Food Chemistry Commons^™

Activity And Nature Of Plasminogen Activators Associated With The Casein Micelle, B. Ismail, L. H. Choi, Lilian M. Were, S. S. Nielsen

Food Science Faculty Articles and Research

In fresh milk, plasminogen, the zymogen form of plasmin (PL), is the predominant form. Therefore, plasminogen activators (PA) can contribute significantly to PL activity in milk. Both tissue-type PA (tPA) and urokinase-type PA (uPA) exist in milk; however, contradictory findings have been reported for which type of PA is most closely associated with the casein micelles. Little is known about the factors that might lead to variations in the individual activities of the PA. The objective of this work was therefore to investigate possible factors that might affect the association of tPA and uPA with the casein micelle and their …

G1600 Freeze Concentration Of Fruit Juices, Durward Smith, Carol Ringenberg, Eric Olson

University of Nebraska-Lincoln Extension: Historical Materials

This publication describes research conducted to examine the feasibility of freeze concentration with small-scale, simple equipment; and research results on juice extraction and concentration from fruit held in frozen storage.

When Grandmother made jelly the wonderful aroma of cooking fruit filled the house. That wonderful aroma was the delicate fruit flavors being evaporated and lost from the jelly. When volatile flavors are retained food has a much better flavor. Freeze concentration of fruit juices is a method of removing water from juices without heating and changing juice flavor. Freeze concentration is effective because a solute in solution has a lower …

Drying Of Post-Harvest Rough Rice With Silica Gel: A Preliminary Investigation, Stephen J. O'Brien, Terry J. Siebenmorgen

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Rice drying operations can encounter problems of over drying and losses in head rice yield (HRY) through the formation of fissures. Typical rice drying methods also utilize large volumes of expensive fossil fuels to dry the kernels. Drying of rice with a solid desiccant such as silica gel has several potential advantages that avoid some of these problems. Two cultivars of long-grain rough rice, ‘Cheniere’ and ‘Wells’ with harvest moisture contents of 17.8% and 22.0%, respectively, were dried over a 48-h period with various ratios of rough rice-to-silica gel. It was found that an intimate mixture of 3:1 rough rice …

Influence Of Sodium Chloride, Calcium, Moisture, And Ph On The Structure And Functionality Of Nonfat Directly Acidified Mozzarella Cheese, Brian M. Paulson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Experiment A explored the influence of sodium on direct acid, nonfat Mozzarella cheese. Cheeses with differing salt levels were obtained by varying dry salt applications (none, 0.5%, and 1.0% NaCl w/w) and hot brine stretching (0%, 5%, and 10% NaCl wt/v). Salt application and salt content influenced cheese moisture, meltability, expressible serum, micro- and ultra-structure, and color. Moisture was highest when cheese was salted before stretching (P = 0.03). Melt was lowest in cheeses that were unsalted (P = 0.05). Cheeses stretched in salt brine had < 1% of the amount of expressible serum found in unsalted cheese (P < 0.0001). Unsalted cheeses had a more open structure with pockets of serum distributed throughout the protein matrix giving it an opaque, white appearance. Salted cheeses had a more homogeneous protein matrix lacking light scattering surfaces, resulting in a translucent cheese. Neither salt concentration nor method of salting affected the calcium content of the cheeses (P > 0.05).

Experiment B explored the influence of calcium, moisture, and …

Prevention Of Pigment Deterioration And Lipid Oxidation In Ground Beef And Pork, Preetha Jayasingh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fresh beef was modified-atmosphere packaged in carbon monoxide or oxygen to prolong red surface color. After comparison of several packaging method using carbon monoxide, steaks pretreated with 5% carbon monoxide for 24 hours and then vacuum packaged had the best combination of color and microbial stability (5 weeks), with the least potential for carbon monoxide inhalation.

In the evaluation of ground beef in high-oxygen, modified-atmosphere-packaging, thiobarbituric-acid numbers increased over time, and the flavor was disliked slightly after 6 or 10 days of storage at 2° Celsius.

The antioxidant effect of milk-mineral was tested in raw and cooked ground pork stored …

Hormone Mediated Transport Of Calcium And Phosphate In Polarized Epithelial Cells, Tremaine M. Sterling

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effects of 1,25(OH)₂D₃, PTH and 25(OH)D₃ on phosphate or calcium uptake were studied in cultured, adherent chick enterocytes over a period of 10 min after hormone addition. Time course studies of cells treated with 130 pM 1,25(OH)₂D₃ showed an increase in ³²P uptake as early as 3 min. Similar studies with 65 pM bPTH(l1-34) resulted in an increase in ⁴⁵Ca uptake only if the cells had been cultured in serum. (OH)D₃, which is not firmly established as an active metabolite of vitamin D, was shown to increase …

Fisheries Research Contract Report No. 6 - Assessment Of The Nutritional Variability Of Lupins As An Aquaculture Feed Ingredient, Brett Glencross, John Curnow, Wayne Hawkins

Fisheries Research Reports

The nutritional value of the kernel meals of three species of lupin (Lupinus albus, L. angustifolius and L. luteus) was compared against each other and a reference ingredient of solvent extracted soybean meal, when fed to rainbow trout (Oncorhynchus mykiss). Each lupin kernel meal was included in test diets at 300 g/kg and also at a greater level, representing 50% of the total protein content in the diet. The digestibility of protein of all lupin kernel meals was better than for the soybean meal. The highest protein digestibility was that from L. luteus kernel meal at 30% inclusion (100%), which …

Sheep Updates 2003 - Meat, Lucy Anderton, Rob Davidson, Keith Croker, Robin Jacob, Rachel Kirby, Steve Meerwald, John Milton, David Pethick

Sheep Updates

This session covers seven papers from different authors: 1. Economic analysis of using terminal sires in a self replacing Merino flock Lucy Anderton, Department of Agriculture Western Australia, Katanning 2. Is the mating of ewe weaners an option for increasing the numbers of lambs in WA? Rob Davidson University of WA, Crawley and Keith Croker Department of Agriculture Western Australia, South Perth 3.Dehydration of lambs at the time of slaughter Robin Jacob, School of Veterinary and Biomedical Sciences, Murdoch University 4.Feeding prime lambs for slaughter Rachel Kirby, Outback Solutions 5. Live sheep export R&D Steve Meerwald, Wellard Rural Exports 6. …

The Influence Of Fat And Water On The Melted Cheese Characteristics Of Mozzarella Cheese, Robert Lloyd Fife

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of reducing the fat content of low-moisture part-skim Mozzarella cheese from 19% to less than 5% on melted cheese properties, i.e., apparent viscosity, cheese melt, and cook color, was investigated. Functional properties of melt and stretch and cook color were evaluated at d 1, 7, 14, and 28. A rapid microwave oven method underestimated the moisture content of the low fat cheeses by approximately 10%. Low fat cheese did not melt as well as did the low-moisture part-skim Mozzarella cheese although the moisture content of the low fat cheese (moisture content ranged from 62.5% to 63.6%) was greater …

Influence Of Storage Duration, Temperature, And Oxygen On Quality Of Stored Dehydrated Foods, Omima Ali Darag

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was undertaken to determine the effect of oxygen absorber packets (OAP) (AGELESS Z.300 E) in improving the shelf-life of selected dried food products, including dried potato pearls, dried sliced apple, dried carrot, white rice, nonfat dry milk, all purpose flour, rolled oats, and wheat. Items were stored at four different temperatures (-20, 10, 21, and 29.5°C) over a period of 24 months with observations at 6-month intervals. Hunter colorimeter, thiobarbituric acid reactive substance (TBARS) germination rate, gluten weight, and volume were parameters used as quality indicators of various dried foods.

Statistical analysis indicated a significant time and temperature …

Aromatic Amino Acid Catabolism By Lactobacillus Spp.: Biochemistry And Contribution To Cheese Flavor Development, Sanjay Gummalla

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Amino acids derived from the degradation of casein in cheese serve as precursors for the generation of desirable and undesirable flavor compounds. Microbial degradation of aromatic amino acids is associated with the formation of aroma compounds that impart putrid-fecal, barny-utensil, and floral off-flavors in cheese, but pathways for their production had not been established. This study investigated Tyr and Phe catabolism by Lactobacillus casei and Lactobacillus helveticus cheese flavor adjuncts under simulated Cheddar cheese-ripening conditions (pH 5.2, 4% NaCl, 15°C, no sugar). Enzyme assays of cell-free extracts and micellar electrokinetic capillary chromatography of supernatants indicated that L. casei and L. …

Biochemistry And Application Of Exopolysaccharide Production In Mozzarella Cheese Starter Cultures, Brent Petersen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study sought to investigate the role of the C₅₅ undecaprenol lipid carrier in the production of exopolysaccharide (EPS), the effect of exopolysaccharide producing (EPS⁺) starter cultures on the viscosity of Mozzarella cheese whey, and the possible protective characteristics of capsular EPS against freezing and freeze drying. Efforts to investigate the role of the lipid carrier in EPS production employed pAMbacA, a plasmid that encodes an enterococcallipid kinase that confers bacitracin resistance by increasing intracellular levels of undecaprenol phosphate lipid carrier. Unfortunately, this avenue of study was thwarted by the inability to demonstrate bacA …

Development Of A Solid Phase Micro-Extraction-Gas Chromatographic Method For The Analysis Of Volatile Components In Vanilla Extracts And Flavourings, Tomislav Sostaric

Theses: Doctorates and Masters

Vanilla is a very important flavouring agent, it is used as a major ingredient in a number of food products. The taste and aroma results from a specific blend of components present in the extract. There are over 170 volatile components, which all contribute to the flavour of the extract. These volatile components can be present in trace amounts or in relatively high concentrations. The range and concentration of volatile components is somewhat characteristic of the vanilla extract and its origin. Due to the high cost and low availability of natural extract, nature-identical and synthetic flavourings are often used to …

Isolation And Identification Of Sterols In Palm Oil And Their Analysis By Gc Adn Gc-Ms, Ai Chen Han

Student Works (2000-2009)

The unsaponifiablc matters were separated from crude palm oil, crude palm kernel oil, and crude palm fibre oil. The sterol fractions were isolated by preparative thin layer chromatography and were then analysed by gas chromatography and combined gas chromatography-mass spectrometry. Qualitative separations of sterols are illustrated. Tables are presented showing the sterol composition determined in the oi ls, values obtained for individual contents are in broad agreement with other published results There were no major differences between crude palm oil, crude palm kernel oil and crude palm fibre oil with respect to their sterols oomposition. P-sitosterol was found as the …

Method Development By Hplc For Separation Of Various Hydrocarbon Groups In Coal Samples From Batu Arang, Selangor, Yong Chee Hui Audrey

Student Works (2000-2009)

A preliminary work involving method development for normal stationary phase (silica) pennits the high-performance liquid chromatographic separation or aliphatic and polyaromatic hydrocarbon (PAHs) classes. The Soxhlet extraction method was applied on the coal rock samples and normal phase (silica) short column clean-up separation from highly polymeric material in the coal extract. Method developed on analytical and preparative normal phase silica HPLC columns were to fractionate coal rock extracts, isocratic elution of hexane: ethyl acetate (95 :5, V:V) was found to be quite a good mobile phase. An alternative fractionation method, preparative thin layer chromatography (TLC), was also investigated to separate …

Looking Back: Cyclamate, Allan Mazur, Kevin Jacobson

RISK: Health, Safety & Environment (1990-2002)

The second in a series re-evaluating hazards identified in the 1950s and 60s.

Analysis Of Phytoestrogens By High Performance Liquid Chromatography, Anne A. Grippo, Yan Xie, Benjamin L. Rougeau, William V. Wyatt

Journal of the Arkansas Academy of Science

Phytoestrogens are biochemicals synthesized in plants which mimic steroidal estrogen activity in mammals. Analysis of these compounds in the legumes which produce them and in body fluids is important to the study of their physiological effects. High pressure liquid chromatography (HPLC) has been found to be an efficient and sensitive method of identification and quantitation of isoflavonoids, one class of phytoestrogen. Here we report the separation of three isoflavonoids, biochanin A, genistein and daidzein using an HPLC system with a Cg reverse phase column and a linear gradient mobile phase containing acetonitrile and acetic acid/water (10/90, v/v) over 60 minutes. …

Tryptophan Catabolism By Lactobacillus Spp. : Biochemistry And Implications On Flavor Development In Reduced-Fat Cheddar Cheese, Sanjay Gummalla

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Amino acids derived from the degradation of casein in cheese serve as precursors for the generation of key flavor compounds. Microbial degradation of tryptophan (Trp) is thought to promote formation of aromatic compounds that impart putrid fecal or unclean flavors in cheese, but pathways for their production have not been established. This study investigated tryptophan catabolism by Lactobacillus casei LC301 and LC202 and Lactobacillus helveticus CNRZ32 and LH212 cheese flavor adjuncts in carbohydrate starvation (pH 6.5, 30 or 37°C, no sugar) and cheese-like conditions (pH 5.2, 4% NaCl, 15°C, no sugar). Enzyme assays of cell-free extracts revealed both species of …

Establishing Threshold Levels Of Nitrite Causing Pinking Of Cooked Meat, Kevin M. Heaton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sporadic problems with pink color defect, or pinking, has occurred in cooked meat products for decades. Pink color can be due to the presence of undenatured myoglobin, denatured globin hemochromes, or nitrosylhemochrome. This research documented the level of added nitrite that produced nitrosylhemochrome in processed meat rolls from fabricated beef round, pork shoulder, turkey breast, and chicken breast. For each meat type, preliminary studies were conducted to narrow the range at which added nitrite caused pinking. Subsequently, the nitrite levels were increased incrementally by 1-ppm, and pink color was measured by trained panelists and by a Hunter color meter. Nitrosylhemochrome …

Evaluation Of Methods Used In Meat Iron Analyses And Iron Content Of Raw, Cooked, And Cured Meats, Eldred Merlyn Clark

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research project was divided into three parts. In the first part, heme, nonheme, and total iron methodologies for meats were evaluated. The accuracy, precision, and specificity of each method were determined by spike recoveries of heme and nonheme iron, and by analysis of National Institute of Science and Technology standard reference materials. The most reliable and practical methods were then used to determine the total, nonheme, and heme iron contents of various meats before and after cooking. The meats analyzed were beef, pork, lamb, chicken, and turkey. The wet-ashing technique was a novel procedure in which nitric acid was …

Effect Of Ph, Fat Level, And Various Browning Agents On Composition, Color, Texture, And Sensory Characteristics Of Dark-Cutting Beef Patties, Igor V. Moiseev

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Extra lean (3.3% fat) and lean (20.0% fat) hamburgers in three pH groups (≤ 6.0; 6.01-6.49; 6.50-6.92) were evaluated for cooking-temperature profile, total process lethality, and physical properties after cooking to 71°C by double-side frying on an electric grill. Neither cooking-temperature profile nor cooking time was affected by hamburger fat content or pH. Double-side frying to 71.1°C internal temperature was adequate for more than 6-log destruction of viable E. coli O157:H7 and Salmonella at the geometrical center of extra lean and lean hamburgers. The coldest spot was on the circumferential surface, as indicated by the presence of a red ring …

Effects Of Iron Fortification On Microbiological, Physical, Chemical, And Organoleptic Properties Of Yogurt, Sharareh Hekmat

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

It has been shown that iron binds strongly to the proteins in milk, and our aim was to determine whether or not this binding was affected by lowering pH in the manufacture of yogurt. Iron-protein complexing was studied using two different techniques. 1) Skim milk was fortified with 10 mg iron/100 ml and the pH of the milk was adjusted to 6.7, 6.2, 5.8, 5.3, 4.5, and 4.0. The milk was fractionated by ultracentrifugation at 52,000 x g for 60 minutes. The pellets and serum were then analyzed for iron, calcium, and phosphorus content by inductively coupled plasma spectroscopy. SDS-PAGE …

Effects Of Whey Protein Concentrate, Phosphate, And Sodium Hydroxide On Texture And Acceptability Of Turkey And Beef Rolls, Igor V. Moiseev

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Processed turkey rolls were prepared with 1 or 3% whey protein concentrates WPC-50 (pH=5.80), WPC-60 (pH=4.53) and WPC-75 (pH=6.85} containing 50, 60 and 75% protein along with controls (phosphate and no phosphate). Control rolls made with 0.5% phosphate had the highest bind strength, and sensory evaluation scores. Only WPC-75 (1%) was acceptable as a binding agent and flavor enhancer. WPC-60 reduced pink discoloration of rolls, but flavor, bind and cohesiveness scores were unacceptably low. WPC-50 was not an effective binding agent. In general, rolls made with 3% WPC had lower scores for intensity of turkey flavor.

Bind strength and sensory …

The Isolation And Identification Of Polyphenolics From Grape Seeds And Their Activity Towards Specific Cell Lines, Joseph A. Reddy

Chemistry & Biochemistry Theses & Dissertations

Grape seed extract is being marketed in France for cardiovascular use and skin care. The active constituents of both these drugs are certain polyphenols called procyanidins. A similar seed extract has now been obtained from Virginia Chardonnay grape seeds. Ten of the major components in this extract have been isolated in their pure form by the semi-preparative HPLC separation on a YMC ODS-AQ (Octadecylsilane-AQ) column. The ODS-Aq column has been shown to have a better resolving capacity compared to the Spherisorb ODS (Octadecylsilane) column previously described in the literature. This has been attributed to the ODSAQ support which has both …

Anaerobic Treatment Of Whey Permeate Using Upflow Sludge Blanket Bioreactors, Seokhwan Hwang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Whey permeate was anaerobically digested in laboratory scale upflow anaerobic sludge blanket reactors. Nine hydraulic retention times between 5 and 0.2 days were examined with a fixed influent concentration of 10.6 ± 0.2 g COD/L.

Chemical oxygen demand removal efficiency ranged from 99.0 to 18.9% and maximum production rate of methane gas was 2.67 L/L/day at a hydraulic loading rate of 12.97 kg COD/m³/day. About 70% of the chemical oxygen demand removed was converted to methane.

Both the nonlinear least square method with 95% confidence interval and linear regression were used to evaluate kinetic coefficients. The maximum substrate …

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 …

Drug Use In Food Animals, Clell V. Bagley Dvm

Archived Food and Health Publications

Publication provides information on the safe use of drugs and antibiotics in food animals.

Bulletin No 4225 - Dairying In Western Australia, Dean Maughan

Bulletins 4000 -

Dairying in Western Australia is a small though very efficient industry. In 1989/90, 480 dairy farmers produced 266 million litres of milk for an estimated return of $84 million. The retail value of milk and dairy products was estimated to be $250 million making dairying a very significant industry in the south-west of Western Australia.

The Use And Acceptability Of Lupin Seed And Sprout As A Food Ingredient, Suzanne Dagnia

Theses : Honours

The purpose of the research was to assess the use and acceptability of the lupin seed and sprout as a human food. Two studies were designed. 1. The first study involved the biochemical analysis and nutritional evaluation of the lupin sprout. Protein Efficiency Ratio, and Apparent Biological Value, Net Protein Utilization, and Digestibility tests measure protein quality. Biochemical assays included nitrogen and hexane extracts, amino acid profile, and selected minerals and anti-nutritive factors. 2. The second quality study investigated the changes that occur as a result of in the eating partial substitution of lupin flour into a wheat flour-based, standard …

Where Are The Risks In Food And What Can You Do About Them?, Charlotte P. Brennand Ph. D.

Archived Food and Health Publications

Publication discusses dangers in foods and how to safely handle and prepare food.