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Full-Text Articles in Life Sciences

The Association Of Seed And Cone Predator Populations And Cone Crop Production In Engelmann Spruce, Dawn E. Cameron May 1987

The Association Of Seed And Cone Predator Populations And Cone Crop Production In Engelmann Spruce, Dawn E. Cameron

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Engelmann spruce (Picea engelmannii Parry ex Engelm.) exhibits cone crop periodicity, producing seed in a cyclic pattern. Variation in seed production has been noted between individuals of a population, but synchronization on a large scale is common. The theory that ultimately these periodic large cone crops have resulted from the selective pressures of seed and cone predators, referred to as the predator satiation hypothesis, is considered. Assuming predator pressures have operated over evolutionary time to select for periodic synchrony, associations between seed and cone predators and cone crop production levels were anticipated. These potential consequences of predator satiation were …


Causes Of Seeding Failure Within The Tooele Fire Rehabilitation Project In Northwestern Utah, Jeffrey S. Murphy May 1987

Causes Of Seeding Failure Within The Tooele Fire Rehabilitation Project In Northwestern Utah, Jeffrey S. Murphy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The original purpose of this study was to examine the influences of ecological site, seeding method and planting season on rangeland seeding success within the Tooele Fire Rehabilitation Project (TFRP) in northwestern Utah. The major objective of the TFRP, designed by the USDI Bureau of Land Management, was to establish a permanent cover of 'Nordan' crested wheatgrass (Aqropyron desertorum (Fischer ex Link) Schultes), 'Luna' pubescent wheat grass (Thinopyrum intermedium ssp. barbulatum (Schur) Barkw. and D. R. Dewey) and 'Alkar' tall wheatqrass (Thinopyrum ponticum (Podp.) Barkw. and D. R. Dewey) on approximately 20,000 ha of rangeland burned by a wildfire in …


Mechanism Of Iron Transport In Mycelia Sterilia Ep-76, Jonathan P. Adjimani May 1987

Mechanism Of Iron Transport In Mycelia Sterilia Ep-76, Jonathan P. Adjimani

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The cyclic trihydroxamic acid, N, N', N' '-triacetylfusarinine C, produced by Mycelia sterilia EP-76, is shown to be a ferric ionophore for this organism. The association constant for ferric-N, N', N' '-triacetylfusarinine C complex was determined to be log K=32.5. Other iron chelating agents, such as rhodotorulic acid, citric acid, or the monomeric subunit of triacetylfusarinine C, N-acetyl- fusarinine, delivered iron to the cells by an indirect mechanism involving iron exchange into triacetylfusarinine C. In vitro ferric ion exchange was found to be rapid with triacetylfusarinine C. Gallium uptake rates comparable to those of iron were observed with the chelating …


Effects Of Phosphorus On No-Till, Minimum-Till, And Conventional Till Irrigated Field Corn, John A. Mckay May 1987

Effects Of Phosphorus On No-Till, Minimum-Till, And Conventional Till Irrigated Field Corn, John A. Mckay

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This investigation involved three tillage treatments, fall plowed (conventional) (moldboard IS-centimeter depth), fall chiseled (ripped) (25-centimeter depth), and no-tillage (zero tillage) replicated four times on an established alfalfa field. Rye was planted in the fall and harvested prior to planting the corn. Soil samples contained an average of 5.9 ppm phosphorus in the 0-30 centimeter soil layer, indicating the need for additional phosphorus. Within each tillage treatment, six rows received 11 kilograms/hectare phosphorus with the seed and 34 kilograms/hectare phosphorus side-dressed. Six rows received 45 kilograms/hectare phosphorus side-dressed, and four rows received 0 phosphorus. All 16 rows received 64 kilograms/hectare …


Investigations Of Field Performance And Physiological Effects Of Metsulfuron And Metsulfuron Combinations On Field Bindweed (Convolvulus Arvensis L.), Hamid Rahimian Mashhadi May 1987

Investigations Of Field Performance And Physiological Effects Of Metsulfuron And Metsulfuron Combinations On Field Bindweed (Convolvulus Arvensis L.), Hamid Rahimian Mashhadi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Field bindweed (Convolvulus arvensis L.) is a noxious perennial weed of many fallow and cropland fields all over the world. Present control methods are not satisfactory for field bindweed. Metsulfuron, 2[[[[(4-methoxy-6-methyl-1,3,5-triazine-2-yl) amino] carbonyl] amino] sulfonyl] benzoic acid, is a new herbicide that has been shown to have activity on bindweed especially when tank mixed with other herbicides. This study was conducted to investigate the field performance and some physiological effects of metsulfuron on field bindweed.

Neither metsulfuron alone nor metsulfuron combinations gave persistent control of field bindweed. Metsulfuron usually increased the activity of other bindweed herbicides. Herbicide application to …


Economic Aspects Of Reproductive Problems In Utah And Southeastern Idaho Dairy Herds, Steve Lemrick May 1987

Economic Aspects Of Reproductive Problems In Utah And Southeastern Idaho Dairy Herds, Steve Lemrick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One hundred eighty-seven survey questionnaires asking for reproductive information for 1985 were sent to dairymen in Utah and Southeastern Idaho. Forty- two herds with current DHI information and whose owners or managers completed and returned the questionnaire were used to estimate economic losses due to reproductive problems, especially excessive days open, in Utah and Southeastern Idaho.

Average days open for herds surveyed were 122.4 days with a standard deviation of 22.6 days, and a range of 89 to 177 days. Several factors were significantly correlated with days open including services per conception, previous calving interval, and missed heats. Missed heats …


Selected Parameters Of Reproduction In Rambouillet And St. Croix Ewes, Ronald Cole Evans May 1987

Selected Parameters Of Reproduction In Rambouillet And St. Croix Ewes, Ronald Cole Evans

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Experiments were conducted to determine the genetic reproductive potential of Rambouillet and St. Croix ewes . Ovulation rate (monthly) and estrus (daily) were observed for two years on 10 ewes of each breed to establish seasonal patterns . Both breeds demonstrated seasonal anestrus from May through July. Ovulation rates reached 2.0 or greater for both breeds during September to November, and decreased to 1.25 by March. Breeding groups for St. Croix and Rambouillet ewes were bred each February and August for five years to establish lambing performance at six month intervals. Age at first lambing was earlier for St. Croix …


Compounds In Bovine Urine Which Change In Concentration During The Estrous Cycle: Possible Pheromones, Scott Kay Johnson May 1987

Compounds In Bovine Urine Which Change In Concentration During The Estrous Cycle: Possible Pheromones, Scott Kay Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

During the last thirty years it has become increasingly apparent that pheromones play a major role in animal communication. Of economic interest to agriculturalists is the role pheromones play in signaling the state of estrus. The ability to efficiently detect estrus is becoming increasingly important, especially in the management of dairy and beef herds, where artificial insemination is used extensively. The understanding of pheromones may eventually provide a solution to this problem.

The purpose of this study was to identify one or more compounds in the urine of cattle which undergo a change in concentration during the estrous cycle.

In …


Effects Of Sire, Ration, And Interaction Of Sire With Ration On Reproductive Performance Of Holstein Dairy Cows, Jen-Hon Justin Chen May 1987

Effects Of Sire, Ration, And Interaction Of Sire With Ration On Reproductive Performance Of Holstein Dairy Cows, Jen-Hon Justin Chen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study was conducted to analyze reproductive data gathered over a ten-year period at the Utah State University Dairy Farm. The study utilized 289 complete first lactations of Holstein cows, including 150 daughters of 10 sires in Trial I and 139 daughters of 8 sires in Trial II. One sire was used in both trials; this was sire 4 in Trial I and sire 18 in Trial II. The study measured ration, season, and sire effects and their interactions on the reproductive performances of dairy cows.

Reproductive traits analyzed were: days from calving to first estrus, days from calving to …


Comparing Different Methods For Determining Moisture In Wheat Using Nesr Infrared Reflectance Spectroscopy, Weider Chang May 1987

Comparing Different Methods For Determining Moisture In Wheat Using Nesr Infrared Reflectance Spectroscopy, Weider Chang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One hundred wheat samples, with moisture ranging from 14.42 %to 7.66 %, were used to test the moisture loss from grinding, the accuracy of moisture content from two different electric moisture meters, and the accuracy and precision of Near Infrared Reflectance Spectroscopy whole wheat moisture determination.

Fifty samples were ground through three grinders, Wiley, Cemotec, and UDY Cyclone grinder. Moisture content was determined from these ground samples, and compared with whole wheat moisture. The Cemotec grinder caused the least amount of moisture loss, followed by Wiley and then UDY Cyclone.

Fifty whole wheat samples were used to calibrate the Tecator …


N2-Fixation In Alfalfa (Medicago Sativa L.) Seedlings And Rhizobium Meliloti L. Grown In Vitro Under Salt And Drought Stresses, Ramzi Muhiddin Mohamad May 1987

N2-Fixation In Alfalfa (Medicago Sativa L.) Seedlings And Rhizobium Meliloti L. Grown In Vitro Under Salt And Drought Stresses, Ramzi Muhiddin Mohamad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Alfalfa, Medicago sativa L., cultivars, breeding lines and germplasm releases (populations) and Rhizobium meliloti L. strains that exhibit nitrogen fixation efficiency and tolerance to salinity and drought stresses should enhance seedling establishment, increase yields, reduce nitrogen dependency on petroleum-based nitrogen fertilizers, and allow wider use of irrigated lands in semiarid and a rid regions. In vitro experiments were conducted to determine relative salt (sodium chloride -- NaCl) tolerance: l) during germination and early seedling growth of 229 alfalfa populations from North Africa, the Middle East and the United States, 2) survival and growth of 92 rhizobial strains obtained from different …


Effects Of Drought On The Survival Of Rhizobium Leguminosarum Biovar Trifolii And The Nodulation Of Subterranean Clover In An Acid Soil, Carmen Bueno May 1987

Effects Of Drought On The Survival Of Rhizobium Leguminosarum Biovar Trifolii And The Nodulation Of Subterranean Clover In An Acid Soil, Carmen Bueno

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Twenty-nine Rhizobium leguminosarum biovar trifolii strains were tested for acidity tolerance in acidified liquid medium. Only 41% of the strains grew at pH 4.1. One acid-tolerant strain, USDA 2160, and one acid-sensitive strain, 162-X-103 from Nitragin Co., were inoculated on seeds of 'Nungarin', 'Seaton Park' and 'Clare' subclover cultivars. The inoculated and pelleted seeds were sown in potted Cluff soil with pH 5.7. Three desiccation levels were imposed by delaying watering for 0, 15 or 30 days. Four gravimetric soil water contents (6.0, 6.6, 10.5 and 12.5%) were maintained under a greenhouse line-source sprinkler system for 7 weeks. The desiccation …


Wood And Forage Production In Cleared And Thinned Dry Tropical Woodland: Implications To Goat Nutrition, Walter H. Schacht May 1987

Wood And Forage Production In Cleared And Thinned Dry Tropical Woodland: Implications To Goat Nutrition, Walter H. Schacht

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wood for firewood, fence posts and construction material and forage for domestic livestock are key resources in the caatinga vegetation zone of northeastern Brazil. This experiment was designed as a preliminary assessment of thinned caatinga as the basis of a production system which optimizes forage and wood production. Two levels of thinning (25% and 55% tree canopy cover) were compared to cleared (0% tree canopy cover) and undisturbed (95% tree canopy cover) caatinga in terms of forage and wood production and goat nutrition.

Clearing and thinning of caatinga vegetation resulted in higher amounts of available forage through the wet ·season …


Vitamin A Status, Anthropometric Measurements, And Food Practices Of Women Of Childbearing Age And Their Preschool Children In Northeast Brazil, Susan Ahlstrom Henderson May 1987

Vitamin A Status, Anthropometric Measurements, And Food Practices Of Women Of Childbearing Age And Their Preschool Children In Northeast Brazil, Susan Ahlstrom Henderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Vitamin A nutrition status was evaluated in 110 pairs of women and their preschool children at rural health posts in two different ecological regions of Northeast Brazil. Serum retinol and carotene, weight, height, tricep skinfold and mid-arm circumference were measured from each mother and child. Nutrition knowledge of mothers, socioeconomic living conditions and consumption of retinol and carotene food sources were assessed.

Nine children (8 percent) and one mother had less than acceptable serum retinol (less than 20 μg/dl). Additionally, 21 percent of the children and six percent of the mothers had "low" serum carotene levels. Thirty-seven percent and 57 …


Autecological And Grazing Control Studies Of Dyers Woad (Isatis Tinctoria L.) On Northern Utah Rangelands, Kassim O. Farah May 1987

Autecological And Grazing Control Studies Of Dyers Woad (Isatis Tinctoria L.) On Northern Utah Rangelands, Kassim O. Farah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dyers woad (Isatis tinctoria L.) is a noxious weed on northern Utah rangelands. Chemical and mechanical means of control are unsuitable for rangelands. A potential alternative, biological control, is difficult due to a lack of basic ecological information. To remedy this, some aspects of the population biology and autecolgy of dyers woad were studied. The feasibility of controlling dyers woad by early spring grazing was also investigated via clipping experiments.

A population study followed the survivorship of experimentally established populations over two years. Fall germinating individuals (1984) overwintered as rosettes twice and all survivors reproduced successfully. Spring germinating individuals …


An Improved Method For Transferring Nucleic Acids To Nylon Membranes, Bruce D. Parker May 1987

An Improved Method For Transferring Nucleic Acids To Nylon Membranes, Bruce D. Parker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Methods currently in use for the separation and identification of specific segments of nucleic acids involve long transfer periods or elaborate apparatuses and result in the production of a single blot. Contamination by organisms or enzymes is always a factor to be dealt with. An improved method for transferring nucleic acids from acrylamide or agarose gels for use in hybridization has been developed. This method uses NaOH as the blotting medium to improve the rate and efficiency of transfer to nylon membranes. As many as six blots can be obtained within one hour using this method. This method is effective …


Cholesterol-Lowering Of Pantethine Is Due To The Hydrolysis Product Cysteamine, Caran Graves May 1987

Cholesterol-Lowering Of Pantethine Is Due To The Hydrolysis Product Cysteamine, Caran Graves

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pantethine, a precursor of coenzyme A, has been shown to reduce serum cholesterol levels in hypercholesterolemic rabbits. The enzyme pantetheinase rapidly hydrolyzes pantethine to the vitamin pantothenic acid and the amino thiol cysteamine.

This study was designed to compare the effect of cysteamine and pantothenate supplementation with that of pantethine on hypercholesterolemic rabbits. New Zealand white rabbits were fed a 0.5% cholesterol diet for 5 weeks; treatment groups received only the high cholesterol diet (control), or a high cholesterol diet supplemented with 1% pantethine, or an equimolar amount of pantothenic acid or cystamine (the disulfide of cysteamine). Blood samples were …


Plasmid-Linked Maltose Utilization In Lactobacillus Spp. Isolated From Meat, Mei-Ling Liu May 1987

Plasmid-Linked Maltose Utilization In Lactobacillus Spp. Isolated From Meat, Mei-Ling Liu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Five strains of Lactobacillus plantarum and four strains of Lactobacillus species isolated from fresh meat were examined for the presence of plasmid DNA. All strains examined contained between one and five plasmids ranging in molecular mass from 1.3 to 51.6 (Mdal). Plasmid-curing experiments suggest that maltose utilization is associated with a 51 Mdal plasmid in Lactobacillus sp. DB29 and 42 Mdal plasmids in Lactobacillus spp. DB27, DB28, DB31. Southern blot DNA-DNA hybridization showed homology between the maltose plasmid from Lactobacillus sp. DB29 and several plasmids from the other Lactobacillus spp.


Fluoride Content In Home-Canned Fruits In Utah, Sydney Ann Mcdonald May 1987

Fluoride Content In Home-Canned Fruits In Utah, Sydney Ann Mcdonald

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research was to determine whether or not canning fruit using fluoridated water made a difference in the fluoride contents of the juice and the pulp. Four cities in Utah were chosen. Two cities were fluoridated (Brigham City and Helper) and two cities were not fluoridated (North Ogden and Price). Three homes were chosen within each city, and three jars of canned fruit (one jar each of apricots, cherries, and peaches) were selected from each home. The fruit samples were freeze-dried, and then the fluoride was measured with a fluoride ion electrode. A difference was found in …


Effects Of Exercise And Cheese Supplemented Diet On Cholesterol And Lipoprotein Fractions In Free-Living Young Human Subjects, Kathleen A. Gabel May 1987

Effects Of Exercise And Cheese Supplemented Diet On Cholesterol And Lipoprotein Fractions In Free-Living Young Human Subjects, Kathleen A. Gabel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ten young adults were divided into an exercising group (n = 6) and sedentary group (n = 4). Smoking, ingestion of alcohol, drugs and oral contraceptives were prohibited during 9 weeks of study. Diets were prepared by university food service. Food consumed was recorded and nutrient intakes were assessed. Cheese was consumed in 84 to 112 gram portions every day for two separate 14 day periods. All other dairy products were prohibited in the diet except 240 ml of two percent milk per day. When cheese was consumed, daily diets contained ca 400 kcal, 100 mg cholesterol, and 700 mg …


Iron Bioavailability Of Meat:Bread Mixtures And Meat Loaves Fed To Anemic And Healthy Rats, Abdullah M. Thannoun May 1987

Iron Bioavailability Of Meat:Bread Mixtures And Meat Loaves Fed To Anemic And Healthy Rats, Abdullah M. Thannoun

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To study the effect of meat (beef) on dietary iron bioavailability from enriched white bread (EWB) or whole wheat bread (WWB), diets were prepared in which the ratios of beef iron to bread iron were 100:0, 75:25, 50:50, 25:75 or 0:100. Hemoglobin regeneration efficiency (HRE), apparent iron absorption, and dry matter absorption were determined using weanling anemic and healthy male rats.

Meat iron was more available than EWB or WWB. Fortification iron in EWB was less available than the iron naturally present in WWB. At the iron dose given, HRE was similar for both anemic and healthy rats. Although healthy …


The Feasibility Of Artificial Insemination Of Dairy Cattle Managed By Fulani Tribesmen In Kaduna State, Nigeria, Christian Olafimihan Ojomo May 1987

The Feasibility Of Artificial Insemination Of Dairy Cattle Managed By Fulani Tribesmen In Kaduna State, Nigeria, Christian Olafimihan Ojomo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study sought to determine: (a) the essential elements of a viable artificial insemination program for the Fulani Tribesmen in Kaduna State, Nigeria, and (b) to determine if the essential elements of a viable artificial insemination program exist in Kaduna State, Nigeria.

This study was conducted from April 15 to May 15, 1985, in the Artificial Insemination (AI) Subcenters of Zaria, Katsina, Kabomo, Kaduna, Ikara, Zonkwa, Kurmin-Biri, and Kauranjuli.

The data presented in this study were collected by personal interviews with Fulani Tribesmen. The population of this study was from a partial list of Fulani Tribesmen who have had AI …


Factors Affecting The Sprouting Response Of Woody Caatinga Species And Their Implications For Improved Caatinga Management, Linda Howell Hardesty May 1987

Factors Affecting The Sprouting Response Of Woody Caatinga Species And Their Implications For Improved Caatinga Management, Linda Howell Hardesty

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In northeast Brazil grazing is a major use of much of the semiarid woodlands (caatinga). Animal production is limited by lack of dry season forage, primarily deciduous tree leaves. Management is constrained by the persistence of undesirable trees that sprout from the stump (coppice). This study evaluates the possibility of manipulating coppicing trees to improve caatinga management, particularly dry season forage production.

The season of cutting can influence coppicing. Trees were cut early and late in the wet and dry seasons. After two years, trees of all species cut in the late wet season produced less biomass than those cut …


Utilization Of Crested Wheatgrass Plants By Cattle Under Several Grazing Regimes, Patricia Selann Johnson May 1987

Utilization Of Crested Wheatgrass Plants By Cattle Under Several Grazing Regimes, Patricia Selann Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Patterns of grazing on individual crested wheatgrass plants were studied using scale maps of plant basal outlines within randomly located plots. The occurrence and extent (part of plant grazed, stubble height) of grazing on each plant was recorded on the maps at two and three day intervals throughout a grazing treatment. Allometric equations for estimating phytomass from plant photosynthetic volume were generated using nonlinear regression analysis. Equations were specific to year. The percent weight remaining in the stubble of a grazed plant was estimated using a second-order polynomial equation relating cumulative percent plant height to cumulative percent plant weight. A …


Comparative Study Of Elongated Chromosomes In Sheep And Goats And A Proposed Standard, Stephen H. Mensher May 1987

Comparative Study Of Elongated Chromosomes In Sheep And Goats And A Proposed Standard, Stephen H. Mensher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A cell synchronization technique was used that consistently yielded numerous elongated chromosomes, which are necessary for producing high-resolution G-banding. The prometaphase stage of contraction was determined to have the greatest utility for detailed comparative analysis and, therefore, was used in the preparation of the proposed standard high-resolution karyotypes and idiogram.

A proposed standard high-resolution G-band karyotype of the domestic sheep and goat is presented, along with a high-resolution G-band idiogram of the goat. The karyotypes presented contain considerably more bands than contemporary karyotypes and provide much greater resolution for linear differentiation. The X chromosome of the sheep is acrocentric, rather …


Effects Of Grazing Intensity By Sheep On The Production Of Atriplex Nummularia And Sheep Live Weight In Jordan, Kamal I. Tadros May 1987

Effects Of Grazing Intensity By Sheep On The Production Of Atriplex Nummularia And Sheep Live Weight In Jordan, Kamal I. Tadros

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rangelands in Jordan are deteriorated due to a combination of harsh environmental conditions and human misuse. Jordan is importing increasingly large quantities of meat and animal products to meet the demand from its growing population. Sheep are supplementarily fed during the dry season and large quantities of grain supplements are imported every year.

Significant success has been attained in the establishment of Atriplex nummularia Lindl. (ATNU) in Jordan. There is, however, a general lack of adequate research to determine if ATNU is effectively utilized by local sheep, to what extent it is utilized and to what extent it tolerates grazing. …


Effects Of Starter Cultures On Short-To Medium-Chain Free Fatty Acid Content And Sensory Properties Of Mutton Summer Sausage, Robert M. Essiaw-Quayson May 1987

Effects Of Starter Cultures On Short-To Medium-Chain Free Fatty Acid Content And Sensory Properties Of Mutton Summer Sausage, Robert M. Essiaw-Quayson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of starter cultures on short- to medium-chain free fatty acid contents am sensory attributes of different batches of summer sausages were determined. The summer sausages were from range ram mutton, and formulated after grinding to contain 23% fat. Commercial starter cultures from different sources, including Micrococcus varians or Micrococcus species and Lactobacillus plantarum, commercial microbial lipase, an indigenous Micrococcus isolate or encapsulated lactic acid were used to prepare the summer sausages. Three batches were made, each batch receiving six different treatments.

Three consumer panels evaluated the sausages for acceptability and a trained screened panel evaluated the products …


Cottage Cheese From Ultrafiltered Skimmilk By Direct Acidification, Jorge Ricardo Ocampo-Garcia May 1987

Cottage Cheese From Ultrafiltered Skimmilk By Direct Acidification, Jorge Ricardo Ocampo-Garcia

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pasteurized skimmilk at 4°C was acidified to pH 5.8 with 85.5% phosphoric acid (136g H3PO4/100 kg skimmilk), then warmed to 54°C and ultrafiltered to a protein concentration 9.1 ± 0.2%. The retentate was heated to 76.5°C for 16 s then cooled to 2°C. Phosphoric acid (85.5%) was added at a rate of 3.41g per kg retentate. The acidified retentate was slowly warmed to 29.5°C (3°C/5 min) when the pH was checked. The pH at this point was no lower than 5.4. Heating was continued until a temperature of 32.2°C was reached. Glucono delta lactone was added …


The Effect Of Ultrafiltration On Protein Quality Of Skimmilk And Cottage Cheese, Rita Y. Y. Tung May 1987

The Effect Of Ultrafiltration On Protein Quality Of Skimmilk And Cottage Cheese, Rita Y. Y. Tung

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Protein quality in freeze-dried skimmilk (SM), regular cottage cheese (RCC), retentate (Ret) and cottage cheese made from ultrafiltrated skimmilk (UFCC) were evaluated by chemical (amino acid score) and biological methods. Biological evaluation was at 5, 8 and 11% protein level in growing rats by measuring biological value (BV), net protein utilization (NPU) and nitrogen efficiency for growth (NEG) over a 14-day period. A 28-day protein efficiency ratio (PER) was determined on the same products at 10% protein level. Effects of added lactose on PER of retentate, regular and UFCC were also evaluated. The most limiting amino acids were cystine + …


Factors Affecting Growth Of Proteinase Positive And Proteinase Negative Streptococcus Cremoris Uc310 In Ultrafiltered Milk Retentate, Brent Karl Pope May 1987

Factors Affecting Growth Of Proteinase Positive And Proteinase Negative Streptococcus Cremoris Uc310 In Ultrafiltered Milk Retentate, Brent Karl Pope

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Whole milks were adjusted to pH 5.8, 6.2, or 6. 7 with HCl and batch pasteurized at 63°C for 30 min. Each was concentrated 5:1 (40% total solids) through a single tube polysulfone membrane Abcor ultrafiltration unit. Lactose (L), casein hydrolysate (CH), and one of two brands of yeast extract (YE1, YE2) were added into cooled retentates at 0.1, 0.3, 0.5, 0. 7 or 0.9% and equilibrated overnight at 4°C. Five percent proteinase positive (Prt+) Streptococcus cremoris UC 310+ (v/w) milk based culture was added. Unfortified retentate was also inoculated with 0.1, 0.3, 0.5, 0. 7 or 0.9% starter and …