Chapter: Operations & Documentation
Section: Process Controls
Sub-Section: F.B.14.15 Smoking

Elements

The regulatory requirements contained in this guideline will be met when:

F.B.14.15 (01) The hot smoking process, achieves a time and internal temperature combination required to produce a ready-to-eat fish product. (Risk Ranking: Significant High)

F.B.14.15 (02) The smokehouse used to process a hot smoked ready-to-eat fish product is regularly tested for cold spots and adjustments are made to the process or to the equipment to control cold spots. (Risk Ranking: Medium)

F.B.14.15 (03) The smoking process does not cause contamination of a smoked fish product. (Risk Ranking: Medium)

Rationale

Cold Smoking

Cold smoking is a process of treating fish with smoke using a time/temperature combination that will not cause significant coagulation of the proteins in the fish flesh but that will cause some reduction of the water activity (e.g. the temperature in the smoking chamber does not exceed 32.2 degrees Celsius). This method involves smoking fish to impart flavour, but it does not cook the fish.

Cold smoking alone does not result in a product that is ready-to-eat (RTE), as there isn’t a lethality step (e.g. heat treatment). A combination of other process steps (e.g. salting, drying) in addition to cold smoking are needed and must be controlled to result in an RTE product. (Refer to FPG Process Controls – Salting, and FPG Process Controls - Drying).

To prevent growth or toxin formation of Clostridium botulinum and other bacterial pathogens, final packaging type and storage conditions must be controlled when producing cold-smoked fish products (Refer to FPG Process Controls – Final Product Controls).

Many parasites can survive the cold-smoking process. Therefore, cold-smoked RTE fish products need to be treated to destroy parasites (Refer to FPG Process Controls – Parasite Control).

Cold-smoked fish products are particularly susceptible to post-process contamination from Listeria monocytogenes (Refer to FPG Process Controls – Final Product Controls).

Hot Smoking

Hot-smoked fish products are RTE products. Hot smoking is a process in which fish is smoked at an appropriate combination of temperature and time that is sufficient to cause the complete coagulation of the proteins in the fish flesh. A combination of other process steps (e.g. salting, drying) are typically used when producing hot-smoked fish. (Refer to FPG Process Controls – Salting, and FPG Process Controls - Drying).

During direct smoking, fish is placed on racks in a chamber and is exposed directly to smoke generated within the chamber. During indirect smoking, smoke is generated externally and then filtered and piped into the smoking chamber. Alternately, a vaporized liquid smoke flavouring can be added as an ingredient during fish processing.

Best practices for hot smoking:

  • loading instructions for smokehouses should be provided to equipment operators
  • products should be placed in smokehouses in a way that avoids crowding and provides adequate spacing and effective circulation of the heating medium
  • products processed together should have uniform thickness and size
  • the internal temperature of a number of fish products at various locations in the smokehouse should be monitored to ensure that internal temperatures are accurately and representatively measured throughout the lot of product
  • the products that are monitored should be the largest pieces, located in the coldest spot(s) within the smokehouse.

Time and Internal Product Temperature

The time and internal temperature combinations achieved during hot smoking process must destroy or inactivate pathogens to produce a safe fish product.

For example:

If the fish product is to be aerobically packaged, a 5D process for reduction of Listeria monocytogenes is required. One example of a method to achieve this is to use the time/temperature combinations in Table 1. To identify the type of packaging, refer to FPG Process Controls – Final Product Controls.

Table 1. Times for a given temperature, minimum holding time at that temperature (minimum dwell time) needed to obtain a 5D lethality of Listeria monocytogenes
Internal Product Temperature (degrees Celsius) Time for 5D Process (Minutes) Listeria monocytogenes
63 11.7
64 8.3
65 5.9
66 4.2
67 3.0
68 2.1
69 1.5
70 1.1
71 0.8
72 0.5
73 0.4
74 0.3
75 0.2
76 0.1
77 0.1
78 0.1
79 0.05
80 0.03
81 0.02
82 0.02
83 0.01
84 0.01
85 0.01
86 0.004
87 0.003

Note: D65°C = 1.18 minutes, z = 6.7°C (from Embarek and Huss 1993)

Reference: Embarek, P.K.B. and Huss, H.H. 1993. Heat resistance of Listeria monocytogenes in vacuum packaged pasteurized fish fillets. International Journal of Food Microbiology 20:85-95.

Achieving the time and internal temperature combination depends on factors such as:

  • the initial and desired end-product temperatures,
  • the size, shape and thickness of the fish product,
  • the spacing between the products and the walls, ceiling and floor of the smokehouse,
  • the location of products within the smokehouse.

Note: Hot- or cold-smoked fish products, or multi-ingredient products that contain smoked fish, that will be anaerobically packaged, must have specific controls for Clostridium botulinum (Refer to FPG Process Controls – Final Product Controls).

After fish products are smoked, the safety of the products should be maintained by:

Cold Spot Testing

Equipment used for hot smoking should be regularly (e.g. as recommended in manufacturer’s instructions, or annually) tested for the presence of cold spots. Cold spots can result in uneven heating and inconsistent temperatures which may permit survival of pathogens in RTE fish products.

One example of an acceptable method to determine cold spots is to refer to the manufacturer’s instructions for the equipment or consult with the manufacturer of the equipment.

The written process control procedure includes instructions for cold-spot testing that are specific to the equipment used (Refer to FPG Process Controls – General).

Hazards from smoke

There are a variety of hazards that can be generated during smoke production. For example, polycyclic aromatic hydrocarbons (PAHs) can be produced during smoke generation and be deposited on smoked fish products. Many PAHs are known or suspected carcinogens.

Best practices to control hazards from smoke:

  • smoke can be generated from hardwood chips or sawdust, wood products used as a smoke source must be suitable for production of food,
  • the sawdust pan used in the smokehouse must be effective for its purpose and easily cleanable,
  • sawdust should not be stored in processing areas, however limited quantities of sawdust may be stored in sealed containers in the area where the smoke is generated,
  • replace direct smoking with indirect smoking methods or smokehouses,
  • suspend fish at a height that protects the product from physical contaminants, such as flames, embers, soot and ash (e.g. if using a direct smoking method, fat should not be allowed to drip down onto an open flame because the burning fat creates excessive smoke which may coat products with PAHs),
  • if smoke is generated outside the smokehouse, there should be proper air circulation for smoke distribution inside the smokehouse,
  • if the smoke is generated inside the smokehouse, a baffle should be used to protect the fish from physical contaminants,
  • avoid heavy smoking methods, the use of medium to low heat (e.g. 300-400 degrees Celsius) can greatly reduce PAH accumulation, however, the formation of PAHs cannot be avoided if the temperature of the process exceeds 400 degrees Celsius,
  • smoke under mild conditions in modern smokehouses supplied with smoke filtered to remove particulates from external generators,
  • liquid smoke used should be suitable for its intended purpose and used in accordance with label instructions.

The process control procedures for smoked products should contain the following technical process information:

Filtered Wood Smoke

Filtered wood smoke (also known as “filtered smoke” or “tasteless smoke”) is used in fish processing to extend the shelf life of fresh and frozen fish products. It is neither a heat treatment method nor a flavouring method. Filtered smoke is allowed in fish products in Canada, but it must be included on the product label using a statement that is acceptable by the Canadian Food Inspection Agency.

Regulatory References

Food Safety and Quality Act, 2001; O. Reg. 465/19 s. 25 (3), 43, 51, 52, 53 (3), 54 (3), 55 (1), 56

  1. (3) Equipment used at a fish processing plant to cook, heat, treat, refrigerate or freeze a fish product must be designed and maintained so that it is effective in achieving any standards or temperatures that are required by this Regulation.
  1. (1) The operator of a fish processing operation in respect of which a licence is required under this Regulation shall ensure that fish products and ingredients are kept at a temperature and humidity that keeps them safe during processing, packaging, labelling, storing and handling.

    (2) The operator shall ensure that the temperature of every refrigerator used for the cooling or storage of fish products is maintained at 4 degrees Celsius or lower.

    (3) The operator shall ensure that the temperature of every freezer used for the freezing or storage of fish products is maintained at a temperature that will keep the products frozen.

    (4) The operator shall ensure that the temperature and humidity of every room in the fish processing plant used by the operation where fish products are received, processed, packaged, labelled, shipped, stored or handled are controlled to prevent the contamination of fish products, ingredients, labelling materials and packaging materials.

  1. (1) The operator of a fish processing operation in respect of which a licence is required under this Regulation shall ensure that written process control procedures are developed, implemented and monitored to effectively identify any risk of contamination of fish products, ingredients, labelling materials and packaging materials and to prevent, eliminate or minimize any identified risk.

    (2) The operator shall ensure that at the time the process control procedures referred to in subsection (1) are performed and monitored, a record is created that includes,

    1. the date the procedure was performed and monitored;
    2. the results of the monitoring, including any deviations from the process control procedures; and
    3. the actions taken in response to any deviations from the process control procedures, including disposing of the fish product or taking measures to produce a safe fish product.

    (3) The operator shall ensure that the process control procedures referred to in subsection (1),

    1. are reviewed as needed in order to,
      1. evaluate whether the procedures are being properly implemented, and
      2. verify the effectiveness of the implemented procedures with respect to producing a safe fish product; and
    2. are updated as needed.

    (4) The operator shall ensure that at the time a review referred to in clause (3) (a) is undertaken, a record is created that includes,

    1. the date the review was performed; and
    2. the results of the review.

    (5) The operator shall ensure that every record created under this section,

    1. is kept for at least one year from the date the record is created; and
    2. is readily accessible.
  2. The operator of a fish processing operation in respect of which a licence is required under this Regulation shall ensure that any regulatable activities engaged in by the operation are performed in a manner that minimizes the risk of contamination of fish products, ingredients, labelling materials and packaging materials and produces fish products that are safe.
  3. (3) The operator shall ensure that each fish product referred to in subsection (1) is prepared in accordance with its corresponding recipe.
  4. (3) The operator shall ensure that with respect to a fish product that is not a ready-to-eat fish product but has the appearance of or could be mistaken for a ready-to-eat fish product, the labelling or packaging materials used for the product,
    1. state that the product requires cooking before consumption; and
    2. include comprehensive cooking instructions.
  5. (1) The operator of a fish processing operation in respect of which a licence is required under this Regulation shall ensure that fish products, ingredients, labelling materials and packaging materials involved in any regulatable activities engaged in by the operation are,
    1. stored and handled in a manner that minimizes the risk of contamination;
    2. stored at a temperature of 4 degrees Celsius or less, if they must be refrigerated; and
    3. are kept frozen, if they must be frozen.
  6. The operator of a fish processing operation in respect of which a licence is required under this Regulation shall ensure that every fish product processed, labelled or packaged by the operation is,
    1. processed, packaged, labelled or stored in accordance with this Regulation; and
    2. safe.