Resume

• 2009

  Doctor of Philosophy (PhD)

  Food Science and Technology

  The University of Georgia

• 1999

  Master of Science (M.S.)

  Microbiology

  General

  HACCP Certification

  Ohio Dept. of Agriculture

• 1995

  Bachelor's degree

  Biology/Biological Sciences

  General

• 74

  Methanococcus maripaludis is a strictly anaerobic

  methane-producing archaeon. Aromatic amino acids (AroAAs) are biosynthesized in this autotroph either by the de novo pathway

  with chorismate as an intermediate

  or by the incorporation of exogenous aryl acids via indolepyruvate oxidoreductase (IOR). In order to evaluate the roles of these pathways

  the gene that encodes the third step in the de novo pathway

  3-dehydroquinate dehydratase (DHQ)

  was deleted. This mutant required all three AroAAs for growth

  and no DHQ activity was detectible in cell extracts

  compared to 6.0 ± 0.2 mU mg−1 in the wild-type extract. The growth requirement for the AroAAs could be fulfilled by the corresponding aryl acids phenylacetate

  indoleacetate

  and p-hydroxyphenylacetate. The specific incorporation of phenylacetate into phenylalanine by the IOR pathway was demonstrated in vivo by labeling with [1-13C]phenylacetate. M. maripaludis has two IOR homologs. A deletion mutant for one of these homologs contained 76

  and 42% lower activity for phenylpyruvate

  p-hydoxyphenylpyruvate

  and indolepyruvate oxidation

  respectively

  than the wild type. Growth of this mutant in minimal medium was inhibited by the aryl acids

  but the AroAAs partially restored growth. Genetic complementation of the IOR mutant also restored much of the wild-type phenotype. Thus

  aryl acids appear to regulate the expression or activity of the de novo pathway. The aryl acids did not significantly inhibit the activity of the biosynthetic enzymes chorismate mutase

  prephenate dehydratase

  and prephenate dehydrogenase in cell extracts

  so the inhibition of growth was probably not due to an effect on these enzymes.

  Two biosynthetic pathways for aromatic amino acids in the archaeon Methanococcus maripaludis

  I am currently a faculty lecturer at The Ohio State University. I teach FDSCTE 1120 (Beer and Wine in Western Culture) FDSCTE 1110 (Chocolate Science)

  FDSCTE 1140 (Kitchen Science)

  and FDSCTE 4536 (Food Safety and Public Health)

  Brian

  Waters

  University of Georgia

  Pike County High School

  The Ohio State University

  University of Georgia

  Griffin

  GA

  I worked on my dissertation entitled \"The difference in production methods on the properties

  stability

  corrosivity and antimicrobial activity of EO water\"

  Graduate Research Assistant

  University of Georgia

  I was responsible for planning and adding content to the website www.worldpeanutinfo.com.

  University of Georgia

  Lab Technician

  My responsibilities were managing a veterinary pathology lab. I performed in situ hybridizations on animal tissues for the purpose of identifying pathogens.

  University of Georgia

  The Ohio State University

  My responsibilities as a lecturer are creating and maintaining courses

  mainly for non-program students. I also work in mentoring

  student group presentations

  program assessment coordination

  and development of MOOCs.

  Lecturer

  Columbus

  Ohio Area

  I was responsible for teaching physical science

  chemistry and biology to high school student (mostly 9th – 11th grades

  college bound and diploma track). I also coached the high school’s junior varsity soccer teams.

  Pike County High School

• Cell Culture

  Food Science

  Fermentation

  Chemistry

  PCR

  Web Project Management

  Lifesciences

  Microbiology

  Teaching

  Laboratory

  Corrosion Monitoring

  Sensory Evaluation

  Gas Chromatography

  Food Service Sanitation

  Science

  Biology

  Molecular Biology

  Food Microbiology

  Sequence Analysis

  Food Chemistry

  Electrolyzed oxidizing water generation methods.

  Yen-Con Hung

  Marcio Amazonas

  This is a review article highlighting the factors involved in the generation of electrolyzed oxidizing water.

  Electrolyzed oxidizing water generation methods.

  Yen-Con Hung

  Chlorine-based sanitizers

  such as electrolyzed oxidizing (EO) water

  are used for the sanitation of food contact surfaces and the prevention of cross contamination in various food processing settings. Several different chlorine species are present in EO water

  and these chlorine species are important to the antimicrobial efficacy. Measurements of free and total chlorine

  hypochlorous acid (HOCl)

  hypochlorite ion (OCl-) and chloride were conducted on chlorinated water and EO water solutions using a variety of commercially available methods. The chlorinated and EO water solutions differed by pH

  initial free chlorine concentration

  chloride concentration and organic compound concentration. It was discovered that these factors influenced the methods used to measure the various chlorine species by differing amounts. The data from this study will help in determining the appropriate methods of measuring free chlorine

  total chlorine and chloride in chlorine-based sanitizers under various conditions.

  Evaluation of different methods for determination of properties of chlorine-based sanitizers

  Effect of chlorine-based sanitizers properties on corrosion of metals commonly found in food processing environment

  Yen-Con Hung

  Jessica Tatum

  In order to gauge the effect of pH and chloride concentration on the corrosion of metal surfaces commonly found in a food processing environment

  different metal samples (stainless steel

  carbon steel

  aluminum

  and copper) were exposed to chlorinated and electrolyzed oxidizing (EO) water. The samples were suspended in the chlorinated and EO solutions in a way to observe corrosion on the metals completely submerged in the solution as well as above the solution’s surface. The pH and chloride concentrations of the chlorinated and EO water samples played a significant role in mass loss for all the metal samples. Increases in surface roughness were linked to pH and chloride concentrations. Metal surfaces left suspended above the solution surfaces showed greater increases in surface roughness compared to the metal surfaces completely submerged in the solutions. This data demonstrates the need for care when selecting and using a chlorine-based sanitizer in food processing environments.

  Effect of chlorine-based sanitizers properties on corrosion of metals commonly found in food processing environment

  Yen-Con Hung

  This study examined the effect of pH of chlorine-based sanitisers on the reaction of free chlorine with compounds present in a variety of food environments. A model food system was first used to determine chlorine reactions with individual organic compounds. Different classes of organic compounds were added to chlorinated water at three different pHs (2.5

  6.0 and 9.3). Free and total chlorine concentrations were recorded in each sample by titrimetric assay. The results show that the level of free chlorine loss is both organic species dependent and pH dependent. Wash water from six different food sources was added to chlorinated water at three different pHs. The peptone plus catechol model appeared to be the best general predictor of free chlorine loss across all the treatments. GC-MS analysis of samples with resorcinol added indicated that chloroform is produced as a primary trihalomethane product at higher pH values. The findings of this study indicate that solution pH

  along with types of organic compound

  plays a significant role on free chlorine loss

  and chlorine loss can be predicted by the protein and phenolic content of the wash solution.

  The effect of organic loads on stability of various chlorine-based sanitisers

  Yen-Con Hung

  Electrolyzed oxidizing (EO) water is a low pH

  high oxidation reduction potential (ORP)

  chlorine-based sanitizer that is being explored as a means to control the spread of foodborne illness in a variety of foods. The main antimicrobial agent in EO water is hypochlorous acid (HOCl). HOCl is a strong oxidant

  and it freely oxidizes many organic compounds. Also

  as a weak acid

  HOCl is able to diffuse through cell membranes and acidify the interior of cells. These properties of HOCl make EO water a versatile bacteriocidal solution that has been explored in produce

  beef

  poultry

  grain

  seafood and food processing areas in the food industry. Also

  the properties of EO water help to define specific roles that the sanitizer can fulfill in the food industry.

  Electrolyzed water in food safety

  The effect of pH and chloride concentration on the stability and antimicrobial activity of chlorine-based sanitizers

  Yen-Con Hung

  Chlorinated water and electrolyzed oxidizing (EO) water solutions were made to compare the free chlorine stability and microbicidal efficacy of chlorine-containing solutions with different properties. Reduction of Escherichia coli O157:H7 was greatest in fresh samples (approximately 9.0 log CFU/mL reduction). Chlorine loss in \"aged\" samples (samples left in open bottles) was greatest (approximately 40 mg/L free chlorine loss in 24 h) in low pH (approximately 2.5) and high chloride (Cl(-) ) concentrations (greater than 150 mg/L). Reduction of E. coli O157:H7 was also negatively impacted (<1.0 log CFU/mL reduction) in aged samples with a low pH and high Cl(-) . Higher pH values (approximately 6.0) did not appear to have a significant effect on free chlorine loss or numbers of surviving microbial cells when fresh and aged samples were compared. This study found chloride levels in the chlorinated and EO water solutions had a reduced effect on both free chlorine stability and its microbicidal efficacy in the low pH solutions. Greater concentrations of chloride in pH 2.5 samples resulted in decreased free chlorine stability and lower microbicidal efficacy.

  The effect of pH and chloride concentration on the stability and antimicrobial activity of chlorine-based sanitizers

  Quincy Teng

  Iris Porat