Fur Chen | Tennessee State University (original) (raw)

Papers by Fur Chen

Consumers are often confused by the product dating systems used by the food manufacturers. Howeve... more Consumers are often confused by the product dating systems used by the food manufacturers. However, they have reported that they consider these dates when purchasing lunchmeats and other ready-to-eat foods. A study was conducted to evaluate changes of microbiological quality of packaged lunchmeat during refrigerated storage as related to the sell-by-date (SBD). Thirty packages of lunchmeat with the same lot number were tested over an extended period. The microbiological quality was satisfactory at the time of purchase. It deteriorated steadily during refrigerated storage regardless of whether the packages were opened or not, and was unsatisfactory at SBD. Food manufacturers should strive to meet the microbiological quality standards and consider the usefulness of the information to consumers when setting a product date.

The sale of ready-to-eat salads has increased over the past years, yet little is known about cons... more The sale of ready-to-eat salads has increased over the past years, yet little is known about consumer usage and the related safety of these products. This study evaluated the changes of microbiological quality of pre-washed spinach and mixed leafy vegetables during refrigeration storage. Microbial loads were determined by aerobic plate count (APC) and Enterobacteriaceae count (EC). The microbiological quality of pre-washed greens varied widely and deteriorated rapidly in a refrigerator. At "best if used by" date, twenty percent of samples had APC of more than 7.0 Log CFU/g and all samples had EC of more than 5.0 Log CFU/g. It is recommended that consumers purchase and eat pre-washed greens in their entirety as far in advance of the "best if used by" date as possible.

Meat Science, 2002

Regulatory controls to prevent the spread of BSE have prohibited the use of certain animal protei... more Regulatory controls to prevent the spread of BSE have prohibited the use of certain animal proteins in feed in several countries. Accurate analytical methods for detecting prohibited material in feedstuffs are needed to ensure compliance with the new regulations. Six IgG class monoclonal antibodies (MAbs) against troponin I (TnI), a thermostable marker protein, have been developed for the detection and differentiation of rendered muscle tissue in animal feed. MAbs 1F9, 2G3 and 7F7 reacted to TnI of all species, including mammalian, poultry and fish, while MAbs 7A12 and 8A12 recognized only mammalian TnI (porcine, bovine, ovine, equine, and deer). MAb 2A8 was able to differentiate TnI of ruminant origin (bovine, ovine and deer) from other species. Three indirect enzyme-linked immunosorbent assays (ELISAs) employing these MAbs were developed for the determination of animal muscle, mammalian muscle or ruminant muscle in animal feeds.

Sensors, 2022

Salmonella is one of the major foodborne pathogens responsible for many cases of illnesses, hospi... more Salmonella is one of the major foodborne pathogens responsible for many cases of illnesses, hospitalizations and deaths worldwide. Although different methods are available to timely detect Salmonella in foods, surface plasmon resonance (SPR) has the benefit of real-time detection with a high sensitivity and specificity. The purpose of this study was to develop an SPR method in conjunction with magnetic nanoparticles (MNPs) for the rapid detection of Salmonella Typhimurium. The assay utilizes a pair of well-characterized, flagellin-specific monoclonal antibodies; one is immobilized on the sensor surface and the other is coupled to the MNPs. Samples of romaine lettuce contaminated with Salmonella Typhimurium were washed with deionized water, and bacterial cells were captured on a filter membrane by vacuum filtration. SPR assays were compared in three different formats—direct assay, sequential two-step sandwich assay, and preincubation one-step sandwich assay. The interaction of flagel...

Quality and safety of muscle foods have been a concern of consumers and regulatory authorities. E... more Quality and safety of muscle foods have been a concern of consumers and regulatory authorities. Enzyme-linked immunosorbent assay (ELISA) has been recognized as a sensitive and suitable analytical method in muscle foods for quality control and enforcement of food safety and labeling regulations. Several monoclonal antibodies (Mabs) have been developed as probing agents in ELISA for quantitative identification of adulterated meat species in fully cooked products. The Mabs developed were raised against heat-treated muscle proteins. The extent of heat treatment of a particular meat species could also be determined by these Mabs by comparing the increased ELISA response with the increase end-point cooking temperature. Therefore, these Mabs could be used to determine the maximum internal cooking temperature of a precooked meat sample to ensure safety of products. A brief review of current techniques and the experimental approach, characterization, and applications of these Mabs are addre...

a study was conducted to evaluate the effectiveness of consumers’ kitchen cleaning practices in r... more a study was conducted to evaluate the effectiveness of consumers’ kitchen cleaning practices in reducing microbiological contamination in home kitchens. One hundred fifty participants completed an in-home survey. a total of 747 samples of kitchen surfaces and 100 samples of kitchen cleaning tools were collected and analyzed for the indicator microorganisms. The reported cleaning practices were compared with various bacterial counts. Kitchen sinks and faucet handles were the most contaminated places in the kitchens. Dishcloths and sponges used for cleaning often contained more bacterial contamination than kitchen surfaces. Our results indicated inefficient cleaning procedures applied by the respondents even though most of them reported incorporating sanitizing agents in their cleaning scheme. Kitchens of respondents who reported cleaning kitchen surfaces on a regular basis had significantly lower contamination levels than those of respondents who reported cleaning the surfaces only w...

Sustainable Development and Biodiversity, 2016

Strawberry production and consumption is experiencing significant growth. Production in the USA h... more Strawberry production and consumption is experiencing significant growth. Production in the USA has doubled since the 1990s. As the domestic demand increases, there is potential to expand production beyond California and Florida into other regions of the country. In the 1950s, strawberries accounted for 25.3 % of the total marketable value of all fruits and vegetables produced in Tennessee, before declining in the 1970s. Acreage in the last 2 decades has been on a slow upward trend. Several counties throughout Tennessee are well suited for the growing of high-quality and high-value strawberries. Efforts are being made to promote production and consumption of organic and naturally grown local strawberries in Tennessee. Strawberry production in parts of China that have a similar climate has also seen considerable growth. Hebei, Shandong, Anhui, and Liaoning are among the largest strawberry producing provinces in the country. In 2014, over 50,000 acres of strawberries were planted in Anhui Province, accounting for over 15 % of all strawberries grown in China. This chapter discusses the production systems, cultural practices including nutrient management, the selection of cover crops, integrated pest management, and weed and disease control in strawberry production in Tennessee and China. Harvesting and postharvesting protocols, marketing channels, safety concerns, current constraints, and future potentials of organic strawberry production are also discussed.

Journal of AOAC INTERNATIONAL, 2000

An enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody to a porcine thermal-sta... more An enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody to a porcine thermal-stable muscle protein was developed for detection of pork in cooked meat products. The assay specifically detects porcine skeletal muscle, but not cardiac muscle, smooth muscle, blood, and nonmuscle organs. No cross-reactivity was observed with common food proteins. Validity of the assay was evaluated with laboratory formulated and commercial meat samples. The detection limit was determined as 0.5% (w/w) pork in heterologous meat mixtures. Overall, intra- and inter-assay coefficients of variation were 5.8 and 7.9%, respectively. The accuracy in analyzing market samples was 100% as verified by product labeling and confirmed by a commercial polycolonal antibody test kit.

Journal of Food Protection, 2018

Contamination on the exterior surfaces of raw poultry packages can be transmitted to hands and fo... more Contamination on the exterior surfaces of raw poultry packages can be transmitted to hands and food contact surfaces during shopping and handling. This study compared the level of microbial contamination and prevalence of foodborne pathogens on the surfaces of raw poultry packages as related to the types of products, types of packaging, and packaging conditions. Packages of whole chicken, cut-up chicken (breast and leg quarter), and ground turkey were purchased from retail stores. Aerobic plate counts (APCs) were significantly different (P < 0.05) among types of products and packaging materials, with ground turkey packages and the heat-sealed, high-walled containers being the lowest. APCs were significantly lower (P < 0.05) when the packages were intact and tight compared with intact and loose. Of the 105 packages, there were 10 (9.5%) with the presence of either Shiga toxin–producing Escherichia coli (STEC) or Campylobacter; of those packages, 6 (5.7%) were positive for STEC,...

Biosensors, 2019

Leafy vegetables have been associated with high-profile outbreaks causing severe illnesses. Timel... more Leafy vegetables have been associated with high-profile outbreaks causing severe illnesses. Timely and accurate identification of potential contamination is essential to ensure food safety. A surface plasmon resonance (SPR) assay has been developed for the detection of Salmonella Typhimurium in leafy vegetables. The assay utilizes a pair of well characterized monoclonal antibodies specific to the flagellin of S. Typhimurium. Samples of romaine lettuce contaminated with S. Typhimurium at different levels (between 0.9 and 5.9 log cfu/g) were pre-enriched in buffered peptone water. Three SPR assay formats, direct assay, sequential two-step sandwich assay, and pre-incubation one-step sandwich assay were evaluated. All three assay formats detect well even at a low level of contamination (0.9 log cfu/g). The SPR assay showed a high specificity for the detection of S. Typhimurium in the presence of other commensal bacteria in the romaine lettuce samples. The results also suggested that fur...

Molecular Biotechnology, 2019

Microbes are ubiquitously distributed in nature and are a critical part of the holobiont fitness.... more Microbes are ubiquitously distributed in nature and are a critical part of the holobiont fitness. They are perceived as the most potential biochemical reservoir of inordinately diverse and multi-functional enzymes. The robust nature of the microbial enzymes with thermostability, pH stability and multi-functionality make them potential candidates for the efficient biotechnological processes under diverse physio-chemical conditions. The need for sustainable solutions to various environmental challenges has further surged the demand for industrial enzymes. Fueled by the recent advent of recombinant DNA technology, genetic engineering, and high-throughput sequencing and omics techniques, numerous microbial enzymes have been developed and further exploited for various industrial and therapeutic applications. Most of the hydrolytic enzymes (protease being the dominant hydrolytic enzyme) have broad range of industrial uses such as food and feed processing, polymer synthesis, production of pharmaceuticals, manufactures of detergents, paper and textiles, and bio-fuel refinery. In this review article, after a short overview of microbial enzymes, an approach has been made to highlight and discuss their potential relevance in biotechnological applications and industrial bio-processes, significant biochemical characteristics of the microbial enzymes, and various tools that are revitalizing the novel enzymes discovery.

Antibodies, 2019

Salmonella Typhimurium is one of the leading causes of foodborne diseases worldwide. Biosensors a... more Salmonella Typhimurium is one of the leading causes of foodborne diseases worldwide. Biosensors and immunoassays utilizing monoclonal antibodies are widely used for the detection and subtyping of S. Typhimurium. However, due to insufficient information on the nature of binding with S. Typhimurium flagellin, the selection of appropriate antibodies for assay development is a cumbersome task. Hence, we aimed to compare the binding kinetics of a panel of monoclonal antibodies and their relative binding sites to flagellin antigen using a surface plasmon resonance biosensor. Initially, the flagellin was captured on the sensor surface through an immobilized anti-flagellin antibody. The interactions of different concentrations of monoclonal antibodies to flagellin were determined, and binding curves were fitted using 1:1 bio-interaction model to calculate the kinetic parameters. For epitope mapping, pairwise comparisons were completed to determine the binding inhibition of each paired combi...

HortScience, 2006

Photorespiration provides a protection mechanism in plants by diverting excessive energy accumula... more Photorespiration provides a protection mechanism in plants by diverting excessive energy accumulated from photochemical reaction, metabolizing toxic products and producing some protective molecules. The authors report cloning and characterization of a glycolate oxidase gene (GOX; NCBI accession DQ442286) and a NADH-dependent hydroxypyruvate reductase gene (HPR; NCBI DQ442287) from Pachysandra terminallis. The DQ442286 had the predicted GOX-like–Riboflavin-5′-phosphate (FMN) conserved domain and the DQ442287 had the predicted adenosine 5′-(alpha-thio)diphospho-5′-ribofuranosylnicotinamide nicotinamide adenine dinucleotide (NAD) binding domain (2-Hacid_DH_C). C-terminal peroxisome targeting signal was predicted to be -ARL for DQ442286 and –SKL for DQ442287. Both genes encoded enzyme proteins that are located in peroxisome and are involved in the photorespiration process. Real-time quantitative reverse-transcriptase polymerase chain reaction was performed to compare transcript level of...

Journal of the American Society for Horticultural Science, 2007

A cysteine proteinase gene (DQ403257) with an open reading frame of 1125 base pairs was isolated ... more A cysteine proteinase gene (DQ403257) with an open reading frame of 1125 base pairs was isolated from Pachysdandra terminalis. The primary translated peptide has a predicted length of 374 amino acids, pI (isoelectric point) of 5.70, and molecular mass of 40.9 kDa. The Peptidase_C1 domain is between residue 141 and 367. The proteinase has a conserved motif Gly-Xaa-Thy-Xaa-Phe-Xaa-Asn in the pro region. Sequence comparison shows that the deduced peptide shares 82% identity with the cysteine proteinase RD19a precursor (RD19) (accession P43296) from Arabidopsis thaliana (L.) Heynh. Real-time quantitative reverse-transcriptase–polymerase chain reaction revealed that the gene is induced by treatments of 1 to 7 days of darkness, 2 hours and 3 to 7 days at 5 °C, and 3 days at 38 °C.

Journal of food protection, 2018

Raw poultry products often are contaminated with Salmonella and Campylobacter, and these bacteria... more Raw poultry products often are contaminated with Salmonella and Campylobacter, and these bacteria can be transmitted through meat juice on the packages. An observational study was conducted to assess consumer exposure to meat juice during shopping and to quantify the transmission of meat juice from poultry packages to hands and other surfaces. Ninety-six participants completed the shopping study; 402 swabs were collected and analyzed for the presence of meat juice by an immunoassay. Overall, meat juice was detected on 61% of poultry package surfaces, 34% of shoppers' hands, 41% of grocery bags, 60% of kitchen surfaces, and 51% of food item surfaces. When meat juice was detected on the purchased poultry packages, the chance of the meat juice being on the shopper's hands, grocery bags, food items, and kitchen surfaces was significantly higher ( P < 0.005) compared with packages on which meat juice was not present. Shoppers who had poultry wrapped separately during checkout ...