Life Sciences Commons^™

Predicting The Growth Of Salmonella Typhimurium On Beef By Using The Temperature Function Integration Technique, James S. Dickson, G. R. Siragusa, J. E. Wray Jr.

James S. Dickson

Lag and generation times for the growth of Salmonella typhimurium on sterile lean beef were modeled as functions of cooling time under various carcass-chilling scenarios. Gompertz growth models were fit to the log10 colony counts over time at each of six temperatures in the range of 15 to 40 degrees C. Lag and generation times were defined as the points at which the second and first derivatives, respectively, of each growth curve attained a maximum. Generation time and lag time parameters were modeled as functions of temperature by use of exponential-decay models. The models were applied to typical beef carcass-cooling …

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 both …

Can Antibiotic Test Kits Be Useful?, Bart Weimer

Archived Food and Health Publications

Publication discusses whether or not antibiotic test kits are useful and what the various results mean.

Collapse Of The Proton Motive Force In Listeria Monocytogenes Caused By A Bacteriocin Produced By Pediococcus Acidilactici, Douglas P. Christensen, Robert W. Hutkins

Department of Food Science and Technology: Faculty Publications

The effect of pediocin JD, a bacteriocin produced by Pediococcus acidilactici JD1-23, on the proton motive force and proton permeability of resting whole cells of Listeria monocytogenes Scott A was determined. Control cells, treated with trypsin-inactivated bacteriocin at a pH of 5.3 to 6.1, maintained a pH gradient and a membrane potential of approximately 0.65 pH unit and 75 mV, respectively. However, these gradients were rapidly dissipated in cells after exposure to pediocin JD, even though no cell lysis had occurred. The pH gradient and membrane potential of the producer cells were also unaffected by the bacteriocin. Whole cells treated …

Ua12/12 Your Healthstyle, Wku Wellness Center

WKU Archives Records

Newsletter created by the Wellness Center regarding services, health and fitness.

Proceedings From The 29th Annual Marschall Italian Cheese Seminar, Various Authors

Cheese Industry Conference

Three 375 lb vats of cultured low moisture pan skim Mozzarella cheese were produced from the same batch of standardized milk and rennet, but using three different rod (Lactobacillus bulgaricus - Marschall ProduciS - Thennorod) and coccus (Streptococcus thermophilus - Mar chall Product - Thennococcus) ratios (9R:IC, 5R:5C, and !R:9C). The total volume and total colony fonning units of culture added was kept constant for all ratios (i.e., I 02 ml/375 I b). Cheese was made with the ·'no-brine·· chee e making method using a I06°F (41° ) cook temperature, 6.4 draw pH *whey), 5.25 milling pH, and 135°F (57°C) …

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

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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, …

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, Spring 1920 to Summer 2023

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 …

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

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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 curd to shift …

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

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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 microbial growth. …

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, Spring 1920 to Summer 2023

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 over high-fat pork sticks made from regular 80:20 …

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, Spring 1920 to Summer 2023

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 treatments were analyzed to verify that …

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

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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 (

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 35°C did …

Zeta-Potential 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, Spring 1920 to Summer 2023

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

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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 (NDM). 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 in 21 day-old …

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

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cation-exchange fast protein liquid chromatography separated whole casein into β-casein A², A¹, and B, K-casein, α_s1-casein, and α_s2-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, A^l, and B; additional breakdown products of β-casein and unidentified peaks; K-casein; α_s1-casein; and α_s2-casein. The calculated composition of the four major caseins correlated well with values obtained …

Pesticide Use On Apples Grown In Connecticut: 1990, James L. Turner Ii, Candace L. Bartholomew

Storrs Agricultural Experiment Station

No abstract provided.

Soy Protein, Phytate, And Iron Absorption In Humans, Richard F. Hurrell, Marcel-A Juillerat, Manju B. Reddy, Sean R. Lynch, Sandra A. Dassenko, James D. Cook

Manju B. Reddy

The effect of reducing the phytate in soy-protein isolates on nonheme-iron absorption was examined in 32 human subjects. Iron absorption was measured by using an extrinsic radioiron label in liquid-formula meals containing hydrolyzed corn starch, corn oil, and either egg white or one of a series ofsoy-protein isolates with different phytate contents. Iron absorption increased four- to fivefold when phytic acid was reduced from its native amount of 49-8.4 to < 0.01 mg/g of isolate. Even relatively small quantities of residual phytate were strongly inhibitory and phytic acid had to be reduced to < 0.3 mg/g of isolate (corresponding to < 10 mg phytic acid/meal) before a meaningful increase in iron absorption was observed. However, even after removal ofvirtually all the phytic acid, iron absorption from the soy-protein meal was still only half that of the egg white control. It is concluded that phytic acid is a major inhibitory factor of iron absorption in soy-protein isolates but that other factors contribute to the poor bioavailability of iron from these products.

Microbiological Decontamination Of Food Animal Carcasses By Washing And Sanitizing Systems: A Review, James S. Dickson, Maynard E. Anderson

James S. Dickson

Microbial contamination of animal carcasses is a result of the necessary procedures required to process live animals into retail meat. The contamination can be minimized by good manufacturing processes, but the total elimination of foodborne pathogenic microorganisms is difficult, if not impossible. A variety of methods have been developed to reduce the levels of contaminating bacteria on carcasses, although most of the current methods focus on washing and sanitizing procedures. The commonly used sanitizing agents include hot water, chlorine, and short-chain organic acids. The effectiveness of these compounds varies by the concentration used, the temperature of the sanitizers and contact …

Phosphorus Sorption By Gravels In Lateritic Soils, D. M. Weaver, G. S.P. Ritchie, R. J. Gilkes

Food Science and Nutrition

The effect of sesquioxidic gravels (>2 mm size fraction) on phosphorus sorption by two gravelly lateritic soils was investigated by phosphorus sorption experiments, X-ray diffraction, autoradiography and electron microscopy.In one soil the abundance and size of gravels decreased downslope. As the gravel content of both soils increased (13-61%), the proportion of large (>8 mm) gravels increased (0-70%). Phosphorus sorption increased in the order: (>2 mm fraction) < (whole soils) < (2 mm) decreased with increasing gravel size and increased with increasing time. Phosphorus sorption by whole soils decreased with increasing gravel content. Phosphorus sorption by the >2 mm fraction was principally by the external surfaces of the gravels. The estimation of phosphorus application rates for lateritic soils depended on the amount of phosphorus required by the plant …

A Low-Temperature Scanning Electron Microscopy Study Of Ice Cream. I Techniques And General Microstructure, K. B. Caldwell, H. D. Goff, D. W. Stanley

Food Structure

The objective of this study was to investigate techniques suitable for viewing the microstructure of ice cream in the frozen and fully hydrated state using low temperature scanning electron microscopy (L T-SEM), and to examine the microstructure of the frozen product. lee cream bad four distinct structural phases: ice crystals, air bubbles, fat globules and serum. Air bubbles, 10 to 60 ~-tm in diameter, were lined with fat globules, 0.5 to 2.5 J.tnl in diameter. Ice cry stals with a mean di ameter of 40 J.Lffi showed a characteri stic reticulat e structure after sublimation. The appearance of the ice …

A Low-Temperature Scanning Electron Microscopy Study Of Ice Cream. Ii. Influence Of Selected Ingredients And Processes, K. B. Caldwell, H. D. Goff, D. W. Stanley

Food Structure

The objective of this study was to examine the influence of processing parameters, viz., incorporation of polysaccharide stabilizers, freezing rates, and storage times and temperatures on the microstructure of ice cream. As the freezing rate was reduced, ice crystals and air bubbles increased in size. However, quenchfreezing also contributed to poor texture; thus an optimum freezing rate exists for the production of suitably- sized ice crystals and texture in ice cream. Model systems of polysaccharide stabilizer solutions were seen to have a characteristic network structure when quenchfrozen which was altered by the addition of sucrose. Stabilized ice cream initially had …

A Moving Optical Fibre Technique For Structure Analysis Of Heterogenous Products: Application To The Determination Of The Bubble-Size Distribution In Liquid Foams, C. G. J. Bisperink, J. C. Akkerman, A. Prins, A. D. Ronteltap

Food Structure

The bubble-size distribution in liquid foams measured as a function of time can be used to distinguish between the physical processes that determine the breakdown of foams. A new method based on an optical fibre technique was developed to measure various foam characteristics e.g. the rate of drainage, the rate of foam collapse, the change in gas fraction, interbubble gas diffusion (disproportionation) and the evolution of the bubble - size distribution during the ageing of the foam. The method consists of an optical sensor that can distinguish between phases with distinct refractive indexes as are found in liquid foams.

Cryo-Scanning Electron Microscopy Investigation Of The Texture Of Cooked Potatoes, J. T. Van Marle, A. C.M. Clerkx, A. Boekestein

Food Structure

The texture of steam-cooked potatoes was investigated by examining the fracture planes of four different cultivars, using cryo-scanning electron microscopy (cryo-SEM), which yielded a good preservation of the hydrated structures in potato tissue . For all cultivars , fracturing after steam -cooking took place between cells preferentially alongside the cell walls. However, textural difference appeared from the degree of intercellular contact, the cell shape and the appearance of cell surfaces. Cells in the fracture planes of firm potatoes had large intercellular contacts. In this case, most of the cells were flat and cell surfaces showed folds and cracks . For …

Relating Spectral Observations Of The Agricultural Landscape To Crop Yield, Craig L. Wiegand, Arthur J. Richardson

Food Structure

Remote sensing and microscopy share several common concerns including wavelength and sensor selection, signal processing, and image analysis. For crop yield assessments, multispectral observations are acquired photographically, videographically, or with opticalmechanical scanners from aircraft and spacecraft. Sensors are chosen at wavelengths of high atmospheric transmission and maximum contrast between the soil background and the vegetation growing out of it. Vegetation indices have been developed that maximize the information about the photosynthetic size of the vegetation in the landscape and, hence, about crop stresses and yield . Three such indices that reduce the multispectral observations to a single numerical index are …

Effect Of Draw Ph On The Development Of Curd Structure During The Manufacture Of Mozzarella Cheese, L. J. Kiely, P. S. Kindstedt, G. M. Hendricks, J. E. Levis, J. J. Yun, D. M. Barbano

Food Structure

The impact of varying the pH of whey at whey drainage (5.9, 6.15 or 6.4) on the development of curd structure during the manufacture of Mozzarella cheese was investigated using scanning electron microscopy. Dramatic changes in curd structure were apparent with stage of manufacture , in particular the stretching step which aligned the protein fibers.

Of additional interest is the effect of draw pH on the structure of curd at whey drainage. When whey was drained at pH 6.4, an open poorly fused network of paracasein particles was observed in the cheese curd. Jn contrast, lowering the draw pH (6.15 …

Ultrastructural Changes In Cherimoya Fruit Injured By Chilling, Margarita Gutierrez, Maria Del Mar Sola, Luis Pascual, Maria Isabel Rodriguez-Garcia, Alberto M. Vargas

Food Structure

Cherimoya (Annona cherimola Mill.) is an important fruit crop that is grown in the South of Spain. Ultrastructural modifications of cherimoya fruit were studied after low-temperature storage. When cherimoya was stored at 4 oc for 6 days, the starch grains did not suffer degradation and the cell walls remained intact. The membrane systems were severely damaged , result ing in a loss of cell compartmentalization. Cherimoya rewarmed to 22 0 C after 9 days of low temperature storage is not able to recover , showing the irreversibility of the ultra structural changes. In addition, disorgani zation of the internal lamella …

The Cellular Structure Of Selected Apple Varieties, K. G. Lapsley, F. E. Escher, E. Hoehn

Food Structure

Apple cultivars (Sauergrauech, Klarapfel, James Grieve, Granny Smith, Mcintosh, Robinette) which had different textures based on sensory and instrumental analysis (particularly in firmness and mealiness) were examined by conventional scanning electron microscopy (SEM), cold-stage SEM (cryoSEM) and confocal scanning laser microscopy (CSLM) using various preparative procedures. Advantages, lim itations and artifacts of each technique are discussed.

SEM with glutaraldehyde-fixation and criticalpoint- drying produced minimal tissue distortion and the fracture pattern and appearance of mealy versus non mealy tissue was different. Freeze-drying unfixed tissue caused cell collapse and firm versus soft varieties could not be differentiated. Freeze-fracturing and cryoSEM of apple …

Thermal Processing Effects On Rice Characteristics, Shuh-Ming Chang, Hsiu-Chen Yang

Food Structure

Whole kernels of four cultivars of milled rice were treated under different conditions according to our traditional methods such as boiling, steaming, autoclaving or roasting with sand. During the vari ous processing conditions, the moisture contents of the kernel , heating temperatures, pressures and heating times were varied. In this paper, the physicochemical properties of those processed samples were investigated and compared.

Based on degree of gelatinization , water absorption index , water solubility index , swelling power, viscoamylograms and X-ray diffraction patterns, the propenies of waxy rice samples arc different from that of non -waxy rice samples. They are …