified peaks; K-casein; αs1-casein; and αs2-casein. The calculated composition of the four major caseins correlated well with values obtained using anion-exchange fast protein ...


Effects Of Potassium Lactate, Encapsulated Citric Acid And Storage Temperature On Microbial Growth And Shelf Life Of Pork Sticks, Yen-Kan Su May 1992

Effects Of Potassium Lactate, Encapsulated Citric Acid And Storage Temperature On Microbial Growth And Shelf Life Of Pork Sticks, Yen-Kan Su

All Graduate Theses and Dissertations

A new product, pork sticks, was developed. Optimum shelf life and safety were major concerns associated with this product. Potassium lactate (3%) or citric acid (0.5%, 0.56%, 0.60% or 0.66%) was added to pork sticks to determine their effects on microbial growth, sensory evaluation, and shelf life when stored frozen (-20°C), refrigerated (2°C), or at room temperature (22°C). Two raw materials, pork blade meat (shoulder meat; 91% lean, 9% fat) and regular 80:20 pork trim (80% lean, 20% fat) were used. The consumer panel preferred lean pork sticks made from blade meat ...


Influence Of Process Parameters In The Manufacture Of Cottage Cheese Curd From Ultrafiltered Skim Milk, Ronald Michael Raynes May 1992

Influence Of Process Parameters In The Manufacture Of Cottage Cheese Curd From Ultrafiltered Skim Milk, Ronald Michael Raynes

All Graduate Theses and Dissertations

A processing procedure for the manufacture of directly acidified cottage cheese curd from 16% total solids ultrafiltered retentate was developed. The effects of preacidification of skim milk before ultrafiltration and heat treatment of retentate were investigated to improve the functional and sensory qualities of retentate curd.

Retentate directly acidified with phosphoric acid and glucono-delta-lactone to pH 4.7 formed a dense, rubbery curd that could not be handled well in a vat. A heat treatment of 71.1°C for 30 min applied to the retentate resulted in a curd with acceptable handling properties. However, this heat treatment caused the ...


Characterization Of Pigments Responsible For Red Or Pink Discoloration In Cooked Pork, Viswasrao M. Ghorpade May 1992

Characterization Of Pigments Responsible For Red Or Pink Discoloration In Cooked Pork, Viswasrao M. Ghorpade

All Graduate Theses and Dissertations

The pigments responsible for pink or red discoloration in cooked vacuum-packaged meat products {bratwurst (pork and beef), ground pork, and pork roasts} were investigated. In bratwurst, this study attempted to characterize the red pigment that appears upon refrigerated storage, and to determine the effect of pH, cooking and storage temperature, and sodium lactate on incidence of red discoloration. Myoglobin was identified in the exudate of samples with red discoloration. Myoglobin levels of cooked products were significantly lower in samples of low initial pH (5.5) or cooked to higher than normal internal temperature (74°C). Red discoloration was associated with ...


Effects Of Stabilizers And Ph Adjustments On Milk Proteins In Uht-Treated Citrus Juice/Skim Milk Blend Drink, Sandra M. Newman May 1992

Effects Of Stabilizers And Ph Adjustments On Milk Proteins In Uht-Treated Citrus Juice/Skim Milk Blend Drink, Sandra M. Newman

All Graduate Theses and Dissertations

A UHT -processed skim milk (85%)/orange juice (15%) drink was developed. Product integrity and stability were maintained by two methods. Proper homogenization of the blend before UHT processing stabilized a drink formulation containing .25% carboxymethyl cellulose and .025% carrageenan. Adjusting the pH of the blend (pH 6.3 and 6.5) resulted in a different stabilization. After 28 days at room temperature, settling of milk solids was 5.2% of volume height in the prehomogenized sample and 86.9% of volume height in the same blend that had not been homogenized prior to UHT processing. After storage, the two ...


Changes Over Time In Sensory Thresholds Of Individuals With Diabetes Mellitus And The Relationship To Food Preference, Marnie Ricks Spencer May 1992

Changes Over Time In Sensory Thresholds Of Individuals With Diabetes Mellitus And The Relationship To Food Preference, Marnie Ricks Spencer

All Graduate Theses and Dissertations

The effect of time on taste threshold was examined in 30 diabetics and 30 control subjects (ages 22-30) who had participated in a sensory study 14 years previously. Detection and recognition taste thresholds for sweet (sucrose), salty (sodium chloride), sour (citric acid), and bitter (quinine sulfate) were assessed using triangle testing. Food preferences related to concentration of the stimuli in model food systems were tested using a nine-point hedonic scale. Mashed potatoes were used as the carrier for different levels of salt. A beverage composed of water, sucrose, and citric acid was varied to measure preferences for sweet and sour ...


Zeta-Potenetial Of Casein Micelles As A Factor In Age Gelation Of Ultra-High Temperature Processed Concentrated Skim Milk, Douglas W. Olson May 1992

Zeta-Potenetial Of Casein Micelles As A Factor In Age Gelation Of Ultra-High Temperature Processed Concentrated Skim Milk, Douglas W. Olson

All Graduate Theses and Dissertations

The effect of ultra-high temperature processing by direct steam injection and room temperature storage of pH-adjusted and unadjusted 3X (volume reduction) skim milk retentate and the effect of storage at various temperatures of 3X skim milk retentate without pH adjustment on their ζ-potential, viscosity, and pH were determined. Pasteurized skim milk was concentrated to 3X by ultrafiltration. In the pH study portions of skim milk retentate were adjusted to pH 6.38 ± .02 with HCl and 6.85 ± .01 and 7.32 ± .02 with NaOH between ultrafiltration and ultra-high temperature processing. In the storage temperature study, storage temperatures used for ...


Properties Of Low-Fat Yogurt Made From Ultrafiltered And Ultra-High Temperature Treated Milk, Richard Alan Dargan May 1992

Properties Of Low-Fat Yogurt Made From Ultrafiltered And Ultra-High Temperature Treated Milk, Richard Alan Dargan

All Graduate Theses and Dissertations

Yogurts were made from intermediate-high temperature (100, 110, 120, and 130°C for 4 or 16 s), ultra-high temperature (140°C for 4 or 16 s), and vat heat (82°C for 20 min) treatments of skim milk fortified to 5% protein by either ultrafiltration or the addition of nonfat dry milk (NOM). Whey protein denaturation in heated milks increased with temperature and holding time from indirect plate heating and was highest in vat-heated milks. Whey protein denaturation and yogurt water-holding capacity increased with protein levels in the fortified milks compared to skim milk. Penetrometer gel strength and stirred viscosity ...


Classification Of Enterococci And Their Roles In Spoilage Of Pork Products And As Sanitary Indicators In Pork Processing , Linda Marie Knudtson Jan 1992

Classification Of Enterococci And Their Roles In Spoilage Of Pork Products And As Sanitary Indicators In Pork Processing , Linda Marie Knudtson

Retrospective Theses and Dissertations

The genus Streptococcus, including the fecal streptococci, has received intensive scrutiny in recent years, resulting in a new genus Enterococcus, rearrangement of species within the genus, and addition of many new species. To clarify the roles of these bacteria in food microbiology, known strains were examined by using conventional tube tests and API Rapid Strep and MicroScan Pos ID panels. Identification schema were devised to identify 13 species of enterococci and S. bovis and S. equinus by using a minimum of supplemental tests. These schema were used for enterococcal species identification to pinpoint possible sources of fecal contamination. Enterococci were ...


Sensory, Chemical And Ultrasonic Measurements Of The Palatability Attributes Of Bovine Skeletal Muscle , Yunus Khatri Jan 1992

Sensory, Chemical And Ultrasonic Measurements Of The Palatability Attributes Of Bovine Skeletal Muscle , Yunus Khatri

Retrospective Theses and Dissertations

Sensory, chemical and physical evaluations of bovine longissimus thoracis (LT) muscle were compared between bulls and steers (n = 299) of three frame sizes (small, medium and large), slaughtered following different times on feed (TOF)-180, 210 and 240 days. Bulls exhibited significantly lower (P < 0.05) marbling scores than steers. Palatability attributes were ranked lower (P < 0.05) for bulls while Warner-Bratzler myofibrillar force (WB-MF) and residual force (WB-RF) values were higher than for steers. Frame size had an impact (P < 0.05) on lipid, marbling and moisture contents for both sexes and fat thickness, tenderness, connective tissue, WB-MF and WB-RF for steers. TOF showed no significant change in marbling amongst bulls. Steers significantly increased in marbling between 180 and 240 days. Palatability remained unchanged for both sexes based on TOF. Small framed steers were most tender. Ultrasonic parameters showed extremely low R[superscript]2-values for palatability. However, R[superscript]2-values were higher for lipid and marbling parameters;Cholesterol and fatty acid composition of LT muscle were determined by gas chromatography-mass spectrometry and gas chromatography, respectively, following stratification by lipid content. TOF did not alter cholesterol content. A significant difference was observed for cholesterol based on sex and different lipid content groups. Cholesterol values reported herein are lower than previously reported results. Steers displayed a significant increase in C14:0 when fed 240 days. C18:0 content declined (P < 0.05) with TOF for bulls while steers exhibited this trend through 210 days on feed. Prolonging TOF revealed higher proportions of unsaturated fatty acids for both sexes. Lipid contents beyond 5% showed significant increases for C18:2 and significant decreases for C18:0 amongst bulls while steers showed significant increases in C18:1 and C18:2 for lipid levels greater than 3%;Sensory tenderness, flavor, WB-MF and myofibril fragmentation index of high pH meat were significantly different from normal pH control samples. Increase in WB-MF, lack of extensive degradation of muscle proteins and the decreased sarcomere length at pH 6.1 resulted in tougher meat than normal or high pH muscles. Gel electrophoresis of dark cutters revealed a lack in appearance of troponin-T to 30 Kd on 12% gels, and the appearance of a 'doublet' on 5% gels. This may account for the unusual tenderness observed.


Hydrolysis Of Fats And Oils By Moist Oat Caryopses , Shantilal Parmar Jan 1992

Hydrolysis Of Fats And Oils By Moist Oat Caryopses , Shantilal Parmar

Retrospective Theses and Dissertations

Various factors affecting the hydrolysis of fats and oils by oat lipase were examined. Variety, growth location and their interaction significantly affected the lipase activity of oats. Harvest of oats at early stages of development produced more lipase activity/unit weight than late harvest;Caryopses produced with an impact-type dehuller exhibited greater lipase activity than those produced by a wringer-type dehuller;The activity of oat lipase at 38 and 42°C was lower than that at 40°C;Addition of 0.004% ethanolamine into the water used to moisten the caryopses, increased the lipase activity, but higher concentrations were inhibitory ...


Rapid Method For Detection Of Muramic Acid And Cadaverine As Indicators Of Microbial Load On Fresh Meats , Carlos Ivan Lebron Jan 1992

Rapid Method For Detection Of Muramic Acid And Cadaverine As Indicators Of Microbial Load On Fresh Meats , Carlos Ivan Lebron

Retrospective Theses and Dissertations

Classical plate counting methods often understate the number of microorganisms when compared with counts made by direct microscopic examination or other methods. In addition, classical plate counting take days to obtain results because of the incubation time. The present study was undertaken to determine the possibility of developing a rapid method for bacterial enumeration based on the examination of muramic acid in pork and beef under both aerobic and anaerobic storage conditions. The muramic acid was measured by a technique in which lactic acid is released from muramic acid molecule followed by the reaction of the lactic acid with p-hydroxydiphenyl ...


Mechanism Of Inhibitory Action Of Potassium Sorbate In Escherichia Coli , Aubrey Francis Mendonca Jan 1992

Mechanism Of Inhibitory Action Of Potassium Sorbate In Escherichia Coli , Aubrey Francis Mendonca

Retrospective Theses and Dissertations

Subbacteriostatic, growth-inhibitory concentrations of potassium sorbate (125, 250, and 500 [mu]g/ml) at pH 5.70 increased the rate of proton translocation, and strongly inhibited the transport of arginine, glutamic acid, phosphate, and sulfate by whole cells of E. coli K12. Potassium sorbate (125 [mu]g/ml) had almost no effect on the uptake of glucose, thymine, or uracil by E. coli 15TAU or E. coli K12 but effectively inhibited the synthesis of DNA, RNA, and protein in both organisms. All three concentrations of sorbate inhibited respiration (oxygen consumption) in E. coli K12 but failed to induce leakage of ...


Characterization Of The Starch-Binding Domain Of Aspergillus Glucoamylase Produced In Escherichia Coli , Ann R. Kusnadi Jan 1992

Characterization Of The Starch-Binding Domain Of Aspergillus Glucoamylase Produced In Escherichia Coli , Ann R. Kusnadi

Retrospective Theses and Dissertations

We have produced intracellularly 8.8, 3.4, and 3.2 mg/l [beta]-galactosidase and two [beta]-galactosidase fusion proteins containing amino acids 498-616 (BSB119), and amino acids 537-616 (BSB80) of Aspergillus glucoamylase I, respectively. The fusion proteins suffered from extensive proteolytic degradation resulting in a mixture of full-size fusion proteins and [beta]-galactosidase. Granular starch adsorption study of these purified [beta]-galactosidase fusion proteins showed that BSB119 had the strongest interaction with granular starch;To overcome the proteolytic degradation problem associated with the [beta]-galactosidase fusion proteins, we have fused three different lengths of starch-binding fragments encoding amino ...


Enhanced Lactic Acid Production By Strain Development And By A Novel Biofilm Reactor , Ali Demirci Jan 1992

Enhanced Lactic Acid Production By Strain Development And By A Novel Biofilm Reactor , Ali Demirci

Retrospective Theses and Dissertations

Chemical mutagenesis with ethyl methanesulfonate followed by selective culturing was used to develop strains of Lactobacillus delbrueckii that tolerated increased lactic acid concentrations while continuously producing the acid. In stirred-tank-batch fermentations, mutant DP3 in 12% glucose, 3% yeast extract-mineral salt-oleic acid medium produced lactic acid more than four times faster than the wild type. Mutant DP3 produced 117 g/l lactic acid compared with 67 g/l for the wild type. Mutant DP3 exhibited faster specific growth rates, shorter lag phases, greater lactic acid fields, and better lactic acid tolerance than the wild type. Mutant DP3 was stable for over ...


Binding Of 14c-Heptanal To Soy Proteins Glycinin And [Beta]-Conglycinin , Sharma Marini Cooray Jan 1992

Binding Of 14c-Heptanal To Soy Proteins Glycinin And [Beta]-Conglycinin , Sharma Marini Cooray

Retrospective Theses and Dissertations

Soy proteins have excellent functional properties that can be utilized in improving the quality of processed foods. The off-flavor problem in soy proteins caused by short chain aliphatic aldehydes interacting with them makes these products unacceptable to the consumers. Upto date the complete removal of the off-flavor from soy products has not been reached. Complete reversibility of flavor binding to soy proteins was assumed in studying ligand binding to soy proteins, which is contradictory to the fact that removal of the off-flavor from soy proteins is almost not feasible. In order to test the validity of this assumption it was ...


Studies On The Effect Of Heat Shock, Culture Conditions, And Packaging Conditions On The Heat Resistance, Recovery, And Virulence Of Listeria Monocytogenes In Ground Pork , Kee-Tae Kim Jan 1992

Studies On The Effect Of Heat Shock, Culture Conditions, And Packaging Conditions On The Heat Resistance, Recovery, And Virulence Of Listeria Monocytogenes In Ground Pork , Kee-Tae Kim

Retrospective Theses and Dissertations

The heat resistance of two Listeria monocytogenes subspecies was determined, according to various heating conditions. In general, serotype 1 was more heat resistant than Scott A, and both subspecies were more heat resistant if packaged aerobically than anaerobically during heating. Cells exposed to 48°C for 2h prior to heating (heat shock) were more heat resistant than nonheat-shocked controls. Less survivors were detected when the cells were inoculated in pork stored for 3 months compared with fresh pork, suggesting that oxidative components can decrease cell survival during heating. Heating the samples at a slow heating rate (1.3°C/min ...


Characterization Of Starch Structures And Properties Of Maize Mutants From The Oh43 Inbred Line , Ya-Jane Wang Jan 1992

Characterization Of Starch Structures And Properties Of Maize Mutants From The Oh43 Inbred Line , Ya-Jane Wang

Retrospective Theses and Dissertations

Starches were isolated from a dent maize (Zea mays L.) inbred line Oh43, from single endosperm mutants and from the double-mutant combinations within Oh43. The thermal properties of the starches, including onset temperature (T[subscript] o), peak temperature, gelatinization temperature range, and enthalpy ([delta]H) of gelatinization and retrogradation and percentage of retrogradation, were determined by differential scanning calorimetry. A Voland-Stevens texture analyzer was used to measure gel strength. Double mutants generally had higher T[subscript] o and [delta]H for gelatinization and lower T[subscript] o for retrogradation, and lower gel strength measurements than those of single mutants. Sixteen ...


Effects Of Phosphates On Pseudomonas Fragi Growth, Protease Production And Activity , Sharon Lynn Kotinek Marsh Jan 1992

Effects Of Phosphates On Pseudomonas Fragi Growth, Protease Production And Activity , Sharon Lynn Kotinek Marsh

Retrospective Theses and Dissertations

The antimicrobial effects of selected inorganic phosphates on the growth of Pseudomonas fragi and protease activity in synthetic medium and in ground pork were studied. Studies were designed to determine the antimicrobial effects of phosphates at concentrations allowed in meat products and at concentrations above this limit. Microbial growth was monitored by traditional antimicrobial tests including the agar dilution method and liquid medium kill curve method. Protease activity was evaluated based on a casein digestion method and was reported per organism or per mg protein. At phosphate concentrations allowed by regulation in a meat product, the phosphates were not found ...