Digital Commons Network^™

Galactose Transport In Streptococcus Thermophilus, Robert W. Hutkins, Howard A. Morris, Larry L. Mckay

Department of Food Science and Technology: Faculty Publications

Although Streptococcus thermophilus accumulated [¹⁴C]lactose in the absence of an endogenous energy source, galactose-fermenting (Gal⁺) cells were unable to accumulate [¹⁴C]galactose unless an additional energy source was added to the test system. Both Gal⁺ and galactose-nonfermenting (Gal^-) strains transported galactose when preincubated with sucrose. Accumulation was inhibited 50 or 95% when 10 niM sodium fluoride or 1.0 mM iodoacetic acid, respectively, was added to sucrose-treated cells, indicating that ATP was required for galactose transport activity. Proton-conducting ionophores also inhibited galactose uptake, although N,N'-dicyclohexyl carbodiimide had no effect. The results suggest …

Effects Of Bulk Starter Media And Proteolytic Lactic Streptococci On Protein Loss In Cheddar Curd Manufacture, Steven A. Winkel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of whey-based and milk-based starter media, and low concentrations (0.02% each) of citrate, phosphate and calcium upon various milk coagulation properties were measured. Samples inoculated with milk-based starter medium had shorter coagulation times, faster rate of curd formation, and greater final curd firmness than those inoculated with externally neutralized whey-based starter. Starter medium treatment was statistically interacted with calcium for coagulation time and rate of curd formation. Citrate addition caused longer coagulation times, slower rates of curd formation, and weaker final coagula. Citrate interacted with calcium and phosphate for several of the parameters measured. Addition of phosphate did …

Effect Of Iron On Residual Nitrite Level In Ground Pork And Model Systems, Changmin Kim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of iron, temperature, and presence of botulinal spores or sodium ascorbate on depletion of nitrite level were determined in meat and model systems. Higher temperature and presence of botulinal spores definitely increased nitrite depletion in a meat system. Added hemoglobin also significantly increased nitrite depletion, while ferrous iron and ferric iron did not significantly decrease nitrite level in a meat system. High temperature and presence of sodium ascorbate increased nitrite depletion in a model system. Only ferrous iron significantly decreased nitrite level in the absence of ascorbate, while ferric iron, heme iron, and ferritin iron did not decrease …

Modifying Lamb/Mutton Flavors In Processed Meat Products By Smoking, Curing, Spicing, Starter Cultures And Fat Modifications. Investigating The Use Of The Technicon Infraalyzer 400r As A Rapid Method For Proximate Analysis, Chima I. Osuala

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mutton meat was tested in different products in order to obtain prototype products in which mutton can effectively be used without the objectionable mutton off flavor. Mutton flavor reduction was achieved in the processed meat products by: (a) lowering mutton fat to a level of 10% or less, (b) using spices, smoking and/or curing, (c) substituting fat from beef or pork for mutton fat, and (d) the action of microbial starter cultures. Four taste panel sessions were set up to rate these products against an all beef or all pork control for consumer acceptability. Taste panel results indicate that flavor …

Effect Of Proteolytic Activity Of Streptococcus Cremoris On Cottage Cheese Yield, Gary W. Stoddard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Using proteinase negative variants of Streptococcus cremoris UC310 or UC320 to manufacture cottage cheese, theoretical yields were increased 1.97% and 1.56% respectively when compared to the theoretical yields of the proteinase positive parents. Yield differences were strain dependent and differences between positive and negative variants were not manifest with strains of UC73 and UC97. It was necessary to produce bulk culture using pH control and to add sufficient nitrogenous stimulant to provide carry-over stimulant into the cheese milk. All cultures examined developed normally even when the bulk medium contained a blend of 5% yeast extract and casein hydrolysate. It was …

Iron Requirement Of Clostridium Botulinum Type A And Characterization Of Iron-Sulfur Proteins In Nitrite Treated And Untreated Botulinal Cells, Divya Shree A. Reddy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of added iron on the growth of Clostridium botulinum type A in a chemically defined medium was studied. Growth of C. botulinum was supported by an iron level of 0.05 ug/ml with maximum growth observed at a level of 3 ug iron/ml.

Electron paramagnetic resonance (EPR) studies were conducted to detect the presence of iron-sulfur centers and iron-nitric oxide complexes in untreated and nitrite treated cell-free extracts of C. botulinum type A. Untreated extracts of C. botulinum exhibited EPR signals in the oxidized and reduced states characteristic of a "HiPiP-type" iron-sulfur center (g=2.02) in the oxidized state and …

Reduction Of Sodium Nitrite And Sodium Chloride In A Cured Meat Product By Using Acid Development To Inhibit Botulinal Toxin Formation, Angsana Assamongkorn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pediococcus acidilactici as a lactic acid producer, and sucrose were added to breakfast strip products in order to reduce added levels of sodium nitrite and sodium chloride and yet limit the growth of Clostridium botulinum and inhibit toxin production. Sucrose at 0.4 or 0.9% with P. acidilactici at 1.0 x 10⁸ cells/g were added during preparation of breakfast strip products prepared with combinations of 40 or 80 ppm sodium nitrite and 1.0 or 2.0% sodium chloride. Other ingredients were added at levels normally used in cured meat products. C. botulinum types A and B at 1,000 spores/g were inoculated …

Estimates Of Soil Solution Ionic Strength And The Determination Of Ph In West Australian Soils, P. J. Dolling, G. S.P. Ritchie

Food Science and Nutrition

The average ionic strength of 20 West Australian soils was found to be 0.0048. The effects of three electrolytes (deionized water, CaCl₂ and KNO₃), three ionic strengths (0.03, 0.005 and soil ionic strength at field capacity, I_s) and two soil liquid ratios (1:5 and 1:10) on the pH of 15 soils were investigated. pH measurements in solutions of ionic strength 0.005 differed the least from measurements made at I_s. The differences that occurred in comparisons with distilled water or CaCl₂ of ionic strength 0.03 (0.01 M) were much greater (≥0.4 pH …

The Role Of Organic Matter In Soil Acidification, G. S.P. Ritchie, P. J. Dolling

Food Science and Nutrition

The pH and buffer capacity of two soils increased or remained constant after incubation with different amounts of plant material (lucerne cham at field capacity and when air dry. For both soils, the pH changes were greater at field capacity, whereas the buffer capacities were independent of the water treatments. The pH changes observed could be explained in terms of the organic anion concentration of the plant material. The results indicate that the initial soil pH and the anion concentration (i.e. the per cent dissociation of soluble organic acids when released into the soil) determine the acidifying effect of organic …

Ultrastructural Studies On The Cultivation Processes And Growth And Development Of The Cultivated Mushroom Agaricus Bisporus, D. A. Wood, G. D. Craig, P. T. Atkey, R. J. Newsam, K. Gull

Food Structure

Scanning electron microscopy (SEM) , transmission electron microscopy and light microscopy have been used to study various processes in the cultivation of the edible mushroom Agaricus bisporus . Mushrooms are cultured on composted wheat straw. The microbial degradation processes during composting have been visualised by TEM and SEM and correlated with microbiological studies . Various modes of attack by the microorganisms on the plant cell walls can be seen. Most rapid degradation occurred on the cuticle and phloem and spread to other cell types. Microbial attack was found to be nonuniform between tissue types and individual cells. The mycelium of …

Fruit Canning Methods, Georgia C. Lauritzen

Archived Food and Health Publications

Publication gives instructions for canning various different types of fruit.

Ultrastructural Ultilization Of Plants By Herbivores, L. H. Harbers

Food Structure

Study of the patterns of ruminal digestion of forages enhances the nutritional knowledge of how specific plant tissues are digested and adds its own dimension by characterizing the specific cells and the complex interactions of ruminal microflora with those tissues. A common pattern of digestibility exists for mono- and dicotyledon leaves: mesophyll and phloem are degraded readily, and sclerenchyma slowly, whereas cuticle and the remaining vascular tissues are rarely utilized . Digestion of stems is limited to parenchymal tissues in monocotyledons and to cortex and parenchyma in dicotyledons. Epidermal silica and cuticle are undigestible and restrict microbial entrance. Calcium oxalate …

The Light Microscopy Of Triglyceride Digestion, John S. Patton, Russel D. Vetter, Margit Hamosh, Bengt Borgstrom, Mats Lindstrom, Martin C. Carey

Food Structure

During fat digestion (lipolysis) a number of physiochemical events can be seen directly by light microscopy. Hydrolysis of emulsified fat droplets bylipases at pHs above about 6.5 proceeds with the formation of visible product phases that may include both crystalline as well as liquid crystalline phases. The crystalline phase is primarily calcium-fatty acid soap and its formation is favored by high calcium concentrations, alkaline pHs, and inhibited by low pH and monoglycerides. The formation of liquid crystalline product phases are favored by low calcium-concentrations. monoglycerides and lipid saturated bile salt solutions. Both phases are solubilized by bile salts but the …

Seed Microstructure: Review Of Water Imbibition In Legumes, Barry G. Swanson, Joe S. Hughes, H. Paul Rasmussen

Food Structure

Scanning electron microscopy (SEM) is an invaluable tool for studying foods and food products. SEM has been particularly va luable in the study of seed microstructure and the ro le of microstructure in water imbibition by legumes. Controversy continues to surround the causes of hard ness in legumes as addi tional research revea ls differences between legumes that imbibe water and legumes that fail to imbibe water. SEM observation of the microstructural changes occurring in legumes during water imbibition ofkrs a better undcrstandi ng of d i ffc rcnces that ex ist betwee n hard and normal beans. Structural changes …

Proceedings From The 22nd Annual Marschall Invitational, Various Authors

Cheese Industry Conference

No abstract provided.

Holiday Bread 'Round The World, Flora Bardwell

Archived Food and Health Publications

Booklet gives a variety of recipes for Holiday Breads from different countries and cultures.

Application Of Electron Spin Resonance Techniques To Model Starch Systems, L. E. Pearce, E. A. Davis, J. Gordon, W. G. Miller

Food Structure

Starch model systems were examined by electron spin resonance (ESR) techniques with either 16-DOXYL-stearic acid or TEMPO spin probes in water or hexane. Room temperature starchwater- 16-DOXYL-stearic acid spectra showed strong adsorption occurred between the starch and probe. Starch-water-TEMPO spectra at room temperature did not show strong adsorption between starch and probe, but did show some slowed motion of the probe as a result of different local environments experienced by the probe within the starch granule. Starch-water-probe spectra from systems heated from 45-95° C showed no major differences from unheated samples. Also, no major spectral differences existed for each starch …

Small Angle X-Ray Scattering Of Hydrated Wheat Starch Granules, M. Yang, J. Grider, J. Gordon, E. A. Davis

Food Structure

Wheat starch:water (1:2) dispersions were studied by small angle x-ray scatter diffractometry (SAXS), and by light, polarizing microscopy, and scanning electron microscopy (SEM). X-ray scatter data were collected in the 64-661 A range. Radii of gyration (Rg) of spherically shaped regions and d-spacings were calculated for samples that were treated as follows: 25° C and run at 25° C; heated to 88° C and run at 82° C; heated to 88° C, stored at 25° C for 2 h or 3 days and run at 25° C; heated to 88° C, stored at 2° C for 3 days and run …

The Microstructure Of Wheat: Its Development And Conversion Into Bread, D, B. Bechtel

Food Structure

Wheat endosperm development has been studied in numerous laboratories. The genera 1 i zed scheme of protein body formation assembled from these data indicates that storage proteins are initially formed in the rough endoplasmic reticulum (RER). The storage proteins in RER may be processed via the Golgi apparatus into vesicles that enlarge by several mechanisms into membrane-bounded protein bodies. The prote in bodies are transported through the cytoplasm to the vacuole where they fuse with the tonoplast and deposit the protein granules into the vacuoles. The protein granules fuse with one another, lose water, and eventually become transformed into the …

Microstructural Changes In Maturing Seeds Of The Common Bean (Phaseolus Vulgaris L.), Joe S. Hughes, Barry G. Swanson

Food Structure

Seeds of Phaseolus vulgaris L. beans were collected at weekly intervals throughout maturation and examined by scanning electron microscopy (SEM). No major structural changes were observed on the surface of the seed coat during the seven week study period. A cross-sectional examination of the seed coat revealed a substantial increase in thickness of the parenchyma cell layer in young seeds followed by a dramatic decrease in thickness as the seed approached maturity. In the cotyledons, the diameter of the storage cells and starch granules increased over time, with distinct protein bodies becoming visible only in the later stages of maturity. …

Rheological And Scanning Electron Microscopic Examination Of Skim Milk Gels Obtained By Fermenting With Ropy And Non-Ropy Strains Of Lactic Acid Bacteria, S. M. Schellhaass, H. A. Morris

Food Structure

Physical and rheological parameters of skim milk gels fermented with slime producing (ropy) cultures and non-ropy cultures were compared. The skim milk gels were made from steamed reconstituted nonfat dry milk inoculated with 2% of a single strain starter culture and incubated at 32, 37, and 45°C until pH 4. 5 + 0.05 was attained.

Skim milk gels fermented by slime-producing strains of Streptococcus thermophilus, Streptococcus cremoris, and Lactobacillus bulgaricus exhibited similar rheological and physical characteristics. Electron micrographs of the ropy skim milk cultures showed that slime produced by the organisms was associated with the cell surface as well as …

Observations On The Air-Serum Interface Of Milk Foams, B. E. Brooker

Food Structure

A new rapid method for the preparation of milk foams for transmission electron microscopy is described . The air-serum interface of foams made from skimmed milk consists of a uniform electron dense layer (5 nm thick) to which casein micelles become secondarily attached . Changes in bubble volume lead to the formation of folds of excess interfacial material which project into the aqueous phase. Using collapsed bubble ghosts to study the attachment of micelles to the airserum interface it was concluded that neither disulphide bridge formation nor hydrophobic interactions were of major importance. Similar preparations of interfacial material but without …

Microstructure Of Spray-Dried And Freeze-Dried Microalgal Powders, L. P. Lin

Food Structure

Chiarella and Spirulina algae were spray-dried and freezedried under several different conditions, and the morphological changes induced were studied by scanning electron microscopy. The internal structure of the particles (granules) was revealed by cryofracturing. The cellular composition of the two algae, method of drying, cell concentration, feed conditions, temperature, and drying times all affected the external morphology of the resulting powders. In the case of spray-drying, at a temperature of 160 °C for 6 sec, the particles shrunk or collapsed; if the drying time was over 10 sec at 160 °C, similar results were observed. The cell concentration affected the …

Effects Of Emulsifying Agents On The Microstructure And Other Characteristics Of Process Cheese - A Review, Marijana Caric, Miroslav Gantar, Miloslav Kalab

Food Structure

Sodium phosphates , polyphosphates, and citrates are melting salts (emulsifying agents) most commonly used in the manufacture of process cheese either alone or in mixtures . Their role during processing is to sequester calcium in the natural cheese, to solubilize protein and increase its hydration and swelling, to facilitate emul sification of fat , and to adjust and stabilize pH.

Changes taking place in natural cheese during processing can be studied by microscopy. Micrographs demonstrating the emulsification of fat , presence of salt crystals, and partial solubilization of protein in labo ratory- made and commercial process cheeses have been used …

Properties Of Calcium Caseinates With Disparate Performance In Imitation Cheese, K. Fleming, R. Jenness, H. A. Morris, R. Schmidt

Food Structure

Two commercial lots of calcium caseinate preparations differing in performance imitation cheese were analyzed for various characteristics. A imitation process cheese manufacturing classified the caseinates as good or poor based on appearances of the finished cheese, emulsification of fat, oiling-off during sheeting and melting properties. The sample which exhibited good functional properties in imitation cheese, had slightly higher calcium (16.4 mg/g protein), non-casein protein (2.87%) and y-casein contents, a higher formal titre (8.95 mg free amino N/g protein), lower water absorption (138 mg/100 g protein), and lower stability to added calcium (8.0 min) than did the other sample (14.6 mg/g, …

Seed Structure And Composition Of Potential New Crops, D. W. Irving, R. Beckler

Food Structure

Prosopis , Ol neya , and Amaranthus have potenti a l economic value as food or feed crops fo r a rid /semi- arid r egions. Ma ture seeds of these genera we r e examined using scanning e l ec tron and fluoresce nce microscopy to define a natomy and localize s t or age s truc tures in cells . Pro t ein bodies, some co nt a ini ng phytin inc lu sions , were l oca li zed in the embryos of five Prosopi s s peci es . Prosopis chilensis wa s the only one …

Effect Of Casein/Fat Ratio On Milk Fat Recovery In Cheddar Cheese, Nana A. Yiadom-Farkye

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cheddar cheese was made by the traditional 4.5-h method from three experimental lots of milk, each standardized to casein/fat ratios of approximately 0.64, 0.67 and 0.70. The effect of casein/fat ratio on milk fat recovery was determined. The effects of milk composition on curd firmness at cutting, cheese composition and resulting yield of cheese were evaluated. Correlations between milk constituents and various cheese components were obtained. Milk fat recovery was unaffected by casein/fat ratios within the limits of 0.64 and 0.71. Average milk fat recovery was 91.58 ± 1.73%. Cheese yield was a function of milk protein, milk fat and …

Comparison Of Several Forms Of Equations For Predicting Cheddar Cheese Yield From Milk Composition, Craig A. Moore

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was conducted to evaluate several forms of equations for predicting Cheddar cheese yields based on the fat and protein content of milk and moisture content of cheese. Production and quality control data from a Cheddar cheese plant for one entire year was used. This included the pounds of milk that went into each vat of cheese, yield of cheese from each vat, cheese moisture from each vat, and fat and protein percentages of the milk.

Seven models were derived to predict the yield of Cheddar cheese. The seven models were statistically fitted to the data by applying the …

The Relationship Between Milk Composition And Swiss Cheese Yields, Adnan S. Ba-Jaber

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

From Cache Valley Dairy Association in Smithfield, Utah, milk from two to three cheese vats plus the corresponding Swiss cheese trimmings, salted cheese, and whey were sampled each week from October 1981 to October 1982. The weights of the Swiss Cheese were recorded. Milk samples were analyzed for fat and protein; cheese samples were analyzed for fat, protein, and moisture; whey samples were analyzed for fat.

By using Gauss-Newton nonlinear Least Squares method of iteration, the data was analyzed. Two formulas for predicting Swiss cheese yield were derived. A good relationship was found to exist between Swiss cheese yield and …

Microstructural Changes In Winged Bean And Soybean During Fermentation Into Miso, K. Saio, H. Suzuki, T. Kobayashi, M. Namikawa

Food Structure

Miso was prepared from winged bean, being substituted for soybean. Microstructural changes of winged bean miso at various stages of the manufacturing processes were studied by means of light and transmission electron microscopies. Soybean was also studied for comparison.

After steaming , winged bean and soybean cells were shrunken and intracellular spaces enlarged and cell wall structure was degraded, showing layered structures and aggregated lumps in intraspaces between cell walls during fermentation into misc . At the end of the fermentation , the PAS reaction with cell walls almost disappeared. Surprisingly the thick cel l walls of winged bean degraded …