Life Sciences Commons^™

Influence Of Processing Conditions On Apparent Viscosity And System Parameters During Extrusion Of Distiller’S Dried Grains-Based Snacks, Poonam Singha, Kasiviswanathan Muthukumarappan, Padmanaban Krishnan

POONAM SINGHA

Influence Of Processing Conditions On Apparent Viscosity And System Parameters During Extrusion Of Distiller’S Dried Grains-Based Snacks, Poonam Singha, Kasiviswanathan Muthukumarappan, Padmanaban Krishnan

Padmanaban Krishnan

The Human/Animal Interface: Emergence And Resurgence Of Zoonotic Infectious Diseases, Michael Greger

Michael Greger, MD, FACLM

Emerging infectious diseases, most of which are considered zoonotic in origin, continue to exact a significant toll on society. The origins of major human infectious diseases are reviewed and the factors underlying disease emergence explored. Anthropogenic changes, largely in land use and agriculture, are implicated in the apparent increased frequency of emergence and reemergence of zoonoses in recent decades. Special emphasis is placed on the pathogen with likely the greatest zoonotic potential, influenzavirus A.

Amyloid Fibrils: Potential Food Safety Implications, Michael Greger

Michael Greger, MD, FACLM

The demonstration of oral Amyloid-A (AA) fibril transmissibility has raised food safety questions about the consumption of amyloidotic viscera. In a presumed prion-like mechanism, amyloid fibrils have been shown to trigger and accelerate the development of AA amyloidosis in rodent models. The finding of amyloid fibrils in edible avian and mammalian food animal tissues, combined with the inability of cooking temperatures to eliminate their amyloidogenic potential, has led to concerns that products such as pâté de foie gras may activate a reactive systemic amyloidosis in susceptible consumers. Given the ability of amyloid fibrils to cross-seed the formation of chemically heterologous …

Probiotics: Finding The Right Regulatory Balance, Diane E. Hoffmann, Claire M. Fraser-Liggett, Frank B. Palumbo, Jacques Ravel, Karen H. Rothenberg, Virginia Rowthorn

Karen H. Rothenberg

Some products marketed as drugs should be excused from Phase I trials, but safety and efficacy claims for dietary supplements should be more tightly regulated.

Probiotics: Finding The Right Regulatory Balance, Diane E. Hoffmann, Claire M. Fraser-Liggett, Frank B. Palumbo, Jacques Ravel, Karen H. Rothenberg, Virginia Rowthorn

Virginia Rowthorn

Some products marketed as drugs should be excused from Phase I trials, but safety and efficacy claims for dietary supplements should be more tightly regulated.

Probiotics: Finding The Right Regulatory Balance, Diane E. Hoffmann, Claire M. Fraser-Liggett, Frank B. Palumbo, Jacques Ravel, Karen H. Rothenberg, Virginia Rowthorn

Diane Hoffmann

Some products marketed as drugs should be excused from Phase I trials, but safety and efficacy claims for dietary supplements should be more tightly regulated.

North Atlantic Vibrio Vulnificus Surveillance From Postharvest Oysters At A Us Shellfish Processing Facility, Kenneth Lavalley, Joseph Dealteris, Michael Rice, Marta Gomez-Chiarri

Marta Gomez-Chiarri

Postharvest surveillance for Vibrio vulnificus by a commercial processing facility was conducted from May 2001 to September 2003. Harvest areas included the Delaware Bay, Long Island Sound and Prince Edward Island. Occurrence followed a seasonal distribution. Low densities were observed in June, increased through August, and became rare by September. Given the ubiquitous nature of marine Vibrios, it was not surprising to find V. vulnificus everywhere, which was investigated. Observations confirmed the importance of strict time/temperature and product handling practices by shellfish harvesters, dealers and processors. Mishandling led to a potentially dangerous and uncharacteristically high V. vulnificus observation.

Covalent Immobilization Of Lysozyme On Ethylene Vinyl Alcohol Films For Nonmigrating Antimicrobial Packaging Applications, V. Muriel-Galet, Joey N. Talbert, P. Hernandez-Munoz, R. Gavara, J. M. Goddard

Joey Talbert

The objective of this study was to develop a new antimicrobial film, in which lysozyme was covalently attached onto two different ethylene vinyl alcohol copolymers (EVOH 29 and EVOH 44). The EVOH surface was modified with UV irradiation treatment to generate carboxylic acid groups, and lysozyme was covalently attached to the functionalized polymer surface. Surface characterization of control and modified films was performed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and dye assay. The value of protein loading after attachment on the surface was 8.49 μg protein/cm2 and 5.74 μg protein/cm2 for EVOH 29 and EVOH 44, respectively, …

Method And System For Lactose-Free Or Lactose-Reduced Milk And Associated Products, Production Thereof, And Associated Processes, Joseph H. Hotchkiss, Joey Talbert

Joey Talbert

A system and method capable of hydrolyzing lactose, where the system includes a support formed from a functionalized hydrophobic polymer that is covalently linked to a hydrophilic molecule covalently that is, in turn, covalently linked to an enzyme such as lactose. The method includes the steps of functionalizing a hydrophobic polymer support, covalently linking a hydrophilic molecule to said functionalized polymer support, and covalently linking an enzyme such as lactase to said hydrophilic molecule. The system and method generally relate to the field of food science and engineering and, more particularly to dairy-based food products and their production including solutions …

Purification And Characterization Of Novel Nucleases From A Thermophilic Fungus, Kyle Landry

Kyle S Landry

A thermophilic fungus was isolated from composted horse manure. The organism was as a Chaetomium sp. by sequencing the highly conserved ITS region of the fungus and comparing to known regions in a genomic database and was referred to as TM-417. TM-417 was found to have an optimal growth temperature of 45 ^oC and an optimal pH of 7.0. An extracellular DNase and RNase was found to be produced by the isolate and were purified 145.58-fold and 127.6-fold respectively using a combination of size exclusion chromatography and a novel affinity membrane purification system. The extent of purification was determined …

Inactivation Of Escherichia Coli By Ozone Treatment Of Apple Juice At Different Ph Levels, Sonal Patil, Vasilis Valdramidis, Patrick Cullen, Jesus Maria Frias, Paula Bourke

Patrick Cullen

This research investigated the efficacy of gaseous ozone for the inactivation of Escherichia coli ATCC 25922 and NCTC 12900 strains in orange juice. Orange juice inoculated with E. coli (106 CFU mL-1) as a challenge microorganism was treated with ozone at 75-78µg mL-1 for different time periods (0-18 min). The efficacy of ozone for inactivation of both strains of E. coli was evaluated as a function of different juice types: model orange juice, fresh unfiltered juice, juice without pulp, and juice filtered through 500mm or 1mm sieves. Fast inactivation rates for total reduction of E. coli were achieved in model …

Phaseolus Beans: Impact On Glycaemic Response And Chronic Disease Risk In Human Subjects, Andrea M. Hutchins, Donna M. Winham, Sharon V. Thompson

Donna Winham

Consumption of Phaseolus vulgaris bean species such as pinto, black, navy or kidney may be beneficial in the prevention and treatment of chronic diseases. In particular, conditions that are promoted by increased glycaemic stress (hyperglycaemia and hyperinsulinaemia) including diabetes, CVD and cancer seem to be reduced in individuals who eat more of these beans. The present paper discusses the influence of P. vulgaris species on glycaemic response and the impact that relationship may have on the risk of developing diabetes, CVD and cancer.

Knowledge Of Young African American Adults About Heart Disease: A Cross-Sectional Survey, Donna Winham, Kathleen M. Jones

Donna Winham

Background: African Americans have higher rates of cardiovascular disease (CVD) mortality than other ethnic groups. Young adults are prime targets for intervention strategies to prevent and reduce disease risk. The study purpose was to determine the level of knowledge of lifestyle risk factors for CVD among young African American adults in Phoenix. The results will be used to guide the development of CVD outreach programs targeted to this population. The Health Belief Model was used as a conceptual framework. Methods: A convenience sample of 172 African American men and women aged 18-26 years completed a questionnaire adapted from the American …

Capsular Serotyping Of Pasteurella Multocida From Various Animal Hosts - A Comparison Of Phenotypic And Genotypic Methods, Thong Kwai Lin

Thong Kwai Lin

One hundred and fourteen strains of Pasteurella multocida were isolated from different domestic animals species (cattle, buffalo, sheep, goat, pig, rabbit, dog, cat), avian species (chicken, duck, turkey) and wild animals (deer, tiger, orang utan, marmoset). The serogroups of P multocida were determined by both conventional capsular serotyping and a multiplex PCR assay targeting specific capsular genes. Based on the conventional serotyping method, the 114 strains of P multocida were subtyped into 55 species-specific (untypeable strains) P. multocida, 15 serogroup A, 23 serogroup B and 21 serogroup D. Based on the multiplex PCR assay on the specific capsular genes associated …

Sucrose Monolaurate Improves The Efficacy Of Sodium Hypochlorite Against Escherichia Coli O157:H7 On Spinach, Dan Xiao, Ran Ye, P. Michael Davidson, Douglas G. Hayes, David A. Golden, Qixin Zhong

David A Golden

It is well-recognized that chlorine has limited efficacy when applied to inactivate pathogens on fresh produce. One of the many factors limiting efficacy is the high interfacial tension of chlorine-based sanitizers that limits the access of chlorine to the microorganisms. In this work, we investigated the efficacy of sodium hypochlorite (200 ppm, pH 6.0) at 4 and 20 °C against Escherichia coli O157:H7 inoculated on baby spinach leaves as affected by the surfactant sucrose monolaurate (SML) at below (100 ppm), above (250 ppm), and well above (10,000 ppm) the critical micelle concentration (CMC) of ~ 200 ppm at 20 °C. …

Process Characteristics And Microbiology Of Fura Produced In Ghana, James Owusu-Kwarteng, Kwaku Tano-Debra, Fortune Akabanda, Richard Glover

James Owusu-Kwarteng

Majority of traditional cereal-based foods consumed in Africa are processed by spontaneous fermentation and are important as weaning foods for infants and as dietary staples for adults. Detailed knowledge of traditional processing is a prerequisite for investigating ways to improve both the nutritional and microbiological qualities of the corresponding product. In this study, the traditional processing of millet into fura, a popular millet-based dumpling consumed throughout West Africa, particularly Nigeria, Burkina-Faso and Ghana was investigated in a range of production units in northern Ghana. Microbiology of the processing was also investigated. Processing steps included soaking or steeping the grains, washing, …

Effect Of Soybean Fortification On Fermentation Characteristics And Consumer Acceptability Of Hausa Koko, A Ghanaian Fermented Porridge, James Owusu-Kwarteng

James Owusu-Kwarteng

ABSTRACT

Objective: To assess the effect of soybean fortification on microbial growth and consumer acceptability of

Hausa koko.

Methodology and results: Hausa koko was prepared from a mixture of soaked millet grains and pre-soaked,

blanched and dehulled soybeans added at 0 to 50 % replacement levels. pH, titritable acidity and microbial

counts were determined before and after the fermentation period using standard methods. The effect of the

added soybean on acceptability was evaluated on a nine point hedonic scale by an untrained panel that is

familiar with Hausa koko. Data were subjected to Analysis of Variance and Tukey testing for …

North Atlantic Vibrio Vulnificus Surveillance From Postharvest Oysters At A Us Shellfish Processing Facility, Kenneth Lavalley, Joseph Dealteris, Michael Rice, Marta Gomez-Chiarri

Michael A Rice

Postharvest surveillance for Vibrio vulnificus by a commercial processing facility was conducted from May 2001 to September 2003. Harvest areas included the Delaware Bay, Long Island Sound and Prince Edward Island. Occurrence followed a seasonal distribution. Low densities were observed in June, increased through August, and became rare by September. Given the ubiquitous nature of marine Vibrios, it was not surprising to find V. vulnificus everywhere, which was investigated. Observations confirmed the importance of strict time/temperature and product handling practices by shellfish harvesters, dealers and processors. Mishandling led to a potentially dangerous and uncharacteristically high V. vulnificus observation.

Single-Cell Microbiology: Tools, Technologies, And Applications, Byron F. Brehm-Stecher, Eric A. Johnson

Byron F. Brehm-Stecher

The field of microbiology has traditionally been concerned with and focused on studies at the population level. Information on how cells respond to their environment, interact with each other, or undergo complex processes such as cellular differentiation or gene expression has been obtained mostly by inference from population-level data. New appreciation for the existence and importance of cellular heterogeneity, coupled with recent advances in technology, has driven the development of new tools and techniques for the study of individual microbial cells. As a result, scientists have been able to characterize microorganisms and their activities at unprecedented levels of detail.

Sensitization Of Staphylococcus Aureus And Escherichia Coli To Antibiotics By The Sesquiterpenoids Nerolidol, Farnesol, Bisabolol, And Apritone, Byron F. Brehm-Stecher, Eric A. Johnson

Byron F. Brehm-Stecher

The sesquiterpenoids nerolidol, farnesol, bisabolol, and apritone were investigated for their abilities to enhance bacterial permeability and susceptibility to exogenous antimicrobial compounds. Initially, it was observed by flow cytometry that these sesquiterpenoids promoted the intracellular accumulation of the membrane-impermeant nucleic acid stain ethidium bromide by live cells of Lactobacillus fermentum, suggesting that enhanced permeability resulted from disruption of the cytoplasmic membrane. The ability of these sesquiterpenoids to increase bacterial susceptibility to a number of clinically important antibiotics was then investigated. In disk diffusion assays, treatment with low concentrations (0.5 to 2 mM) of nerolidol, bisabolol, or apritone enhanced the susceptibility …

Further Evaluation Of A Multiplex Pcr For Differentiation Of Salmonella Paratyphi A From Other Salmonellae, Thong Kwai Lin

Thong Kwai Lin

Salmonella enterica serovar Paratyphi A is a causative agent of paratyphoid fever. The clinical syndrome caused by paratyphoid fever overlaps with other febrile illnesses and cannot be distinguished from typhoid fever. Conventional methods used for diagnosis are time consuming, costly, and labor-intensive. We evaluated the specificity, sensitivity, and application of a multiplex polymerase chain reaction (PCR) previously developed by the method (Ou, H.Y, Teh, C.S.J., Thong, K.L., et al., J. Mol. Diagn., 9, 624-630, 2007) using 6 S. Paratyphi A, 22 S. Typhi, and 85 other Salmonella serovars as well as 36 non-Salmonella strains. The detection limit of the multiplex …

Hydrophobic Probe Binding Of Β-Lactoglobulin In The Native And Molten Globule State Induced By High Pressure As Affected By Ph, Kio3 And N-Ethylmaleimide, Jian Yang, Joseph R. Powers, Stephanie Clark, A. Keith Dunker, Barry G. Swanson

Stephanie Clark

High hydrostatic pressure (HHP) at 500 MPa and 50 °C induces β-LG into the molten globule state. Retinol, cis-parinaric acid (CPA), and 1-anilino-naphthalene-8-sulfonate (ANS) fluorescence from pH 2.5 to 10.5 in the presence of the native and molten globule states of β-LG indicate that retinol binds to β-LG in the calyx, CPA at the surface hydrophobic site, and ANS in multiple hydrophobic sites. HHP treatment results in a decrease of β-LG affinity for retinol and CPA, suggesting conformational changes in the calyx and surface hydrophobic site of β-LG during HHP treatment. β-LG treated by HHP in the presence of N-ethylmaleimide …

Β-Lactoglobulin Molten Globule Induced By High Pressure, Jian Yang, A. Keith Dunker, Joseph R. Powers, Stephanie Clark, Barry G. Swanson

Stephanie Clark

Beta-lactoglobulin (beta-LG) was treated with high hydrostatic pressure (HHP) at 600 MPa and 50 degrees C for selected times as long as 64 min. The intrinsic tryptophan fluorescence of beta-LG indicated that HHP treatment conditions induced a conformational change. HHP treatment conditions also promote a 3-fold increase in the extrinsic fluorescence of 1-anilinonaphthalene-8-sulfonate and a 2.6-fold decrease for cis-paraneric acid, suggesting an increase in accessible aromatic hydrophobicity and a decrease in aliphatic hydrophobicity. Far-ultraviolet circular dichroism (CD) spectra reveal that the secondary structure of beta-LG converts from native beta-sheets to non-native alpha-helices following HHP treatment, whereas near-ultraviolet CD spectra reveal …

Delayed-Incubation Method For Microbiological Analysis Of Environmental Specimens And Samples, James S. Dickson, M. H. Brodsky, C. A. Davidson, M. J. Pettis, T. L. Tieso

James S. Dickson

Five laboratories compared the quantitative recovery of heterotrophic bacteria, yeasts and molds, coliforms, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus from a variety of naturally contaminated food and water samples, using traditional incubation procedures and a delayed-incubation method. Refrigeration of inoculated media for up to 3 days prior to incubation was shown to be a viable option for many quantitative analyses, but needs to be validated for each application. Some inoculated media withstood refrigeration for up to 7 days prior to incubation without any detrimental effect on the recovery of target cells, while the incubation of other media for similar …

Cell Surface Charge And Initial Attachment Characteristics Of Rough Strains Of Listeria Monocytogenes, James S. Dickson

James S. Dickson

The relative negative surface charge and hydrophobicity of four bacterial strains were evaluated by gravity flow and spin column methods. There was no significant difference between the two methods, indicating that spin column chromatography is an acceptable alternative method of determining cell surface charge or hydrophobicity. Six strains of Listeria monocytogenes which exhibited rough colony appearance were evaluated for surface charge and hydrophobicity and their ability to contaminate beef muscle tissue. With one exception, all of the rough strains exhibited greater net negative surface charge and reduced ability to contaminate beef during the initial stages of attachment. Since greater net …

Antimicrobial Effects Of Trisodium Phosphate Against Bacteria Attached To Beef Tissue, James S. Dickson, C. G. Nettles Cutter, G. R. Siragusa

James S. Dickson

Sliced beef tissue was artificially contaminated with Salmonella typhimurium, Listeria monocytogenes and Escherichia coli OI57:H7. The contaminated tissue was immersed in 8, 10 and 12% solutions of trisodium phosphate at 25, 40 and 55°C with contact times of up to 3 min. The concentration of the trisodium phosphate solution was not a significant factor in reducing the populations of the bacteria on either lean or adipose tissue. Reductions in bacterial populations of I to 1.5 loglocycles were obtained on lean tissue contaminated with the gram-negative pathogens, although less reduction in population was seen with L. monocytogenes. Greater reductions in bacterial …

Bacterial Starvation Stress And Contamination Of Beef, James S. Dickson, J. F. Frank

James S. Dickson

Salmonella typhimurium, Listeria monocytogenes, ad Escherichia coli 0157;H7 were starved by suspending washed cells in phosphate buffer for 5 days at 10, 25 or 37 degrees C. Starved bacteria were evaluated for their ability to attach to beef tissue and their sensitivity to acetic acid sanitizing. Starvation stress generally decreased the numbers of bacteria which attached to the tissue when compared to control bacterial cultures grown to late logarithmic growth phase. Starvation temperature was negatively correlated to the numbers of attached bacteria. Starvation slightly increased the sensitivity of attached S. typhimurium and L. monocytogenes cells to acetic acid, but did …

Isolation Of Listeria Spp. From Feces Of Feedlot Cattle, James S. Dickson, G. R. Siragusa, E. K. Daniels

James S. Dickson

Healthy feedlot beef cattle were surveyed for the presence of Listeria spp. in fecal grab samples taken over 3 months. Composite samples were made from 224 individual animals each month. Listeria monocytogenes was isolated from one composite sample (4%) from the first sampling and not from the subsequent two. Listeria innocua was found in composite samples from all three samplings at levels of 17, 9, and 35%, respectively. From the individual samples comprising the Listeria spp.—positive composites, L. monoytogenes was isolated from one sample (3%) in the second sampling but not in the first or third samplings. L. innocua was …

A Computer-Controlled Spray Chill Unit For Red Meat Carcasses, Maynard E. Anderson, James S. Dickson, Mark M. Hulse, Scott T. Drummond, John D. Crouse, Robert T. Marshall

James S. Dickson

A computer controlled and operated spray chill unit which can be used in future research studies for both spray chilling and decontamination of red meat carcasses is described. The unit consists of two parts: (1) an electromechanical system, and (2) a data acquisition/control system. Design concepts for the spray chill system are (1) versatility, (2) rapid change of spray parameters, and (3) computer control of the electromechanical system. An added feature is the computer data collection system for recording information related to each carcass (pH of muscle, surface and internal tissue temperatures, and weights of each half carcass during the …