Eggs are a popular ingredient in many recipes. However, you may have come across the term “pasteurized egg” and felt unsure about its meaning. Well, pasteurized eggs have emerged as a response to the need for reducing the risk of foodborne illnesses associated with raw or undercooked eggs. Since their introduction during the early 20th century, the pasteurization of eggs has evolved and become a widely practiced method to ensure safer consumption of eggs and egg products.
WHAT IS PASTEURIZED EGG?
When an egg pasteurized, this means it has been treated with a mild heat treatment called pasteurization. Pasteurization involves subjecting eggs to heat at a precise temperature for a specific duration. This effectively kills potentially harmful pathogens while preserving the egg’s quality and nutritional value. This process provides an added layer of safety, making pasteurized eggs suitable for raw or lightly cooked consumption, such as in recipes that call for uncooked eggs.
Pasteurized eggs offer an alternative to traditional, non-pasteurized eggs, providing individuals with options for increased food safety and peace of mind. For this reason, pasteurized eggs are an appealing choice for individuals with compromised immune systems, pregnant women, or those who prefer an extra measure of assurance.
The process of pasteurizing eggs not only provides peace of mind for consumers, but also offers a valuable solution for those who desire or require the use of raw or lightly cooked eggs in their culinary endeavors. Pasteurized eggs have undergone the necessary heat treatment to reduce the risk of Salmonella contamination, making them safe for consumption without the need for extensive cooking.
HOW EGG PASTEURIZATION WORKS
Salmonella, a common form of bacteria found in raw eggs, could pose a health concern to consumers. Within 12 to 72 hours of ingestion, an individual may have abdominal pains, diarrhea, vomiting, and fever. Contrary to popular assumption, Salmonella in eggs is caused mostly by the chicken that lay the egg, rather by poor handling during transportation or storage. The membrane around the yolk of an egg degrades with time. This eventually permits bacteria to enter the yolk and contaminate it. This is significant because raw egg yolks are utilized in some recipes, such as mayonnaise, and eggs with “runny” yolks.
One important aspect to note is that determining whether an egg harbors Salmonella is impossible without proper preparation and cooking. By thoroughly cooking egg dishes, the heat kills any potential Salmonella bacteria that may be present, ensuring food safety. Since Salmonella is a living organism, it thrives in warm temperatures and is hindered by colder (refrigerator) temperatures. Additionally, exposure to high temperatures effectively eradicates the bacteria.
Pasteurizing the egg significantly reduces the risk of Salmonella contamination. During pasteurization, eggs are subjected to specific temperatures to eliminate Salmonella. Heating eggs at 140°F (60°C) for 5 minutes or at 190°F (8°C) for 1 minute is essential for effectively killing the bacteria. In the United States, liquid whole egg must undergo a heat treatment of 3.5 minutes at a temperature of 140°F (60°C), as per the regulations set by the United States Department of Agriculture (USDA). According to the agency, pasteurized eggs in their shells should be refrigerated and are typically suitable for use within a period of three to five weeks.
PASTEURIZED EGGS IN COOKING AND FOOD MANUFACTURING
When it comes to uncooked foods like mayonnaise, the use of pasteurized raw eggs becomes crucial in maintaining food safety standards. Unlike unpasteurized shell eggs, pasteurized eggs do not support bacterial growth, making them a preferred choice for manufacturing or retail operations where adequate heat treatment is not applied to foods containing eggs.
Unpasteurized shell egg whites used to make raw meringues are regarded as a “low-risk” food. This is because meringues have a high sugar content, which binds to and reduces the amount of water that is available for bacterial growth. As a result, bacteria’s needs for water activity are not met, which restricts their ability to grow and spread. Additionally, because pasteurization removes the possibility of hazardous microorganisms present in raw eggs, using pasteurized egg whites in meringue recipes offers an additional level of safety.
While pasteurized egg whites offer advantages in terms of safety, its biggest disadvantage lies in its altered functional properties. Eggs are rich in proteins. The proteins in egg whites can be denatured or undergo structural changes during pasteurization, potentially leading to alterations in emulsifying, foaming, or gelling abilities. This can impact the texture, stability, and overall quality of certain dishes or food products that rely on the unique properties of unpasteurized egg whites.
This is especially true when a recipe calls for whipped egg whites. Pasteurized egg whites may have a reduced ability to whip and create volume compared to unpasteurized egg whites. This can be a disadvantage when making recipes that require stiff peaks or incorporating air into mixtures, such as soufflés, meringues, or chiffon cakes. The altered protein structure due to pasteurization may result in less stable foams and reduced overall volume.
For more this, this article should help: Why You Should Not Use Pasteurized Egg (Whites)
PASTEURIZING EGG AT HOME
Due to a number of considerations, pasteurizing eggs at home can be difficult and sometimes dangerous. While pasteurizing eggs in a controlled commercial environment is conceivable, doing so at home could not produce the same level of safety. Eggs are pasteurized at home by being heated in a pot over a stovetop for 3 minutes at a constant temperature of 140°F. The eggs are then rapidly stopped from cooking by placing them in a dish of icy water.
The biggest concern here is achieving the appropriate internal temperature during pasteurization. Pasteurization requires precise temperature control and timing to effectively eliminate pathogens while preserving the quality of the eggs. Home kitchen equipment may not provide the same level of accuracy and consistency as commercial pasteurization processes, making it difficult to achieve the desired result. To assure food safety, commercial pasteurization procedures are rigorously tested and adhere to recognized protocols.
Home pasteurization methods may not satisfy the same standards or have been extensively scientifically confirmed. Without a defined approach, it is difficult to validate the efficacy of home pasteurization techniques.
For this reason, it is typically suggested that commercially pasteurized eggs be used for safety and consistency instead of pasteurized egg at home. Commercial pasteurized eggs are subjected to a controlled and validated technique to ensure successful pathogen elimination while retaining egg quality. The United States Food and Drug Administration (FDA) must approve any procedure used for pasteurizing eggs in-shell.
References
N. A. Michael Eskin, F. Shahidi (2013). Biochemistry of Foods (3rd edition). Academic Press.
J. Jay, M. Loessner, D. Golden (2005). Modern Food Microbiology (7th edition). Springer.
I. Shaw (2013. Food Safety: The Science of Keeping Food Safe. John Wiley & Sons, Ltd.
V. Vaclavik, E. Christian (2014). Essentials of Food Science (4th edition). Springer.
N. A. Michael Eskin, F. Shahidi (2013). Biochemistry of Foods (3rd edition). Academic Press.
J. Provost, K. Colabroy, B. Kelly, M. Wallert (2016). The Science of Cooking: Understanding the Biology and Chemistry Behind Food and Cooking. John Wiley & Sons, Inc.
