10.3 Hazard analysis and critical control points (HACCP)
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10.3.1 Preprocessing steps - converting raw foods to ingredients
Fruit and vegetables as raw materials start as living cells and as such can vary in composition, colour, flavour structure and nutrient content. Thus a key part of describing a process is the preparation of detailed specifications for ingredients and packaging materials to ensure that final product performance and composition specifications can be met with the specified process and equipment. This is only possible if ingredients are preprocessed to the desired specifications.
Thus the processing of foods must be separated into two broad areas: preparation of raw fruit and vegetables for further processing to consumer products or ingredients; assembly of preprocessed ingredients to finished consumer products.
The assembly of preprocessed ingredients to finished consumer products will be discussed to illustrate principles used to describe a process for quality control. These principles apply to the conversion of raw foods to processed products. The chief differences are the variations in raw product specifications and certain washing, peeling, size reduction and blanching or heat treatment steps needed to convert highly variable raw materials to standardized ingredients.
Typical operations using in converting raw fruits and vegetables to processed- ingredients for packaging and preservation or prior to a further heat treatment processing are as follows:
Harvesting or Gathering -- > Transport -- > Storage -- > Washing -- > Size Grading -- > Peeling (Removal of outer surface) -- > Size Reduction -- > Separation of waste -- > Sorting Inspection--> Storage
10.3.2 Process description for Quality Control
One of the most important specifications of a product is its safety in terms of microbial contamination, freedom from hazardous chemicals and absence of foreign materials such as metal pieces, non-edible parts such as pits or woody stem material and dirt, insect parts or other extraneous material.
The microbial safety of processed fruits and vegetables is of prime importance from a quality viewpoint. The following analysis is to provide a description of a process to help ensure that microbial safety can be achieved with a minimum opportunity for failure of the finished product to meet specifications.
10.3.3 Process operations
Food processing steps require a detailed description when microbial safety is a concern. The reason for this is that ingredients, packages, equipment, and the surroundings all potentially can contaminate the final product with pathogenic or spoilage microorganisms. Table 10.3.1 is a simple process description from a Hazard Analysis point of view.
Further, if the conditions of pH (acidity), temperature, moisture and nutrient level are suitable, rapid microbial growth is possible on processing equipment and in the food itself. Thus while microbiological specifications can be written for incoming ingredients, actual microbial counts can increase during each process step if the process is not designed properly.
One of the first requirements for the description of a process is to determine if an individual process step will increase (+), decrease (-) or result in nonchange (=) in the microbial content of food undergoing the processing step. This can be determined from the chemical and physical conditions of the food and surroundings in each processing step.
The physical and chemical conditions of a food passing through a processing step can be recorded for each process step needed to prepare a finished product.
Fig. 10.3.1 is an example of a process for preparing a canned juice drink using a hot fill to prevent subsequent spoilage. A hot fill can be used since the product has pH below 4.5 and thus is considered an acid product. The product contains four ingredients: fruit concentrate, flavour mix, sugar and water. Two package components are shown: the can and the can cover.
Individual processing steps are identified in the preparation of the canned juice drink from warehouse inventory to just prior to can labelling. Processing steps needed to prepare the package for filling and sealing are listed on the right side of the chart.
For purpose of analyses the juice drink must have a pH of 3.8, a fill temperature of no lower than 190° F and must leave the cooling tunnel at a temperature below 90° F. These requirements are highlighted in their appropriate column to ensure that the proper process control and quality control procedures are in place.
Fig. 10.3.1 has a column titled: "Potential for microbial growth if out of control". This column is included to allow each step to be challenged from a microbiological viewpoint. "What ifs" will show whether the specified Critical Control Points will protect the product from microbial failure.
Two sources of failure are evident. The can fill temperature must be 190° F or above and regular can and lid inspections are needed to ensure that double-seals are always within specifications. The pH of the system may be less critical since the fruit concentrate will bring the pH below 4.5 even without the dry mix.
The process steps shown above can be contrasted with the process used in the preparation of a vacuum packed, refrigerated, cooked meat soup (shown in Figure 10.3.2). This product depends on low temperatures for preservation as well as low vegetative microbial counts.
Equipment sanitation, prevention of air borne contamination during filling, seal integrity and rapid cooling are essential parts of the process.
Even with these requirements in control, the heat treatment given the products (heating to 200° F), with a variable 0-60 min hold) is not sufficient to inactivate Clostridium botulinum. Thus the product must be cooled to 35° F within 40 minutes to prevent any possible germination and outgrowth of Clostridium botulinum spores.
Further, the manufacturer of this product must provide a means to ensure that the product is used within a specified time and is always kept at or below 35° F if it is to be released to the public.
|2. Transport||Fork lift|
|3. Storage||Storage tank|
|4. Weigh dry ingred.||Scale||+||Poor sanitation|
|5. Weigh wet ingred.||Weigh Kettle|
|7. Heat||Kettle||=||Low temp.||195|
|9. Delay||Surge tank||=||Low temp.||190|
|10. Filler bowel level||Valve||=||Sanitation||190|
|11. Separation||Pipe filter||=||Sanitation||190|
|12. Can fill||Filler||=||Low temp.||190|
|13. Lid coding||Coder|
|14. Seam||Double seamer||+||(Poor seams)||190|
|15. Lid sterilisation||Can inverter||=||190|
|16. Hold delay||Conveyor||=||190|
|17. Can cooling||Cooling tunnel||=||90|
|18. Drying||Can dryer||+||Insufficient heat, leaks|
Source: D.F. Farkas (1991)
** "Potential for microbial growth if out of control"
*** pH of the product is 3.8
Figure 10.3.1 Canned juice drink- Inventory of process steps for ingredients, packages and process conditions to provide a basis for Hazard Analysis (HACC)
10.3.4 Food processes in general
The above figures show typical product preparation sequences for a thermally preserved and a refrigerated products. It is important to know the following information to determine the microbial safety of a product and to determine what quality control actions will be needed to achieve a safe product when used under the conditions for which it was designed.
First, all raw material, ingredients and packaging materials in contact with the food must be specified and if needed tested to meet specifications.
Second, it is important that an element of food be observed as it enters, passes through and leaves the process. This "ride" on a particle of the food should provide the following data at each process step from entry to discharge:
Further if preservatives are required to prevent microbial growth, their addition point and concentration throughout the entire food mass should be shown. Finally for products which depend on a sealed package one should check the seal integrity of each container produced.
As one rides along the food as it travels through each step it is necessary also to observe the number and types of microorganisms entering or leaving the food and if these numbers are increasing (+), decreasing (-) or remaining the same (=).
These data when reviewed for quality control procedures will help ensure a safe, reliable and cost effective process.
Figure 10.3.2 Vacuum packed refrigerated meat soup. Inventory of process steps for ingredients, packages and process conditions to provide a basis for Hazard Analysis
10.3.5 Hazard analysis and critical control points (HACCP) in food industry - steps to be considered
- Consumer safety (e.g. foreign bodies, microbiology, aflatoxins, pesticides, heavy metals, monomers, etc.);
- Edible quality of the product (e.g. taste, texture, colour, smell, appearance, etc.).
TABLE 10.3.1 Simple process description for hazard analysis
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