Nanobubbles: A Novel Approach to Produce Washing
There are many ways to define quality produce: color, taste, and texture. Fresh, quality produce would tick all these boxes, but are they enough? Apart from quality, consumers value safety when they choose products from the market. Tasty produce won't matter if it will compromise their health.
Understanding Produce Pathogens
According to WHO, contaminated food and water cause around 600 million infections and 420,000 deaths annually. It continues to be a serious health risk today, both in developed and developing countries. There are several species of bacteria that can unwittingly infect unclean produce. Some of these are included in the main group of food-borne pathogenic bacteria including Salmonella, Campylobacter, and Shiga-toxin producing Escherichia coli (STEC & EHEC).
Listeria monocytogenes isn't on the WHO list, but it is of serious concern in the United States as it can cause listeriosis, a disease reported usually after eating fresh vegetables. It gave rise to a deadly epidemic that prompted researchers to develop the field of Listeriomics, an integration of all published genomic, transcriptomic, and proteomic data of Listeria species.
How Do Producers Keep Their Produce Clean?
To survive several steps of food processing, produce pathogens form biofilms. This allows them to attach to food surfaces more effectively and to resist antibiotic treatments and disinfectants. Unfortunately, washing your produce with water won't always do the trick of removing these harmful pathogens from your food. Producers and vendors think that proper handling and simple hygiene and handwashing can ensure clean produce. However, food pathogens can be extremely persistent. With the right substrate and conditions, some of the remedial bacteria in the food might grow and easily form another biofilm.
Therefore, these measures may help but won't solve the problem. Nanotechnology has been used in recent years for food processing and food contact packaging. The technology uses nanomaterials like zinc oxide, iron oxide, and carbon black to improve food quality, flavor, and color, and increase the food's shelf life by inhibiting the growth of food pathogens. They can also be used as biosensors and chemosensors to detect foodborne pathogens such as E. coli, Salmonella enterica, Vibrio cholerae, and Campylobacter jejuni. The only problem is, there are potential hazards for nanoparticle use.
What are Nanobubbles?
In recent research, scientists have potentially found a more effective and safer way to get rid of food pathogens and ensure produce safety. Nanobubble technology uses ozone-filled "bubbles" or gaseous cavities for ultrasonic cleaning and extensive removal of bacterial biofilms on surfaces. It also works against algae, viruses, and parasite cysts.
Since 1904, ozone has been commercially used for the treatment of potable water. It is the most powerful oxidizing agent that's permitted for use. It proves more effective than traditional methods as it also uses acoustic-carbonic acid microbubbles to successfully kill the microbes, prohibiting them from re-growing and producing another biofilm. This can also work against antibiotic-resistant and spore-forming pathogens as it uses a different mechanism called oxidation to disrupt bacterial cell walls leading to cell rupture and immediate death of the cell.
In recent years, the use of Nanobubbles for produce safety has gained popularity. The study by Bialoszewski and colleagues in 2011 proved the effectiveness of ozonated fluid against antibiotic-resistant Staphylococcus aureus and Pseudomonas aeruginosa. It was also effective in disinfecting the freshwater fish, Nile tilapia, of its pathogenic bacteria, Vibrio parahaemolyticus. In Japanese aquaculture systems, researchers succeeded in removing this bacteria via ozone nanobubbles (NB-O3) from whiteleg shrimp. Vibrio parahaemolyticus may cause early mortality syndrome or hepatopancreatic necrosis disease in shrimp, resulting in soft, darkened shells and mottling. Not only does it sterilize the food, but nanobubbles can also clean the stainless steel surfaces used in food handling, allowing for maximum food safety.
Apart from its effectiveness, there are other benefits of using nanobubbles instead of traditional bactericidal agents. It is the more environment-friendly option as no pollutants are released in creating nanobubbles. What's more, any waste produced in the process can be safely released in waterways and surface drains. The wastewater can even be recycled and used in other grey water applications.
Lastly, excess nanobubbles can simply auto-decompose, leaving no residues, which is an attractive feature for consumers.
Keeping Your Produce Clean and Safe
As responsible producers, your consumers' health should be of utmost importance. Nanobubbles technology is a powerful and sustainable way to clean produce from leafy greens to fruits to vegetables to even the surfaces used in food handling. If you are looking into using this technology, Eurofins scientists would be happy to work with you on process validation and efficacy studies.
To discuss further, contact Eurofins, your partner in food quality and safety. See our Produce testing and risk management solutions here!
