The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
John W. Austin - One of the best experts on this subject based on the ideXlab platform.
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EFFECT OF FILMS OF DIFFERENT OXYGEN TRANSMISSION RATE ON TOXIN PRODUCTION BY CLOSTRIDIUM BOTULINUM TYPE E IN VACUUM PACKAGED COLD AND HOT SMOKED TROUT FILLETS
Journal of Food Safety, 2000Co-Authors: Isabelle Dufresne, James P. Smith, Ilsemarie Tarte, Burke Blanchfield, John W. AustinAbstract:Studies were done to determine the effect of film oxygen transmission rate (OTR) on the time to toxicity in vacuum packaged cold and hot smoked rainbow trout fillets challenged with C. botulinum type E (10 2 spores/g) and stored at refrigerated conditions (4C), and under mild (8C) and moderate (12C) temperature abuse conditions. While no samples were toxic at 4C, toxin was detected within 28 days at 8C for cold smoked trout fillets vacuum packaged in films with high OTR. Toxin was also detected for most vacuum packaged hot smoked trout fillets within 14-28 days at 8C, with the exception of trout fillets packaged in films with an OTR > 10,000 cc/m 2 /day. In most cases at 8C, spoilage, based on odor/color scores, preceded or occurred simultaneously with Toxigenesis. At 12C all cold and hot smoked trout were toxic after 14-21 days and samples packaged in films with an OTR
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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
Journal of Food Safety, 2000Co-Authors: Isabelle Dufresne, James P. Smith, Ilsemarie Tarte, Burke Blanchfield, John W. AustinAbstract:Studies were conducted to determine the effect of various levels of headspace oxygen (0-100%, balance CO 2 ) 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 (10 2 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/m 2 /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 O 2 , 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 O 2 or film transmission rate, need to be considered to ensure the safety of MAP trout fillets, particularly at moderate temperature abuse conditions.
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Effect of pH and CO2 on growth and toxin production by Clostridium botulinum in English-style crumpets packaged under modified atmospheres
Journal of food protection, 1999Co-Authors: Daphne Phillips Daifas, James P. Smith, Burke Blanchfield, John W. AustinAbstract:The effect of pH and CO2 on both growth of and toxin production by Clostridium botulinum in English-style crumpets, packaged under modified atmospheres was investigated using a 2 x 2 factorial experiment. English-style crumpets (water activity, 0.990; pH 6.5 and 8.3) were inoculated with C. botulinum spores types A and proteolytic B (500 spores/g), packaged in either 60% CO2 (balance N2) or 100% CO2, stored at ambient temperature (25 degrees C), and monitored daily for toxicity. Toxin was detected after 4 days in crumpets packaged in 60% CO2, irrespective of initial product pH. Toxin production was delayed 1.5 to 3 days in crumpets packaged under 100% CO2. Analysis of variance indicated a significant interaction effect of pH and %CO2 on time of earliest toxin detection. Delay of toxin production was greatest for high pH (8.3) crumpets. All products were organoleptically acceptable at the time of Toxigenesis, and therefore, high moisture-high pH bakery products, if contaminated with spores of C. botulinum, could become hazardous if packaged in atmospheres containing CO2.
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Growth and toxin production by Clostridium botulinum in English-style crumpets packaged under modified atmospheres.
Journal of food protection, 1999Co-Authors: Daphne Phillips Daifas, James P. Smith, Burke Blanchfield, John W. AustinAbstract:To determine the safety of a high moisture bakery product, packaged under modified atmospheres, challenge studies were done on English-style crumpets (water activity [a(w)] 0.990, pH 6.5) inoculated postbaking with Clostridium botulinum types A and proteolytic B spores (5 X 10(2) spores/g). Products were packaged either in air, in air with an Ageless FX200 oxygen absorbent, or in a CO2/N2 (60:40) gas mixture, stored at ambient temperature (25 degrees C), and monitored for toxicity daily. All inoculated crumpets were toxic within 4 to 6 days and were organoleptically acceptable at the time of Toxigenesis. Counts of C. botulinum increased to approximately 10(5) CFU/g at the time of toxicity. To determine the effect of baking on product safety, subsequent challenge studies were done on crumpets inoculated with 5 x 10(2) spores/g (baked weight basis) prior to baking. All crumpets were toxic after only 6 days, irrespective of packaging conditions, and Toxigenesis again preceded spoilage. Temperature profile studies showed that the maximum internal temperature reached during baking was 97 degrees C, and the total baking process was equivalent to 0.03 min at 121 degrees C. The actual time to toxin production in both studies (4 to 6 days) correlated well with the predicted time (3.4 days) using the U.S. Department of Agriculture Pathogen Modeling Program (version 5.1) for proteolytic strains of C. botulinum. These studies confirm that high moisture bakery products, if contaminated with C. botulinum spores either pre- or postbaking, could pose a public health hazard, if packaged in air (in a high gas barrier package where O2 was depleted and CO2 was generated during storage) or under modified atmosphere packaging conditions and stored at ambient temperature.
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CHALLENGE STUDIES WITH CLOSTRIDIUM BOTULINUM TYPE E IN A VALUE‐ADDED SURIMI PRODUCT STORED UNDER A MODIFIED ATMOSPHERE
Journal of Food Safety, 1998Co-Authors: André Lyver, James P. Smith, John W. Austin, F.m. Nattress, Burke BlanchfieldAbstract:Challenge studies were carried out on raw, cooked, and sterilized surimi nuggets, inoculated with 10 -1 spores/g of C. botulinum type E spores. All products were packaged in air and air with an Ageless SS oxygen absorbent and stored at 4, 12 and 25C. Toxin was not detected in any raw product throughout storage (28 days). The absence ofToxigenesis was attributed to the low pH (4.1-4.3) due mainly to the growth of lactic acid bacteria (10 7 CFU/g). Toxin was also not detected in any cooked product after 28 days. Product pH did not decrease as previously (due to the absence Of LAB), but counts of C. botulinum still decreased throughout storage. In sterile nuggets, C. botulinum counts increased to 10 6 cfu/g at both 12 and 25C, respectively, by 28 days. Lactic acid bacteria and Bacillus spp. were not detected throughout the 28 days storage period. Toxin was detected by days 28 and 14 at 12 and 25C, respectively, and Toxigenesis preceded spoilage. The absence of toxin in cooked nuggets was attributed to the anti-botulinal role by Bacillus species, the predominant spoilage bacteria in cooked nuggets.
J.y. Ikawa - One of the best experts on this subject based on the ideXlab platform.
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Clostridium botulinum Growth and Toxigenesis in Shelf‐Stable Noodles
Journal of Food Science, 1991Co-Authors: J.y. IkawaAbstract:Unacidified and acidified noodles were inoculated with a composite of C botulinum types A and B spores. Noodles were cooked, packaged in oxygen-permeable polypropylene bags, steamed, cooled, then stored aerobically at 7 or 23 degrees C, or anaerobically at 30 degrees C. Toxin did not develop in any aerobically stored samples at pH less than or equal to 4.5. Toxin developed in samples with pH >5.0, stored aerobically and anaerobically. In addition, toxin was detected in one anaerobically incubated acidified unit where pH had been increased by microbial growth. Proper acidification of product prevented toxic growth of C botulinum.
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clostridium botulinum growth and Toxigenesis in shelf stable noodles
Journal of Food Science, 1991Co-Authors: J.y. IkawaAbstract:Unacidified and acidified noodles were inoculated with a composite of C botulinum types A and B spores. Noodles were cooked, packaged in oxygen-permeable polypropylene bags, steamed, cooled, then stored aerobically at 7 or 23 degrees C, or anaerobically at 30 degrees C. Toxin did not develop in any aerobically stored samples at pH less than or equal to 4.5. Toxin developed in samples with pH >5.0, stored aerobically and anaerobically. In addition, toxin was detected in one anaerobically incubated acidified unit where pH had been increased by microbial growth. Proper acidification of product prevented toxic growth of C botulinum.
James P. Smith - One of the best experts on this subject based on the ideXlab platform.
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EFFECT OF FILMS OF DIFFERENT OXYGEN TRANSMISSION RATE ON TOXIN PRODUCTION BY CLOSTRIDIUM BOTULINUM TYPE E IN VACUUM PACKAGED COLD AND HOT SMOKED TROUT FILLETS
Journal of Food Safety, 2000Co-Authors: Isabelle Dufresne, James P. Smith, Ilsemarie Tarte, Burke Blanchfield, John W. AustinAbstract:Studies were done to determine the effect of film oxygen transmission rate (OTR) on the time to toxicity in vacuum packaged cold and hot smoked rainbow trout fillets challenged with C. botulinum type E (10 2 spores/g) and stored at refrigerated conditions (4C), and under mild (8C) and moderate (12C) temperature abuse conditions. While no samples were toxic at 4C, toxin was detected within 28 days at 8C for cold smoked trout fillets vacuum packaged in films with high OTR. Toxin was also detected for most vacuum packaged hot smoked trout fillets within 14-28 days at 8C, with the exception of trout fillets packaged in films with an OTR > 10,000 cc/m 2 /day. In most cases at 8C, spoilage, based on odor/color scores, preceded or occurred simultaneously with Toxigenesis. At 12C all cold and hot smoked trout were toxic after 14-21 days and samples packaged in films with an OTR
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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
Journal of Food Safety, 2000Co-Authors: Isabelle Dufresne, James P. Smith, Ilsemarie Tarte, Burke Blanchfield, John W. AustinAbstract:Studies were conducted to determine the effect of various levels of headspace oxygen (0-100%, balance CO 2 ) 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 (10 2 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/m 2 /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 O 2 , 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 O 2 or film transmission rate, need to be considered to ensure the safety of MAP trout fillets, particularly at moderate temperature abuse conditions.
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Effect of pH and CO2 on growth and toxin production by Clostridium botulinum in English-style crumpets packaged under modified atmospheres
Journal of food protection, 1999Co-Authors: Daphne Phillips Daifas, James P. Smith, Burke Blanchfield, John W. AustinAbstract:The effect of pH and CO2 on both growth of and toxin production by Clostridium botulinum in English-style crumpets, packaged under modified atmospheres was investigated using a 2 x 2 factorial experiment. English-style crumpets (water activity, 0.990; pH 6.5 and 8.3) were inoculated with C. botulinum spores types A and proteolytic B (500 spores/g), packaged in either 60% CO2 (balance N2) or 100% CO2, stored at ambient temperature (25 degrees C), and monitored daily for toxicity. Toxin was detected after 4 days in crumpets packaged in 60% CO2, irrespective of initial product pH. Toxin production was delayed 1.5 to 3 days in crumpets packaged under 100% CO2. Analysis of variance indicated a significant interaction effect of pH and %CO2 on time of earliest toxin detection. Delay of toxin production was greatest for high pH (8.3) crumpets. All products were organoleptically acceptable at the time of Toxigenesis, and therefore, high moisture-high pH bakery products, if contaminated with spores of C. botulinum, could become hazardous if packaged in atmospheres containing CO2.
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Growth and toxin production by Clostridium botulinum in English-style crumpets packaged under modified atmospheres.
Journal of food protection, 1999Co-Authors: Daphne Phillips Daifas, James P. Smith, Burke Blanchfield, John W. AustinAbstract:To determine the safety of a high moisture bakery product, packaged under modified atmospheres, challenge studies were done on English-style crumpets (water activity [a(w)] 0.990, pH 6.5) inoculated postbaking with Clostridium botulinum types A and proteolytic B spores (5 X 10(2) spores/g). Products were packaged either in air, in air with an Ageless FX200 oxygen absorbent, or in a CO2/N2 (60:40) gas mixture, stored at ambient temperature (25 degrees C), and monitored for toxicity daily. All inoculated crumpets were toxic within 4 to 6 days and were organoleptically acceptable at the time of Toxigenesis. Counts of C. botulinum increased to approximately 10(5) CFU/g at the time of toxicity. To determine the effect of baking on product safety, subsequent challenge studies were done on crumpets inoculated with 5 x 10(2) spores/g (baked weight basis) prior to baking. All crumpets were toxic after only 6 days, irrespective of packaging conditions, and Toxigenesis again preceded spoilage. Temperature profile studies showed that the maximum internal temperature reached during baking was 97 degrees C, and the total baking process was equivalent to 0.03 min at 121 degrees C. The actual time to toxin production in both studies (4 to 6 days) correlated well with the predicted time (3.4 days) using the U.S. Department of Agriculture Pathogen Modeling Program (version 5.1) for proteolytic strains of C. botulinum. These studies confirm that high moisture bakery products, if contaminated with C. botulinum spores either pre- or postbaking, could pose a public health hazard, if packaged in air (in a high gas barrier package where O2 was depleted and CO2 was generated during storage) or under modified atmosphere packaging conditions and stored at ambient temperature.
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CHALLENGE STUDIES WITH CLOSTRIDIUM BOTULINUM TYPE E IN A VALUE‐ADDED SURIMI PRODUCT STORED UNDER A MODIFIED ATMOSPHERE
Journal of Food Safety, 1998Co-Authors: André Lyver, James P. Smith, John W. Austin, F.m. Nattress, Burke BlanchfieldAbstract:Challenge studies were carried out on raw, cooked, and sterilized surimi nuggets, inoculated with 10 -1 spores/g of C. botulinum type E spores. All products were packaged in air and air with an Ageless SS oxygen absorbent and stored at 4, 12 and 25C. Toxin was not detected in any raw product throughout storage (28 days). The absence ofToxigenesis was attributed to the low pH (4.1-4.3) due mainly to the growth of lactic acid bacteria (10 7 CFU/g). Toxin was also not detected in any cooked product after 28 days. Product pH did not decrease as previously (due to the absence Of LAB), but counts of C. botulinum still decreased throughout storage. In sterile nuggets, C. botulinum counts increased to 10 6 cfu/g at both 12 and 25C, respectively, by 28 days. Lactic acid bacteria and Bacillus spp. were not detected throughout the 28 days storage period. Toxin was detected by days 28 and 14 at 12 and 25C, respectively, and Toxigenesis preceded spoilage. The absence of toxin in cooked nuggets was attributed to the anti-botulinal role by Bacillus species, the predominant spoilage bacteria in cooked nuggets.
Burke Blanchfield - One of the best experts on this subject based on the ideXlab platform.
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EFFECT OF FILMS OF DIFFERENT OXYGEN TRANSMISSION RATE ON TOXIN PRODUCTION BY CLOSTRIDIUM BOTULINUM TYPE E IN VACUUM PACKAGED COLD AND HOT SMOKED TROUT FILLETS
Journal of Food Safety, 2000Co-Authors: Isabelle Dufresne, James P. Smith, Ilsemarie Tarte, Burke Blanchfield, John W. AustinAbstract:Studies were done to determine the effect of film oxygen transmission rate (OTR) on the time to toxicity in vacuum packaged cold and hot smoked rainbow trout fillets challenged with C. botulinum type E (10 2 spores/g) and stored at refrigerated conditions (4C), and under mild (8C) and moderate (12C) temperature abuse conditions. While no samples were toxic at 4C, toxin was detected within 28 days at 8C for cold smoked trout fillets vacuum packaged in films with high OTR. Toxin was also detected for most vacuum packaged hot smoked trout fillets within 14-28 days at 8C, with the exception of trout fillets packaged in films with an OTR > 10,000 cc/m 2 /day. In most cases at 8C, spoilage, based on odor/color scores, preceded or occurred simultaneously with Toxigenesis. At 12C all cold and hot smoked trout were toxic after 14-21 days and samples packaged in films with an OTR
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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
Journal of Food Safety, 2000Co-Authors: Isabelle Dufresne, James P. Smith, Ilsemarie Tarte, Burke Blanchfield, John W. AustinAbstract:Studies were conducted to determine the effect of various levels of headspace oxygen (0-100%, balance CO 2 ) 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 (10 2 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/m 2 /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 O 2 , 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 O 2 or film transmission rate, need to be considered to ensure the safety of MAP trout fillets, particularly at moderate temperature abuse conditions.
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Effect of pH and CO2 on growth and toxin production by Clostridium botulinum in English-style crumpets packaged under modified atmospheres
Journal of food protection, 1999Co-Authors: Daphne Phillips Daifas, James P. Smith, Burke Blanchfield, John W. AustinAbstract:The effect of pH and CO2 on both growth of and toxin production by Clostridium botulinum in English-style crumpets, packaged under modified atmospheres was investigated using a 2 x 2 factorial experiment. English-style crumpets (water activity, 0.990; pH 6.5 and 8.3) were inoculated with C. botulinum spores types A and proteolytic B (500 spores/g), packaged in either 60% CO2 (balance N2) or 100% CO2, stored at ambient temperature (25 degrees C), and monitored daily for toxicity. Toxin was detected after 4 days in crumpets packaged in 60% CO2, irrespective of initial product pH. Toxin production was delayed 1.5 to 3 days in crumpets packaged under 100% CO2. Analysis of variance indicated a significant interaction effect of pH and %CO2 on time of earliest toxin detection. Delay of toxin production was greatest for high pH (8.3) crumpets. All products were organoleptically acceptable at the time of Toxigenesis, and therefore, high moisture-high pH bakery products, if contaminated with spores of C. botulinum, could become hazardous if packaged in atmospheres containing CO2.
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Growth and toxin production by Clostridium botulinum in English-style crumpets packaged under modified atmospheres.
Journal of food protection, 1999Co-Authors: Daphne Phillips Daifas, James P. Smith, Burke Blanchfield, John W. AustinAbstract:To determine the safety of a high moisture bakery product, packaged under modified atmospheres, challenge studies were done on English-style crumpets (water activity [a(w)] 0.990, pH 6.5) inoculated postbaking with Clostridium botulinum types A and proteolytic B spores (5 X 10(2) spores/g). Products were packaged either in air, in air with an Ageless FX200 oxygen absorbent, or in a CO2/N2 (60:40) gas mixture, stored at ambient temperature (25 degrees C), and monitored for toxicity daily. All inoculated crumpets were toxic within 4 to 6 days and were organoleptically acceptable at the time of Toxigenesis. Counts of C. botulinum increased to approximately 10(5) CFU/g at the time of toxicity. To determine the effect of baking on product safety, subsequent challenge studies were done on crumpets inoculated with 5 x 10(2) spores/g (baked weight basis) prior to baking. All crumpets were toxic after only 6 days, irrespective of packaging conditions, and Toxigenesis again preceded spoilage. Temperature profile studies showed that the maximum internal temperature reached during baking was 97 degrees C, and the total baking process was equivalent to 0.03 min at 121 degrees C. The actual time to toxin production in both studies (4 to 6 days) correlated well with the predicted time (3.4 days) using the U.S. Department of Agriculture Pathogen Modeling Program (version 5.1) for proteolytic strains of C. botulinum. These studies confirm that high moisture bakery products, if contaminated with C. botulinum spores either pre- or postbaking, could pose a public health hazard, if packaged in air (in a high gas barrier package where O2 was depleted and CO2 was generated during storage) or under modified atmosphere packaging conditions and stored at ambient temperature.
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CHALLENGE STUDIES WITH CLOSTRIDIUM BOTULINUM TYPE E IN A VALUE‐ADDED SURIMI PRODUCT STORED UNDER A MODIFIED ATMOSPHERE
Journal of Food Safety, 1998Co-Authors: André Lyver, James P. Smith, John W. Austin, F.m. Nattress, Burke BlanchfieldAbstract:Challenge studies were carried out on raw, cooked, and sterilized surimi nuggets, inoculated with 10 -1 spores/g of C. botulinum type E spores. All products were packaged in air and air with an Ageless SS oxygen absorbent and stored at 4, 12 and 25C. Toxin was not detected in any raw product throughout storage (28 days). The absence ofToxigenesis was attributed to the low pH (4.1-4.3) due mainly to the growth of lactic acid bacteria (10 7 CFU/g). Toxin was also not detected in any cooked product after 28 days. Product pH did not decrease as previously (due to the absence Of LAB), but counts of C. botulinum still decreased throughout storage. In sterile nuggets, C. botulinum counts increased to 10 6 cfu/g at both 12 and 25C, respectively, by 28 days. Lactic acid bacteria and Bacillus spp. were not detected throughout the 28 days storage period. Toxin was detected by days 28 and 14 at 12 and 25C, respectively, and Toxigenesis preceded spoilage. The absence of toxin in cooked nuggets was attributed to the anti-botulinal role by Bacillus species, the predominant spoilage bacteria in cooked nuggets.
Daphne Phillips Daifas - One of the best experts on this subject based on the ideXlab platform.
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Effect of pH and CO2 on growth and toxin production by Clostridium botulinum in English-style crumpets packaged under modified atmospheres
Journal of food protection, 1999Co-Authors: Daphne Phillips Daifas, James P. Smith, Burke Blanchfield, John W. AustinAbstract:The effect of pH and CO2 on both growth of and toxin production by Clostridium botulinum in English-style crumpets, packaged under modified atmospheres was investigated using a 2 x 2 factorial experiment. English-style crumpets (water activity, 0.990; pH 6.5 and 8.3) were inoculated with C. botulinum spores types A and proteolytic B (500 spores/g), packaged in either 60% CO2 (balance N2) or 100% CO2, stored at ambient temperature (25 degrees C), and monitored daily for toxicity. Toxin was detected after 4 days in crumpets packaged in 60% CO2, irrespective of initial product pH. Toxin production was delayed 1.5 to 3 days in crumpets packaged under 100% CO2. Analysis of variance indicated a significant interaction effect of pH and %CO2 on time of earliest toxin detection. Delay of toxin production was greatest for high pH (8.3) crumpets. All products were organoleptically acceptable at the time of Toxigenesis, and therefore, high moisture-high pH bakery products, if contaminated with spores of C. botulinum, could become hazardous if packaged in atmospheres containing CO2.
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Growth and toxin production by Clostridium botulinum in English-style crumpets packaged under modified atmospheres.
Journal of food protection, 1999Co-Authors: Daphne Phillips Daifas, James P. Smith, Burke Blanchfield, John W. AustinAbstract:To determine the safety of a high moisture bakery product, packaged under modified atmospheres, challenge studies were done on English-style crumpets (water activity [a(w)] 0.990, pH 6.5) inoculated postbaking with Clostridium botulinum types A and proteolytic B spores (5 X 10(2) spores/g). Products were packaged either in air, in air with an Ageless FX200 oxygen absorbent, or in a CO2/N2 (60:40) gas mixture, stored at ambient temperature (25 degrees C), and monitored for toxicity daily. All inoculated crumpets were toxic within 4 to 6 days and were organoleptically acceptable at the time of Toxigenesis. Counts of C. botulinum increased to approximately 10(5) CFU/g at the time of toxicity. To determine the effect of baking on product safety, subsequent challenge studies were done on crumpets inoculated with 5 x 10(2) spores/g (baked weight basis) prior to baking. All crumpets were toxic after only 6 days, irrespective of packaging conditions, and Toxigenesis again preceded spoilage. Temperature profile studies showed that the maximum internal temperature reached during baking was 97 degrees C, and the total baking process was equivalent to 0.03 min at 121 degrees C. The actual time to toxin production in both studies (4 to 6 days) correlated well with the predicted time (3.4 days) using the U.S. Department of Agriculture Pathogen Modeling Program (version 5.1) for proteolytic strains of C. botulinum. These studies confirm that high moisture bakery products, if contaminated with C. botulinum spores either pre- or postbaking, could pose a public health hazard, if packaged in air (in a high gas barrier package where O2 was depleted and CO2 was generated during storage) or under modified atmosphere packaging conditions and stored at ambient temperature.