Does Pasteurization Neutralize Avidin in Eggs?

December 31, 2025 •

4 min read

Avidin, a protein found in raw egg whites, has been known to bind the B-vitamin biotin, potentially limiting its bioavailability. This has led many to question whether commercial pasteurization is a sufficient heat treatment to neutralize avidin and release biotin. The short answer is yes, pasteurization does neutralize avidin, making the biotin more accessible. However, the process is not always 100% effective and depends on specific time and temperature parameters.

Quick Summary

This guide explains the process of avidin neutralization during pasteurization, detailing the required time and temperature. It covers the biochemical interaction between avidin and biotin, the impact on nutritional value, and compares the effectiveness of different cooking methods for inactivating avidin.

Key Points

Pasteurization Neutralizes Avidin: Commercial pasteurization processes heat liquid eggs sufficiently to denature the avidin protein, effectively neutralizing its ability to bind biotin.
Heat Destroys Avidin's Function: The high temperatures used in pasteurization break down the protein structure of avidin, destroying its biotin-binding site.
Residual Activity Can Occur with Incomplete Heating: Inconsistent or short-duration home cooking, like lightly fried or poached eggs, may not fully neutralize avidin, potentially leaving some active protein.
High Temperature and Time are Key: Complete avidin inactivation requires both a sufficiently high temperature and an adequate holding time, which commercial pasteurization ensures.
Biosecurity, Not Just Nutrition: Beyond releasing biotin, pasteurization also serves the critical food safety function of killing harmful bacteria like Salmonella.
Excessive Raw Egg White Consumption is the Risk: Biotin deficiency is primarily a concern when large quantities of raw egg whites are consumed over extended periods, not from occasional, mildly undercooked eggs.

Understanding the Avidin-Biotin Interaction

Avidin is a glycoprotein found primarily in the egg white (albumen) of birds, reptiles, and amphibians. Its natural function is thought to be an antimicrobial defense, as it starves bacteria of the essential B-vitamin, biotin, by binding to it with an extremely high affinity. This bond is one of the strongest non-covalent interactions known in nature.

When consumed in raw eggs, avidin can bind to biotin in the human digestive system, preventing its absorption. While mild biotin deficiency from this cause is rare in individuals with a balanced diet, excessive consumption of raw egg whites can lead to a condition known as "egg white injury," characterized by symptoms of biotin deficiency such as hair loss and dermatitis.

The Mechanism of Avidin Inactivation by Heat

Heat treatment, such as cooking or pasteurization, denatures the avidin protein. Denaturation is the process by which a protein loses its tertiary and quaternary structure, rendering it non-functional. For avidin, this means its binding site for biotin is destroyed, preventing it from sequestering the vitamin.

However, avidin is surprisingly heat-stable. Complete inactivation of its biotin-binding capacity requires sufficient time and temperature exposure, which can vary depending on the specific heating method. This is why simple, brief cooking methods may not fully inactivate all avidin, leaving some residual activity.

How Pasteurization Affects Avidin

Pasteurization is a heat treatment process that destroys pathogenic microorganisms like Salmonella by heating liquid eggs to a specific temperature for a set duration. Commercial pasteurization processes are designed to be effective against pathogens, but they are also effective at denaturing the avidin protein.

For example, one commercial process mentioned involves heating liquid egg whites to 134°F for 3.5 minutes, a process that is designed to both kill Salmonella and neutralize avidin. The heat-treatment parameters are carefully controlled to ensure safety without excessively damaging the nutritional quality of the eggs. Therefore, commercially pasteurized liquid egg whites are generally considered safe for consumption and have minimal avidin activity.

Comparison of Avidin Inactivation by Different Cooking Methods


Cooking Method	Temperature/Duration	Effect on Avidin	Biotin Bioavailability	Key Considerations
Pasteurization	Approx. 134°F (56.7°C) for 3.5 min	Significantly Neutralized	High	Precise, controlled heating; standard for liquid eggs.
Boiling	100°C for >4 minutes	Almost complete inactivation with sufficient time	Highest with proper cooking	Cooking time is crucial; rapid boiling might leave some residual activity.
Frying	Varies widely based on temperature	Partial Inactivation (approx. 33% residual activity)	Moderate	Inconsistent heat distribution and shorter cooking times can leave significant avidin active.
Poaching	Simmering water (approx. 71-82°C)	Moderate Inactivation (approx. 71% residual activity)	Low-Moderate	Center of the egg may not reach high enough temperature for long enough.

Factors Influencing Avidin Neutralization

Several factors can influence the effectiveness of heat treatment in neutralizing avidin:

Temperature: Higher temperatures generally lead to faster denaturation.
Duration: A longer holding time at a specific temperature allows for more complete protein denaturation.
Homogeneity of Heating: For home cooking, ensuring the egg is heated evenly and thoroughly is key. Undercooked portions may still contain active avidin.

Importance of Fully Neutralizing Avidin

While residual avidin activity from slightly undercooked eggs is unlikely to cause a biotin deficiency in a healthy person with a diverse diet, it is important to understand the implications for certain groups. Individuals who consume excessive amounts of egg whites, such as bodybuilders, or those with underlying health conditions, may be more vulnerable to the effects of residual avidin. For these reasons, choosing pasteurized or fully cooked eggs is the safest option.

It is also worth noting that the egg yolk contains a significant amount of biotin. In whole eggs, the biotin from the yolk can help to offset the binding effect of avidin from the white, assuming the egg is cooked thoroughly. The issue becomes more pronounced when only raw egg whites are consumed or used in recipes.

For more detailed information on avidin, biotin, and their biochemical relationship, consult the reputable scientific and medical resources such as this summary from the National Institutes of Health.

Conclusion

In summary, commercial pasteurization is an effective method for neutralizing avidin in egg whites, making biotin available for absorption. This controlled heat treatment is specifically engineered to ensure food safety by eliminating pathogens like Salmonella, and in doing so, it also denatures avidin. While some home cooking methods may leave residual avidin activity, thoroughly cooking eggs will also deactivate the protein. For raw preparations, such as in certain sauces or protein shakes, commercially pasteurized liquid eggs are the safest choice to avoid any risk of biotin deficiency.

Frequently Asked Questions

No, it is highly unlikely. The pasteurization process is designed to effectively neutralize avidin, the protein that binds biotin in raw egg whites, making commercially pasteurized liquid eggs a safe option.

Thoroughly scrambling eggs, which involves cooking the entire egg to a high temperature, is very effective at neutralizing avidin. However, if the eggs are undercooked, some residual avidin activity may remain.

Yes. Commercially pasteurized liquid eggs are heat-treated to eliminate harmful pathogens, including Salmonella, making them safe for raw applications like mayonnaise, dressings, and protein shakes.

Avidin has an extremely high affinity for biotin, and each molecule of avidin can bind up to four molecules of biotin.

No, avidin is found in the egg white (albumen). The egg yolk contains a rich source of biotin, which is protected from avidin's binding action by the separation of the yolk and white.

Research suggests that boiling for over 4 minutes is required to achieve complete inactivation of avidin's biotin-binding capacity.

In laboratory settings, avidin can be chemically modified to alter its binding properties. However, for food preparation and safety, heat treatment remains the standard and most effective method.