bluuebunny/crossref_metadata_2025_split huggingface dataset:
ADENOSINE TRIPHOSPHATE ENHANCES THE FLUORESCENCE OF 4′,6‐DIAMIDINO‐2‐PHENYLINDOLE (DAPI)‐LABELED ESCHERICHIA COLI O157:H71
Authors: TU SHU‐I , PATTERSON DEIDRE , UKNALIS JOE 
Published: April 2007

ABSTRACT Live cells of E. coli O157:H7 were labeled by 4′,6‐diamidino‐2‐phenylindole (DAPI) in buffers of different pH. The extent of labeling was relatively insensitive to pH in the range of 6.5 to 9.5. The fluorescence intensity of ± 104 DAPI‐labeled bacteria per mL in optical cuvettes could be detected by a luminescence spectrometer. With a fluorescence microplate reader attachment, less than 103 of labeled bacteria could be measured. DAPI‐labeling inhibited the growth and respiratory activities of the bacteria. The addition of 0.5 to 6 mM concentrations of ATP induced a substantial increase in the fluorescence of labeled bacteria. Maximal enhancement by ATP was observed from bacteria still maintaining low levels of physiological activities. The enhancement favored more alkaline media with pH greater than 9. A replacement of ATP with ADP or AMP diminished the extent of enhancement. Other triphosphate nucleotides did not enhance fluorescence of DAPI‐labeled bacteria. Comparable ATP enhancements were also observed with Pseudomonas alcaligenes and Shewanella putrefaciens. Solubilization/destruction of cell membranes of labeled bacteria by detergents essentially eliminated the ATP enhancement. Absorption and fluorescence spectroscopic measurements indicated that ATP could interact with free and bound DAPI. These results suggest that observed ATP enhancement in fluorescence intensity of DAPI labels in intact cells may be applied to increase the sensitivity of microorganism detection.
A QUANTITATIVE MICROTITER PLATE HEMOLYSIS ASSAY FOR LISTERIA MONOCYTOGENES
Authors: SAMPATHKUMAR B. , TSOUGRIANI E. , YU L.S.L. , KHACHATOURIANS G.G. 
Published: April 2007

ABSTRACT All virulent strains of L. monocytogenes produce the extracellular SH‐activated hemolysin, listeriolysin O, while nonhemolytic strains of L. monocytogenes are avirulent suggesting that the expression of this hemolysin is necessary for virulence of L. monocytogenes. Hence, testing for hemolysis becomes clinically relevant for an isolate identified as L. monocytogenes. However, the quantification and interpretation of this characteristic on blood agar poses several problems. Hence we have proposed a simple quantitative microtiter plate hemolysis assay. The assay is made of SRBC (3% SRBC in PBS) in microtiter plates to which CASO‐cultured cell‐free supernatants of L. monocytogenes or other test cultures are added. After mixing, the plates are incubated at 37C for 15–30 min and the hemolysis is visually read as CHU and MHU, as well as by a 620 nm scan for absorbancy. Percent hemolysis is calculated. We feel that this assay should prove to be of significance in a microbiology laboratory in which routine hemolysis assays are conducted.
MICROBIOLOGICAL QUALITY OF THE DAIRY PRODUCT PEDHA AND ITS IMPROVEMENT USING GAMMA RADIATION
Authors: BANDEKAR JAYANT , KAMAT ANU , THOMAS PAUL 
Published: April 2007

ABSTRACT Eighteen pedha samples procured from A and B grade retail shops were examined for their overall microbiological quality and for the presence of foodborne pathogens viz. Staphylococcus aureus, Salmonella sp., Coliforms, Listeria monocytogenes, Yersinia enterocolitica and Bacillus cereus. The microbiological quality of pedha samples from B grade shops was very poor as compared to pedha from A grade shop as evidenced by the very high total bacterial counts (6 × 107 cfu/g), high counts of S. aureus (as high as 7 × 106 cfu/g) and presence of coliforms and Listeria and Yersinia sp. in 33% of the samples. All the samples from A grade shops were also positive for S. aureus though negative for coliforms, Yersinia, Salmonella, Listeria and B. cereus. Gamma irradiation of pedha at a dose of 3kGy at 0C reduced overall bacterial load by five log cycles and S. aureus and coliforms could be totally eliminated. However, 5 kGy dose was necessary to eliminate S. aureus if the initial number exceed 1 × 105 cfu/g. Inoculated pack studies confirmed that 3 kGy dose was sufficient for the complete elimination of up to 1 × 105 cfu/g of S. aureus. A dose of 3 kGy had minimal effect on the sensory quality of pedha and even pedha samples irradiated at 5 kGy dose were acceptable. Treatment with 3 kGy dose of gamma radiation totally eliminated S. aureus and coliforms in pedha, thereby ensuring their microbial safety.
RESIDUE TESTING AND CONTROL STRATEGIES
Authors: MACNEIL JAMES D. 
Published: April 2007

ABSTRACT The need for residue testing and controls basically derives from two imperatives, the safety of the food supply and requirements imposed in trade. Maximum residue limits (MRLs) for pesticides, veterinary drugs, intentional food additives and potential contaminants, such as mycotoxins, are set for various food commodities based on toxicological assessment. Regulatory testing on domestically produced goods reveals the prevalence of a particular residue in a specific food commodity and also serves as a means to assess the effectiveness of the product registration system, while testing conducted on imports is primarily a verification of the effectiveness of the regulatory program in the exporting country. For industry, testing is required to demonstrate due diligence or to ensure that a product meets the specifications of an export market or a specific contract. Testing programs should be appropriate to meet the intended use. A survey to determine incidence of violations requires a test that detects residues above the MRL, while a dietary exposure study requires methodology that detects residues with the maximum achievable sensitivity. Tests conducted to certify a product for export or to fulfill the requirements of a contract should ensure that the product is in compliance with the market or contract requirement. If the requirement is “no detectable residues”, a very sensitive test method may be required. In many countries, there is a developing consensus that while government has a role in conducting work that is in the public interest, such as ensuring the safety of the food supply within a level of statistical assurance, it is ultimately the producer of the food who is responsible for the safety of the product or for ensuring that the product meets market or contract requirements. Various aspects of this changing regulatory, trade and consumer environment will be considered, with examples of the roles now played by governments and industry to ensure the safety and quality of food products.
CONTROLLED QUALITY MEAT: THE DUTCH EXPERIENCE
Authors: BEKMAN HENK 
Published: April 2007

ABSTRACT During the last few years there is a growing feeling in the Dutch livestock and meat industry that it is essential to change from a product oriented to a more market‐oriented production (from quantity to quality). This is mainly due to developments such as a more intense international competition, stagnant or declining meat consumption and negative pressure on the consumers’ image of meat. Counteracting these developments is only possible if every part of the production chain contributes (in close cooperation with each other) to achieve a better control of the whole production process: from conception to consumption. For a number of years an extensive research program has been carried out to set up a system of Integrated Quality Control (IKB). This has led to a “total quality concept” which includes the safety and quality of the product, the production method, care for the environment, and human and animal health. This paper discusses the basic elements (structure and content) of this quality concept. The extent of implementation of the IKB‐concept depends on the particular sector, but it is at around 70% for pigs and broilers. For IKB in veal, current participation is over 90%.
EDIBLE COATING AS PRESERVATIVE CARRIERS TO INHIBIT YEAST ON TAIWANESE‐STYLE FRUIT PRESERVES
Authors: CHEN MIN‐JANE , WENG YIH‐MING , CHEN WENLUNG 
Published: April 2007

ABSTRACT Edible coatings composed of methyl cellulose, glycerol, and fatty acid (stearic acid or palmitic acid) were tested as the preservative carriers for inhibition of surface microbial growth on Taiwanese‐style fruit preserves. These intermediate moisture foods, preserved by high sugar concentrations, spoil mainly by osmophilic yeasts growing on the surface. Two types of fruit preserves (Ten‐shing mei and Ching‐shuan mei) prepared from plum were covered with edible coatings containing benzoic acid. Two osmophilic yeasts (Zygosaccharomyces rouxii and Zygosaccharomyces mellis) were used as testing microorganisms. Yeast growth was inhibited when both fruit preserves contained 50–100 μg of benzoic acid (per gram). Furthermore, fruit preserves covered with edible coating showed no differences compared to uncoated samples in sensory evaluation. The results suggested that edible coating could serve as food additive carriers.
CAMPYLOBACTER JEJUNI: A BACTERIAL PARADOX
Authors: SOLOMON ETHAN B. , HOOVER DALLAS G. 
Published: April 2007

ABSTRACTCampylobacter jejunihas become recognized worldwide as a leading cause of diarrheal disease and foodborne gastroenteritis. Contaminated water, raw milk, and poultry appear to be the most common vehicles of transmission ofC. jejuniin humans. It is estimated thatC. jejunicauses between one to seven million cases of enteritis per year in the United States, resulting in 100 to 500 deaths. Although some people believeC. jejunicauses more cases of food poisoning than any other single agent, C. jejunihas been demonstrated to be extremely susceptible to a wide variety of antimicrobial treatments, food processing methods, and environmental stresses, in addition to being difficult to culture and maintain in the laboratory. The focus of this paper is to overview the current status ofC. jejuni,its epidemiological aspects, the fundamentals of its virulent capabilities, as well as to address the paradox that presents itself: How can an organism of such limited hardiness and growth capabilities be responsible for an ever‐increasing level of human foodborne disease?
COMPARISON OF MARGIN OF SAFETY BETWEEN SENSORY SPOILAGE AND ONSET OF CLOSTRIDIUM BOTULINUM TOXIN DEVELOPMENT DURING STORAGE OF MODIFIED ATMOSPHERE (MA)‐PACKAGED FRESH MARINE COD FILLETS WITH MA‐PACKAGED AQUACULTURED FISH FILLETS
Authors: REDDY N.R. , SOLOMON H.M. , RHODEHAMEL E.J. 
Published: April 2007

ABSTRACT The margin of safety between shelf‐life (onset of sensory spoilage) and potential time to toxin production by Clostridium botulinum type E in retail type packages of fresh marine cod fillets packaged in high barrier film under selected atmospheres [100% air, a modified atmosphere (MA) containing 75% CO2:25% N2, and vacuum] and stored under refrigeration (4C) and temperature‐abuse conditions (8 and 16C) was investigated. Margin of safety data of MA‐packaged marine cod fillets was also compared with MA‐packaged aquacultured tilapia, catfish, and salmon fillets. Sensory spoilage preceded onset of toxin presence for the marine cod fillets packaged in any of the atmospheres and storage temperatures tested. At 4C, none of the marine cod fillets packaged in either atmosphere developed toxin, even 20 days after spoilage, as determined by sensory characteristics. During storage at refrigeration and mild (8C) temperature‐abuse conditions, MA‐packaged marine cod showed a greater margin of safety compared to aquacultured tilapia, catfish, and salmon packaged under the same atmospheres and conditions. Fat content appeared to potentially influence the margin of safety in MA‐packaged aquacultured fresh fish fillets during storage.
PRESENCE OF LISTERIA IN MEXICAN CHEESES
Authors: SALTIJERAL JORGE A. , ALVAREZ VALENTE B. , GARCIA BEATRIZ 
Published: April 2007

ABSTRACT The presence of Listeria was investigated in ripened cheeses (Chihuahua, Manchego) and fresh cheese (Panela) from street vendors and retail stores in Mexico City. Cheeses were tested for Listeria, pH, NaCl, moisture and fat. Listeria selective cold enrichment was used to recover Listeria from positive samples. Fresh cheese had the lowest pH and NaCl contents and the highest moisture Chihuahua and Manchego cheeses made with pasteurized milk were negative for Listeria. Panela cheese samples were the most contaminated. The presence of Listeria was 65% in fresh cheeses: Listeria murrayi 20%, Listeria inoccua 15%, Listeria grayi 15%, and Listeria monocytogenes 15%. L. monocytogenes serotypes 1/2a, 1/2b and 4b were isolated from positive samples.
INJURY AND SURVIVAL OF AEROMONAS HYDROPHILA 7965 AND YERSINIA ENTEROCOLITICA 9610 FROM HIGH HYDROSTATIC PRESSURE
Authors: ELLENBERG LESLEY , HOOVER DALLAS G. 
Published: April 2007

ABSTRACT Responses of Aeromonas hydrophila 7965 and Yersinia enterocolitica 9610 to high hydrostatic pressure were investigated in microbiological media and meat. Cultures were pressurized from 51 to 304 megaPascals (MPa) for 15 min in 200 mM sodium phosphate buffer (pH 7.0), tryptic soy broth and radiation‐sterilized ground pork. Trends in pressure response were similar in all three pressure menstrua. A 7‐log10 CFU/g reduction of A. hydrophila in pork resulted from treatment of 253 MPa for 15 min. A 7‐log10 CFU/g reduction of Y. enterocolitica in pork resulted from treatment of 304 MPa for 15 min. Pressure‐induced injury of both pathogens was detected in all pressure menstrua at most pressure levels. No growth of either pathogen occurred in irradiated pork after pressurization of 128–203 MPa for 15 min and storage at 4C for 14 days; however, an upshift to 30C of cold‐stored A. hydrophila in pork resulted in growth after a lag time of approximately 10 h, and an upshift to 30C of cold‐stored Y. enterocolitica in pork resulted in recovery of injured cells within 2 h, and growth after a lag time of 4–6 h. This suggests that temperature abuse (30C) of pressure‐processed pork for greater than 6 h would allow growth and possibly repair of A. hydrophila and Y. enterocolitica which survive following pressure treatment. Although neither the processor nor the consumer would likely abuse the product to such an extent, the results suggest that A. hydrophila and Y. enterocolitica have the ability to repair or grow following pressure treatment in pork.
SURVEY OF APPLE GROWING, HARVESTING, AND CIDER MANUFACTURING PRACTICES IN WISCONSIN: IMPLICATIONS FOR SAFETY
Authors: ULJAS HEIDI E. , INGHAM STEVEN C. 
Published: April 2007

ABSTRACT To evaluate the safety of current apple growing, harvesting and cider manufacturing practices in Wisconsin, cider manufacturers were contacted in a three‐phase survey. Results revealed that seasonal, small‐scale production was characteristic of the industry. Most cider mills produced less than 5,000 gal/year; only 6% produced more than 20,000 gal/year. Most cider makers used only tree picked apples (86%), inspected apples before washing (94%), washed (93%) and brushed (87%) apples, but only 16% of mills sanitized washed apples. Most mills (92%) sanitized cider making equipment after each use; however, only a few sanitized between custom pressing apples from different customers. Respondents reported that they strived to improve cider safety by pasteurization (43% of all cider), UV light treatment (4%), use of preservatives (30%), and HACCP (17%). For 31% of all cider, however, processors relied solely on refrigeration and/or freezing. These results show that most cider mills practice many steps believed to enhance cider safety, but results also identify procedures that must be addressed to further improve cider safety.
EFFECT OF HEADSPACE OXYGEN AND FILMS OF DIFFERENT OXYGEN TRANSMISSION RATE ON TOXIN PRODUCTION BY CLOSTRIDIUM BOTULINUM TYPE E IN RAINBOW TROUT FILLETS STORED UNDER MODIFIED ATMOSPHERES
Authors: DUFRESNE ISABELLE , SMITH JAMES P. , LIU JIUN NI , TARTE ILSEMARIE , BLANCHFIELD BURKE , AUSTIN JOHN W. 
Published: April 2007

ABSTRACT Studies were conducted to determine the effect of various levels of headspace oxygen (0–100%, balance CO2) or film oxygen transmission rate (OTR) on the time to toxicity in modified atmosphere packaged (MAP) fresh trout fillets challenged with C. botulinum type E (102 spore/g) and stored under moderate temperature abuse conditions (12C). In all cases, trout were toxic within 5 days, irrespective of the initial levels of oxygen in the package headspace. However, spoilage preceded toxigenesis. Packaging of trout fillets in low gas barrier films, with OTRs ranging from 4,000 to 10,000 cc/m2/day at 24C and 0% relative humidity, also had no effect on time to toxicity in all MAP trout fillets. All fillets were toxic within 4–5 days and spoilage again preceded toxigenesis. This study has shown that the addition of headspace O2, either directly to a package or indirectly by using a low gas barrier film, had no influence on the time to toxigenesis or spoilage. Additional barriers, other than headspace O2 or film transmission rate, need to be considered to ensure the safety of MAP trout fillets, particularty at moderate temperature abuse conditions.
SURVIVAL OF THREE SALMONELLA SEROTYPES ON BEEF TRIMMINGS DURING SIMULATED COMMERCIAL FREEZING AND FROZEN STORAGE
Authors: DYKES G.A , MOORHEAD S.M. 
Published: April 2007

ABSTRACT This study investigated the survival of three Salmonella serotypes (S. Brandenberg, S. Dublin and S. Typhimurium) on beef trimmings during simulated commercial freezing, frozen storage for 9 months and subsequent abusive slow thawing and refreezing conditions. This was achieved by plating samples monthly and after thawing and refreezing on nonselective Tryptic Soy Agar (TSA) and selective Xylose Lysine Desoxycholate Agar (XLD) and incubating both at 37C for 24 h to determine Salmonella counts, aerobic counts and the presence, if any, of sublethal injury of this pathogen. Two freezing temperatures (−18C or −35C) to simulate slow or rapid freezing respectively, and two inoculation levels (103 cfu g−1 or 105 cfu g−1) were used. Aerobic counts and counts of all the Salmonella serotypes did not change significantly (p > 0.05) during frozen storage or for any of the other treatments applied in this study. This finding was attributed to the insulating nature of the subcutaneous fat layer in this manufacturing cut. These results are important with respect to food safety associated with ground beef processing.
CONSUMER PREFERENCES FOR PATHOGEN‐REDUCING TECHNOLOGIES IN BEEF1
Authors: FINGERHUT KRISTA , ZHANG PING , FOX JOHN , BOLAND MICHAEL 
Published: April 2007

ABSTRACT Two surveys were conducted by mail to evaluate consumers’ preferences for beef treated by the steam and hot‐water pasteurization technologies, in a comparison with beef treated by irradiation and nontechnology treated “regular” beef. More than 64% of the respondents reported that they preferred ground beef treated by irradiation to that treated by the two pathogen‐reducing technologies. More than 87% of the respondents stated that they preferred ground beef treated by the two technologies to nontechnology treated beef. Sixty percent of the respondents reported that they were willing to pay for beef treated by the two pathogen‐reducing technologies with an averaged willingness‐to‐pay of 0.36/lb over nontechnology treated beef. Compared with their counterparts; women, those having a better self‐reported health status, and those with children at home (≥ 18 years of age) were more likely to report a preference for beef treated by the two heat‐related pasteurization technologies. The income level of the respondents was negatively associated with their preference for beef treated by the two heat‐related pasteurization technologies. The strong consumer preference coupled with willingness‐to‐pay for beef treated by the two pathogen‐reducing technologies, suggest that consumers are willing to bear the cost of using these technologies if beef packers would invest in such technologies as a means of improving the quality of their products.
EFFECT OF IONIZING RADIATION ON BEEF BOLOGNA CONTAINING SOY PROTEIN CONCENTRATE
Authors: SOMMERS C.H. , FAN X. , NIEMIRA B.A. , HANDEL A.P. 
Published: April 2007

ABSTRACT Soy protein concentrate (SPC), an extender, is a common additive in ready‐to‐eat (RTE) meat products. SPC contains antioxidants that could potentially interfere with the ability of ionizing radiation to eliminate Listeria monocytogenes from RTE meat products. When L. monocytogenes was inoculated into cooked beef bologna emulsion containing 0, 1.75, or 3.5% SPC the gamma radiation D10 values, at radiation doses of 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kGy, were 0.66, 0.68, and 0.71kGy, respectively. Soluble antioxidant power, as determined by the Ferric Reducing Antioxidant Power (FRAP) assay was 1958, 3572, and 5494 mol in bologna emulsion containing 0, 1.75 and 3.5% SPC, respectively. Soluble antioxidant power was not affected by ionizing radiation. SPC did not prevent ionizing radiation induced lipid oxidation as determined by Thiobarbituric Acid Reactive Substance (TBARS) assay. Hunter color analysis of both unirradiated and irradiated bologna slices containing SPC indicated decreased a value as a result of irradiation, while the addition of SPC helped maintain b‐value and L‐value. The inclusion of SPC did not represent a barrier to ionizing radiation pasteurization of fine emulsion sausages for the parameters examined.
EFFECT OF APPLE DECAY PROPORTION ON THE PATULIN, FUMARIC ACID, HMF AND OTHER APPLE JUICE PROPERTIES
Authors: KADAKAL ÇETIN , NAS SEBAHATTIN 
Published: April 2007

ABSTRACT Starking apples, classified by the decay proportion on the fruit surface as sound, 30, 60 or 100% decayed were used in the production of apple juice. Then patulin, fumaric acid, HMF, pH, brix and Hunter L, a and b values of apple juice samples were determined. Patulin and fumaric acid analysis were done with HPLC. The patulin concentration in juice samples produced with Starking apples that are sound, 30, 60 and 100% decayed ranged between 0.0–15.9 μg/kg, 47.1–500.3 μg/kg, 156.4–2257.5 μg/kg, 54.9–2508.6 μg/kg, respectively. The fumaric acid concentration in the same juice samples ranged between 0.00–0.20 mg/kg, 0.23–0.69 mg/kg, 0.41–2.08 mg/kg and 1.40–4.14 mg/kg. In general, the color values (L, a, b) of the samples produced from 100% decayed apples measured by reflectance with a Hunter colorimeter were low when compared with the others.
VIRULENCE RESPONSE OF A SALMONELLA TYPHIMURIUM HILA:LACZY FUSION STRAIN TO SPENT MEDIA FROM PURE CULTURES OF SELECTED BACTERIA AND POULTRY CECAL MIXED CULTURE
Authors: NUTT J.D. , KUBENA L.F. , NISBET D. J. , RICKE S. C. 
Published: April 2007

ABSTRACT Virulence gene expression in Salmonella is triggered by a variety of environmental factors including changes in the gastrointestinal environment of birds during different dietary regimes. The objective of this study was to determine if growth of specific microorganisms alters the environmental conditions sufficiently to signal Salmonella Typhimurium virulence response. Spent media was obtained from a Salmonella Typhimurium hilA:lacZY fusion strain, a poultry Salmonella Typhimurium strain, Eschcrichia coli K12, and Lactobacillus caseii Spent media samples were collected after 2, 4, 8 and 24 h of growth in brain heart infusion broth (BHI) and M9 media, β‐galactosidase assays were performed on the samples to determine virulence expression. Virulence response to Salmonella, spent media was 2‐fold greater than Lactobacillus spent media at 4, 8 and 24 h growth (P < 0.05). Virulence expression almost doubled when exposed to Salmonella Typhimurium (NONA) spent media compared to mixed culture spent media at 4 h, and Salmonella Typhimurium (NONA) was significantly higher than mixed culture spent media at 24 h (P < 0.05). Based on these results, it appears that growth of similar bacterial species may alter the composition of rich media sufficiently to influence virulence.