Relationship Between Water Activity of Fresh Pasta and Toxin Production by Proteolytic Clostridium botulinum

1991 ◽  
Vol 54 (3) ◽  
pp. 162-165 ◽  
Author(s):  
KATHLEEN A. GLASS ◽  
MICHAEL P. DOYLE
Keyword(s):  
Water Activity ◽  
Clostridium Botulinum ◽  
Toxin Production ◽  
Principal Factor ◽  
Modified Atmosphere ◽  
Fresh Pasta ◽  
Sampling Times

Four types of fresh pasta (meat- or cheese-filled tortellini and flat noodle linguine or fettucine) were prepared with different water activities, inoculated with proteolytic Clostridium botulinum spores, packaged under a modified atmosphere, and stored at either 4 or 30°C for 8 to 10 weeks. Products were assayed for botulinal toxin at appropriate sampling times. No toxin was detected in any fresh pasta held at 4°C for up to 8 weeks. However, toxin was detected in meat tortellini with aw of 0.99 and 0.95 at 2 and 6 weeks, respectively, when held at 30°C. Toxin was not detected in tortellini with an aw of 0.94 or below held at 30°C for 10 weeks. Toxin was produced at 2 weeks in linguine at aw 0.96 and held at 30°C, whereas no linguine or fettucine at aw 0.93 or 0.95 and held at 30°C was toxic during 10 or 8 weeks, respectively. The aw of fresh pasta is a principal factor in preventing botulinal toxin production by proteolytic C. botulinum in temperature-abused products. A survey of commercially available fresh pasta revealed that most flat noodles were below the aw limit for botulinal toxin production, whereas most of the filled pasta had aw values which permitted toxin production if temperature abuse occurred.

A Survey of Water Activity and pH Values in Fresh Pasta Packed under Modified Atmosphere Manufactured in Argentina and Uruguay

2000 ◽  
Vol 63 (7) ◽  
pp. 965-969 ◽  
Author(s):  
CAROLINA SCHEBOR ◽  
JORGE CHIRIFE
Keyword(s):  
Water Activity ◽  
Clostridium Botulinum ◽  
Modified Atmosphere ◽  
Ph Values ◽  
Fresh Pasta

The water activity (aw) and pH values of commercially available filled fresh pasta and gnocchi packed under modified atmosphere and manufactured in Argentina and Uruguay were examined. The retail survey included 58 samples (several brands) of filled pasta and 11 samples of gnocchi. Fillings consisted of different combinations of cheese (various types), beef, ricotta, ham, chicken, and spinach. The survey revealed that the aw values of the 58 samples of filled pasta ranged from 0.916 to 0.973, and their pH values ranged from 5.2 to 7.0. The aw of gnocchi was consistently higher and ranged from 0.936 to 0.983, with pH values from 4.8 to 6.4. Some samples of filled pasta and most gnocchi samples were found to have aw and pH values that would support growth of spores of Clostridium botulinum, if present, under conditions of temperature abuse (i.e., 30 °C).

Effect of Salt Level and Nitrite on Toxin Production by Clostridium botulinum Type E Spores in Smoked Great Lakes Whitefish1

1987 ◽  
Vol 50 (3) ◽  
pp. 212-217 ◽  
Author(s):  
S. L. CUPPETT ◽  
J. I. GRAY ◽  
J. J. PESTKA ◽  
A. M. BOOREN ◽  
J. F. PRICE ◽  
...  
Keyword(s):  
Great Lakes ◽  
Water Activity ◽  
Salt Concentration ◽  
Clostridium Botulinum ◽  
Toxin Production ◽  
Water Phase ◽  
Salt Level ◽  
Botulinum Type ◽  
Clostridium Botulinum Type E ◽  
Average Water

The effect of salt level and nitrite on botulinal safety of smoked whitefish was investigated. An average water-phase (wp) salt concentration of 4.4% inhibited outgrowth of Clostridium botulinum type E spores (103 spores/g) for over 35 d in temperature-abused (27°C) smoked whitefish. Incorporation of nitrite (220 mg/kg) during brining to the smoked salted (4.4%, wp) whitefish inhibited toxin production for 56 d at 27°C. An average salt concentration of 6.2% (wp), with or without nitrite, totally inhibited toxin production for the duration of the study (83 d). The effect of pH and water activity in temperature-abused smoked whitefish as a means of controlling toxin production by C. botulinum type E spores was evaluated.

Toxin Production by Clostridium botulinum Type E in Packaged Channel Catfish

1997 ◽  
Vol 60 (11) ◽  
pp. 1358-1363 ◽  
Author(s):  
PING CAI ◽  
MARK A. HARRISON ◽  
YAO-WEN HUANG ◽  
JUAN L. SILVA
Keyword(s):  
Channel Catfish ◽  
Clostridium Botulinum ◽  
Modified Atmosphere Packaging ◽  
Toxin Production ◽  
Storage Conditions ◽  
Mouse Bioassay ◽  
Modified Atmosphere ◽  
Oxygen Barrier ◽  
Botulinum Type ◽  
Clostridium Botulinum Type E

Channel catfish were inoculated with 3 to 4 log spores/g of a mixed pool of four strains of C. botulinum type E (Beluga, Minnesota, G21-5, and 070) and were packaged with an oxygen-permeable overwrap, in an oxygen-barrier bag with a modified atmosphere of CO2-N2 (80:20) or in a master bag with the same modified atmosphere. Packaged fish were stored at either 4°C and sampled at intervals over 30 days or at 10°C and sampled at intervals over 12 days. An additional master bag treatment in which overwrap-packaged catfish was stored first at 4°C, then removed from the master bags and stored at 10°C, was sampled at intervals over 18 days. Toxin production was evaluated using the mouse bioassay. Aerobic psychrotrophic and anaerobic populations were enumerated, and product spoilage characteristics were noted. Under abusive storage conditions of 10°C, there was no difference among the potential for toxin production in the packaged fish, with botulinum toxin detected on fish from each package type by day 6. At 4°C, toxin production was detected on day 9 in the overwrapped packages, while it was on day 18 in the modified atmosphere packaging. No toxin was found in the master bags held continually at 4°C. Toxin was detected on day 18 from samples initially held at 4°C in the master bag and subsequently held at 10°C. Spoilage preceded toxin production for samples stored at 4°C for each type of packaging. At 10°C, spoilage and toxin detection times coincided.

Growth and Toxin Production by Clostridium botulinum in Steamed Rice Aseptically Packed under Modified Atmosphere

2005 ◽  
Vol 68 (5) ◽  
pp. 1005-1011 ◽  
Author(s):  
YOSHIAKI KASAI ◽  
BON KIMURA ◽  
SUSUMU KAWASAKI ◽  
TETSUYA FUKAYA ◽  
KINYA SAKUMA ◽  
...  
Keyword(s):  
Clostridium Botulinum ◽  
Toxin Production ◽  
Modified Atmosphere ◽  
Atmospheric Conditions ◽  
Low Oxygen ◽  
Three Samples ◽  
Two Samples ◽  
Oxygen Conditions ◽  
Rice Water ◽  
Foodborne Botulism

Sales and consumption of ready-to-eat aseptic steamed rice products have increased manyfold in Japan over the past 10 years. To determine the safety of steamed rice (water content 60%, pH 6.5) aseptically packaged under modified atmosphere, challenge studies were performed using a mixture of Clostridium botulinum proteolytic strains (five strains of type A and five strains of type B). Atmospheric conditions of 0 and 15% oxygen (with 5% CO2 and 5% N2 as the balance) were used. No neurotoxins were detected, and organoleptically acceptable conditions persisted for 24 weeks at 15% oxygen conditions. However, botulinum neurotoxin was found in one of three samples at 12 weeks and in one of two samples at 24 weeks at 0% oxygen and 30°C. When samples were inoculated with C. botulinum with amylase (0% oxygen), neurotoxin and sample spoilage was detected after only 1 week of storage. Challenge studies using proteolytic strains of C. botulinum mixed with Bacillus subtilis (amylase formers) also were performed with atmosphere conditions of oxygen at 0, 5, 10, and 15% (with 5% CO2 and 5% N2 as the balance). Under 10 and 15% oxygen conditions, neurotoxin was not detected after 1 week of storage, but sample spoilage was detected after the same period. Under 0% oxygen conditions, neurotoxin was detected at 1 week, but the sample remained organoleptically acceptable even after 2 weeks of storage. Both neurotoxin and sample spoilage were detected at 1 week of storage under 5% oxygen conditions. Based on these results, cocontamination of amylase-producing Bacillus with C. botulinum would increase the risk of foodborne botulism when aseptic rice samples are packed under low-oxygen conditions (<5%). Therefore, to ensure the safety of these products, packing under atmospheric containing more than 10% oxygen is recommended.

Shelf Life and Toxin Development by Clostridium botulinum during Storage of Modified-Atmosphere- Packaged Fresh Aquacultured Salmon Fillets

1997 ◽  
Vol 60 (9) ◽  
pp. 1055-1063 ◽  
Author(s):  
N. R. REDDY ◽  
H. M. SOLOMON ◽  
H. YEP ◽  
M. G. ROMAN ◽  
E. J. RHODEHAMEL
Keyword(s):  
Shelf Life ◽  
Clostridium Botulinum ◽  
Storage Temperature ◽  
Toxin Production ◽  
Modified Atmosphere ◽  
Surface Ph ◽  
Modified Atmospheres ◽  
C Storage ◽  
Clostridium Botulinum Type E ◽  
Time To Onset

Shelf life (onset of sensory spoilage) and the potential for toxin production by Clostridium botulinum type E in retail-type packages of fresh aquacultured salmon fillets packaged in high-barrier film bags under selected atmospheres (100% air, a modified atmosphere containing 75% CO2:25% N2, and vacuum) and stored under refrigeration (4°C) and temperature-abuse conditions (8 and 16°C) were investigated. Chemical spoilage indicators (trimethylamine and surface pH) and microbial populations were compared with sensory spoilage characteristics. Storage temperature influenced the time to onset of both sensory spoilage and toxin development in salmon fillets packaged in all atmospheres. The shelf life of fillets packaged in all atmospheres decreased with increase of storage temperature from 4 to 16°C. Trimethylamine content associated with the onset of spoilage for 100% air-packaged fillets increased as storage temperature increased. However, for modified-atmosphere-packaged fillets, the trimethylamine content associated with the onset of spoilage increased as storage temperature decreased from 8 to 4°C. Surface pH was not a good spoilage indicator for modified-atmosphere-packaged fillets. Toxin development preceded sensory spoilage at 16°C storage for fillets packaged in modified atmospheres. Toxin development coincided with sensory spoilage or was slightly delayed for the fillets packaged in all the atmospheres at 8°C storage. At 4°C none of the fillets packaged in either of the atmospheres developed toxin, even 20 days after spoilage as determined by sensory characteristics.

Effect of Sodium Lactate on Toxin Production, Spore Germination and Heat Resistance of Proteolytic Clostridium botulinum Strains

1994 ◽  
Vol 57 (4) ◽  
pp. 327-330 ◽  
Author(s):  
P.C. HOUTSMA ◽  
A. HEUVELINK ◽  
J. DUFRENNE ◽  
S. NOTERMANS
Keyword(s):  
Water Activity ◽  
Low Temperatures ◽  
Clostridium Botulinum ◽  
Thermal Destruction ◽  
Incubation Temperature ◽  
Toxin Production ◽  
Inhibitory Effect ◽  
Sodium Lactate ◽  
Medium Ph ◽  
Yeast Extract Medium

The effect of sodium lactate and sodium lactate combined with sodium chloride (NaCl) on toxin production by proteolytic strains of Clostridium botulinum was determined in peptone-yeast extract medium, pH 6.1. Both inhibitors were also tested for their effect on thermal destruction of spores. Additionally, the effect of sodium lactate on germination of spores was assessed. The inhibitory effect of sodium lactate was dependent on the applied incubation temperature. The best inhibition was obtained at low temperatures. Toxin production was delayed at 15 and 20°C by sodium lactate concentrations of 2 and 2.5%, respectively. Complete inhibition of toxin production at 15, 20 and 30°C occurred at concentrations of 3, 4 and >4%, respectively. Further, sodium lactate inhibited germination of the C. botulinum spores, which may partially explain the inhibitory effect of sodium lactate on growth and toxin formation. The inhibitory effect of NaCl at concentrations resulting in an identical water activity value as obtained by sodium lactate was negligible, indicating that the inhibitory effect of sodium lactate was not caused by decreasing water activity. No clear synergistic effect of sodium lactate (1.5 or 2.5%) and NaCl (2.1%) was observed.

Evaluation of Factors Involved in Antibotulinal Properties of Pasteurized Process Cheese Spreads

1986 ◽  
Vol 49 (7) ◽  
pp. 526-531 ◽  
Author(s):  
N. TANAKA ◽  
E. TRAISMAN ◽  
P. PLANTINGA ◽  
L. FINN ◽  
W. FLOM ◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Water Activity ◽  
Clostridium Botulinum ◽  
Toxin Production ◽  
Inhibitory Effect ◽  
Low Ph ◽  
Disodium Phosphate ◽  
Minimum Number ◽  
Process Cheese ◽  
Design Experiments

Pasteurized process cheese spreads with various levels of sodium chloride, disodium phosphate, moisture and pH were challenged with spores of Clostridium botulinum types A and B. Response surface methodology was used to design experiments that would yield maximum results with the minimum number of trials. Supplemental experiments were added to further clarify the response and to examine combinations of special interest. A total of 304 treatment combinations (batches) was incubated at 30°C, and five samples from each batch were taken at predetermined intervals up to 42 wk of incubation and tested for botulinal toxin. Sodium chloride and disodium phosphate inhibited botulinal toxin production with similar effectiveness. The inhibitory effect of low pH (<5.7) and low moisture (<54%) levels on botulinal toxin production was as expected, i.e., as either pH or moisture went up, it was necessary to increase sodium chloride and/or phosphate concentrations to compensate. Differences in water activity between cheese spreads with different compositions were observed but they were too small to use for controlling the properties of the products, e.g., a range of 9% in moisture level (51 to 60%) produced only 0.022 variation in water activity. Combinations of the above factors were developed for safe pasteurized process cheese spreads containing up to 60% moisture.

Botulism Challenge Studies of a Modified Atmosphere Package for Fresh Mussels: Inoculated Pack Studies

2012 ◽  
Vol 75 (6) ◽  
pp. 1157-1166 ◽  
Author(s):  
C. R. NEWELL ◽  
LI MA ◽  
MICHAEL DOYLE
Keyword(s):  
Lactic Acid ◽  
Botulinum Toxin ◽  
Shelf Life ◽  
Storage Temperature ◽  
Modified Atmosphere Packaging ◽  
Toxin Production ◽  
Modified Atmosphere ◽  
Gas Composition ◽  
Plate Counts ◽  
Sampling Times

A series of botulism challenge studies were performed to determine the possibility of production of botulinum toxin in mussels (Mytilus edulis) held under a commercial high-oxygen (60 to 65% O2), modified atmosphere packaging (MAP) condition. Spore mixtures of six strains of nonproteolytic Clostridium botulinum were introduced into mussel MAP packages receiving different packaging buffers with or without the addition of lactic acid bacteria. Dye studies and package flipping trials were conducted to ensure internalization of spores by packed mussels. Inoculated mussel packages were stored at normal (4°C) and abusive (12°C) temperatures for 21 and 13 days, respectively, which were beyond the packaged mussels' intended shelf life. Microbiological and chemical analyses were conducted at predetermined intervals (a total of five sampling times at each temperature), including total aerobic plate counts, C. botulinum counts, lactic acid bacterial counts, package headspace gas composition, pH of packaging buffer and mussel meat, and botulinum toxin assays of packaging buffer and mussel meat. Results revealed that C. botulinum inoculated in fresh mussels packed under MAP packaging did not produce toxin, even at an abusive storage temperature and when held beyond their shelf life. No evidence was found that packaging buffers or gas composition influenced the lack of botulinum toxin production in packed mussels.

Incidence of Clostridium botulinum in Vegetables Packaged under Vacuum or Modified Atmosphere

1996 ◽  
Vol 59 (1) ◽  
pp. 59-61 ◽  
Author(s):  
TIMOTHY LILLY ◽  
HAIM M. SOLOMON ◽  
E. JEFFERY RHODEHAMEL
Keyword(s):  
Clostridium Botulinum ◽  
Type A ◽  
Toxin Production ◽  
Mouse Bioassay ◽  
Modified Atmosphere ◽  
Type B ◽  
Green Pepper ◽  
Botulinum Type ◽  
Negative Controls ◽  
Anaerobic Environment

Because modified atmosphere-packaged (MAP) vegetables may provide an anaerobic environment conducive to Clostridium botulinum growth and toxin production, the incidence of C. botulinum spores in commercially available, precut MAP vegetables was determined. One-pound (454-g) packages of MAP vegetables were aseptically opened, added to freshly steamed and cooled sterile trypticase-peptone-glucose-yeast extract broth and incubated at 35°C for 7 days. Positive and negative controls were included with each sampling. After incubation the broth cultures were tested for toxicity by the standard mouse bioassay. Of the 1,118 MAP vegetable packages examined, one package each of shredded cabbage, chopped green pepper, and Italian salad mix contained C. botulinum type A spores. One additional salad mix (main ingredient, escarole) contained both C. botulinum type A and type B spores. Results indicated a low overall incidence rate (0.36%) of C. botulinum spores in commercially available precut MAP vegetables.

Toxin Production by Clostridium botulinum in Shelf-Stable Pasteurized Process Cheese Spreads

1979 ◽  
Vol 42 (10) ◽  
pp. 784-786 ◽  
Author(s):  
D. A. KAUTTER ◽  
T. LILLY ◽  
R. K. LYNT ◽  
H. M. SOLOMON
Keyword(s):  
Water Activity ◽  
Drug Administration ◽  
Clostridium Botulinum ◽  
Toxin Production ◽  
Good Manufacturing Practice ◽  
Type B ◽  
Blue Cheese ◽  
Canned Foods ◽  
Shelf Stable ◽  
Process Cheese

Five non-refrigerated, pasteurized process cheese spreads, considered shelf-stable, were studied for their ability to support growth and toxin production by spores of Clostridium botulinum types A and B. Based on pH and water activity (aw) Cheese with Bacon, Limburger, Cheese Whiz, Old English, and Roka Blue cheese spreads were selected for the study. The pH ranged from 5.05 to 6.32 and the aw from 0.930 to 0.953. Fifty jars of each cheese spread were inoculated with 24,000 spores each; an additional 50 jars of the Cheese with Bacon spread received 460 spores each. The inoculum consisted of five type A and five type B strains in 0.1 ml of 0.85% NaCl. At 35 C, 46 jars of Limburger and 48 jars of Cheese with Bacon spread, which received the greater inoculum, became toxic starting at 83 and 50 days, respectively. One jar of Cheese with Bacon spread which received 460 spores became toxic. The average toxicity of the Limburger was 3000 MLD/ml of extract as compared with 54 MLD/ml for the Cheese with Bacon spread. Results of this study will be considered in determining whether these cheese spread products should be treated as low-acid canned foods under the Good Manufacturing Practice Regulations of the Food and Drug Administration.

Sign in / Sign up

Export Citation Format

Share Document