Chapter 4 - Meat Processing Controls and Procedures
4.16 Fermentation

This page is part of the Guidance Document Repository (GDR).

Looking for related documents?
Search for related documents in the Guidance Document Repository

Fermentation relies on good control over a complex and precise combination of time, temperature, nitrites, salt concentration, pH and aw factors to ensure food safety.

4.16.1 Control Program Requirements for Fermented Meat Products

It is the operator's responsibility to develop and implement Control Programs that meet the requirements outlined in this section.

4.16.1.1 Incoming Materials

The operator must have a program in place to assess the incoming product. This program should outline specifications for the incoming ingredients.

Records of microbiological tests performed on ingredients must be available to the inspector on request.

4.16.1.2 Facility and Equipment Requirements

Equipment used in the fermentation process must be included in the operator's prerequisite control programs. These must include the following elements:

  • Temperature in the fermentation, drying and smoking chambers must be uniform and controlled to prevent any fluctuation that could impact on the safety of the final product.
  • Fermentation, drying and smoking chambers must be equipped with a shatter resistant indicating thermometer, (or equivalent), with graduations of 1°C or less. If mercury thermometers are used, their mercury columns must be free from separations. All thermometers must be located such that they can be easily read.
  • Fermentation and smoking chambers must be equipped with a recording thermometer for determining degree-hours calculations in a reliable manner. Recording thermometers are also preferable in drying and aging rooms but, in these rooms, it may be sufficient to read and record the temperatures 2 times a day.
  • Drying and aging rooms must be equipped with humidity recorders in order to prevent uncontrolled fluctuations of the relative humidity. The only alternative to an automatic humidity recorder in these rooms would be for the company to manually monitor and record ambient humidity twice a day (morning and afternoon) every day with a properly calibrated portable humidity recorder.
  • For routine monitoring, accurate measurement electronic pH meters (± 0.05 units) should be employed. It is important that the manufacturer's instructions for use, maintenance and calibration of the instrument as well as recommended sample preparation and testing be followed.
  • When the aw of a product is a critical limit set out in the HACCP plan for a meat product, accurate measurement devices must be employed. It is important that the manufacturer's instructions for use, maintenance and calibration of the instrument be followed.

4.16.1.3 Starter Culture

The operator must have a control program in place to prevent the transmission of pathogens from when using the inoculum from a previous batch (back slopping) to initiate the fermentation process of a new batch. These must include:

  • The storage temperature must be maintained at 4°C or less and a pH of 5.3 or less.
  • Samples for microbiological analysis must be taken to ensure that the process is in line with the specifications.
  • The frequency of sampling is to be adjusted according to compliance to specifications.
  • Any batch of inoculum which has a pH greater than 5.3 must be analysed to detect at least Staphylococcus aureus. Only upon satisfactory results will this inoculum be permitted for use in back slopping.

4.16.1.4 Chemical Acidification

If product is chemically acidified by addition of citric acid, gluconodelta-lactone or another chemical agent approved for this purpose, controls must be in place and records kept to ensure that a pH of 5.3 or lower is achieved by the end of the fermentation process.

4.16.1.5 Water Activity Critical Limits

The aw may be reduced by adding solutes (salt, sugar) or removing moisture.

Approximate minimum levels of aw (if considered alone) for the growth of:

molds: 0.61 to 0.96

yeasts: 0.62 to 0.90

bacteria: 0.86 to 0.97

  • Clostridium botulinum: 0.95 to 0.97
  • Clostridium perfringens: 0.95
  • Enterobacteriaceae: 0.94 to 0.97
  • Pseudomonas fluorescens: 0.97
  • Salmonella: 0.92 - 0.95
  • Staphylococcus aureus: 0.86

parasites: Trichinella spiralis will survive at an aw of 0.93 but is destroyed at an aw of 0.85 or less.

The above levels are based on the absence of other inhibitory effects such as nitrite, competitive growth, sub-optimum temperatures, etc., which may be present in meat products. In normal conditions, Staphylococcus aureus enterotoxins are not produced below aw 0.86, although in vacuum packed products this is unlikely below aw 0.89.

4.16.2 Pathogen Control

4.16.2.1 Time and Temperature for Fermented Products

The operator is required to implement a control program based on 4.16.2.1.1, Fermentation Done at a Constant Temperature (Constant Temperature Process) and 4.16.2.1.2, Fermentation Done at Different Temperatures (Variable Temperature Processes) to control pathogens.

Certain strains of the bacteria Staphylococcus aureus are capable of producing a highly heat stable toxin that causes illness in humans. Above a critical temperature of 15.6°C, Staphylococcus aureus multiplication and toxin production can take place. Once a pH of 5.3 is reached, Staphylococcus aureus multiplication and toxin production are stopped.

Degree-hours are the product of time as measured in hours at a particular temperature multiplied by the "degrees" measured in excess of 15.6°C (the critical temperature for growth of Staphylococcus aureus). Degree-hours are calculated for each temperature used in the process. The limitation of the number of degree-hours depends upon the highest temperature in the fermentation process prior to the time that a pH of 5.3 or less is attained.

The operator is encouraged to measure temperatures at the surface of the product. Where this is not possible, the operator should utilize fermentation room temperatures. The degree hour calculations are based on fermentation room temperatures. Temperature and humidity should be uniform throughout the fermentation room.

A process can be judged as acceptable provided the product consistently reaches a pH of 5.3 using:

  • fewer than 665 degree-hours when the highest fermentation temperature is less than 33°C;
  • fewer than 555 degree-hours when the highest fermentation temperature is between 33° and 37°C; and
  • fewer than 500 degree-hours when the highest fermentation temperature is greater than 37°C.

4.16.2.1.1 Fermentation Done at a Constant Temperature (Constant Temperature Process)

When fermentation is done at a constant temperature, operators can either use the following table or the calculation method (see examples below) for determining degree-hours limits and maximum time for fermentation at a given room temperature.

Fermentation Done at a Constant Temperature (Constant Temperature Process)
Degree-hours limit
for the
corresponding
temperature
Fermentation room
temperature (°C)
Maximum allowed
hours to achieve
a pH of 5.3
(based on guideline)
665 20 150.0
665 22 103.4
665 24 78.9
665 26 63.8
665 28 53.6
665 30 46.2
665 32 40.5
555 33 31.8
555 34 30.1
555 35 28.6
555 36 27.2
555 37 25.9
500 38 22.3
500 40 20.5
500 42 18.9
500 44 17.6
500 46 16.4
500 48 15.4
500 50 14.5

Examples of how to use the calculation method for constant temperature processes:

Example 1:

Fermentation room temperature is a constant 26°C. It takes 55 hours for the pH to reach 5.3.

Degrees above 15.6°C: 26°C - 15.6°C = 10.4°C
Hours to reach pH of 5.3: 55
Degree-hours calculation: (10.4°C) x (55) = 572 degree-hours

The corresponding degree-hours limit (less than 33°C) is 665 degree-hours.

Conclusion: Example 1 meets the guideline because its degree-hours are less than the limit.

Example 2:

Fermentation room temperature is a constant 35°C. It takes 40 hours for the pH to reach 5.3.

Degrees above 15.6°C: 35°C - 15.6°C = 19.4°C
Hours to reach pH of 5.3: 40
Degree-hours calculation: (19.4°C) x (40) = 776 degree-hours

The corresponding degree-hours limit (between 33 and 37°C) is 555 degree-hours.

Conclusion: Example 2 does not meet the guideline because its degree-hours exceed the limit - hold the product and refer to sub-section 4.16.2.1.3.

4.16.2.1.2 Fermentation Done at Different Temperatures (Variable Temperature Process)

When the fermentation takes place at various temperatures, each temperature step in the process is analyzed for the number of degree-hours it contributes. The degree-hours limit for the entire fermentation process is based on the highest temperature reached during fermentation.

Example 1:

It takes 35 hours for product to reach a pH of 5.3 or less. Fermentation room temperature is 24°C for the first 10 hours, 30°C for second 10 hours and 35°C for the final 15 hours.

Step 1

Degrees above 15.6°C: 24°C - 15.6°C = 8.4°C
Hours to reach pH of 5.3: 10
Degree-hours calculation: (8.4°C) x (10) = 84 degree-hours

Step 2

Degrees above 15.6°C: 30°C - 15.6°C = 14.4°C
Hours to reach pH of 5.3: 10
Degree-hours calculation: (14.4°C) x (10) = 144 degree-hours

Step 3

Degrees above 15.6°C: 35°C - 15.6°C = 19.4°C
Hours to reach pH of 5.3: 15
Degree-hours calculation: (19.4°C) x (15) = 291 degree-hours

Degree-hours calculation for the entire fermentation process = 84 + 144 + 291 = 519

The highest temperature reached = 35°C

The corresponding degree-hour limit = 555 (between 33°C and 37°C)

Conclusion: Example 1 meets the guideline because its degree-hours are less than the limit.

Example 2:

It takes 38 hours for product to reach a pH of 5.3 or less. Fermentation room temperature is 24°C for the first 10 hours, 30°C for the second 10 hours and 37°C for the final 18 hours.

Step 1

Degrees above 15.6°C: 24°C - 15.6°C = 8.4°C
Hours to reach pH of 5.3: 10
Degree-hours calculation: (8.4°C) x (10) = 84 degree-hours

Step 2

Degrees above 15.6°C: 30°C - 15.6°C = 14.4°C
Hours to reach pH of 5.3: 10
Degree-hours calculation: (14.4°C) x (10) = 144 degree-hours

Step 3

Degrees above 15.6°C: 37°C - 15.6°C = 21.4°C
Hours to reach pH of 5.3: 18
Degree-hours calculation: (21.4°C) x (18) = 385.2 degree-hours

Degree-hours calculation for the entire fermentation process = 84 + 144 + 385.2 = 613.2

The highest temperature reached = 37°C

The corresponding degree-hour limit = 555 (between 33°C and 37°C)

Conclusion: Example 2 does not meet the guidelines because its degree-hours exceed the limit; hold the product and refer to sub-section 4.16.2.1.3

4.16.2.1.3 Disposition of Lots Which Have Not Met Degree-hours Limits

The operator must notify the CFIA of each case where degree-hours limits have been exceeded. Such lots must be held and samples of product submitted for microbiological laboratory examination after the drying period has been completed. Analyses should be done for Staphylococcus aureus and its enterotoxin, and for principal pathogens, such as E. coli O157:H7, Salmonella, and Clostridium botulinum and Listeria monocytogenes.

  • If the bacteriological evaluation proves that there are fewer than 104 Staphylococcus aureus per gram and that no enterotoxin or other pathogens are detected, then the product may be sold provided that it is labelled as requiring refrigeration.
  • In the case of a Staphylococcus aureus level higher than 104 per gram with no enterotoxin present the product may be used in the production of a cooked product but only if the heating process achieves full lethality applicable to the meat product.
  • In the case where Staphylococcus aureus enterotoxin is detected in the product the product must be destroyed.

4.16.2.2 E. coli and Salmonella Control Options in Fermented Sausages

In order to suitably control these hazards and prevent incidents of food borne disease, registered establishments who manufacture fermented sausages are required to use one of the five following options for the control of verotoxinogenic E. coli including E. coli O157:H7 and Salmonella when they make this type of product.

The operator is required to use one of the five (5) options outlined in this section when manufacturing a dry or semi-dry fermented meat sausage product:

  • establishments which use beef as an ingredient in a dry or semi-dry fermented meat sausage;
  • establishments which store or handle uncooked beef on site;
  • establishments which obtain raw meat from a supplying establishment which stores or handles uncooked beef on site.

Establishments which do not use beef and do not obtain meat ingredients from establishments which handle beef are not currently required to use one of the five options for the control of E. coli O157:H7 in dry/semi-dry fermented sausages. However, they must validate through a microbiological testing program that their process will not result in the presence of E. coli O157:H7 or Salmonella in the finished product.

To ensure that all of the requirements corresponding to the selected option are met, and to suitably demonstrate this, operators of registered establishments who manufacture a dry/semi-dry fermented sausage are required to complete a copy of Annex K "Option used for the control of E. coli O157:H7 in dry and semi-dry fermented sausage" for each different product and attach all the required information.

This material will be screened by the Inspector in Charge and forwarded to the Area Program Specialist for verification.

An establishment must use option 3 if option 1, 2, 4 or 5 are not used. If an establishment which is required to do end product testing as per option 3 refuses to do the required testing on the finished product, the CFIA must detain the affected product, take measures to prevent cross-contamination of other product and inform the establishment that, if they do not provide the necessary test results within 60 days, the affected product will be treated as inedible and condemned.

4.16.2.2.1 Option 1:

Include as part of the manufacture of the sausage, one of the following heat processes which are recognized as controlling E. coli O157:H7.

Under this option, it is not required to test for E. coli O157:H7. Time and temperature controls will be documented in the same manner as is required for other similar cooking processes (refer to section 4.4 of this chapter).

Heat process recognized as controlling Escherichia coli O157:H7 where it is not required to test for Escherichia coli O157:H7
Minimum internal temperature
maintained during the entire process
Minimum processing time in minutes
after the minimum temperature
has been reached
130°F (54.4°C) 121
131°F (55°C) 97
132°F (55.6°C) 77
133°F (56.1°C) 62
134°F (56.7°C) 47
135°F (57.2°C) 37
136°F (57.8°C) 32
137°F (58.4°C) 24
138°F (58.9°C) 19
139°F (59.5°C) 15
140°F (60°C) 12
141°F (60.6°C) 10
142°F (61.1°C) 8
143°F (61.7°C) 6
144°F (62.2°C) 5
145°F (62.8°C) 4

This table is identical to the roast beef cooking table with one exception: the minimum processing time for a minimum internal product temperature of 145°F/62.8°C is 4 minutes instead of "instantaneous". This difference is because the sausage product's smaller size results in a much quicker cooling and decreased cumulative lethality.

4.16.2.2.2 Option 2:

Use a manufacturing process (combination of fermentation, heating, holding and/or drying) which has already been scientifically validated to achieve a 5D reduction of E. coli O157:H7.

Manufacturing processes used to make fermented sausages are only considered effective against E. coli O157:H7 if it is shown that they achieve a 5D reduction, or more, of E. coli O157:H7. The manufacturing process used must be evaluated in a scientific manner consistent with the challenge study recommendations (refer to Option 5) of this section.

Under this option, it is not required to test each lot for E. coli O157:H7 or Salmonella. The operator is required to implement a microbiological testing program for E. coli 0157 and Salmonella as a verification procedure for their process.

The operator must maintain suitable records to demonstrate that all of the critical control points (CCP) for the process have been met (for example, casing diameter, fermentation room (green room) thermographs, pH at the end of the fermentation step of the process, aw.)

The following processes have been scientifically validated as achieving a 5D or greater reduction of E. coli O157:H7.

The following processes have been scientifically validated as achieving a 5D or greater reduction of Escherichia coli O157:H7
Fermentation
chamber
temperature
pH at the end of
fermentation
process
Casing
diameter
Subsequent process (dry, hold or cook) Reference
70°F (21°C) > 5.0 < 55 mm heat (1 hr @ 110°F and 6 hrs @ 125°F) 1
90°F (32°C) < 4.6 < 55 mm hold @ 90°F for > 6 days 1
90°F (32°C) < 4.6 < 55 mm heat (1 hr @ 110°F then 6 hrs @ 125°F) 1
90°F (32°C) < 4.6 56 to 105 mm heat (1 hr @100°F, 1 hr @ 110°F, 1 hr @ 120°F, then 7 hrs @ 125°F) 1
90°F (32°C) > 5.0 56 to 105 mm heat (1 hr @100°F, 1 hr @ 110°F, 1 hr @ 120°F, then 7 hrs @ 125°F) 1
96°F (36°C) < 5.0 < 55 mm heat (1 hr @ 128°F internal product temperature) and dry (at 55°F and 65% relative humidity to a moisture protein ratio of < 1.6:1) 2
110°F (43°C) < 4.6 < 55 mm hold @ 110°F for > 4 days 1
110°F (43°C) < 4.6 56 to 105 mm hold @ 110°F for > 4 days 1
110°F (43°C) > 5.0 56 to 105 mm hold @ 110°F for > 7 days 1

1 Nicholson, R., et al, Dry fermented sausage and Escherichia coli O157:H7. National Cattlemen's Beef Association, Research Report Number 11-316, Chicago, Illinois, 1996.

2 Hinkens, J.C., et al, Validation of Pepperoni Processes for Control of Escherichia coli O157:H7, Journal of Food Protection, Volume 59, Number 12, 1996, pp. 1260-1266.

4.16.2.2.3 Option 3:

Where the manufacturing process does not correspond to one of the processes set out under options 1, 2 or 4 of this section and has not been assessed in accordance with option 5 of this section, the operator is required to test and hold each production lot pending satisfactory results.

  • The definition of lot for the purposes of sampling must be statistically sound and must correspond to product manufactured under the same conditions. A lot cannot exceed a single day's production.
  • For each lot, the operator must take 30 samples of finished product and submit them for analysis. The sampling plan must be representative of the lot.
  • Each sample must consist of at least 25 g of product. Samples must be taken in accordance with standard microbiological techniques to avoid contamination of product. Sampling of intact product packages is strongly recommended. It is unacceptable to take multiple samples from one intact package as this is not considered statistically representative of the lot.
  • It is acceptable to combine a maximum of three (3) samples into a composite for purposes of analysis when testing is done for E. coli O157:H7 and Salmonella.
  • At a minimum, each composite sample must be tested for the presence of E. coli O157:H7 and Salmonella.
  • The method used to analyse the end product samples must be one of the methods listed in Health Canada's Compendium of Analytical Methods, Volume 3, Laboratory Procedures for the Microbiological Analysis of Foods (ISBN 0-921317-17-4).
  • Results must be reported in writing, identified as to the lot of product being tested and must include individual results for each test performed, method used and minimum sensitivity of the test used.
  • Product will be held under the control of the operator until the written results of analysis have been received. In order to be released, all tests must be negative for the presence of E. coli O157:H7 and Salmonella and any other pathogens tested.
  • In case of a positive result for either E. coli O157:H7 or Salmonella or another pathogen the entire lot must be held and either submitted to an accepted lethality process or be destroyed. Possible cross-contamination of other lots must also be assessed.
  • Records of test results must be kept for a minimum of 24 months beyond the release date of the product.

4.16.2.2.4 Option 4:

This option specifically requires a microbiological testing program of raw meat and batter for E. coli 0157:H7 and Salmonella as part of the operator's existing HACCP system and a manufacturing process (fermentation and holding, heating and/or drying) which has been scientifically validated as achieving at least 2D reduction of E. coli O157:H7.

Manufacturing processes used to make fermented sausages are considered partially effective against E. coli O157:H7 if it is shown that they achieve 2D to 5D reduction of E. coli O157:H7. The manufacturing process used must be evaluated in a scientific manner consistent with the challenge study recommendations (refer to Option 5, sub-section 4.16.2.2.5). A number of manufacturing processes have been scientifically demonstrated as achieving a 2D to 5D reduction. The sampling program must be in accordance with the following requirements:

  • The definition of lot for the purposes of sampling must be statistically sound and must correspond to product manufactured under the same conditions. A lot cannot exceed a single day's production. Provided that effective controls for tracing product are in place and all corresponding dry fermented sausage manufacturing processes have been validated as achieving at least a 2D reduction of E. coli O157:H7, it would be acceptable to conduct one single series of sampling on batter which is used in different sausages. A lot cannot exceed one day's production of raw batter.
  • For each lot, the operator must take 15 samples of raw batter and submit them for analysis. The sample plan must be representative of the lot.
  • Each sample must consist of at least 25 g of product. Samples must be taken in accordance with standard microbiological techniques to avoid contamination of product. Sampling of intact product packages is strongly recommended. It is unacceptable to take multiple samples from one intact package as this is not considered statistically representative of the lot.
  • It is acceptable to combine a maximum of three (3) samples into a composite for purposes of analysis when testing is done for E. coli O157:H7 and Salmonella.
  • At a minimum, each composite sample must be tested for the presence of E. coli O157:H7 and Salmonella.
  • The method used to analyse the end product samples must be one of the methods listed in Health Canada's Compendium of Analytical Methods, Volume 3, Laboratory Procedures for the Microbiological Analysis of Foods (ISBN 0-921317-17-4).
  • Results must be reported in writing, identified as to the lot of product being tested and must include individual results for each test performed, method used and minimum sensitivity of the test used.
  • Product will be held under the control of the operator until the written results of analysis have been received. In order to be released, all tests must be negative for the presence of E. coli O157:H7 and Salmonella and any other pathogens tested.
  • In case of a positive result for either E. coli O157:H7 or Salmonella or another pathogen the entire lot must be held and either submitted to an accepted lethality process or be destroyed. Possible cross-contamination of other lots must also be assessed.
  • Records of test results must be kept for a minimum of 24 months beyond the release date of the product.

For reference, the following methods have been scientifically documented as achieving a minimum 2D reduction in E. coli O157:H7:

The following methods have been scientifically documented as achieving a minimum 2D reduction in Escherichia coli O157:H7
Fermentation
chamber
temperature
pH at the end of fermentation Casing
diameter
Subsequent process
(dry, hold or cook)
Reference
70°F (21°C) > 5.0 56 to 105 mm heat(1 hr@ 110°Fand 6 hours @ 125°F) 1
90°F (32°C) < 4.6 56 to 105 mm hold @ 90°F for 7 days then dry 1
90°F (32°C) > 5.0 56 to 105 mm hold @ 90°F for 7 days then dry 1
110°F (43°C) > 5.0 < 55 mm hold @ 110°F for 7 days then dry 1
110°F (43°C) > 5.0 56 to 105 mm heat (1 hr @ 110°F and 6 hours @ 125°F) 1

1 Nicholson, R., et al, Dry fermented sausage and Escherichia coli O157:H7. National Cattlemen's Beef Association, Research Report Number 11-316, Chicago, Illinois, 1996.

4.16.2.2.5 Option 5:

This option is a validation challenge study to demonstrate that the manufacturing process achieves as 5D reduction of E. coli 0157:H7.

Establishments which elect to use this option to demonstrate that their manufacturing process achieves a 5D reduction of E. coli O157:H7, may be able to manufacture product according to the requirements of Option 2 (e.g., not be required to test each lot of product for E. coli O157:H7 and Salmonella). Alternatively if their manufacturing process achieves a 2D reduction of E. coli O157:H7 they may be able to manufacture product according to the requirements of Option 4 (e.g., HACCP system and testing of raw batter).

The operator must make a request for the evaluation of the alternative manufacturing process to the Meat Programs Division and the Food Safety Division. Upon completion of a successful evaluation, the operator must be provided in writing stating that the CFIA has evaluated the process for its ability to control E. coli O157:H7 and that it does not object to the operator using the process. Until such confirmation is received, the operator must manufacture product in accordance to one of the other 4 options outlined in this section.

4.16.2.2.6 Challenge Study Protocol Requirements

  • This validation should not be conducted within an actual food manufacturing facility. Work should be conducted in a Biosafety level II facility by appropriately trained personnel. Following use, autoclave all inoculated product and sanitize processing equipment. Follow appropriate procedures for the disposal of waste.
  • Types and numbers of strains of E. coli O157:H7 to use as an inoculum: at least five (5) strains of E. coli O157:H7 should be used including representatives of strains associated with human illness and strains isolated from meat and poultry products. One isolate from an outbreak associated with a dry fermented sausage product must be included.
  • Methods of production, enumeration and standardization of inoculum: Individual cultures of each strain should be prepared by inoculating an appropriate growth media, such as Tryptic Soy or Trypticase Soy broth, supplemented with 1% glucose and incubating for 18 to 24 hours at 37°C to obtain stationary phase cells. The additional glucose is added to ensure that the inoculum is pre-adapted for acid tolerance. Cultures should be grown the day prior to product inoculation with a minimum holding period prior to actual use. Each strain should be centrifuged, washed and resuspended in 0.1% peptone broth. Dilutions of each strain should be made to yield approximately equal numbers of each of the five strains. The five strains should be thoroughly mixed prior to being used as an inoculum. After the mixed working inoculum is prepared, the viable count of the mixture should be determined by direct surface plating on MacConkey sorbitol agar (MSA). Each of the individual strains in the inoculum should contribute about 20% of the total inoculum.
  • Size of inoculum to be used: the final concentration of E. coli O157:H7 in the meat mixture should be no less than 2.0 x 107 CFU/g of meat mixture. The actual inoculum level in the meat mixture should be confirmed by sampling the inoculated meat mixture immediately after the inoculation using the above media. At this concentration, product can be serially diluted and direct plated without the need for enrichment to recover low levels of inoculum. The initial inoculum level was chosen to allow direct enumeration of at least a 5 log reduction in the level of the inoculum between the initial count in the meat mixture and the finished product.
  • Method of inoculation to be used: the inoculum must be added to the meat and mixed prior to the addition of the other ingredients or a starter culture to the meat mixture. The use of a non-inhibitory, food grade, green dye added to the inoculum may aid in determining the uniform distribution of inoculum. The following procedure is recommended:
    • add inoculum to meats while grinding or chopping the meats to the desired consistency;
    • mix in cure (if used), salt and spices;
    • blend in starter culture (if used) near end of mixing cycle; and
    • stuff batter into casings.
  • Stuffing product into casings: Inoculated product should be stuffed into casing as usual to approximate normal production procedures. A shorter length may be used as long as the length is approximately twice the diameter of the stuffed casing.
  • Sample size, sampling time, sampling location and number of samples to test: Select two sausage sticks at the end of the drying period (finished product). From each stick selected, cut multiple cross-sectional slices from multiple locations on each stick to a final analytical sample weight of 25 g per stick.
  • Methods of microbial analysis: Blend each of the two 25 gram samples (one per stick) in separate 225 ml portions of buffered peptone water. Serially dilute the homogenates in buffered peptone water and surface plate 0.1 ml portions from the dilutions onto MSA plates in duplicate. Count plates after incubation at 42°C overnight. Confirm 5-10 randomly selected colonies by serological and biochemical methods as necessary. Report count per gram of finished product. Report initial inoculum level.
  • Number of replicates: a minimum of three replicates of the study should be performed. Three separate formulation batches can, however, be processed concurrently following stuffing.

    Therefore, total number of samples for microbiological analysis:

    Time zero (0) = 2
    After fermentation = 0
    During drying = 0
    End drying = 2
    Total = 4
    Number of replicates x 3
    Total samples = 12

  • Measurement of process parameters used to determine when a product is finished at each stage of production (control program criteria): Duplicate uninoculated samples of the product which are collected after stuffing and at each production stage should be assayed for moisture, fat, protein, salt content, pH, aw, and titratable acidity.

    Therefore, total number of samples for additional analysis:

    Time zero (0) = 2
    After fermentation = 2
    During drying = 2
    End drying = 2
    Total = 8
    Number of replicates x 3
    Total samples = 24

4.16.2.3 Controls For the aw and pH of Product

The aw and pH values are critical in the control of pathogens as well as to ensure shelf-stability in all semi-dry and dry fermented meat products. Each production lot must be tested for aw and/or pH in order to verify that the critical limits are met.

Although aw measurement is mandatory only for shelf stable products, it is strongly recommended that the operator determine the aw values achieved for each product type they manufacture and for each production line. Once this has been established, frequent regular checks should be made.

4.16.3 Requirements for Shelf Stable Fermented Meat Products

For all fermented meat products, in order to minimize the danger of outgrowth of Clostridium botulinum spores and development of the botulinal toxin in fermented product, nitrite/nitrate shall be added at a minimum level of 100 ppm along with a minimum of 2.5% of salt.

In order to be considered "shelf-stable" and not require refrigeration, a fermented meat product must have a minimum of 100 ppm nitrite/nitrate, a minimum of 2.5% of salt, meet degree hours requirements (4.16.2.1) and meet one of the following sets of specific requirements.

  • The pH of the finished product is of 4.6 or less, regardless to its final aw.
  • The aw of the finished product is 0.85 or less, regardless of its final pH.
  • The pH is 5.3 or lower at the end of the fermentation period and the end product has an aw of 0.90 or lower.

The level of nitrate-nitrite should not interfere with the process of fermentation.

Fermented products which do not meet these requirements must be labeled with a refrigeration statement.

Operators of registered establishments who wish to market a meat product without a refrigeration declaration which does not meet the "shelf stable" criteria set out above, must submit a request for the acceptance of their proposal to the Inspector in Charge. The submission must be accompanied by detailed recipe, formulation and processing information for the product. Submissions will be sent to the Area Program Specialist for review with a Food Safety Microbiology Specialist and Health Canada.

Date modified: