About 48 million cases of Foodborne illnesses (FBIs) are estimated to occur every year in the US. These are diseases caused by contamination of foods with bacteria, viruses, protozoa, parasites and toxic chemicals. Clostridium difficile infections (CDIs) are an important health-care and community associated problem. Since C. difficile spores have...
Analytical chemistry is an essential qualitative and quantitative tool to describe foods and biomaterials and their changes during production, processing and distribution. In this work, rapid analytical procedures for the extraction and quantification of components in fluid milk and diatom fermentation broth were developed. Analytical methods to measure the concentration...
Soluble surimi wash water (SWW) proteins could be recovered using chitosan (Chi) complexed with alginate (Chi-Alg) generating co-products for feed formulations. Chi with a degree of deacetylation (DD) of 84% complexed with Alg at a mixing ratio (MR) of 0.2 was used to study Chi-Alg concentration and treatment time protein...
Spores of foodborne pathogens such as Clostridium botulinum, Clostridium perfringens and Bacillus cereus are widely distributed in nature. Presence of those spores in food products, particularly C. botulinum spores in vacuum packed, ready-to-eat low-acid products, is a great safety concern. The research here described is a first effort towards understanding...
Equipment and procedures for the rapid measurement of the water vapor
permeability of polymer films and food coatings has been evaluated. The
method uses an electronic sensor to measure the concentration increase in
water vapor diffusing through a film into a chamber of known volume. Air of
known humidity is...
The lag phase, the specific growth rate, the minimum a [subscript w]
required for growth and the temperature characteristic of
Fsendomonas fluorescens, Brochothrix thermosphacta, Salmonella
typhlmurium, Streptococcus faecalis and, Staphylococcus aureus
have been studied in liquid model media under controlled temperature
and a [subscript w] conditions. The results show that...
A commercially important polyelectrolyte, xanthan, was chosen for
a systematic analysis of the relationship between molecular
conformation and surface properties. In the first study the effects
of ionic strength, xanthan concentration and temperature on the
xanthan molecular conformation were investigated by potentiometric
titration. The effects of the same factors and...
The validation and potential use of mathematical models to estimate the
shelf-life of refrigerated food exposed to temperature abuse and basing such
estimations on microbial growth was analyzed. Combined heat transfer, microbial
growth models, and non-parametric statistical procedures formed a computer-based
predictive tool to assess shelf-life and estimate the accuracy...
The use of edible coatings in combination with antimicrobial
agents enhances the microbial stability of foods. In this study we
evaluated the potassium sorbate and sorbic acid permeability of an
edible methylcellulose (MC) - palmitic acid (PA) film with a MC:PA
ratio of 3:1.
Permeability cell measurements were used to...
Edible coatings controlling preservative migration from
surface to food bulk could inhibit surface microbial growth
which is often the main cause of spoilage for many food
products. In this project we focused our attention upon
methylcellulose, hydroxypropyl methylcellulose, and chitosan as
the structural component for such edible films. These films...
Chitosan has been proposed as a "natural" coagulating agent to solve wastewater problems. The main hindrance in this commercial chitosan application has been its low cost effectiveness. The hypothesis in our research is that chitosan complexes with natural polyanions is more effective than chitosan alone, particularly in recovering low concentration...
Quantitative procedures were developed to determine the effect of variability in the model parameters required for the estimation of microbial shelflife and thermal processing time. Monte Carlo simulations combined with these predictive models were implemented in Microsoft Excel™. In the first study,
predictive models were used for shelf-life predictions based...
The aroma of milk has been often defined as bland and pleasant, yet characteristic. Conventional thermal processing of milk can certainly extend shelf life, but inevitably changes its flavor. High pressure processing has been suggested as an alternative for milk pasteurization with improved fresh flavor retention. The objective of this...
Static ultra-high pressure (200, 270, and 340 MPa) and sinusoidal and
step-pressure (0-270 MPa) pulses were compared by determining their effects on
bacteria and yeast survival counts. Samples were commercial pineapple chunks
used as is and fresh cut pineapple and pineapple juice inoculated with
Saccharomyces cerevisiae 2407-1a. Surviving bacteria and...
The principal aim of this study was the use and evaluation of dynamic
modeling techniques to identify mathematical models for cereal drying rates and
quality changes that best describe thin-layer malt drying data. Seven thin-layer
malt drying experiments were performed at the Great Western Malting pilot
facilities, Vancouver, WA. Malt...
The thermal denaturation of proteins has been extensively studied using several methods including differential scanning calorimetry (DSC). A custom-built optical system was used to study thermal effects on protein as an alternative method to DSC measurements. It was used to investigate the thermal stability of bovine serum albumin (BSA) with...
Clostridium perfringens is the causative agent of a wide variety of diseases in animals and humans. C. perfringens can produce more than 15 toxins. However, individual strains produce a subset of these toxins. Although a small percentage of C. perfringens isolates (mostly belonging to type A) produce C. perfringens enterotoxin...
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Mahfuzur R. Sarker J. Antonio Torres
Clostridium perfringens is the causative agent of