Introduction

Food and beverage manufacturers must follow federal, provincial and/or municipal regulations with respect to food safety. The information provided below is generalized information only. It is the responsibility of a food or beverage processor to comply with food safety regulations as they apply to the products they process and provide for sale to customers. There is both civil and regulatory liability that may arise from failure to meet food safety standards, regulations and requirements.

Canadian consumers want safe, nutritious food throughout the year. Canada’s climate often limits the production of food for up to six months of the year. Storing food is an option, however once food is harvested, it may deteriorate due to:

  • micro-organisms (for example, yeast, mold, bacteria)
  • intrinsic (naturally occurring) enzymes
  • temperature
  • moisture
  • insects and vermin

The risk of spoilage and demand for convenience has resulted in a market, where food is processed in a way that meets consumer preferences, preserves nutrition and meets food safety requirements.

The Safe Foods for Canadians Act and Safe Food Regulations do not define the term “to process.” In general, the term “to process” refers to a series of steps taken to prepare a food and/or a series of changes to a food. In lay terms, processing can be understood as the steps taken to prepare for sale and prevent spoilage. This may include washing and wrapping.

Ontario’s Meat Regulation (O. Reg. 31/05) defines the term “preserved”, with respect to meat products subject to Ontario’s provincial regulations, to mean salted, pickled, dried, cured, smoked or treated by other similar means permitted under this Regulation but does not include refrigerated or frozen.

In this section you will learn:

  • processing methods
  • packaging methods
  • hurdle technology, processes and inter-related compliance

New food and beverage manufacturers must understand that compliance with food safety licensing, regulations, standards and best manufacturing practices does not supersede or in any way exempt them from the need to comply with other regulations. There are federal and provincial environmental and labour acts as well as municipal zoning and planning bylaws for which compliance is triggered by the technology, process and/or products used to process food and beverages.

Some ingredients may trigger compliance requirements under Ontario’s Toxicity Act or the Canadian Environmental Protection Act. Some processes have emissions which trigger emissions reporting or will limit building permits. Some processes trigger worker safety requirements. Previous sections address some of these regulations.

In order to connect the dots, it helps to understand this connection and understand this in lay terms. Food safety regulations and guidelines do not separate things like chemical and physical processing. However, municipal, labour and environmental regulations may overlap. The information provided below is intended to help you understand the overlap.

While you are planning your facility, it is important to also pay attention to worker safety based on the equipment you will use to process food. Equipment guarding, heat shields, air venting and protective gear may vary depending upon the kind of processing you do.

More details on processing methods can be found in Appendix A. For more information, please contact the Agricultural Information Contact Centre at 1-877-424-1300 or ag.info.omafra@ontario.ca.

Processing methods

The properties of a food may be altered using:

  • water activity adjustment (for example, drying, salting, addition of sugar)
  • use of approved food additives (for example, addition of other ingredients and/or approved food additives)
  • pH adjustment and control

Consumers today are increasingly wary of ingredients on a food label they cannot pronounce or whose function they do not understand. You may want to consider which chemicals you use to process your products.

Water activity adjustment

Water is the most important factor in controlling the rate of deterioration of a food. However, knowledge of the moisture content of a food is not enough to predict its stability. It is the availability of water for microbial, enzymatic, or chemical activity that determines the shelf life of foods. This water availability is measured as water activity (aw).

Water activity is measured on a scale of 0 to 1, where 0 indicates no water and 1 indicates all water. For example, the water activity of pure water is 1.0 but a dry cracker has a water activity of about 0.2. A reduction in water activity does not kill microorganisms, however it does inhibit growth and prevent toxin formation.

The majority of food spoilage and pathogenic micro-organisms are inhibited in food where the water activity is below 0.9, however some pathogens may require a lower water activity (for example, 0.85 or below) or a combination of factors to inhibit growth (see Hurdle technology).

Food additives

Health Canada’s Lists of Permitted Food Additives are available online and indicate all additives permitted for use in Canada, the foods that they are permitted in, their functions and limits (where applicable). This list of additives has also been vetted for compliance under the Canadian Environmental Protection Act. The list is not aligned with Ontario’s Toxics Reduction Act. Some permitted food additives, based on the volume used by a processor, trigger specific regulatory requirements. For more information refer to the Toxics Reduction Act, 2009, S.O. 2009, c. 19.

Acidification/pickling

Every micro-organism has a minimum, optimum and maximum pH for growth. Yeasts and molds can grow at low pH, but 4.6 is generally considered the level that will prevent the growth and toxin production for pathogens. A pathogen is any micro-organism that causes illness such as food poisoning or food intoxication. Like water activity, pH is primarily a means of growth inhibition and not a method for destruction of existing pathogens.

A pH level of 4.6 is used as a divider between high-acid and low-acid foods.

Naturally high-acid foods include peaches (pH 4.0), orange juice (pH 3.5) and apples (pH 3.5). In general, most fruits are high acid. However, some tropical fruits including pineapple might fall in the pH range above 4.6 depending upon growing conditions. Examples of low-acid foods (pH above 4.6) are: fresh fish (pH 6.3), canned green beans (pH 5.0), bread (pH 5.5) and fresh ham (pH 6.2). Low-acid foods include protein foods, most vegetables, starch-based foods and a variety of others.

Some foods that are naturally low-acid are processed in a way that makes them a high-acid food. This is called acidification. Examples of foods that are processed to lower the pH include pickled fish and pickled peppers that use an acidulant (such as vinegar) to lower the pH, or olives and sauerkraut that use a fermentation process to produce lactic acid that reduces pH.

Several other methods are available to you for processing and preserving foods, including the following:

  • sterilization
  • sous vide
  • pasteurization
  • blanching
  • microwaving
  • frying
  • refrigeration
  • freezing
  • irradiation
  • dehydration/drying
  • emulsifying
  • homogenization
  • extrusion
  • marinating/basting
  • salting
  • curing
  • smoking

Thermal processing

Thermal processing is different from the cooking process because the goal is to achieve commercial sterilization. Commercial sterilization is the destruction of all pathogenic and spoilage micro-organisms in foods and inactivation of enzymes by heating. Thermal processing is used to produce canned foods (also known as products packaged in hermetically sealed containers).

Low-acid foods (pH greater than 4.6), such as meat and vegetables, must be subjected to extreme conditions to destroy all pathogens. Sterilization that occurs in a retort (a large pressure cooker), can achieve the high temperatures required for sterilization. For example, canned foods may be heated under pressure to at least 121°C (249.8°F) for varying times.

Extreme conditions are applied to ensure that Clostridium botulinum (C. botulinum) spores are destroyed during processing. If untreated, surviving spores will grow into the vegetative form of C. botulinum under anaerobic conditions (the absence of oxygen) and produce the deadly botulinum toxin.

The spores are only destroyed by high heat during the thermal (canning) process or can be inhibited at pH values of less than 4.6. Validating a thermal process for your product must be done by an appropriate laboratory or technology centre with a thermal process authority.

Sous vide

French for “under vacuum,” sous vide is a method of cooking food sealed in airtight plastic bags in a water bath for longer than normal cooking times (72 hours in some cases) at an accurately regulated temperature much lower than normally used for cooking, typically around 55°C (131°F) to 60°C (140°F) for meats and higher for vegetables. The intention is to cook the item evenly and avoid overcooking the exterior. This keeps the food juicier. If performed correctly, the sous vide method will destroy pathogens but does not sterilize the food, so all foods processed using this method must be kept below 4°C (39°F) during its retail life to prevent spoilage. As well, the processor must determine the “shelf life” (the length of time that product retains its safety) of the food.

Pasteurization

Pasteurization is the process of heating a food (usually a liquid) to or below its boiling point for a defined period. The purpose is to destroy all pathogens, reduce the number of micro-organisms, inactivate enzymes and extend the shelf life of the food product.

Pasteurization is mostly used on liquids such as milk and juices, with raw milk being the most common pasteurized food. Pasteurization will destroy pathogens that may be found in raw milk however, it does not destroy all micro-organisms. This is the reason all fluid dairy products must be stored below 4°C (39°F).

High-temperature/short-time pasteurized (HTST) milk is heated for 15 seconds at 72˚°C (161.6 °F) and Ultra-high-temperature (UHT) pasteurized milk is heated for 2 seconds at 135°C (275°F). UHT may impart a distinct cooked flavor to the product — and products are only shelf stable if UHT is combined with aseptic packaging. There is a greater loss of flavour from foods that are exposed to heating for longer times. Therefore, temporary stability (for example, limited shelf life) is only obtained with some foods where prolonged heating would destroy its quality.

Blanching

Blanching is a slight heat treatment (hot water or steam) that is applied mostly to vegetables before canning or freezing.

Blanching is used before freezing and canning to inactivate enzymes present in foods that may cause deteriorative reactions to foods during processing and storage. These reactions include colour and texture changes, off-flavours, and a decrease in nutritional value.

Microwaving

Microwave ovens are rarely used for processing large quantities of food. They are mainly of interest if you cater to the convenience food market, with products such as frozen entrées.

Microwave ovens use electromagnetic radiation to excite water molecules in food. The actual waves penetrate only about 25 cm (10 in.) from the source of the radiation. Within the food, the waves only penetrate 1.9 to 2.5 cm (3/4 to 1 in.) on all sides. As a result, the actual ovens must be limited in size. Heat is produced within the food by the friction of water molecules which spreads to the centre of the food by conduction.

Small portions are cooked rapidly in microwave ovens. As the quantity of food increases, however, the efficiency is lost.

Frying

Frying differs from other methods of heat processing in that the cooking medium is hot oil. Because of the big difference between the temperature of the oil and the food, as well as the small size of the food pieces, cooking is completed in a relatively short time, anywhere from 20 seconds to 6 minutes.

Fried foods are known for their characteristic crispy outer surface as well as their high fat content. The fat that is absorbed by the food product varies from 10-40%, depending on the time the food is immersed in the oil.

Par-fried foods are partially cooked foods that are fried for a desirable golden and crispy exterior but require further cooking by the consumer.

Continuous fryers are often used in the food industry. Unless consumed immediately after frying, foods must be refrigerated or frozen to ensure their safety and quality.

Frying equipment must be vented. All vented air is an emission. When vented emissions also contain heat, odour and oil from the vent plume, this may complicate your regulatory approvals under Ontario’s Environmental Protection Act.

Most processes are now covered under a simplified Environmental Activity and Sector Registry. Frying processes may trigger the need for a full Environmental Compliance Agreement (ECA). It is also important to double check your local municipal zoning and site planning approval requirements when an ECA is required.

Refrigeration

Refrigerators should be set to 4°C (39°F) or below for hazardous foods (check applicable regulations for temperature requirements), to control the growth of micro-organisms in foods.

The quality of foods that cannot be dried or canned can be extended by refrigeration. Examples are perishable fruits and vegetables, meat and poultry, cheese, yogurt, fresh salsa and soy milk. These products have a limited shelf life because refrigeration only slows bacterial growth, it does not prevent it.

Refrigeration equipment has emissions. In 2014, the Canadian Environmental Protection Act (CEPA) issued a code of practice regarding the elimination of halocarbons used in refrigeration systems. This code outlines refrigeration equipment maintenance; and handling and disposal requirements for refrigerants.

New and small processors often consider the purchase of used equipment in order to manage start-up and ongoing capital investment costs. The cost-effectiveness of some used equipment will depend upon the refrigerants that the equipment uses. The change out of refrigerants is not a simple replacement. Refrigeration units that use now-banned refrigerants may also need to be retrofitted to be able to use permitted refrigerants to operate properly. It is important your equipment vendor and refrigeration service provider both ensure that you meet this requirement.

Refrigerant use (such as the use of ammonia compressors) may also trigger reporting compliance. Refrigeration:

  • reduces the respiration rate of fruits and vegetables, which slows down the reactions that promote spoilage
  • extends the storage life of commercially processed foods

Freezing

Freezing can be used to increase the shelf-life of perishable food products. Freezing may also be used as a food safety control for certain product types. Freezing halts the growth of micro-organisms but does not destroy them. If processed carefully, a frozen food product will maintain quality in color, texture and flavor for a long shelf life.

If the product is not prepared and frozen properly, enzymes from the food and micro-organisms in the frozen food may lead to degradation of the food.

While many home freezers are held at -10°C (14°F), commercial freezers are under -18°C (-0.4°F). At this temperature, the growth of micro-organisms is stopped. Deteriorative microbial reactions will still occur, but over a much longer time.

During freezing, the water in food forms ice crystals. The rate of this phenomenon has a big impact on the quality of frozen foods.

Slow freezing (for example, home freezer):

  • Large ice crystals form, which puncture cell walls, releasing cellular fluid.
  • Results in shrunken appearance of thawed food.

Rapid freezing (for example, blast freezer):

  • Small, numerous ice crystals form.
  • No change to cell structure.

The shelf life of frozen foods is largely dependent on storage conditions. Under ideal conditions, frozen foods can have a shelf life of one year.

However, if foods are continuously exposed to warmer temperatures, such as by the opening and closing of freezer doors, then heat shock occurs. In heat shock, ice melts and re-forms into larger ice crystals. The best example is ice cream, which has a gritty texture if large ice crystals have developed.

Irradiation

Irradiation is the process of applying low doses of gamma radiation to food products. Irradiation is permitted in Canada to:

  • prevent sprouting in potatoes and onions
  • control insect infestation of wheat flour
  • reduce the microbial load of ground spices

In the future, irradiation may become more widely used to process various other food products and it is expected to replace fumigation, ensure hygienic quality and reduce the dependence on refrigeration.

Dehydration/drying

Dehydration or drying lowers the water activity to inhibit the growth of microorganisms. It is one of the oldest methods of food preservation and was traditionally carried out by using the sun as a source of heat.

This application is used for preservation, convenience and cost savings. Dried soup mixes, dried fruit, dried meats, powdered milk and spices are just a few examples of dehydrated foods.

Spray drying and freeze drying are two drying methods used widely today. In spray drying, a liquid food is atomized into a fine, dry powder. Examples include natural and artificial flavours and milk powders. Freeze drying involves first freezing the food and then removing the ice, leaving a high quality, porous dried food.

Emulsification

An emulsion is a system containing two liquid phases that do not mix, where one phase (dispersed phase) is distributed throughout the other phase (continuous phase) in the form of very small droplets. Generally, there are two types of emulsions:

  • oil in water (o/w)
  • water in oil (w/o)

An example of an o/w emulsion is salad dressing and an example of a w/o emulsion is butter.

Homogenization

Homogenization is used to stabilize an emulsion. More specifically, it is the reduction in size and the increase in number of droplets of the dispersed phase by the application of intense shearing forces.

Generally, homogenization is applied to change the functional properties or improve the texture of emulsions. For example, most fluid milk sold at the retail level is homogenized to improve its stability and most caramel fillings are homogenized to increase their smoothness.

Extrusion

In extrusion, a food is compressed and worked to form a semi-solid mass. This mass is then forced through a restricted opening, or die, to create a desired texture or shape. The purpose of this application is simply to provide a greater variety of textured foods to consumers.

Food may also be cooked while extruded. This is referred to as extrusion cooking or hot extrusion. Some extruded food products include sausages, licorice, puffed wheat and cornflakes.

Packaging methods

Modified atmosphere packaging (MAP)

MAP modifies the composition of the internal atmosphere of a package of food, often to lower the amount of oxygen (O2) to slow down the growth of aerobic micro-organisms (in an oxygenated environment) and the speed of oxidation reactions. The removed oxygen can be replaced with nitrogen (N2) or carbon dioxide (CO2). Carbon monoxide (CO), for example, can be used for keeping the red colour of meat.

Rebalancing of gases inside the packaging can be achieved using active techniques, such as gas flushing and compensated vacuum, or passively, by designing breathable films known as equilibrium modified atmosphere packaging (EMAP). Food, such as fresh pasta, can be packaged in a modified atmosphere package.

Vacuum packaging

Vacuum packaging is where air is mechanically extracted from the package immediately prior to sealing. The product is placed in a low oxygen permeable bag. The bag is placed in the vacuum machine where air is mechanically evacuated from the package and a heat seal is formed. The film is held tight against the product. There is no air or atmosphere left in the package. Several foods, such as smoked fish are vacuum packaged.

However, while vacuum packaging may stabilize the quality of foods, foods that can support the growth of microorganisms must be refrigerated.

Smoke houses

As with frying, a smoke house may trigger full ECA approval due to the nature of the air emissions. Municipal zoning and site plan approvals may also be restricted or need to be addressed.

Hurdle technology

Hurdle technology is a concept that was developed to address the consumer demand for more natural, fresh-like foods. It is a way for food processors to employ only mild preservation techniques to their food products.

Hurdle technology uses a combination of processing methods to control or eliminate pathogens.

Some of the more common hurdles processing techniques that can be used in tandem include:

  • pasteurization plus refrigeration
  • reduction of water activity (aw)
  • addition of salt
  • addition of nitrites/nitrates
  • blanching plus further processing
  • freezing
  • modified atmosphere packaging (MAP)
  • reduction of pH
  • preservatives
  • refrigeration
  • irradiation

The only way to ensure you are using the correct combination of hurdle technologies is to have qualified resource conduct quality and safety shelf-life studies.

Examples of hurdle processing can be found in traditional and recently developed foods, such as yogurt and prepackaged fresh salads. The hurdles employed in yogurt manufacturing include low temperatures, high acid and competitive microbial flora. Those used to prepare prepackaged fresh salads include low temperatures and modified atmospheres. For fermented sausages, the hurdles include the use of preservatives, (for example, salt and nitrite), high acid (increase in pH) and reduced water activity.

Batch versus continuous processing

Food is processed in either separate batches or a continuous system. Although there are advantages and disadvantages to each method, choice in the matter is restricted only to those replacing or setting up a new processing line. Generally, batch systems are used to produce small quantities of food, whereas larger volumes are required for continuous systems.

Advantages of batch processing:

  • greater flexibility to change product formulation and rates
  • lower equipment costs
  • easier operation and control

Advantages of continuous processing:

  • lower operation and labour costs
  • less floor space required as compared to multiple batch processes
  • easier to control and maintain uniformity