The Seven Recipe Processes
All recipes can be clustered into seven process styles (Figure 6-1) in terms of vegetative cell destruction and toxin-spore control. These are:
Design for control of infective microorganisms
and toxin-producing microorganisms
Thick foods, such
as large pieces of meat and poultry, may have high levels of surface contamination.
Usually, these products are cooked or roasted slowly in an oven.
During this time, vegetative pathogens on the surface of roasts or poultry
are inactivated. The hazard control point for a large piece of meat
occurs after it has been cooked, when it is left for some period of time
for carving and serving. Often during serving, the meat will be at
100 to 110ºF (37.8 to 43.3ºC). Therefore, if it is not
served and consumed in a period of approximately 2 to 5 hours, there is
a serious risk that the C. perfringens in the meat will have enough
time to multiply to an illness-causing level. The critical control
point for any thick food is after it has been cooked, and the control is
using the foods within the time / temperature constraints of Table 5-1.
Thin foods. The problem with thin foods is that the center most likely will be contaminated (e.g., Salmonella in eggs, Trichinella spiralis in pork, E. coli O157:H7 in hamburger, etc.). The cooking process can be so fast that the infective microorganisms in the center of the food may not be inactivated with heat. There is also the problem of non-uniform heating (as occurs in a microwave oven), allowing vegetative cells to survive. After the food is cooked, since thin foods are usually individual portions, they probably will be eaten almost immediately, and spores will have no chance to outgrow, nor will S. aureus have time to grown and produce a toxin. Thus, the critical control point is correct, uniform heating of the food to temperatures for times that assure adequate pasteurization.
Hot sauces and food products such as soups and gravies are heated sufficiently during preparation or production to easily destroy vegetative cells. However, spores survive. Therefore, if the soups and sauces are not kept hot, above 130ºF (54.4ºC) after cooking, spores of C. perfringens and other microorganisms can grow out, multiply, and make people ill if not cooled continuously for times and temperatures necessary to prevent their growth. For sauces heated to low temperatures, such as Hollandaise sauce made with raw egg, a combination of low-temperature heating and acid formulation accomplish pasteurization. If the pH of the sauce is less than 4.1, salmonellae will be inactivated.
Fruits, vegetables, and starches are contaminated with both vegetative pathogens and spores, and perhaps chemicals. All raw fruits and vegetables must be double washed in a clean, sanitized vegetable preparation sink, or other clean, sanitized container. Each washing will reduce the organisms approximately 10 to 1 (133). Therefore, overall, there will be a pathogen reduction of about 102 on the surface of the fruits and vegetables. This is the only control for contamination of fruits and vegetables that are to be consumed raw. Hence, washing in a clean, sanitized equipment is an extremely important critical procedure. If the fruits or vegetables are cooked and have a pH above 4.6, C. botulinum and B. cereus will become a serious hazard. Hot fruits and vegetables must be kept above 130ºF (54.4ºC) to prevent spore outgrowth, or cooled continuously to 45ºF (7.2ºC) within 15 hours, and held at 41°F (5.0°C) or less.
Breads and batters are inherently safe because, initially, breads are fermented with yeast or sourdough bacteria that provide safety by competitive exclusion. These products are cooked to a high temperature, over 180ºF (82.2ºC), for a period of time that is sufficient to destroy any infective microorganisms that may have contaminated and multiplied in the product. However, baked products that are iced, filled, and manipulated after baking must be handled with care. Hand washing becomes an important critical control point; otherwise, pathogenic microorganisms can be introduced, which will make the baked products hazardous. Other critical controls include correctly pasteurizing and cooling hazardous fillings such as egg- and milk-containing fillings and custards.
Cold combination products are typically a protein mixed with a sauce such as mayonnaise and a starch such as macaroni (e.g. macaroni salad with tuna, egg, or cheese). The critical control procedures involve making certain that no microorganisms grow during the ingredient cooling step, and then preventing cross-contamination during mixing. If all ingredients are cooled to 41ºF (5.0ºC) and kept below 50ºF (10.0ºC) during mixing, there is no hazard from growth and toxin production by S. aureus or proteolytic C. botulinum. Using salads that are stored at less than 41ºF (5.0ºC) in less than 10 days assures safety from pathogen multiplication.
Hot combination products, such as casseroles, are safer than cold combinations in that if there is some infective microorganism contamination during the mixing step, the organisms can be inactivated during reheating. However, there will be spore and S. aureus contamination when the ingredients are mixed. If S. aureus, B. cereus, or C. botulinum are allowed to multiply due to careless handling of food after cooking, the toxins produced by these pathogens will not be inactivated in the reheating step. Casseroles must be kept below 50ºF (10.0ºC) until heating, and then heated to above 130ºF (54.4ºC) in less than 6 hours to prevent multiplication of C. perfringens during cooking.
Recipe Flow Charting
The first step in applying HACCP principles to recipes is to do a process flow chart. Figure 6-2 is a simple illustration of a recipe flow chart. There are three columns identified as a, b, and c columns. The b column shows subprocesses as to what is done at a given point in the a column. The c column shows subprocesses at a given point in the b column. Each step is numbered sequentially from 1 to the end. Food processes such as making beef stew for lunch in a institutional kitchen can easily require 150 steps.
One problem with most recipes is that the sequence when first diagrammed is illogical and inefficient. By flow diagramming the recipe, the proper order in which steps should be accomplished in order to minimize labor and maximize safety becomes obvious.
First, the vegetables are cut or chopped, because these food items change the least in quality while waiting to be combined. Next, sauces are made, because they can be put into a bain marie and held hot without much deterioration in quality. Next, the meat is cooked to the point at which the pre-prepared vegetables, which take less cooking time, can be added. Then, the sauce is combined at the correct point, and the product is finished, panned or bagged, and served. An important point is not to cook the meat first and let it remain at ambient temperatures while sauces and vegetables are prepared. Clearly, this procedure could lead to food safety problems.
At each step in the flow, the step is identified by one of the five industrial engineering symbols, Operate, Transport, Delay, Inspect, and Store. The use of these five terms is very important to recipe analysis, because it allows comparing the safety and efficiency of one recipe with another. The optimum recipe has a minimum of Operate and Transport steps to achieve the desired sensory properties for the finished product. Ideally, it should have no Delay steps. It has an optimum number of Inspect steps, whereby the employee is given specific instructions to verify the quality and safety of the product. Finally, there is only one Store step at the end. Any unnecessary delay in Store steps represent hazard control points.
Each step has provisions for "temperature in" (Ti) of the food, the "temperature out" (To) of the food, and the time (t) it will take to complete the step. When this information is used in combination with the growth and death temperatures and times previously listed, it is possible to validate the control of vegetative and spore pathogens in a process. (If Figure 6-2 does not print properly, click here for separate image.)
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