bluuebunny/crossref_metadata_2025_split huggingface dataset:
USE OF IRRADIATION TO KILL ENTERIC PATHOGENS ON MEAT AND POULTRY1
Authors: THAYER D.W. 
Published: April 2007

ABSTRACT Ionizing radiation can be an effective step in a HACCP program to kill enteric pathogens associated with meat and poultry products. The populations of most common enteric pathogens such as Campylobacter jejuni, Escherichia coli O157:H7, Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, and Aeromonas hydrophila can be significantly decreased or eliminated by low‐dose (< 3.0 kGy) treatments with ionizing radiation. Only the enteric viruses and the endospores of the genera Clostridium and Bacillus are highly resistant to ionizing radiation, and even these are affected to some degree. Temperature effects must be carefully considered, as reduced irradiation temperatures not only result in fewer adverse changes in the sensorial properties of meat and poultry products, but they also may demand that greater radiation doses be used to inactivate the foodborne pathogen. Equations have been developed that predict the effects of low‐dose ionizing radiation treatments on several enteric pathogens associated with meat and poultry. In some cases substrate‐specific differences in radiation resistance have been found. Irradiation in combination with vacuum packaging or modified‐atmosphere packaging has increased both safety and shelf‐life for some types of refrigerated products. High‐dose irradiation treatments of enzyme‐inactivated meat or poultry products in vacuo at subfreezing temperatures can be used to prepare sterile, shelf‐stable products with excellent sensorial properties. Such products have been used extensively by military organizations, NASA during space flights, yachtsman, and hospitals. Contemporary research will be reviewed.
IMPACT OF TRANSPORT AND RELATED STRESSES ON THE INCIDENCE AND EXTENT OF HUMAN PATHOGENS IN PIGMEAT AND POULTRY
Authors: MULDER R.W.A.W. 
Published: April 2007

ABSTRACT Meat products are very important sources of protein in the human diet. The contamination of these products with pathogenic microorganisms, such as Salmonella and Campylobacter, make both production and consumption of them a precarious proposition. Several methods can decrease the level of contamination with these pathogenic microorganisms. However, there are still situations of high microbial load which cannot be explained and are often attributed to stress. This paper describes the effect of transport, husbandry and nutrition practices on contamination of slaughtered products. Examples of the stress occurring during fattening, catching and loading, transport and conditioning at the processing plant, are given.
INDIVIDUAL AND COMBINED LISTERICIDAL EFFECTS OF SODIUM LACTATE, POTASSIUM SORBATE, NISIN AND CURING SALTS AT REFRIGERATION TEMPERATURE
Authors: BUNCIC S. , FITZGERALD C.M. , BELL R.G. , HUDSON J.A. 
Published: April 2007

ABSTRACT The individual and combined antilisterial activity of the preservatives sodium lactate (4%), potassium sorbate (0.3%) and nisin (400 IU/ml), in either the presence or absence of the curing salts nitrite (125 ppm) and polyphosphate (0.5%), was assessed in buffered BHI broth (pH 5.5) during incubation at 4C. A cocktail of the strain Listeria monocytogenes NCTC 7973 and two food derived strains was used as the inoculum in challenge studies. In the absence of the preservatives, L. monocytogenes grew in the presence of polyphosphate but not in the presence of nitrite or a combination of nitrite and polyphosphate. The antilisterial action of nitrite was predominantly bacteriostatic in nature. Lactate acting alone, or in the presence of curing salts, produced a bacteriostatic effect. Sorbate acting alone had a bacteriostatic effect. Sorbate acting in the presence of nitrite or nitrite and polyphosphate produced a marked listericidal effect, reducing the population by 6.7 logs and 5.4 logs, respectively. Nisin acting alone produced an almost immediate 90% listericidal response (1 log population decrease), but initial numbers were restored within 14 days by regrowth. Regrowth was eliminated when nisin was used in combination with lactate, nitrite or nitrite and polyphosphate. The combination of lactate and sorbate offered no advantage over the use of sorbate alone. Sorbate and nisin acting in combination produced an enhanced listericidal effect, which was also seen in the presence of curing salts, but was delayed. No listericidal advantage over sorbate‐nisin combination was achieved through the use of the lactate‐sorbate‐nisin combination. The combined use of sorbate and nisin offers promise as a means of eliminating L. monocytogenes from low pH cured meat products. The efficacy of this preservative combination remains to be evaluated in a meat system before its practical application can be considered.
REDUCTION OF LISTERIA MONOCYTOGENES, ESCHERICHIA COLI O157:H7 AND SALMONELLA TYPHIMURIUM DURING STORAGE ON BEEF SANITIZED WITH FUMARIC, ACETIC, AND LACTIC ACIDS1
Authors: PODOLAK R.K. , ZAYAS J.F. , KASTNER C.L. , FUNG D.Y.C. 
Published: April 2007

ABSTRACT Cylindrical samples of beef semitendinosus muscle were dipped into an inoculum of Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella typhimurium. After air drying for 10 min, samples were sanitized by dipping in fumaric acid (1.0 or 1.5%), lactic acid (1%) or acetic acid (1.0%) solutions for 15 or 30 s at 55C. The 1.5% fumaric acid was most inhibitory against L. monocytogenes, resulting in inactivation of this pathogen after 7 days of storage. Samples treated with 1.0% and 1.5% fumaric acid solutions for 30 sec gave 2.54 and 1.51 log10 reductions, respectively, in S. typhimurium population compared to nontreated samples. The 1.5% fumaric acid treatments for 30 s exerted the maximum inhibition of E. coli O157:7. Acetic and lactic acid treatments were significantly less effective in reducing populations of the tested pathogens than fumaric acid treatments. As the sanitizing time in acid solutions increased from 15 to 30 s, the numbers of surviving organisms were reduced significantly.
GROWTH/SURVIVAL OF NATURAL FLORA AND LISTERIA MONOCYTOGENES ON REFRIGERATED UNCOOKED PORK AND TURKEY PACKAGED UNDER MODIFIED ATMOSPHERES
Authors: MANO S.B. , DE FERNANDO G.D. GARCIA , LOPEZ‐GALVEZ D. , SELGAS M.D. , GARCIA M.L. , CAMBERO M.I. , ORDOÑEZ J.A. 
Published: April 2007

ABSTRACTListeria monocytogenes was inoculated onto fresh pork and turkey slices. Inoculated and control samples were packaged under modified atmospheres (100% N2, and 20%/80% and 40%/60% CO2O2) or air in plastic bags of low gas permeability. Samples were stored at 1 and 7C. Samples stored in air showed a similar microbiological pattern to that usually observed in fresh meat stored aerobically. Packaging under modified atmospheres extended the meat shelf‐life. Bacterial growth was strongly inhibited at 1C, particularly in samples stored under CO2/O2 enriched atmospheres. Temperature and pH were critical factors for L. monocytogenes growth. This pathogen grew only on pork (initial pH 5.3) packaged in air and stored at 7C. No L. monocytogenes growth was observed at 1C in any atmosphere assayed. However, growth on turkey (initial pH 6.0) was marked at 7C in all atmospheres tested, while at 1C, this bacterium grew weakly only on samples stored in air.
INHIBITION OF SURFACE GROWTH OF TOXIGENIC AND NONTOXIGENIC ASPERGILLI AND PENICILLIA BY EUGENOL, ISOEUGENOL AND MONOLAURIN
Authors: MANSOUR NADA , YOUSEF AHMED E. , KIM JIN‐GAB 
Published: April 2007

Sabouraud dextrose agar, containing up to 300 ppm of eugenol, isoeugenol or monolaurin, was prepared. Eight strains of mycotoxin and non‐mycotoxin‐producing Aspergillus spp. and Penicillium spp. were tested. Spore suspensions were spotted in the center of agar plates and the linear (radial) growth rate was measured during incubation. All agents inhibited mold growth, but isoeugenol and eugenol were more effective than monolaurin. The average decreases in linear growth rate in the presence of eugenol, isoeugenol and monolaurin were 56, 43 and 11% at 100 ppm and 81, 85 and 15% at 200 ppm, respectively. At 300 ppm eugenol and isoeugenol, all fungi were inhibited completely; however, monolaurin (up to 2000 ppm) did not prevent mold growth. Except for P. viridicatum NRRL 6062, the molds tested did not vary significantly (at p=0.05) in degree of inhibition by any particular antifungal agent.A. parasiticus was grown in a yeast extract dextrose broth containing 100 ppm of the antifungal agents. Decreases in mycelial dry weight in the presence of eugenol, isoeugenol and monolaurin were 5.3, and 7.9, 10.5%, respectively. The corresponding reductions in aflatoxin B1 synthesized were 58, 57 and 25%. In conclusion, eugenol and isoeugenol have strong antifungal properties which are best manifested when the surface growth of molds on solid media is monitored.
PASTEURIZATION OF VACUUM‐SEALED PACKAGES OF SUMMER SAUSAGE INOCULATED WITH LISTERIA MONOCYTOGENES
Authors: ROERING ANN M. , WIERZBA RACHEL K. , IHNOT ANNE M. , LUCHANSKY JOHN B. 
Published: April 2007

ABSTRACT Packages containing chubs of summer sausage were inoculated with about 108 cfu/mL of a three‐strain mixture of Listeria monocytogenes and vacuum sealed. The fate of the pathogen was then monitored after pasteurization at 150F (66C), 170F (77C), 190F (88C) and 21 OF (99C) for 0 to 240 s. Pathogen numbers were reduced by about 3 log10 cfu per gram within 30, 60, or 90s at 21 OF (99C), 190F (88C), or 170F (77C), respectively, whereas numbers were reduced by <2.0 log10 cfu per gram after 240 s of heating at 150F (66C). The calculated D values were 2.08 min at 150F (66C), 0.84 min at 170F (77C), 0.37 min at 190F (88C), and 0.28 min at 21 OF (99C). These results establish the feasibility of using pasteurization to control L. monocytogenes in packaged summer sausage.
GROWTH RESPONSE OF A SALMONELLA TYPHIMURIUM POULTRY ISOLATE TO PROPIONIC ACID UNDER AEROBIC AND ANAEROBIC CONDITIONS
Authors: KWON Y.M. , HA S.D. , RICKE S.C. 
Published: April 2007

ABSTRACT Organic acids have long been used as additives in poultry feed to reduce microbial populations, including Salmonella spp. Propionic acid addition to poultry feed has a potential role in reducing Salmonella spp. in the chicken intestine. In this study, in vitro growth response of S. typhimurium isolated from poultry to propionic acid under aerobic and anaerobic conditions was determined. When grown in tryptic soy broth (TSB) containing buffered propionic acid (BPA), the growth rate of S. typhimurium gradually decreased as the level of BPA increased and broth pH decreased. No growth was detected with BPA concentrations greater than 3% (volume/volume) of the broth. When the growth rates of S. typhimurium in aerobic and anaerobic TSB were compared at two pH levels (pH 5.0 and 7.0), the growth inhibition of S. typhimurium by propionic acid was markedly suppressed by anaerobiosis at both pHs, as indicated by significantly (p<0.05) higher half‐inhibition constants (K°). Also, the growth rates of S. typhimurium in the presence of propionic acid were dramatically reduced by the decrease in pH from 7.0 to 5.0. The results of this study indicated that the growth inhibitory effect of propionic acid against S. typhimurium strains was enhanced by pH decrease and suppressed by anaerobiosis, suggesting that the growth response of S. typhimurium to propionic acid in the chicken intestine might be affected by the environmental conditions such as pH and anaerobiosis.
FUNGAL BIOTA ISOLATED FROM SPANISH CHEESES
Authors: BARRIOS Ma J. , MEDINA L.M. , LOPEZ Ma C. , JORDANO R. 
Published: April 2007

ABSTRACT Fungal biota, with special reference to the genus Penicillium, was studied in 52 samples of commercial cheeses (10 fresh, 17 semiripened and 25 ripened) made from different types of milk (cow, ewe, goat and mixed) produced in southern Spain. In 41 of the total of cheeses analyzed (79%) molds were isolated. Penicillium was identified in 63% of the samples, Mucor spp. in 27%, Geotrichum candidum in 17% and Cladosporium herbarum in 10%; eleven other fungal genera were detected ranging from 2 to 4%. Thirty‐five species of Penicillium were analyzed with the following distribution: 7 in fresh cheese, 16 in semiripened cheese and 30 in ripened cheese. The incidence of Penicillium spp. was also greater in the cheeses with a higher degree of ripeness, i.e. 20% in fresh cheese, 71% in the semiripened and 76% in the ripened cheese.
INACTIVATION OF THE BSE AGENT
Authors: TAYLOR D. M. 
Published: April 2007

ABSTRACT Bovine spongiform encephalopathy (BSE) belongs to a distinct group of transmissible degenerative encephalopathies (TDE) that includes scrapie in sheep and Creutzfeldt‐Jakob disease (CJD) of humans. These fatal neurological diseases are caused by unconventional but uncharacterized transmissible agents that have a number of unusual properties; this includes a high degree of resistance to inactivation. The only disinfectant that appears to be completely effective against high titres of TDE infectivity is sodium hypochlorite. Exposure to 1 to 2 M sodium hydroxide has a substantial but incomplete effect, as does autoclaving at temperatures between 132 and 138C for up to an hour; however, a combination of 2 M sodium hydroxide and autoclaving, even at the more modest temperature of 121C for 30 min, appears to be completely effective. With lower titres of infectivity, less rigorous regimes may be effective. For example, although most of the rendering procedures used to manufacture meat and bone meal (MBM) throughout the European Union (EU) have been found to be incapable of inactivating BSE and scrapie agents, one method which appeared to be effective with moderate titres of BSE and scrapie agent, involved exposure to steam at 133C for 20 min. This procedure is now the only one approved within the EU for the manufacture of MBM for feeding animals, excluding ruminants; however, the UK has introduced a ban on feeding MBM to any farmed species because of the occurrence of a new variant form of CJD in the UK which appears to have been caused by the BSE agent. Although the clinical signs of scrapie in sheep are entirely attributable to neurological dysfunction, tissues such as spleen and lymph nodes are known to become infected before those of the central nervous system. In contrast, the only tissues which have been found to become infected in cattle with natural BSE are brain, spinal cord and retina. These are no longer used in animal or human foodstuff. Because scrapie agent has no known association with human disease there has been no restriction in the past on using any sheep tissues, including brain, as human food; however, it is known from experimental studies that the BSE agent can infect sheep by the oral route to cause a disease that is clinically and neurohistopathologically indistinguishable from scrapie. It is also known that the spleen becomes infected in such sheep. Sheep in the UK could theoretically have become infected with the BSE agent through the feeding of infected MBM before the feed‐ban in 1988. There are now measures in place that prevent the head, spinal cord, and spleen of sheep being incorporated into foodstuff.
RESIDUES – A FOOD SAFETY PROBLEM?
Authors: O'KEEFFE MICHAEL , KENNEDY ORLA 
Published: April 2007

ABSTRACT Considerable time, regulation and consumer concern is associated with the question of chemical residues in food. Potential residues in food span a broad range from natural contaminants (mycotoxins) through environmental contaminants (dioxins, PCBs), agrochemicals (nitrates, pesticides), veterinary drugs (anthelmintics, antibiotics), prohibited substances (hormonal growth promoters), chemicals arising in processing (nitrosamines), packaging components (plasticisers) to contaminants arising in domestic food preparation (heavy metals). The occurrence or avoidance of these chemicals as residues in food is to a greater or lesser extent under the control of the food producer, processor and consumer in the activities of growing/producing, treating, storing, processing, packaging and cooking. The fundamental question is to what extent do or can residues in food constitute a food safety hazard for the consumer. Many of these substances are regulated as to their use and as to their acceptable levels in food while others, by their nature, arise as more random occurrences and, as such, are less prone to regulation. Of particular concern to the producer, processor and retailer of food is what steps may be taken to ensure that the food supply is safe. Best practice in plant and animal husbandry by the producer, in sourcing of material and in control of food manufacturing by the processor, and in sourcing of food products by the retailer combine to assure the safety of food to the consumer. This paper describes the various classes of chemicals which can arise as residues in food, particularly agrochemicals and veterinary drugs, the usage patterns which decrease/increase the likelihood of the occurrence of residues at unacceptable levels, how and in what form(s) residues can occur in foods, and the contribution of food processing to a reduction or otherwise of residue levels in food consumed. Consideration will be given, also, to quantifying the risk posed by chemical residues in food and to a study of the results from a Residue Database and from residue monitoring/surveillance as an indicator of risk to the consumer.
RECOVERY AND GROWTH OF SOME FOOD‐BORNE PATHOGENS IN IRRADIATED LOW AND HIGH FAT FISH DURING STORAGE AT 2‐4C
Authors: KAMAT ANU , THOMAS PAUL 
Published: April 2007

ABSTRACT This report presents results of the investigations carried out to understand the role of fat levels in fish on postirradiation recovery/survival and growth of four pathogens generally encountered in seafoods. Fish of low [golden anchoy, (Coillia dussumierij, 0.39%] as well as high fat [Indian sardine, (Sardinella longiceps), 7.1 %] content (with endogenous biota were inoculated separately with cells of Listeria monocytogenes 036, Yersinia enterocolitica 5692, Bacillus cereus and Salmonella typhimurium; and irradiated at doses of 1 and 3 kGy. The number of viable organisms for each was monitored for two weeks at 2‐4C on appropriate selective media. The four pathogens studied exhibited variation in their ability to recover from radiation damage as evidenced in terms of lag period; but their recovery and subsequent growth was not influenced by the fat levels offish. No increased growth of any of the pathogens tested was evidenced in irradiated fish, when compared with nonirradiated one.
ANTIFUNGAL EFFECTS OF SORBIC ACID AND PROPIONIC ACID AT DIFFERENT pH AND NaCl CONDITIONS
Authors: RAZAVI‐ROHANI S.M. , GRIFFITHS M.W. 
Published: April 2007

ABSTRACT The effect of pH (7, 5.6, 3.5), NaCl concentration (3 to 20% w/v) and EDTA on the antifungal activity of sorbic acid and propionic acid (Ca salt) against Candida spp., Sporothrix sp., Fusarium sp., Penicillium spp., Paecilomyces sp. and Aspergillus spp. was investigated by the Spiral Gradient End Point Test. Sorbic acid was active against most yeasts and molds, and in the presence of EDTA, which enhanced the effect of sorbic acid, all the organisms tested were inhibited. Sorbic acid was most effective at low pH. The inhibitory effect of sorbic acid increased with increasing NaCl concentration for all test organisms. Propionic acid was not as active as sorbic acid, but when combined with EDTA the inhibition was improved for some of the molds tested. Increasing or decreasing the pH did not change the antifungal activity of propionic acid. Synergistic effects of NaCl occurred at concentrations higher than 10%, but when EDTA was added, the inhibition was seen even at the lower NaCl concentrations.
PREDICTIVE MODEL FOR THE COMBINED EFFECT OF TEMPERATURE, pH, SODIUM CHLORIDE, AND SODIUM PYROPHOSPHATE ON THE HEAT RESISTANCE OF ESCHERICHIA COLI O157:H71
Authors: JUNEJA VIJAY K. , MARMER BENNE S. , EBLEN BRIAN S. 
Published: April 2007

ABSTRACT The effects and interactions of heating temperature (5–62.5C), pH (4 – 8), NaCl (0 – 6%, w/v), and sodium pyrophosphate (0 – 0.3%, w/v) on the heat resistance of a four strain mixture of Escherichia coli O157:H7 in beef gravy were examined. Thermal death times were determined using a submerged coil heating apparatus. The recovery medium was plate count agar supplemented with 1% sodium pyruvate. Decimal reduction times (D‐values) were calculated by fitting a survival model to the data with a curve fitting program. The D‐values were analyzed by second order response surface regression for temperature, pH, NaCl and sodium pyrophosphate levels. The four variables interacted to affect the inactivation of the pathogen. Thermal resistance of E. coli O157:H7 can be lowered by combining these intrinsic factors. A mathematical model describing the combined effect of temperature, pH, NaCl and sodium pyrophosphate levels on the thermal inactivation of E. coli O157:H7 was developed. The model can predict D‐values for any combinations of temperature, pH, NaCl and sodium pyrophosphate that are within the range of those tested.
EFFECT OF GAMMA IRRADIATION ON AFLATOXIN B1 PRODUCTION BY ASPERGILLUS FLAVUS IN GROUND BEEF STORED AT 5C
Authors: YOUSSEF BOTHAINA M. , MAHROUS SOUZAN R. , AZIZ NAGY H. 
Published: April 2007

ABSTRACT The effect of γ‐irradiation for controlling the production of aflatoxin B1 by Aspergillus flavus in ground beef stored at 5C for 2 weeks was investigated. Aspergillus, Penicillium, Cladosporium, Mucor, Scopulariopsis, Candida and Rhodotorula were the most common fungal genera contaminating ground beef. A. flavus and A. niger were the most common Aspergillus spp. Aspergillus flavus isolates were able to produce aflatoxin B1 in ground beef. Only 3 (20%) samples of ground beef were contaminated with aflatoxin B1 (25–45 μg/Kg). Gamma irradiation dose levels resulted in an immediate reduction in the total numbers of A. flavus. No growth or aflatoxin B1 production occurred at 1.50 kGy during storage.
PROTEIN PROFILE CHANGES IN ACID ADAPTED LISTERIA MONOCYTOGENES EXHIBITING CROSS‐PROTECTION AGAINST AN ACTIVATED LACTOPEROXIDASE SYSTEM IN TRYPTIC SOY BROTH
Authors: RAVISHANKAR SADHANA , HARRISON MARK A. , WICKER LOUISE 
Published: April 2007

ABSTRACT Foodborne pathogens often tolerate and survive environmental stress conditions including extreme acidity to varying degrees. One possible reason for this survival may be the production of protective stress proteins during acid shock (ASR) and/or tolerance (ATR) responses. The ASR and ATR of Listeria monocytogenes strains V7, V37 and CA in tryptic soy broth without dextrose acidified with lactic acid were studied. Possible cross‐protection of acid adapted cells against an activated lactoperoxidase system was also determined. The strains were either directly challenged at pH 4.0 and 3.5 to study their ASR or initially adapted at pH 5.5 for the equivalent of 1 generation before challenging at pH 4.0 and 3.5 to study their ATR. Adapted and nonadapted cells were challenged at pH 4.5 with or without an activated lactoperoxidase system. In all cases viability was determined by enumeration over a period of 24 or 48 h after challenge and the production of stress proteins analyzed by 2‐dimensional gel electrophoresis. While there were some differences in the survival responses for each strain, the acid adapted cells of each strain survived to a greater degree than nonadapted cells at both pH 4.0 (at least 10 fold at 24 h) and pH 3.5 (at least 1000 fold at 6 h) but not at pH 4.5. The acid adapted cells exposed to the lactoperoxidase system survived better (at least 5‐fold) than their nonadapted counterparts for all 3 strains at 24 and 48 h. The 2‐dimensional gel analysis for all 3 strains showed that the adapted and nonadapted cells underwent a change in their physiology, (at pH 4.0 compared to the control at pH 7.0; at pH 4.5 with the addition of lactoperoxidase system components) in that there was induction as well as repression of several proteins.