In today’s world, food hunger and insecurity are not due to lack of food. Right now, the world produces enough food to feed every adult and child currently alive on the planet. Yet, about 673 million people worldwide faced hunger in 2024, and 18.3 million households in the United States struggled with food insecurity in that same year.
Food waste or loss contributes greatly to this food paradox. It is estimated that a fifth of all food produced globally is lost before reaching someone’s table. Unharvested crops due to low prices, unsold food in retail stores, and uneaten leftovers in people’s homes contribute to this growing problem. In the US, the Department of Agriculture (USDA) estimates that between 30–40 percent of the food is wasted, with 31 percent of it being lost at the retail and household levels. Food losses affect more than just people; the current food production process, which includes livestock, fertilizer use in soil, agricultural machinery, transportation, and discarded food rotting in landfills also contributes to up to 10 percent of global greenhouse gas emissions.
Researchers believe science could help transform this dire scenario. From innovative solutions that improve food monitoring and minimize spoilage to approaches that extend produce shelf life, these technologies aim at minimizing the impact of food losses on people’s lives and the planet.
Bioagents to Tackle Foodborne Illnesses
Food contamination is a major cause of food loss and waste. Microorganisms in the soil and water can contaminate produce and cereals prior to harvest, while inadequate handling and improper sanitation of equipment used for food processing can lead to contamination and cross-contamination in food facilities.1
To reduce food contamination and minimize the risk of foodborne illnesses—preventable diseases caused by eating food contaminated with either pathogens or harmful substances— appropriate monitoring and decontamination of food products in the supply chain is key.
Globally, consumption of unsafe food leads to 866 million illnesses and 1.5 million deaths each year. Pathogen exposure is the primary cause of foodborne diseases, accounting for nearly 860 million cases in 2021. Even though stringent regulations and technologies have been set in place to make food safer, the burden of consuming unsafe food, as evidenced by the recent Cyclospora outbreak in the US, still calls for alternatives.
For McMaster University biomedical engineer Tohid Didar, bacteriophages hold great promise to tackle food safety issues. “I call them ‘organic antimicrobials,’” said Didar, whose team seeks to develop innovative ways to apply phage-targeted bacterial killing as a tool for food decontamination.
In recent years, the Food and Drug Administration has approved phage-based products for decontaminating food with major foodborne pathogens; yet limitations, including how to keep phages alive for extended periods, have hindered their broad implementation in the supply chain.
To make bacteriophages last, Didar’s team has developed phage-loaded microgels that hold billions of viruses and can be applied to food surfaces as either peelable patches or sprayable solutions.2 The team makes the microgels by mixing phages and a small molecule crosslinker to form a nanofibrous hydrogel that self-assembles within days.
Using the microgels, the researchers effectively eliminated a multidrug resistant strain of Escherichia coli from lettuce and raw meat.2 While these phage-based strategies worked to decontaminate food surfaces, Didar’s team is also testing approaches to facilitate their penetration deeper into the food.
Akansha Prasad, a graduate student in Didar’s lab, leads this work, which uses microneedles to deliver the viruses past the food surface. To develop an effective microneedle patch, the researchers tried out different polymer-phage combinations and used food-specific tests, such as vacuuming and tumbling, to simulate conditions frequently seen on production lines.3 Prasad explained that they selected real-world-inspired testing approaches as an effective way to characterize the phage patches and bring them closer to a final application.
The phage-loaded microneedle patches not only effectively eliminated E. coli contamination from meat but could also deliver a bacteriophage cocktail that simultaneously eradicated E. coli and Salmonella enterica contaminants. “When [the phage cocktail] worked, it was incredible,” Prasad recalled. “It's just this patch that you can throw on a variety of products, and it works really well.”
Nitin Nitin, a food engineer at the University of California, Davis, is also exploring bio-based approaches to reduce food spoilage. In Nitin’s case, he has turned his attention to yeasts and their ability to deliver compounds.
Using microorganisms as delivery vehicles is not new. In the 1970s, scientists studying Saccharomyces cerevisiae described how the baker’s yeast could encapsulate both water and fat-soluble compounds depending on its biochemical composition.4 However, these bio-based delivery systems faced stability limitations that precluded their use as biocontrol strategies.
Scientists like Nitin are overcoming some of these limitations. Over a decade ago, Nitin became interested in exploring microorganisms as carriers of antimicrobials. To turn yeasts into sanitizer carriers, his team leverages the yeast cell wall. The fungus’ outer layer components, such as chitin and mannoproteins, increase its affinity for other microbes, while the cell wall lipid content dictates the yeast’s ability to encapsulate antimicrobials that dissolve in lipids or water. By manipulating the fungus’ growth medium either by adding salts or forcing substances through the yeast’s cell wall using a vacuum, the researchers can change the yeast’s ability to encapsulate different compounds. According to Nitin, this process does not require sophisticated equipment, expanding its potential applications. “We want to find solutions not only to the challenges in a developed economy like the United States, but in developing countries at a low cost,” he said. “We want to find technologies that people can adopt anywhere in the world.”
Nitin’s team has characterized the delivery of both synthetic and natural antimicrobials, focusing on yeast carriers to tackle biofilms, which are known to enhance resistance to sanitizing agents and represent a major challenge for the food industry.5 The researchers showed, for instance, that the encapsulation of a chlorine-binding polymer in yeast microcarriers eliminated pathogenic bacteria and fungi in biofilms more effectively than a conventional treatment using a chlorine-based sanitizer.6
Nitin’s work on natural antimicrobials has focused on essential oils, which have emerged as eco-friendly alternatives to traditional decontaminating agents, such as chlorine- and ammonium-based compounds. Essential oils are blends of metabolites derived from plants. Their great diversity allows for the creation of a variety of antimicrobial preparations that target many microbes through different mechanisms. These include the disruption of microbial plasma membrane integrity and interference with key metabolic pathways.7 Even though scientists have studied essential oil applications as antimicrobials since the 2000s, making them a viable option for the food industry has faced challenges, including the oils’ volatility, non-specific interactions with organic matter, and high cost.
Nitin believes that yeast carriers may help overcome some of these limitations. “When bound in the [yeast] cell, they are quite stable,” he explained. “They can last for a longer period of time but still retain the efficacy to interact with the microbes and release upon contact, providing a more targeted delivery.” In a recent study, Nitin’s team showed that yeasts could encapsulate thymol, the major component of thyme oil, which has antimicrobial activities, and effectively inactivate bacterial biofilms on food-contact surfaces.8
The New Frontier of Food Monitoring: Smart Packages and Artificial Intelligence
Besides preventing foodborne diseases, monitoring food is also key to keeping track of food freshness. Even though the United States implemented food product dating over a century ago to keep people informed about the status of their food purchases, the commonly used ‘best before’ date labels are known to cause consumers confusion and lead to unnecessary food waste.9
Didar’s team has been working on alternatives to conventional methods of assessing food freshness by making food packaging ‘intelligent’ to provide real-time monitoring of food quality. “We can prevent the waste that happens at that final stage or have sensors that could monitor the packaging throughout the [food production] process,” he explained.
On this front, Didar’s team developed biosensors to create a lab-in-a-package system. This is a smart food packaging that combines fluorescent probe biosensors for pathogen detection with a membrane that provides the reagents needed for microbial identification. The system is placed inside a food tray similar to the foam trays used to sell meat at grocery stores, and it is designed to facilitate sampling of fluids naturally released by food. To detect the probes’ signals, producers can use portable fluorescence scanners and generate images that they can visualize on a smartphone.10 “Lab-in-a-package was the first time we tried to actualize these [biosensors] into continuous monitoring without the need to even open a package,” Prasad said.
Researchers are also testing machine-learning-based models to facilitate food monitoring throughout the supply chain. Nitin, who is among these scientists, believes that AI could be easily implemented into microbiology labs across the food industry as it does not require sophisticated equipment, thus simplifying data analysis. “Such tools can provide a framework where we can have quicker diagnostics [at] lower cost, something that is translatable to everybody in the world,” he noted.
Using an AI-based model, Nitin’s team showed that they could identify E. coli on lettuce homogenates within three hours, significantly reducing the detection time compared to conventional culture methods that might take several days.11,12 In a more recent study, the researchers demonstrated that they could also train AI-based models to differentiate bacterial contaminants from three types of food debris—food particles that might affect a model’s accuracy in real-world scenarios.13 Nitin’s team is currently working on making these machine-learning models more generalizable so they can identify more types of food debris more easily and distinguish them from microbial contaminants. “Once we have a well-trained model, we may need very little data to train it on a new pathogen or new bacterial or fungal target. That makes it a lot more efficient,” he said. His team is also training AI models to distinguish between species within a bacterial genus, creating approaches that differentiate harmful from commensal bacteria present on food and direct decontamination efforts towards pathogenic microbes.
Science to Make Food Last
Researchers are also exploring how to extend the shelf life of perishable produce as another approach to address food waste. Globally, 25 percent of all fruits and vegetables are lost between harvest and retail, with this issue being more severe in the Global South, where countries lack infrastructure and face economic constraints.
At the Massachusetts Institute of Technology (MIT), researchers led by materials engineer Benedetto Marelli are designing new technologies to preserve food using silk, an abundant natural fiber produced by arthropods like the Bombyx mori caterpillar.
Marelli’s team is particularly interested in the silk protein fibroin, a non-toxic, edible macromolecule that can be obtained from by-products of the textile industry at low cost. Previous work by Marelli showed that fibroin’s self-assembling properties can create a transparent food coating that extends fruit’s shelf life for about a week.14
Now his team is exploring fibroin-based microneedles to deliver compounds to plants, similar to Prasad’s work using microneedles to deliver bacteriophages deep into food. Compared to sprayable options, microneedles can deliver shelf-stabilizing compounds at lower concentrations into fruits and require no repeated treatments, explained Yangyang Han, a research scientist at the Singapore-MIT Alliance for Research and Technology Center who has worked with Marelli on the technology.
Recently, Han and her colleagues showed that silk microneedles can effectively deliver physiological doses of melatonin, a hormone that regulates growth and senescence in plants.15 The scientists showed that melatonin-loaded microneedle patches delayed the yellowing of Pak choi leaves and prolonged the product's shelf life by 10 days under refrigeration and four days without refrigeration—a set of findings Han noted were “quite surprising.”16
Tianxi Yang, a food and analytical scientist at the University of British Columbia, is also devising new approaches to reduce fresh produce losses.
In Yang’s case, her team combines nanotechnology with analytical chemistry to develop nanoparticle-based coating solutions with antimicrobial properties. In particular, they focus on metal-phenolic networks (MPNs), which are aggregates containing metal ions and phenolic ligands that self-assemble to form complex structures. These structures are not only antimicrobials, explained Yang, but the metal ions they contain are also often dietary micronutrients. Their inclusion on food as a coating could help address micronutrient deficiencies in different populations. “It's not only about the food product. We are trying to bring something that can promote human health [too],” she said.
Scientists first described MPNs in the early 2010s, but their application in the agriculture and food sectors has only been explored more recently. Yang’s team was among the first to test these applications. By combining MPNs with starch nanoparticles, her team found they could enhance the MPNs’ coating properties, making fresh fruit firmer for longer, delaying its ripening, and inhibiting bacterial growth.17 The researchers also found that MPN-based coatings may help remove pesticide residue from fresh produce, addressing public health concerns about the presence of these substances in produce and their negative impact on human health.18 “We call it a triple function [as] it removes pesticides, kills bacteria, and preserves produce,” Yang explained.
While many of these approaches may be ready for real-world application, challenges remain in adopting them into the food supply pipeline. As many strategies could lead to increased food costs, encouraging producers and consumers to embrace these technologies despite this is one such challenge. “The minute you introduce any sort of technology, [who] does pay the cost? Because producers would rather push it to the consumer, but the minute the consumer pays the cost, even if it's a matter of cents driving up the product cost, a consumer probably won't be inclined to use the technology,” said Prasad. “That is why it is a constant push and pull between not only innovating solutions, but innovating solutions in the most cost-effective manner,” she added.
Food suppliers and manufacturers will also need to find ways to reduce people’s hesitancy about consuming products that are in contact with non-food-native agents. Strategies to do this could include familiarizing consumers with concepts like nanotechnology and smart packaging and clearly showing the unique benefits these approaches bring to food.19
Despite these limitations on the consumer’s end and the challenges that food waste and insecurity pose to the world, Prasad believes that people should keep an optimistic outlook. “The future of food freshness and food monitoring is still positive because we know where the change is needed, and we know what the next frontier is,” she said. “It's just now a matter of science, and the science always comes.”