The fight for safe food: emerging technologies offer new solutions to combat food contamination and fraud.
Imagine a jug of milk in your refrigerator that turns red when it has spoiled or produce packaging that transmits a warning icon when its shelf life has run out--these advancements in food safety technology are on the horizon.
One of the biggest issues in food safety is the risk of foodborne illnesses. The CDC estimates that one in six Americans get sick each year due to foodborne illnesses, and 128,000 are hospitalized.
Dangerous bacteria is increasingly contaminating a wider variety of foods as well. Listeria for example, which is typically associated with cheeses, is now causing recalls in frozen vegetables and prepackaged salads.
Produce and other foods come into contact with an array of bacteria and contaminants during the many stops along the food supply chain, making it increasingly difficult to ensure the safety of these products.
One drawback to current food safety testing methods is that it can take up to a week for a production company to know if a batch of supply has become contaminated. Now, research coming out of UC Davis is looking to drastically change that time frame.
Jeremy Warren, former UC Davis postdoc in plant pathology, and founder and CEO of Astrona Biotechnologies, is developing a technology that reduces testing time down to just one hour. His research team began experimenting with the technology at UC Davis, and the initiative grew into a spinoff company.
According to Warren, produce companies spend $4.5 billion every year to ensure their product is safe, but people are still getting sick. Warren pointed to the length of time it currently takes to test for pathogens as one cause. Currently, companies take a sample and ship it to a third-party lab where the bacteria needs to be cultured, which can take 24 hours. By the time a company receives its test results back, a few days or a week may have gone by and during that time, the potentially contaminated product may have already been sent to stores, leading to recalls.
Astrona's RNA-based detection platform can identify a pathogen's presence at any point of the supply chain and deliver results in one hour.
As Warren explained to Laboratory Equipment, this is done through four steps--capture, wash, amplify and detect. A sample swab is isolated to free the RNA of the bacteria. Warren said using RNA in conjunction with the platform's proprietary capture protein and sequence-specific tag eliminates the need for cell culturing and provides near-immediate results. The pathogenic RNA researchers want to examine is separated, and everything else is washed away. The team also developed a proprietary isothermal amplification to create a signal from the RNA and amplify it to determine through a color reading if the sample is contaminated.
The current product that incorporates the technology is a disposable kit that costs $50. Each kit can detect one pathogen--salmonella, E.coli, Listeria--with sensitivity that meets USDA guidelines.
A future version will be an automated machine with data tracking software. The innovation was chosen to be presented at the Ag Innovation Showcase this month, which offers an opportunity to highlight promising startups and research projects pursuing solutions in ag-biotech, renewable energy, sustainable materials and more.
Smart packaging, devices
In July, the Institute of Food Technologists (IFT) Annual Meeting & Expo brought together more than 20,000 food professionals from industry, government and academia to highlight the latest trends and advancements in food safety, as well as address challenges in the field.
One of the overarching themes of this year's conference was determining how to bring some of the latest technologies that are now incorporated in the food supply chain down to a consumer level.
Consumers crave the same information that manufacturers and retailers are equipped with, so the goal is to provide every household with products that can replace unreliable expiration dates or "best if used by" dates, and instead give real-time information to prevent food waste and health risks.
Claire Sand, adjunct professor of packaging at Michigan State University and owner of Packaging Technology & Research, shared her insight on the progression of "intelligent packaging" during an IFT symposium titled, "Where Science Feeds Innovation."
TTI, or time temperature indicators, have become a standard in the food industry and are now required by retailers. They can be placed on pallets of food products and linked to RFID chips to view data from a smartphone or other device. As the name states, a TTI lets retailers and manufacturers know how long a specific product has been exposed to certain temperatures, which provides information into whether the package has spoiled or runs the risk of growing bacteria. The indicator can also be used as a reference to know how long a product will last on store shelves.
"Food spoilage is often dependent on time and temperature because food deterioration occurs as products age and temperatures rise. Lipid oxidation, enzymatic browning, nonenzymatic browning and microbial growth escalate with increased temperature and time," Sand wrote in a recent report.
But as Sand explained to Laboratory Equipment, the next phase of this food safety innovation is to expand beyond TTIs and bring the technology to a consumer level.
"The technology is there, we just need to extend it," she said.
One way is through degradation sensors, which can analyze the amount of bacteria that may be present.
Food Quality Sensor International has developed such a product with its SensorQ. The smart sensor label sits inside the wrapping of uncooked meat or poultry and can determine spoilage by measuring levels of volatile basic nitrogen. When the label is orange, the meat is fresh, but if it turns a tan color, it means the bacteria inside the product has reached a critical level and has spoiled.
These types of smart sensors and labels have been slowly introduced throughout the last few years, but they have not yet been adopted across the industry.
One crucial challenge in bringing these types of technologies to a consumer level is honing in on how to make TTIs and other sensors, as well as "intelligent packaging," customizable for different varieties of foods.
For example, Sand pointed out that the shelf life among produce varies by season and the conditions it was grown under, so indicators and intelligent packaging would need to be tailored to the product depending on these variables.
Sand said because agricultural variation is regional, produce is a more difficult avenue for intelligent packaging. Fish has also proven to be much more varied than previously thought.
Studies have shown that microbes vary greatly based on what water source they are from, so a salmon caught in one area of the world may contain different microbes than those caught in another region of the world. Where fish is washed and processed can also play a role based on the local water used, which again would spread different bacteria based on the location.
This is where current TTIs may give off false readings, and incorrectly tell a consumer that a food spoiled before it actually has. The technology relies solely on temperature readings and length of exposure and doesn't account for other variables. Luckily, the enhanced capabilities of degradation sensors can reveal the exact safety and quality of food in a consumer's refrigerator.
Another obstacle for food scientists is enhancing current packaging and indicators to accommodate the "clean label" movement. Consumers are increasingly interested. in purchasing goods without preservatives, which are what enable long shelf lives. Without preservatives and other processed ingredients, much better packaging will be needed to compete with the longer shelf lives we've become accustomed to.
Sand is currently assisting clients in the bakery industry to develop a mold inhibitor and developing another device for a client in the meat industry that could provide microbial decay measurements.
Food production facilities have rigorous cleaning and sanitization protocols to prevent contamination, but anything from door knobs, countertops, produce containers and other equipment that is transported in and out of the area can become a source of microbial contamination.
"There's a lot of opportunity to improve safety, quality and sustainability of our food supply through design of new materials and modification of existing ones," Julie Goddard, associate professor in the Department of Food Science at Cornell University, told Laboratory Equipment.
Goddard's team is working on developing an enhanced polymer coating for production facilities to reduce the likelihood of cross-contamination. She presented the innovative development at the IFT meeting.
The polymer coating works by incorporating two functional groups to inactivate microbes. When the coating is bound to a surface, one of the functional groups can bind with chlorine, which is one way to inactivate microbes. The coating also has within it functional groups that are "cationic amines"--another effective way to inactive microbes.
"Because these antimicrobial functional groups are bound to the polymer structure, which is bound to the surface its coating, they don't leave the coating. So it is long-lasting, and unlikely to migrate from the coating into food," explained Goddard.
Goddard's coating could be applied to a stainless steel work table, plastic conveyor belt or another food contact material and reduce the amount of microbes that could potentially adhere to the surface and pose a risk of cross-contamination.
The coating has shown to inactivate more than 99.99 percent of Listeria monocytogenes, but is still a few years away from being commercially available, according to Goddard. Additional research on performance under true operating conditions is currently underway.
"The goal of a coating like this is not to replace the need for cleaning and sanitization, but rather to add a sort of 'boost' so that in between cleanings, the materials that contact our food resist contamination," said Goddard.
Adulteration and other food fraud tactics have also become growing concerns among the industry. The 2008 Chinese milk scandal where formula was adultered with melamine, and more recently the UK meat scandal of beef products containing horse meat are just a couple examples of food fraud cases that caught the world's attention. But because food fraud is so difficult to detect and ingredients can be altered at any point during the production process, situations can go unnoticed.
Despite the horse meat scandal grabbing international attention, further UK testing revealed that 40 percent of lamb takeaways still contain other undisclosed meat, and more than 60 percent of ham and cheese pizzas tested contain neither ham nor cheese.
Currently, testing the authenticity of food products can involve liquid chromatography and gas chromatography mass spectrometry (LCMS and GCMS), nuclear magnetic resonance spectroscopy or polymerase chain reaction (PCR) techniques. However, existing methods tend to only search for one, long DNA sequence to analyze, which could break down during food processing and lead to inaccurate results.
MD. Eaqub Ah, of the University of Malaya, and fellow researchers wanted to develop an alternative approach that would be more reliable than PCR techniques in detecting food adulteration in processed meats.
In a study published in the Journal of Agricultural and Food Chemistry, the team tested a new technique that looked for pairs of short DNA sequences from beef, buffalo and pork in hot dogs. The testing showed that their target sequences were stable under food processing conditions.
They used the approach on 20 franks labeled as "beef" that were purchased from markets in Malaysia and found "rampant" substitution of beef with buffalo. However, the analysis showed purity in the pork materials.
According to Ali, the team is now proceeding toward testing other products like gelatin used in yogurts, confectioneries, beauty items and pharmaceutical capsules. But the scope is even broader.
"This concept could be used in the development of improved methods for disease diagnostics, forensic investigations and other genetic screening tests in food, medicine and agriculture," said Ali.
Adding or altering ingredients in foods not only has safety issues, but can cause cultural dilemmas as well if a consumer unknowingly eats a meat product that violates their religious dietary restrictions.
Almost any type of food can be a target of fraud, but the most common items are very processed foods, because it is easier to hide an abnormal ingredient in the product. On the other side of the spectrum, more refined and expensive products can also fall victim. Premium olive oil, for example, is difficult to pinpoint and a less expensive oil can easily be added to dilute the product, but still sell at a high-end price.
Honey is another popular target because it is visibly tough to tell the difference between an authentic product and one that has been tampered with. Richard Evershed, professor of biogeochemistry at University of Bristol explained during a podcast with The Guardian that high fructose corn syrup has the same "runny" look as honey, and the sugar composition is almost identical, requiring highly sensitive and precise testing methods.
Therefore, Evershed reiterated that it is necessary to develop advanced analytical techniques, such as isotopic analysis, molecular biology and a range of classic physical, chemical and biological methods to test for food authenticity and detect non-compliant products.
by Lauren Scrudato, Associate Editor
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|Article Type:||Cover story|
|Date:||Sep 1, 2016|
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