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Anette Granly Koch - One of the best experts on this subject based on the ideXlab platform.
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application of leuconostoc carnosum for biopreservation of cooked meat products
Journal of Applied Microbiology, 2003Co-Authors: Tomas Jacobsen, Birgitte Bjorn Budde, Anette Granly KochAbstract:T . J A C O B S E N , B . B . B U D D E A N D A . G . K O C H . 2003. Aims: To optimize the practical use of the bacteriocin producing Leuconostoc carnosum 4010 in order to inhibit the growth of Listeria monocytogenes in sliced meat products. Methods and Results: Four different methods for biopreservation using the partially purified bacteriocin or the living Culture of Leuc. carnosum 4010 were evaluated. The methods using the living Protective Culture added to the sliced gas packed meat product were more effective in preventing growth of L. monocytogenes than the use of the partially purified leucocins 4010 or bacteriocin produced during fermentation before heat treatment of the saveloy. The application method giving the highest reduction in L. monocytogenes used nozzles for sprinkling the Protective Culture on all surfaces of each slice of the meat product. In the control samples without the Protective Culture, L. monocytogenes grew to ca .1 0 7 CFU g )1 , whereas for the application method using nozzles for distributing the Protective Culture, counts of L. monocytogenes never exceeded 10 CFU g )1 during 4 weeks of storage at 10� C. Conclusions: The live cells of the bacteriocin producing Leuc. carnosum 4010 was the most efficient method as it inhibited the growth of L. monocytogenes in cooked, sliced and gas packed saveloy stored at 5 and 10� C for 4 weeks. Significance and Impact of the Study: The results indicate that biopreservation with lactic acid bacteria is a suitable alternative to chemical preservatives. An even distribution of the Protective Culture was found to be essential for the efficacy of the Protective Culture in pilot plant trials.
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leuconostoc carnosum 4010 has the potential for use as a Protective Culture for vacuum packed meats Culture isolation bacteriocin identification and meat application experiments
International Journal of Food Microbiology, 2003Co-Authors: Birgitte Bjorn Budde, Tomas Jacobsen, Tina Hornbaek, Vibeke Barkholt, Anette Granly KochAbstract:Abstract A new Culture, Leuconostoc carnosum 4010, for biopreservation of vacuum-packed meats is described. The Culture originated from bacteriocin-producing lactic acid bacteria (LAB) naturally present in vacuum-packed meat products. Approximately, 72,000 colonies were isolated from 48 different vacuum-packed meat products and examined for antibacterial activity. Bacteriocin-producing colonies were isolated from 46% of the packages examined. Leuc. carnosum was the predominant bacteriocin-producing strain and Leuc. carnosum 4010 was selected for further experiments because it showed strong antilisterial activity without producing any undesirable flavour components in meat products. For identification of the bacteriocins produced, partial purification was carried out by ammonium sulphate precipitation, dialysis, and cation exchange chromatography. SDS-PAGE analysis revealed two bands with inhibitory activity corresponding to molecular sizes of 4.6 and 5.3 kDa. N-terminal amino acid sequencing showed that Leuc. carnosum 4010 produced two bacteriocins highly similar or identical to leucocin A and leucocin C. Application experiments showed that the addition of 107 cfu/g Leuc. carnosum 4010 to a vacuum-packaged meat sausage immediately reduced the number of viable Listeria monocytogenes cells to a level below the detection limit and no increase of L. monocytogenes was observed during storage at 5 °C for 21 days. The results presented demonstrate that Leuc. carnosum 4010 is suitable as a new Protective Culture for cold-stored, cooked, sliced, and vacuum-packed meat products.
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leuconostoc carnosum 4010 has the potential for use as a Protective Culture for vacuum packed meats Culture isolation bacteriocin identification and meat application experiments
International Journal of Food Microbiology, 2003Co-Authors: Birgitte Bjorn Budde, Tomas Jacobsen, Tina Hornbaek, Vibeke Barkholt, Anette Granly KochAbstract:A new Culture, Leuconostoc carnosum 4010, for biopreservation of vacuum-packed meats is described. The Culture originated from bacteriocin-producing lactic acid bacteria (LAB) naturally present in vacuum-packed meat products. Approximately, 72,000 colonies were isolated from 48 different vacuum-packed meat products and examined for antibacterial activity. Bacteriocin-producing colonies were isolated from 46% of the packages examined. Leuc. carnosum was the predominant bacteriocin-producing strain and Leuc. carnosum 4010 was selected for further experiments because it showed strong antilisterial activity without producing any undesirable flavour components in meat products. For identification of the bacteriocins produced, partial purification was carried out by ammonium sulphate precipitation, dialysis, and cation exchange chromatography. SDS-PAGE analysis revealed two bands with inhibitory activity corresponding to molecular sizes of 4.6 and 5.3 kDa. N-terminal amino acid sequencing showed that Leuc. carnosum 4010 produced two bacteriocins highly similar or identical to leucocin A and leucocin C. Application experiments showed that the addition of 10(7) cfu/g Leuc. carnosum 4010 to a vacuum-packaged meat sausage immediately reduced the number of viable Listeria monocytogenes cells to a level below the detection limit and no increase of L. monocytogenes was observed during storage at 5 degrees C for 21 days. The results presented demonstrate that Leuc. carnosum 4010 is suitable as a new Protective Culture for cold-stored, cooked, sliced, and vacuum-packed meat products.
Tomas Jacobsen - One of the best experts on this subject based on the ideXlab platform.
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application of leuconostoc carnosum for biopreservation of cooked meat products
Journal of Applied Microbiology, 2003Co-Authors: Tomas Jacobsen, Birgitte Bjorn Budde, Anette Granly KochAbstract:T . J A C O B S E N , B . B . B U D D E A N D A . G . K O C H . 2003. Aims: To optimize the practical use of the bacteriocin producing Leuconostoc carnosum 4010 in order to inhibit the growth of Listeria monocytogenes in sliced meat products. Methods and Results: Four different methods for biopreservation using the partially purified bacteriocin or the living Culture of Leuc. carnosum 4010 were evaluated. The methods using the living Protective Culture added to the sliced gas packed meat product were more effective in preventing growth of L. monocytogenes than the use of the partially purified leucocins 4010 or bacteriocin produced during fermentation before heat treatment of the saveloy. The application method giving the highest reduction in L. monocytogenes used nozzles for sprinkling the Protective Culture on all surfaces of each slice of the meat product. In the control samples without the Protective Culture, L. monocytogenes grew to ca .1 0 7 CFU g )1 , whereas for the application method using nozzles for distributing the Protective Culture, counts of L. monocytogenes never exceeded 10 CFU g )1 during 4 weeks of storage at 10� C. Conclusions: The live cells of the bacteriocin producing Leuc. carnosum 4010 was the most efficient method as it inhibited the growth of L. monocytogenes in cooked, sliced and gas packed saveloy stored at 5 and 10� C for 4 weeks. Significance and Impact of the Study: The results indicate that biopreservation with lactic acid bacteria is a suitable alternative to chemical preservatives. An even distribution of the Protective Culture was found to be essential for the efficacy of the Protective Culture in pilot plant trials.
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leuconostoc carnosum 4010 has the potential for use as a Protective Culture for vacuum packed meats Culture isolation bacteriocin identification and meat application experiments
International Journal of Food Microbiology, 2003Co-Authors: Birgitte Bjorn Budde, Tomas Jacobsen, Tina Hornbaek, Vibeke Barkholt, Anette Granly KochAbstract:Abstract A new Culture, Leuconostoc carnosum 4010, for biopreservation of vacuum-packed meats is described. The Culture originated from bacteriocin-producing lactic acid bacteria (LAB) naturally present in vacuum-packed meat products. Approximately, 72,000 colonies were isolated from 48 different vacuum-packed meat products and examined for antibacterial activity. Bacteriocin-producing colonies were isolated from 46% of the packages examined. Leuc. carnosum was the predominant bacteriocin-producing strain and Leuc. carnosum 4010 was selected for further experiments because it showed strong antilisterial activity without producing any undesirable flavour components in meat products. For identification of the bacteriocins produced, partial purification was carried out by ammonium sulphate precipitation, dialysis, and cation exchange chromatography. SDS-PAGE analysis revealed two bands with inhibitory activity corresponding to molecular sizes of 4.6 and 5.3 kDa. N-terminal amino acid sequencing showed that Leuc. carnosum 4010 produced two bacteriocins highly similar or identical to leucocin A and leucocin C. Application experiments showed that the addition of 107 cfu/g Leuc. carnosum 4010 to a vacuum-packaged meat sausage immediately reduced the number of viable Listeria monocytogenes cells to a level below the detection limit and no increase of L. monocytogenes was observed during storage at 5 °C for 21 days. The results presented demonstrate that Leuc. carnosum 4010 is suitable as a new Protective Culture for cold-stored, cooked, sliced, and vacuum-packed meat products.
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leuconostoc carnosum 4010 has the potential for use as a Protective Culture for vacuum packed meats Culture isolation bacteriocin identification and meat application experiments
International Journal of Food Microbiology, 2003Co-Authors: Birgitte Bjorn Budde, Tomas Jacobsen, Tina Hornbaek, Vibeke Barkholt, Anette Granly KochAbstract:A new Culture, Leuconostoc carnosum 4010, for biopreservation of vacuum-packed meats is described. The Culture originated from bacteriocin-producing lactic acid bacteria (LAB) naturally present in vacuum-packed meat products. Approximately, 72,000 colonies were isolated from 48 different vacuum-packed meat products and examined for antibacterial activity. Bacteriocin-producing colonies were isolated from 46% of the packages examined. Leuc. carnosum was the predominant bacteriocin-producing strain and Leuc. carnosum 4010 was selected for further experiments because it showed strong antilisterial activity without producing any undesirable flavour components in meat products. For identification of the bacteriocins produced, partial purification was carried out by ammonium sulphate precipitation, dialysis, and cation exchange chromatography. SDS-PAGE analysis revealed two bands with inhibitory activity corresponding to molecular sizes of 4.6 and 5.3 kDa. N-terminal amino acid sequencing showed that Leuc. carnosum 4010 produced two bacteriocins highly similar or identical to leucocin A and leucocin C. Application experiments showed that the addition of 10(7) cfu/g Leuc. carnosum 4010 to a vacuum-packaged meat sausage immediately reduced the number of viable Listeria monocytogenes cells to a level below the detection limit and no increase of L. monocytogenes was observed during storage at 5 degrees C for 21 days. The results presented demonstrate that Leuc. carnosum 4010 is suitable as a new Protective Culture for cold-stored, cooked, sliced, and vacuum-packed meat products.
Birgitte Bjorn Budde - One of the best experts on this subject based on the ideXlab platform.
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application of leuconostoc carnosum for biopreservation of cooked meat products
Journal of Applied Microbiology, 2003Co-Authors: Tomas Jacobsen, Birgitte Bjorn Budde, Anette Granly KochAbstract:T . J A C O B S E N , B . B . B U D D E A N D A . G . K O C H . 2003. Aims: To optimize the practical use of the bacteriocin producing Leuconostoc carnosum 4010 in order to inhibit the growth of Listeria monocytogenes in sliced meat products. Methods and Results: Four different methods for biopreservation using the partially purified bacteriocin or the living Culture of Leuc. carnosum 4010 were evaluated. The methods using the living Protective Culture added to the sliced gas packed meat product were more effective in preventing growth of L. monocytogenes than the use of the partially purified leucocins 4010 or bacteriocin produced during fermentation before heat treatment of the saveloy. The application method giving the highest reduction in L. monocytogenes used nozzles for sprinkling the Protective Culture on all surfaces of each slice of the meat product. In the control samples without the Protective Culture, L. monocytogenes grew to ca .1 0 7 CFU g )1 , whereas for the application method using nozzles for distributing the Protective Culture, counts of L. monocytogenes never exceeded 10 CFU g )1 during 4 weeks of storage at 10� C. Conclusions: The live cells of the bacteriocin producing Leuc. carnosum 4010 was the most efficient method as it inhibited the growth of L. monocytogenes in cooked, sliced and gas packed saveloy stored at 5 and 10� C for 4 weeks. Significance and Impact of the Study: The results indicate that biopreservation with lactic acid bacteria is a suitable alternative to chemical preservatives. An even distribution of the Protective Culture was found to be essential for the efficacy of the Protective Culture in pilot plant trials.
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leuconostoc carnosum 4010 has the potential for use as a Protective Culture for vacuum packed meats Culture isolation bacteriocin identification and meat application experiments
International Journal of Food Microbiology, 2003Co-Authors: Birgitte Bjorn Budde, Tomas Jacobsen, Tina Hornbaek, Vibeke Barkholt, Anette Granly KochAbstract:Abstract A new Culture, Leuconostoc carnosum 4010, for biopreservation of vacuum-packed meats is described. The Culture originated from bacteriocin-producing lactic acid bacteria (LAB) naturally present in vacuum-packed meat products. Approximately, 72,000 colonies were isolated from 48 different vacuum-packed meat products and examined for antibacterial activity. Bacteriocin-producing colonies were isolated from 46% of the packages examined. Leuc. carnosum was the predominant bacteriocin-producing strain and Leuc. carnosum 4010 was selected for further experiments because it showed strong antilisterial activity without producing any undesirable flavour components in meat products. For identification of the bacteriocins produced, partial purification was carried out by ammonium sulphate precipitation, dialysis, and cation exchange chromatography. SDS-PAGE analysis revealed two bands with inhibitory activity corresponding to molecular sizes of 4.6 and 5.3 kDa. N-terminal amino acid sequencing showed that Leuc. carnosum 4010 produced two bacteriocins highly similar or identical to leucocin A and leucocin C. Application experiments showed that the addition of 107 cfu/g Leuc. carnosum 4010 to a vacuum-packaged meat sausage immediately reduced the number of viable Listeria monocytogenes cells to a level below the detection limit and no increase of L. monocytogenes was observed during storage at 5 °C for 21 days. The results presented demonstrate that Leuc. carnosum 4010 is suitable as a new Protective Culture for cold-stored, cooked, sliced, and vacuum-packed meat products.
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leuconostoc carnosum 4010 has the potential for use as a Protective Culture for vacuum packed meats Culture isolation bacteriocin identification and meat application experiments
International Journal of Food Microbiology, 2003Co-Authors: Birgitte Bjorn Budde, Tomas Jacobsen, Tina Hornbaek, Vibeke Barkholt, Anette Granly KochAbstract:A new Culture, Leuconostoc carnosum 4010, for biopreservation of vacuum-packed meats is described. The Culture originated from bacteriocin-producing lactic acid bacteria (LAB) naturally present in vacuum-packed meat products. Approximately, 72,000 colonies were isolated from 48 different vacuum-packed meat products and examined for antibacterial activity. Bacteriocin-producing colonies were isolated from 46% of the packages examined. Leuc. carnosum was the predominant bacteriocin-producing strain and Leuc. carnosum 4010 was selected for further experiments because it showed strong antilisterial activity without producing any undesirable flavour components in meat products. For identification of the bacteriocins produced, partial purification was carried out by ammonium sulphate precipitation, dialysis, and cation exchange chromatography. SDS-PAGE analysis revealed two bands with inhibitory activity corresponding to molecular sizes of 4.6 and 5.3 kDa. N-terminal amino acid sequencing showed that Leuc. carnosum 4010 produced two bacteriocins highly similar or identical to leucocin A and leucocin C. Application experiments showed that the addition of 10(7) cfu/g Leuc. carnosum 4010 to a vacuum-packaged meat sausage immediately reduced the number of viable Listeria monocytogenes cells to a level below the detection limit and no increase of L. monocytogenes was observed during storage at 5 degrees C for 21 days. The results presented demonstrate that Leuc. carnosum 4010 is suitable as a new Protective Culture for cold-stored, cooked, sliced, and vacuum-packed meat products.
Juan J Cordoba - One of the best experts on this subject based on the ideXlab platform.
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evaluation of the efficacy of debaryomyces hansenii as Protective Culture for controlling listeria monocytogenes in sliced dry cured ham
Lwt - Food Science and Technology, 2020Co-Authors: Alberto Alia, Alicia Rodríguez, Juan J Cordoba, Carmen Garcia, Maria J AndradeAbstract:Abstract The anti-Listeria monocytogenes activity of 30 Debaryomyces hansenii strains was evaluated to be used as Protective Cultures in sliced dry-cured ham. Some of the yeast strains exhibited inhibitory potential against the L. monocytogenes strains S2, S4-2, S12-1 and S7-2 belonging to the serotypes 1/2a, 1/2b, 1/2c and 4b, respectively, when they were co-inoculated in a dry-cured ham-based medium at 0.95 and 0.93 water activity (aw). The antagonistic activity varied with the yeast and bacterium strains and the aw. The most active strain (D. hansenii 258H) was selected for assessing its activity on slices of dry-cured ham. D. hansenii 258H showed a limited action and even a promotion of the L. monocytogenes growth in the slices of dry-cured ham. In addition, the upregulation of some key virulence genes of L. monocytogenes and the unsuitability appearance on the slices of dry-cured ham inoculated with D. hansenii 258H suggest that such yeast is not a good candidate to be used as Protective Culture against L. monocytogenes in sliced dry-cured ham. Such effect should be considered even if D. hansenii is not used as a Protective Culture due to its presence as native microbial population in dry-cured ham.
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development of a multiplex qpcr method for simultaneous quantification in dry cured ham of an antifungal peptide penicillium chrysogenum strain used as Protective Culture and aflatoxin producing moulds
Food Control, 2014Co-Authors: Victoria Bernaldez, Alicia Rodríguez, Alberto Martin, Daniel Lozano, Juan J CordobaAbstract:A multiplex qPCR method to quantify the implantation of the antifungal-peptide-producing Penicillium chrysogenum RP42C and aflatoxin-producing moulds including a non-competitive IAC in dry-cured ham was developed. For this, the primer pairs F/R-Pc, F/R-omt and Tub-F1/R1 and the TaqMan probes, P-Pc, OMTprobe and Tubprobe targeting the pgafp, omt-1 and β-tubulin genes, respectively, were used. The ability of the optimized qPCR method to quantify simultaneously both non-toxigenic and toxigenic moulds in inoculated dry-cured ham was demonstrated since efficiency values ranged from 102.1 to 111.1%, and the limit of detection was between 2 and 3 log cfu/cm2 for both antifungal-peptide- and aflatoxin-producing moulds. In addition, suitability of multiplex qPCR to test implantation of Protective P. chrysogenum as well as growth of aflatoxigenic strain in a controlled model system was carried out successfully. The multiplex qPCR allowed demonstrating that the Protective strain of P. chrysogenum RP42C limits growth of the aflatoxin-producing Aspergillus flavus strain on dry-cured ham. These findings were confirmed by the results of aflatoxin analysis, since aflatoxin B1 was not detected when the Protective P. chrysogenum RP42C was inoculated. Furthermore, the multiplex qPCR including an IAC quantified efficiently the implantation of Protective Culture P. chrysogenum RP42C in dry-cured ham after 6 months of incubation. Thus, the multiplex qPCR should be considered a sensitive and rapid tool to monitor the implantation of fungal Protective Cultures and to determine growth of aflatoxin-producing moulds in dry-cured ham as well.
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effect of penicillium nalgiovense as Protective Culture in processing of dry fermented sausage salchichon
Food Control, 2013Co-Authors: Victoria Bernaldez, Juan J Cordoba, Mar Rodriguez, Mirian Cordero, Luis Polo, Alicia RodríguezAbstract:Abstract In this work the implantation of a Protective Culture of Penicillium nalgiovense on commercial dry-fermented sausages “salchichon” and its effect over presence of mycotoxin-producing moulds belonging to contamination origin was evaluated. In addition, the suitability of real-time quantitative PCR (qPCR) as a rapid and sensitive method to test implantation of Protective Culture throughout the “salchichon” processing was also tested. Dry-fermented sausages “salchichon” inoculated with a non-toxigenic Protective P. nalgiovense and subjected to three different commercial ripening processes were analysed. At first, ability of P. nalgiovense strain to avoid growth of an ocratoxin A (OTA)-producing strain and its mycotoxin production in a controlled model system was demonstrated. P. nalgiovense was quantified by a qPCR designed on the basis of the ITS region and values higher than 106 ufc/cm2 in both inoculated and non-inoculated “salchichon” were obtained. This technique should be considered a good tool to verify the implantation of Protective Culture of P. nalgiovense. Producing moulds of aflatoxins, OTA, patulin, sterigmatocystin and verrucosidin and the corresponding mycotoxins were not detected in any dry-fermented sausages tested, including those non-inoculated ones. Thus, presence of P. nalgiovense is inhibiting growth of toxigenic moulds. Utilization of a non-toxigenic fungal Protective Culture in dry-fermented sausage “salchichon” processing should be considered as a good tool in the preventive programmes to avoid growth of toxigenic moulds.
Alicia Rodríguez - One of the best experts on this subject based on the ideXlab platform.
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influence of an industrial dry fermented sausage processing on ochratoxin a production by penicillium nordicum
International Journal of Food Microbiology, 2021Co-Authors: Josue Delgado, Felix Nunez, Juan J Rondan, Alicia RodríguezAbstract:Abstract Dry-fermented sausages are prone to be colonised by Penicillium nordicum, which is one of the main ochratoxin A (OTA)-producing species. Its ability to produce this mycotoxin on dry-fermented sausages has been reported. However, the influence of the conditions of a traditional processing of a Spanish dry-fermented sausage and the intrinsic physicochemical parameters of this product such as water activity (aw) and pH on OTA production has not been studied yet. Thus, the aim of this study was to evaluate the influence of traditional processing (interaction of relative humidity (RH) x temperature x ripening days) on the evolution of pH and aw during maturation of dry-fermented sausage “salchichon” and its relationship with OTA synthesis by P. nordicum. The expression of otapks and otanps genes, both involved in the biosynthesis of the mycotoxin, was also assessed. For this, 27 raw sausages were inoculated with P. nordicum and ripened for 26 days in a drying chamber (3 days at 5 °C and 84% RH, 17 days at 12 °C and 84% RH, and 6 days at 12 °C and 80% RH). From results, although it seems that the pH slightly influenced on OTA biosynthesis, the aw had a great impact on this mycotoxin production. In fact, the two highest OTA concentrations found coincided with a dramatic rise of the aw value (0.92 aw) by day 18 of incubation when the RH of the drying chamber was still 84% and at the end of the incubation time when the aw decreased noticeably (0.87 aw). The expression of the otapks and otanps genes correlated with the OTA produced by P. nordicum. Results from this work confirm that the traditional processing of Spanish dry-fermented sausages favours itself OTA synthesis by P. nordicum. Our findings may help in informed decision-making in relation to RH/temperature of drying chambers and shortening of the ripening process. This may be then effectively incorporated into the hygienic production system in the framework of HACCP together with other measures including the use of Penicillium nalgiovense as Protective Culture or the monitoring of otapks gene expression, and aw during the processing of dry-fermented sausages. All these strategies together may put ochratoxigenic Penicillia at a disadvantage and minimise OTA contamination risks in dry-fermented sausages.
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evaluation of the efficacy of debaryomyces hansenii as Protective Culture for controlling listeria monocytogenes in sliced dry cured ham
Lwt - Food Science and Technology, 2020Co-Authors: Alberto Alia, Alicia Rodríguez, Juan J Cordoba, Carmen Garcia, Maria J AndradeAbstract:Abstract The anti-Listeria monocytogenes activity of 30 Debaryomyces hansenii strains was evaluated to be used as Protective Cultures in sliced dry-cured ham. Some of the yeast strains exhibited inhibitory potential against the L. monocytogenes strains S2, S4-2, S12-1 and S7-2 belonging to the serotypes 1/2a, 1/2b, 1/2c and 4b, respectively, when they were co-inoculated in a dry-cured ham-based medium at 0.95 and 0.93 water activity (aw). The antagonistic activity varied with the yeast and bacterium strains and the aw. The most active strain (D. hansenii 258H) was selected for assessing its activity on slices of dry-cured ham. D. hansenii 258H showed a limited action and even a promotion of the L. monocytogenes growth in the slices of dry-cured ham. In addition, the upregulation of some key virulence genes of L. monocytogenes and the unsuitability appearance on the slices of dry-cured ham inoculated with D. hansenii 258H suggest that such yeast is not a good candidate to be used as Protective Culture against L. monocytogenes in sliced dry-cured ham. Such effect should be considered even if D. hansenii is not used as a Protective Culture due to its presence as native microbial population in dry-cured ham.
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Enterococcus faecium: a promising Protective Culture to control growth of ochratoxigenic moulds and mycotoxin production in dry-fermented sausages
Mycotoxin Research, 2019Co-Authors: Micaela Álvarez, Felix Nunez, Alicia Rodríguez, Belén Peromingo, Mar RodriguezAbstract:Moulds positively contribute to the development of typical characteristic flavour and aroma of dry-fermented sausages. However, some mould species, such as Penicillium nordicum and Penicillium verrucosum , may contaminate this product with ochratoxin A (OTA). For this reason, the control of toxigenic moulds is needed. Strategies based on the use of antifungal microorganisms present in the native microbial population in the dry-fermented sausage processing could be a promising strategy. The aim of this work was to study the effect of Enterococcus faecium strains on P. nordicum and P. verrucosum growth and OTA production in a dry-fermented sausage-based medium at conditions of temperature and water activity similar to those occurring during the ripening of these meat products. Six strains were screened to evaluate their growth capacity and antifungal activity against P. nordicum and P. verrucosum at three fixed temperatures related to the sausage ripening. The two E. faecium strains that decreased growth of both species were chosen to further evaluate their effect on growth of P. verrucosum and P. nordicum and their mycotoxin production under conditions simulating the dry-fermented sausage ripening. The presence of E. faecium SE920 significantly reduced OTA production of P. nordicum although it did not affect P. verrucosum . E. faecium SE920, isolated from dry-fermented sausages, could be a good candidate to reduce OTA production by P. nordicum in dry-fermented sausages.
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development of a multiplex qpcr method for simultaneous quantification in dry cured ham of an antifungal peptide penicillium chrysogenum strain used as Protective Culture and aflatoxin producing moulds
Food Control, 2014Co-Authors: Victoria Bernaldez, Alicia Rodríguez, Alberto Martin, Daniel Lozano, Juan J CordobaAbstract:A multiplex qPCR method to quantify the implantation of the antifungal-peptide-producing Penicillium chrysogenum RP42C and aflatoxin-producing moulds including a non-competitive IAC in dry-cured ham was developed. For this, the primer pairs F/R-Pc, F/R-omt and Tub-F1/R1 and the TaqMan probes, P-Pc, OMTprobe and Tubprobe targeting the pgafp, omt-1 and β-tubulin genes, respectively, were used. The ability of the optimized qPCR method to quantify simultaneously both non-toxigenic and toxigenic moulds in inoculated dry-cured ham was demonstrated since efficiency values ranged from 102.1 to 111.1%, and the limit of detection was between 2 and 3 log cfu/cm2 for both antifungal-peptide- and aflatoxin-producing moulds. In addition, suitability of multiplex qPCR to test implantation of Protective P. chrysogenum as well as growth of aflatoxigenic strain in a controlled model system was carried out successfully. The multiplex qPCR allowed demonstrating that the Protective strain of P. chrysogenum RP42C limits growth of the aflatoxin-producing Aspergillus flavus strain on dry-cured ham. These findings were confirmed by the results of aflatoxin analysis, since aflatoxin B1 was not detected when the Protective P. chrysogenum RP42C was inoculated. Furthermore, the multiplex qPCR including an IAC quantified efficiently the implantation of Protective Culture P. chrysogenum RP42C in dry-cured ham after 6 months of incubation. Thus, the multiplex qPCR should be considered a sensitive and rapid tool to monitor the implantation of fungal Protective Cultures and to determine growth of aflatoxin-producing moulds in dry-cured ham as well.
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effect of penicillium nalgiovense as Protective Culture in processing of dry fermented sausage salchichon
Food Control, 2013Co-Authors: Victoria Bernaldez, Juan J Cordoba, Mar Rodriguez, Mirian Cordero, Luis Polo, Alicia RodríguezAbstract:Abstract In this work the implantation of a Protective Culture of Penicillium nalgiovense on commercial dry-fermented sausages “salchichon” and its effect over presence of mycotoxin-producing moulds belonging to contamination origin was evaluated. In addition, the suitability of real-time quantitative PCR (qPCR) as a rapid and sensitive method to test implantation of Protective Culture throughout the “salchichon” processing was also tested. Dry-fermented sausages “salchichon” inoculated with a non-toxigenic Protective P. nalgiovense and subjected to three different commercial ripening processes were analysed. At first, ability of P. nalgiovense strain to avoid growth of an ocratoxin A (OTA)-producing strain and its mycotoxin production in a controlled model system was demonstrated. P. nalgiovense was quantified by a qPCR designed on the basis of the ITS region and values higher than 106 ufc/cm2 in both inoculated and non-inoculated “salchichon” were obtained. This technique should be considered a good tool to verify the implantation of Protective Culture of P. nalgiovense. Producing moulds of aflatoxins, OTA, patulin, sterigmatocystin and verrucosidin and the corresponding mycotoxins were not detected in any dry-fermented sausages tested, including those non-inoculated ones. Thus, presence of P. nalgiovense is inhibiting growth of toxigenic moulds. Utilization of a non-toxigenic fungal Protective Culture in dry-fermented sausage “salchichon” processing should be considered as a good tool in the preventive programmes to avoid growth of toxigenic moulds.
