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

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.

2004 ◽  
Vol 67 (8) ◽  
pp. 1765-1769 ◽  
Author(s):  
KATHLEEN A. GLASS ◽  
ERIC A. JOHNSON

Ingredients used in the manufacture of reduced-fat process cheese products were screened for their ability to inhibit growth of Clostridium botulinum serotypes A and B in media. Reinforced clostridial medium (RCM) supplemented with 0,0.5, 1, 2, 3, 5, or 10% (wt/vol) of various ingredients, including a carbohydrate-based fat replacer, an enzyme-modified cheese (EMC) derived from a Blue cheese, sweet whey, modified whey protein, or whey protein concentrate, did not inhibit botulinal growth and toxin production when stored at 30°C for 1 week. In contrast, RCM supplemented with 10% soy-based flavor enhancer, 10% Parmesan EMC, or 5 or 10% Cheddar EMC inhibited botulinal toxin production in media for at least 6 weeks of storage at 30°C. Subsequent trials revealed that the antibotulinal effect varied significantly among 13 lots of EMC and that the antimicrobial effect was not correlated with the pH or water activity of the EMC.


1986 ◽  
Vol 49 (7) ◽  
pp. 526-531 ◽  
Author(s):  
N. TANAKA ◽  
E. TRAISMAN ◽  
P. PLANTINGA ◽  
L. FINN ◽  
W. FLOM ◽  
...  

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.


1987 ◽  
Vol 50 (3) ◽  
pp. 212-217 ◽  
Author(s):  
S. L. CUPPETT ◽  
J. I. GRAY ◽  
J. J. PESTKA ◽  
A. M. BOOREN ◽  
J. F. PRICE ◽  
...  

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.


2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Giuseppe Merialdi ◽  
Mattia Ramini ◽  
Giovanni Parolari ◽  
Silvana Barbuti ◽  
Maria Angela Frustoli ◽  
...  

The objective of this study was to investigate <em>Clostridium botulinum</em> growth and toxin production in the industrially manufactured Italian Parma ham. The study focuses on the Parma ham production phase identified as maximum risk to <em>C. botulinum</em> proliferation, <em>i.e.</em> the transition from cold phase (salting and resting) to a phase carried out at temperature between 15 and 23°C (drying). A preliminary in vitro test was carried out in order to verify the capability of 6 <em>C. botulinum</em> strains (1 type A, 4 type B, and 1 type E strains) to grow in conditions of temperature, pH and NaCl concentration comparable to those of the beginning stage of ham drying. Five <em>C. botulinum</em> strains grew at 20°C and pH 6, four strains produced toxin when inoculated at a concentration equal to 10<sup>3</sup> cfu/mL at NaCl concentration of 4%, while when the inoculum concentration was 10 cfu/mL, NaCl concentration of 3% resulted the toxin-genesis limiting factor. An experimental contamination with a mixture of the 5 <em>C. botulinum</em> strains selected by the preliminary in vitro test was performed on 9 thighs inoculated at the end of the resting phase. The study was designed to evaluate the potential growth and toxin production in extremely favourable conditions for the bacterium. Type B proteolytic <em>C. botulinum</em> toxin was produced after 14 days of incubation at 20°C in 2 thighs characterised by high weight, low number of days of resting and anomalous physiochemical characteristics [one for very low NaCl concentration (1.59%), the other for elevated pH (6.27) and both for high water activity values (&gt;0.970)]. The results of this research confirm that the cold resting step is a critical phase in the production process of Parma ham for the investigated hazard. Based on the present study, the long resting phase adopted in the manufacturing of Parma ham is proven effective to prevent the growth of <em>C. botulinum</em>, an event which could not otherwise be excluded if the hams were processed under less stringent technological conditions.


1991 ◽  
Vol 54 (3) ◽  
pp. 162-165 ◽  
Author(s):  
KATHLEEN A. GLASS ◽  
MICHAEL P. DOYLE

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.


1994 ◽  
Vol 57 (4) ◽  
pp. 295-300 ◽  
Author(s):  
KARL F. ECKNER ◽  
WENDY A. DUSTMAN ◽  
ANNA A. RYŚ-RODRIGUEZ

Pasteurized process cheese spread was manufactured with moisture contents of 52, 54, 56 and 60%. Three different types of phosphate emulsifier were used, disodium ortho-phosphate and two commercially-available polyphosphates, S9 and S9H. Pasteurized, processed cheese spreads were inoculated with approximately 1 × 104 Clostridium botulinum spores/gram cheese in the cook kettle, held 3 min at 80°C, hot-filled into glass containers, and incubated at 30°C. Samples were analyzed over 30 weeks for growth of C. botulinum and toxigenesis. Toxin was first detected in 60% moisture cheese with disodium ortho-phosphate as the emulsifier at 8 weeks and in 60% moisture cheese with the test polyphosphates as the emulsifier when tested at 20 weeks. None of the other cheese formulations were toxic at 20 weeks. Toxin production correlated statistically to time, moisture, pH and phosphate type.


2010 ◽  
Vol 73 (5) ◽  
pp. 993-1002 ◽  
Author(s):  
IRVING J. PFLUG

The incidence of botulism in canned food in the last century is reviewed along with the background science; a few conclusions are reached based on analysis of published data. There are two primary aspects to botulism control: the design of an adequate process and the delivery of the adequate process to containers of food. The probability that the designed process will not be adequate to control Clostridium botulinum is very small, probably less than 1.0 × 10−6, based on containers of food, whereas the failure of the operator of the processing equipment to deliver the specified process to containers of food may be of the order of 1 in 40, to 1 in 100, based on processing units (retort loads). In the commercial food canning industry, failure to deliver the process will probably be of the order of 1.0 × 10−4 to 1.0 × 10−6 when U.S. Food and Drug Administration (FDA) regulations are followed. Botulism incidents have occurred in food canning plants that have not followed the FDA regulations. It is possible but very rare to have botulism result from postprocessing contamination. It may thus be concluded that botulism incidents in canned food are primarily the result of human failure in the delivery of the designed or specified process to containers of food that, in turn, result in the survival, outgrowth, and toxin production of C. botulinum spores. Therefore, efforts in C. botulinum control should be concentrated on reducing human errors in the delivery of the specified process to containers of food.


2002 ◽  
Vol 65 (1) ◽  
pp. 130-139 ◽  
Author(s):  
M. E. PETERSON ◽  
R. N. PARANJPYE ◽  
F. T. POYSKY ◽  
G. A. PELROY ◽  
M. W. EKLUND

Water phase sodium chloride (WPS) levels of 1.8 to 3.0% in combination with heat pasteurization for 15 min at temperatures of 75, 80, 85, and 90°C were evaluated as methods for the inactivation or inhibition of nonproteolytic, psychrotrophic Clostridium botulinum types B and E in crab analogs (imitation crab legs) subsequently stored at 10 and 25°C. Samples inoculated with 102 type B or E spores per g prior to pasteurization remained nontoxic for 120 days at 10°C and for 15 days at 25°C. With 104 type E spores per g and 80°C pasteurization, ≥2.4 and 2.7% WPS was required for inhibition at 10 and 25°C storage, respectively. Pasteurization at 85°C decreased the inhibitory level of WPS to 2.1% at 10°C and to 2.4% at 25°C. When the inoculum was 104 type B spores per g, samples with 2.7% WPS were toxic after 80 days of storage at 10°C. Samples inoculated with 103 type B spores per g and processed at 85°C remained nontoxic for 15 days at 25°C with a WPS of ≥2.4%. When pasteurization was carried out before inoculation and packaging, 1.8% WPS prevented toxin production by 102 and 104 type E spores per g for 30 days at 10°C, and this time period increased as the WPS concentrations increased. Three percent WPS prevented toxin production by 104 type E spores per g in vacuum-packaged analogs stored 110 days at 10°C. Pasteurization processes used in these experiments, however, do not inactivate the heat-resistant proteolytic types of Clostridium botulinum. Therefore, the most important factor controlling the growth of this bacterium is continuous refrigeration below 3.0°C or frozen storage of the finished product.


1987 ◽  
Vol 50 (4) ◽  
pp. 330-336 ◽  
Author(s):  
GENERO W. GARCIA ◽  
CONSTANTIN GENIGEORGIS ◽  
SEPPO LINDROTH

In factorial design experiments we inoculated fresh salmon fillets with a spore pool of 13 nonproteolytic strains of Clostridium botulinum type B, E, and F at 6 levels (10−1 to 104/50 g of fillet), and incubated at 1, 4, 8, 12 and 30°C under modified atmospheres (MA) of vacuum, 100% CO2 and 70% CO2 + 30% air for up to 60 d. The earliest time we detected toxin in the fillets at 30, 12 and 8°C, irrespective of MA, was after 1, 3–9 and 6–12 d of storage and required 100–103, 101–103, 101–102 spores/fillet. The probability (P) of toxin production was significantly (P&lt;0.05) affected by temperature (T), MA storage time (ST), MA × T, MA × ST and T × ST. Only type B toxin was detected in the toxic fillets. No toxin was detected in fillets stored at 4°C for up to 60 d. Toxin detection coincided with spoilage at 30°C, but preceded spoilage at 8 and 12°C, and followed spoilage at 4°C. Using linear and logistic regression analysis, best fit equations were derived relating the length of the lag phase and P of toxin production to T, ST, MA and spore inoculum level.


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