Microscopic bacteria in a nano-emulsion liquid.

Do Nano-Emulsions in Your Food Really Keep Bacteria Away? The Truth Revealed!

Rhea Morgan in Science & Nature June 2025 • 3 min read.

"A new study investigates the real impact of nano-emulsions on bacterial survival and growth in food, challenging common beliefs about their antimicrobial properties."

In the world of food production, innovation is constant. One such innovation is the use of nano-emulsions—tiny droplets, less than a micrometer in diameter, dispersed within a liquid. These nano-emulsions are added to foods to improve texture, appearance, and even taste. They've also been touted for their potential to fight off bacteria, keeping our food safe from spoilage and harmful pathogens.

But do nano-emulsions really live up to the hype? While many studies have praised their antimicrobial properties, others have found little to no effect. This inconsistency has led to confusion and skepticism among food scientists and manufacturers alike.

A groundbreaking new study has dived deep into this debate, seeking to clarify whether nano-emulsions truly impact bacterial survival and growth in food. The results might surprise you.

Nano-Emulsions: The Claimed Superpower Against Bacteria

Microscopic bacteria in a nano-emulsion liquid.

Nano-emulsions have become increasingly popular due to their potential to enhance food quality. They promise improvements such as reducing the need for fats and emulsifiers, boosting emulsion stability, enhancing appearance, and even improving taste. Some studies suggest that nano-emulsions can combat various harmful bacteria, including well-known culprits like Bacillus cereus, Escherichia coli, and Listeria monocytogenes.

The secret behind this antimicrobial action is believed to be the structure of the nano-emulsions themselves. When these tiny droplets are formed under high-energy processes like ultrasonication or high-pressure homogenization, they become thermodynamically driven to merge with lipid-containing microorganisms. This fusion can disrupt the bacterial membrane, leading to cell damage and death. However, not all research agrees on this mechanism or its effectiveness.

Improved Food Properties: Enhance texture, appearance, and taste.
Antimicrobial Activity: Combat harmful bacteria like E. coli and Listeria.
Membrane Disruption: Nano-droplets fuse with bacterial membranes, causing cell damage.

To resolve these conflicting reports, researchers conducted a detailed study focusing on four bacterial species: Staphylococcus epidermidis, Bacillus cereus, Lactobacillus acidophilus, and various strains of Escherichia coli. They aimed to determine whether nano-emulsions could indeed inhibit bacterial growth and disrupt their cell membranes. The study also explored how different formulations and bacterial characteristics might influence these effects.

The Verdict: Nano-Emulsions Need a Second Look

The study's findings suggest that the antimicrobial activity of nano-emulsions may be more nuanced than previously thought. Factors like formulation and specific antimicrobial agents play a significant role. Nano-emulsions are a promising tool in food technology, but their antimicrobial capabilities should be carefully evaluated and not taken for granted.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.foodres.2017.08.064, Alternate LINK

Title: Do Oil-In-Water (O/W) Nano-Emulsions Have An Effect On Survival And Growth Of Bacteria?

Subject: Food Science

Journal: Food Research International

Publisher: Elsevier BV

Authors: Hani El Kadri, Putu Virgina Partha Devanthi, Tim W. Overton, Konstantinos Gkatzionis

Published: 2017-11-01

Everything You Need To Know

What exactly are nano-emulsions, and what are they used for in food?

Nano-emulsions are tiny droplets, less than a micrometer in diameter, dispersed within a liquid. They are used in food production to potentially improve texture, appearance, and taste. Some studies have suggested they can fight off bacteria. However, the effectiveness of nano-emulsions as antimicrobial agents is still under investigation and varies depending on the specific formulation and bacteria involved. The study indicates that nano-emulsions may not be as universally effective against bacteria as previously thought and should be carefully evaluated for their antimicrobial properties.

How are nano-emulsions supposed to kill bacteria in food?

The antimicrobial activity of nano-emulsions is believed to stem from their ability to merge with lipid-containing microorganisms, disrupting the bacterial membrane and leading to cell damage and death. When these droplets are formed under high-energy processes like ultrasonication or high-pressure homogenization, they become thermodynamically driven to merge with lipid-containing microorganisms. However, research findings are inconsistent, and the actual impact can vary. This process aims to prevent food spoilage and ensure food safety by reducing harmful bacteria.

Which specific types of bacteria were studied to test nano-emulsions?

The study focused on bacterial species, including Staphylococcus epidermidis, Bacillus cereus, Lactobacillus acidophilus, and various strains of Escherichia coli. These bacteria were chosen to determine whether nano-emulsions could inhibit their growth and disrupt their cell membranes. Understanding how nano-emulsions interact with different bacteria is crucial for assessing their overall effectiveness as a food safety measure.

What does the research say about how well nano-emulsions work to kill bacteria?

The findings suggest that the antimicrobial activity of nano-emulsions is influenced by factors like the specific formulation used and the particular antimicrobial agents present. This means that the effectiveness of nano-emulsions can vary, and their antimicrobial capabilities should be carefully evaluated rather than assumed. It highlights the complexity of using nano-emulsions in food technology and the need for thorough testing.

Besides killing bacteria, what other benefits do nano-emulsions offer in food production?

Nano-emulsions enhance food quality by improving texture, appearance, and taste. They also have the potential to reduce the need for fats and emulsifiers and boost emulsion stability. Some studies indicate that nano-emulsions can combat harmful bacteria like Bacillus cereus, Escherichia coli, and Listeria monocytogenes. While promising, their actual antimicrobial capabilities require careful evaluation, as their effectiveness is not guaranteed across all formulations and bacterial species.