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PubMed1969

Influence of pasteurization and lye treatment on the fermentation of spanish-style manzanilla olives.

The effect of lye concentration and pasteurization on the fermentation of Spanish-style Manzanilla green olives was investigated. Results showed that a rapid, normal fermentation always occurred when the proper lye was used, and only in the case of an inappropriate alkaline treatment could pasteurization help the growth of lactobacilli. Although pasteurization does not seem to affect color of processed olives, texture tests gave lower values for pasteurized samples than for those obtained from nonpasteurized olives.

Journal Article↗

PubMed1993

Inactivation of human immunodeficiency virus type I in human milk: effects of intrinsic factors in human milk and of pasteurization.

Human milk was inoculated with human immunodeficiency virus type I (HIV-1) or with HIV-1-infected cells in volumes and containers typically used in human milk banks. The inoculated milk was pasteurized at 62.5 degrees C for 30 minutes in a water bath, i.e., conditions currently in use or proposed for human milk pasteurization. The process of HIV-1 inoculation and pasteurization effectively inactivated the infectivity of both cell-free HIV-1 and HIV-1-infected cells. No virus was recovered after the process, even after repeated subculturing in attempts to rescue the virus. Pasteurization reduced the infectious titer of cell-free HIV-1 and HIV-1-infected cells by more than 5 logs and 6 logs respectively. Human milk contains one or more components that inactive HIV-1 but that are not toxic for the cells used to replicate virus. These components have not been identified, but physical and solubility properties are consistent with characteristics of lipids.

Disinfection↗

PubMed1998

Steam pasteurization of commercially slaughtered beef carcasses: evaluation of bacterial populations at five anatomical locations.

A steam pasteurization process (patent pending) has been shown to effectively reduce pathogenic bacterial populations on beef tissue and to significantly reduce naturally occurring bacterial populations on commercially slaughtered beef carcasses. The objective of this study was to determine the effectiveness of the steam pasteurization treatment for reducing bacterial populations at several anatomical locations on commerically slaughtered carcasses. Before and after pasteurization treatment (82.2 degrees C, 6.5-s exposure time), a sterile sponge was used to sample 300 cm2 at one of five locations (inside round, loin, midline, brisket, or neck). Eighty carcasses (40 before treatment and 40 after treatment) were sampled per anatomical location over 2 processing days. Before treatment, aerobic plate counts (APCs) were found to be highest (P < or = 0.01) at the midline (4.5 log10 CFU/100 cm2), intermediate at the inside round, brisket, and neck (ca. 3.8 log10 CFU/100 cm2), and lowest at the loin (3.4 log10 CFU/100 cm2). After treatment, APCs at all locations were reduced significantly (P < or = 0.01). The inside round, loin, and brisket had the lowest (P < or = 0.01) APCs (ca. 2.6 log10 CFU/100 cm2), whereas the midline and neck had APCs of 3.1 and 3.3 log10 CFU/100 cm2, respectively. The lower reduction in APCs at the neck area indicated that the treatment may not be as effective there, possibly because of the design of the pasteurization equipment. Generic Escherichia coli populations were low at all locations before treatment, with populations on 32% of all carcasses sampled being less than the detection limit of the study (5.0 CFU/100 cm2). After treatment, E. coli populations were significantly lower (P < or = 0.01) than populations before treatment and 85% of all carcasses sampled had E. coli populations below the detection limit. The maximum E. coli population detected after treatment was 25 CFU/100 cm2. For enteric bacterial populations, no differences were observed in the effectiveness of the treatment among the five carcass locations.

Abattoirs↗

PubMed1999

Residual alkaline phosphatase activity in pasteurized milk heated at various temperatures--measurement with the fluorophos and Scharer rapid phosphatase tests.

Milk containing three levels of milkfat (skim [0.5%], lowfat [2.0%], and whole [3.25%]) were heat treated at five different temperatures (59, 61, 63, 65, and 67 degrees C) using a laboratory scale, batch pasteurization method. Heated milk samples were removed at 5-min intervals, immediately cooled, and then assayed using the quantitative fluorometric method and the qualitative Scharer rapid test. Mean alkaline phosphatase (ALP) activity values as measured with the Fluorophos method decreased in all milk preparations as the time of sampling and temperature of heating increased. Samples representing the three fat levels and heat treated at 63 degrees C for 30 min, the minimum time/temperature allowed by the 1995 pasteurized milk ordinance (PMO), had ALP activity values <100 mU/liter. All values were below the 350 mU/liter standard for fluid milk products established by the Food and Drug Administration and cited in the 1995 PMO. Evaluation of the milks for adequacy of pasteurization with the Scharer rapid method indicated that those same milks were adequately pasteurized.

Alkaline Phosphatase↗

PubMed2001

Attachment of bacteria to beef from steam-pasteurized carcasses.

The extent to which a bacterial cocktail containing equal numbers of Pseudomonas fragi NCTC 10689, Listeria monocytogenes BL5/2, Salmonella Typhimurium LT2, and Escherichia coli JM 109 attached to loin surface cuts (7 by 5 cm) derived from steam-pasteurized beef carcasses has been evaluated. The extent of attachment was categorized as loosely attached (removed by rinsing), firmly attached (released by stomaching), and irreversibly bound. No significant difference (P > 0.10) in the attachment of bacteria to steam-pasteurized carcasses was found compared with control loin samples that had received no treatment. No significant difference (P > 0.05) was also found in the attachment strength between the different bacterial species tested. Most bacteria inoculated onto the loin cuts were reversibly bound, since they had been removed by rinsing and stomaching. The irreversible attachment of bacteria to loin cuts was found to vary significantly (P < 0.01) among the different carcass sets used but was independent of whether the carcass had undergone steam pasteurization treatment. Use of a bioluminescent strain of E. coli showed that cells bound preferentially to cut edges and convoluted areas on the loin surface and could not be removed by rinsing. The possible mechanisms of bacterial attachment and the suitability of steam pasteurization to remove contamination incurred during slaughter are discussed.

Animals↗

PubMed2004

Reduction of Salmonella by two commercial egg white pasteurization methods.

The effect of pH, processing temperatures, and preheating steps in two commercial egg white pasteurization procedures (Armour and Standard Brands methods) were evaluated using a five-strain cocktail of Salmonella. We devised a benchtop pasteurization system that would more closely resemble the two commercial processes than could the traditional capillary tube method. The pasteurization methods both require hydrogen peroxide to be metered into the egg white stream between a required initial preheat step and the main heating regimen. Both processes were evaluated at three pH levels (pH 8.2, 8.6, 9.0), at four temperatures (51.7 degrees C/125 degrees F, 53.1 degrees C/127.5 degrees F, 54.4 degrees C/130 degrees F, 55.8 degrees C/132.5 degrees F), and over four residence times to allow calculation of D-values at each temperature. When compared at the minimum allowable time and temperatures for each process, our results showed at least a 1-log greater log reduction (P < 0.05) for the Standard Brands method than the Armour method in 10 of 12 of the pH and temperature combinations tested. Almost all runs at any given temperature showed more reduction at pH 9.0 than at pH 8.2 except for the Standard Brands method at 54.4 degrees C and 55.8 degrees C, which showed the most consistent reduction across all three pH levels tested. Analysis of the preheat portion of the two methods showed that there was no contribution (P > 0.05) toward Salmonella reduction when compared with the identical process without the preheating step. We generally observed a greater reduction of Salmonella with egg white at pH 9.0 that is typical of older, off-line processing than with low pH egg white (i.e., 8.2) that is typical of modern in-line processing facilities. This difference was as much as 3.5 log cycles depending on the processing conditions. The data has been used to make recommendations for minimum processing conditions for hydrogen peroxide-based egg white pasteurization.

Colony Count, Microbial↗

PubMed2004

Surface pasteurization of whole fresh cantaloupes inoculated with Salmonella poona or Escherichia coli.

Numerous outbreaks of salmonellosis by Salmonella Poona have been associated with the consumption of cantaloupe. Commercial washing processes for cantaloupe are limited in their ability to inactivate or remove this human pathogen. Our objective was to develop a commercial-scale surface pasteurization process to enhance the microbiological safety of cantaloupe. Populations of indigenous bacteria recovered from cantaloupes that were surface pasteurized at 96, 86, or 76 degrees C for 2 to 3 min were significantly (P < 0.05) lower than those of the controls. Whole cantaloupes, surface inoculated with Salmonella Poona RM 2350 or Escherichia coli ATCC 25922 to a final cell concentration of ca. 5 log CFU/cm2 were stored at 4 degrees C or room temperature (RT = 19+/-1 degrees C) for up to 72 h before processing. Treatments at 76 degrees C for 2 to 3 min at 24 h postinoculation resulted in a reduction in excess of 5 log CFU/cm2 of Salmonella Poona and E. coli populations. Cantaloupes that were surface pasteurized and stored at 4 degrees C for 21 days retained their firmness qualities and had no visible mold growth compared with the controls, which became soft and moldy. These results indicate that surface pasteurization will enhance the microbiological safety of cantaloupes and will extend the shelf life of this commodity as well. Storage of untreated inoculated cantaloupes at RT for 24 to 72 h postinoculation caused a significant (P < 0.05) increase in Salmonella Poona and E. coli populations compared with storage at 4 degrees C. This indicates that cantaloupes should be refrigerated as soon as possible following harvest to suppress the growth of any possible contaminant on the rind.

Colony Count, Microbial↗

PubMed2005

Eradicating Listeria monocytogenes from fully cooked franks by using an integrated pasteurization-packaging system.

Surface pasteurization by applying steam or hot water before or after packaging of processed foods may be used to eliminate pathogens such as Listeria monocytogenes from ready-to-eat meat and poultry products. Surface pasteurization treatment with a mixture of pressurized steam and hot water was integrated into a continuous vacuum-packaging system to reduce L. monocytogenes from fully cooked franks. The franks (2.54 cm diameter by 15.24 cm length) were surface inoculated to contain up to 6 log CFU/cm2 L. monocytogenes. The inoculated franks were treated at 121 degrees C for 1.5 s in an arrangement of six franks per packaging chamber followed by immediate vacuum sealing of the top films of food packages in the same unit. A 3-log CFU/cm2 reduction of L. monocytogenes on fully cooked franks was obtained using the integrated pasteurization-packaging system. The pasteurization depth was 1.27 mm below the surfaces of the franks. This process provides a commercially applicable means of ensuring food safety by effectively eradicating L. monocytogenes from ready-to-eat meat and poultry products at the very last possible step of food packaging before reaching retail consumers.

Animals↗

PubMed2005

Detection of viable Mycobacterium avium subsp. paratuberculosis in retail pasteurized whole milk by two culture methods and PCR.

Cattle with Johne's disease can shed live Mycobacterium avium subsp. paratuberculosis (MAP) in their milk, and MAP can survive under simulated commercial pasteurization conditions. In several studies conducted in the United Kingdom and Canada, MAP DNA has been detected in retail pasteurized milk samples; however, in one study in the United Kingdom viable MAP was identified in commercially pasteurized milk. A double-blind study involving two laboratories was undertaken to evaluate retail pasteurized whole milk in the United States. Marshfield Clinic Laboratories used solid culture medium (Herrold's egg yolk agar slants with mycobactin J and amphotericin B, nalidixic acid, and vancomycin), and TREK Diagnostic Systems, Research and Development used liquid culture medium (ESP culture system). Cultures at both laboratories were confirmed by PCR. A total of 702 pints of retail whole milk were purchased in three of the top five milk-producing states (233 from California, 234 from Minnesota, and 235 from Wisconsin) over a 12-month period and were tested for the presence of viable MAP. The criteria used for identifying samples as positive for viable MAP were similar to those followed by most laboratories (positive culture with PCR confirmation). The combined data from the two laboratories revealed the presence of viable MAP in 2.8% of the retail whole milk pints tested. Although the number of samples containing viable MAP was similar among states (P > 0.05), there was a seasonal effect on the presence of viable MAP in retail milk (P = 0.05). More MAP-positive samples were identified during the third quarter of the year (July through September). Of the 22 brands of retail milk tested, 12 (55%) yielded at least one sample positive for viable MAP.

Animals↗

PubMed1990

[Microbiology in Montpellier before Pasteur's era].

Until Pasteur's discoveries, pathology included several verified but unexplained clinical data such as hospital infections, venereal and contagious diseases, and so on.... It is easy to imagine how important what the discovery of the germs life since it gave a logical explanation to a whole of coherent facts. Nevertheless this discovery was preceded by a long period during which the idea of transmissible germs slowly appeared. French and foreign Faculties are enrolled in this "prehistory" and there Montpellier played a significant part since microbiology had been directly admitted, during Pasteur's lifetime. In 1983, a research center named Buisson-Bertrand was created. In 1897 a chair was opened and one Institut Pasteur built in 1918. It was the first Institut Pasteur created in the provinces.

Academies and Institutes↗

PubMed1986

Pasteurization as an efficient method to inactivate blood borne viruses in factor VIII concentrates.

Heat treatment at 60 degrees C for 10 h in solution (pasteurization) was introduced into the manufacturing process of factor VIII concentrate (Haemate P) in order to considerably reduce the risk of transmission of human pathogenic viruses to haemophiliacs. The results of experimental and clinical studies with regard to hepatitis B, non-A, non-B hepatitis, acquired immune deficiency syndrome (AIDS) and herpes virus infections are reviewed. From this data it is concluded that pasteurization of factor VIII results in a product which is safe with regard to these viral infections. Furthermore, it was shown that pasteurization does not form new antigenic determinants on the factor VIII molecule and compared with the native product does not alter the physiological properties of this protein in patients. In comparison to these advantageous properties of the pasteurized product a slight loss of coagulant activity seems to be acceptable. This loss of yield, however, does not influence the quality or the amount of factor VIII in the final container used for the therapy of haemophilia A patients.

Deltaretrovirus↗

PubMed1984

[Inactivation of viruses in Factor XIII concentrate by pasteurization].

The use of a pasteurization step (heating in solution to 60 degrees C for 10 h) makes it possible to inactivate viruses, thus increasing the safety of the preparations. Using Factor XIII concentrate solution, it can be shown that hepatitis B virus and 10 other virus species are inactivated. Pasteurized Factor XIII was produced from starting material containing a total of 10(5.7) CID50 hepatitis-B virus (10(3.5) CID50/ml; CID = chimpanzee infectious dose). This Factor XIII preparation was injected in 4 chimpanzees; they remained healthy over an observation period of 37 weeks, whereas the 2 chimpanzees that received nonheated starting material developed hepatitis B. Furthermore, Rous-sarcoma, Epstein-Barr, cytomegalo, herpes simplex, measles, and rubella virus added to Factor XIII solution are inactivated by pasteurization within 2 h, mumps virus within 8 h, and adeno, polio, and vaccinia virus within 10 h. Pasteurizing of clotting factor preparations during the manufacturing process is a suitable for inactivating viruses and thereby increasing the safety of the preparations.

Animals↗

PubMed1993

Immunogenicity and efficacy of a recombinant DNA hepatitis B vaccine, GenHevac B Pasteur in high risk neonates, school children and healthy adults.

The immunogenicity and the protective efficacy of a recombinant DNA hepatitis B vaccine, GenHevac B Pasteur with or without passive immunization with hepatitis B immunoglobulin (HBIG) in high risk neonates born from HBsAg and HBeAg positive mothers was evaluated. Twenty-six neonates (group A) received HBIG 100 IU intramuscularly at birth plus GenHevac B Pasteur 20 micrograms at birth, 1, 2 and 12 months of age while another 23 neonates (group B) received only GenHevac B Pasteur vaccine. Forty high risk newborns who received no immunization served as control group. It was found that at months 4, 12, 13 and 24 the seroconversion rate in both group A and B were very high in the range of 95-100% with the GMT ranging from 10-160,000 mlU/ml. In the control group of infants, 85% had HBsAg positive at one year of age but it was only 3.8% and 8.7% in vaccinated groups A and B, respectively. The protective efficacy in neonates group A and B were 95.5% and 89.8% at one year, respectively, with no statistically significant difference. In 46 normal school children (group C) and 48 healthy adults (group D) who received the same dose of GenHevac B Pasteur the seroconversion rates at month 4 after receiving 3 doses of vaccination were 97.8% and 83.3% in group C and group D, respectively. At month 12, the seroconversion rate in group C rose to 100% and was significantly higher than the 89.6% of group D.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

[Louis Pasteur (1822-1895). A century later].

An overview of the amazing series of successive and diverse items worked on by the chemist and physicist Pasteur starts with the asymmetry of paratartrates, switches over to the fermentations and ends in the fight against diseases of invertebrates and vertebrates, including man. It is the wonderful story of an exceptional contribution to the advancement of knowledge, which was made possible by his keen observation skill, his rigorous and innovative methods and his careful judgement. A retrospective analysis of the inner man may impair somewhat the fame of Pasteur. He was a lonely man, in need of solitude to be able to make full use of his thinking capacity, foreboding secretiveness and shrewdness , which are contradictory to his careful writing down day after day of all the details of his thinking and research in his notebooks by now available to the scientific community. He was furthermore selfish, domineering, inflexible, impulsive and inclined to engage in endless controversies. But on the contrary his motivation to accept new assignments was subordinate to their public welfare value and as a rule he endeavoured to work on the problems in the field and in association with those concerned. He was courageous when struck by a cerebral hemorrhage at middle age, so that its aftermath hardly hampered his research activities. The dimness cast on his personality is not up to his pioneer role within a general conservative climate among the medical and even scientific profession, antagonistic to innovation. Pasteur has been a founder of stereochemistry, microbiology and its applications, immunology, bacterial vaccines, pasteurisation and a promotor of prevention and hygiene. These overwhelming achievements justify to keep alive the recognition of the outstanding stature of Pasteur.

Chemistry↗

PubMed1997

[Chest wall reconstruction with pasteurized autogenous bone grafts after resection of desmoid tumor--a case report].

We reported a case of twenty-two years old woman who underwent seventh operation for recurrent desmoid tumor of posterior area of the lower zone of the left chest wall. For complete resection of the tumor, wide resection of the chest wall including 6th to 12th ribs was done. We used autobone grafts at the tumor site to reconstruct her bony thorax. The sixth, seventh, and ninth ribs were used as pasteurized autogenous bone grafts; they were heated in water at 60 degrees C for 30 minutes then cool, and replaced to the bony thoracic area. Her postoperative state was good and no complication was observed. Pasteurization process makes tumor tissue necrotic, and pasteurized bone has osteoinductive activity and have mechanical strength similar as that of fresh bone graft. So, we concluded that pasteurized autogenous bone grafting may be a useful method for chest wall reconstruction.

Adult↗

PubMed2000

Comparative genomics uncovers large tandem chromosomal duplications in Mycobacterium bovis BCG Pasteur.

On direct comparison of minimal sets of ordered clones from bacterial artificial chromosome (BAC) libraries representing the complete genomes of Mycobacterium tuberculosis H37Rv and the vaccine strain, Mycobacterium bovis BCG Pasteur, two major rearrangements were identified in the genome of M. bovis BCG Pasteur. These were shown to correspond to two tandem duplications, DU1 and DU2, of 29 668 bp and 36 161 bp, respectively. While DU1 resulted from a single duplication event, DU2 apparently arose from duplication of a 100 kb genomic segment that subsequently incurred an internal deletion of 64 kb. Several lines of evidence suggest that DU2 may continue to expand, since two copies were detected in a subpopulation of BCG Pasteur cells. BCG strains harbouring DU1 and DU2 are diploid for at least 58 genes and contain two copies of oriC, the chromosomal origin of replication. These findings indicate that these genomic regions of the BCG genome are still dynamic. Although the role of DU1 and DU2 in the attenuation and/or altered immunogenicity of BCG is yet unknown, knowledge of their existence will facilitate quality control of BCG vaccine lots and may help in monitoring the efficacy of the world's most widely used vaccine.

BCG Vaccine↗

PubMed2000

Composition and calcium status of acid whey from pasteurized, UHT-treated and in-bottle sterilized milk.

Whey extracts were obtained from pasteurized, UHT-treated and in-bottle sterilized milks. After acidic precipitation of casein the concentration of protein, NPN, lactose, lipid, calcium, magnesium and potassium was determined. Among the parameters examined, protein content was significantly reduced in the whey extracts from UHT-treated and in-bottle sterilized milks compared with that from pasteurized milk, while lactose content was increased. Calcium extracted in whey was at least 80% of total calcium of the milk. The total calcium to protein ratio of whey was increased as a function of the thermal treatment of milk, while ionic calcium was about 50% of total calcium in all whey extracts. In vitro protein digestibility was found to be significantly lower in whey from UHT-treated and in-bottle sterilized milks than in that from pasteurized milk. Parallel estimation of the percentage of ionic calcium and of the solubility of proteins in the pH range 2-10 indicated that calcium was not involved in the pH-dependent solubility of proteins extracted in the whey, the extent of solubility being essentially a function of the thermal treatment of milk. The results suggest that calcium was not responsible for the formation of soluble protein macroaggregates with impaired digestibility that are present in whey from milk subjected to heat treatment of increasing intensity.

Animals↗

PubMed1990

In-home pasteurization of raw goat's milk by microwave treatment.

Raw milk has been implicated as an important source of infection with the common bacterial agents associated with gastroenteritis. While established methods of home pasteurization can be cumbersome and tedious, we have demonstrated that a domestic microwave oven can be used effectively to reduce aerobic plate counts in raw goat's milk by up to 6 log cycles without impairing the organoleptic quality. Good keeping quality of the irradiated product was demonstrated by the 7-day holding standard plate count. Petrifilm SM and Petrifilm VRB were used successfully under field conditions. Further investigation must be undertaken to demonstrate that this method is equivalent to the legally accepted pasteurization procedures for the inactivation of such pathogenic bacteria as Salmonella spp., Listeria monocytogenes and the pasteurization standard Coxiella burnetti.

Animals↗