We all felt the guilt when the fruits and vegetables take place before we could eat them. Now, MIT and Singapore-Mit Alliance For Research and Technology (SMART) researchers have shown that they can extend the shelf life of the plants harvested by injecting melatonin by using biodegradable micro-headlines.
This is a big problem because the problem of food waste goes far beyond our salads. More than 30% of the world’s food is lost after its harvest – enough to feed more than a billion people. Refrigeration is the most common way to preserve food, but it requires energy and infrastructure to which many regions of the world cannot afford or lack access.
Researchers think that their system could offer an alternative or supplement to refrigeration. Center for their approach are micro-linge patch in silk. Microseedles can cross the hard and waxy skin of plants without causing stress response and provide precise amounts of melatonin in the internal plants of plants.
“This is the first time that we have been able to apply these micro-escomas to prolong the conservation time of a fresh culture,” explains Benedetto Marelli, principal of the study, associate professor of civil and environmental engineering at MIT, and director of the Wild Card mission of the MIT Climate Project. “We thought we could use this technology to deliver something that could regulate or control post-harvest physiology of the plant. Finally, we examined the hormones, and melatonin is already used by plants to regulate these functions. The food we waste could feed about 1.6 billion people. Even in the United States, this approach could one day develop access to healthy foods. ”
For the study, which appears today in Nano lettersMarelli and researchers from small intelligent plots applied from micro-needles containing melatonin at the base of the pak choy vegetables with leafy. After the application, the researchers found that melatonin had been able to extend the shelf life of vegetables of four days at room temperature and 10 days during refrigeration, which could allow more cultures to reach consumers before being wasted.
“Post-harvest waste is a huge problem. This problem is extremely important in the emerging markets of Africa and Southeast Asia, where many cultures are produced but cannot be maintained in the journey of farms on the markets, “explains Sarojam Rajani, co-author of the study and principal principal researcher at Temasek Life Sciences Laboratory in Singapore.
Destiny
For years, Marelli’s Lab explores the use of micro-light for things such as delivery of nutrients to crops and plant health surveillance. Microseedles made from silk fibroin protein are not toxic and biodegradable, and Marelli previous work described the means to make them on a large scale.
To test the ability of MiConeEdle to extend food storage time, researchers wanted to study their ability to provide a hormone known to affect the senescence process. In addition to helping humans sleeping, melatonin is also a natural hormone in many plants that help them regulate growth and aging.
“The dose of melatonin that we deliver is so weak that it is entirely metabolized by cultures, so this would not significantly increase the amount of melatonin normally present in food; We will not be more melatonin than usual, ”explains Marelli. “We have chosen Pak Choy because it is a very important harvest in Asia, and also because Pak Choy is very perishable.”
Pak Choy is generally harvested by cutting the leafy plant of the root system, exposing the base of growth which offers easy access to the vascular beams which distribute water and nutrients to the rest of the plant. To start their study, the researchers first used their micro-actors to inject a fluorescent dye into the base to confirm that the vascular system could spread the color throughout the plant.
The researchers then compared the conservation time of ordinary Pak Pak Pak Pak which had been sprayed with or dive into melatonin, finding no difference.
With their established reference shelf life, the researchers applied small plots of micro-wheels filled with melatonin at the bottom of Pak Choy plants in hand. They then stored the plants processed, as well as controls, in plastic boxes at room temperature and under refrigeration.
The team assessed the plants by monitoring their weight, their visual appearance and their chlorophyll concentration, a green pigment that decreases as plants age.
At room temperature, the leaves of the untreated control group began to yellow in two or three days. On the fourth day, yellowing accelerated to the point that plants probably could not be sold. The plants treated with silk micro-essies loaded with melatonin, on the other hand, remained green on the fifth day, and the yellowing process was considerably delayed. Weight loss and the reduction of the chlorophyll of treated plants also slowed down considerably at room temperature. Overall, the researchers estimated that the plants treated in the micro-los have retained their harmful value until the eighth day.
“We have clearly seen that we could improve the shelf life of Pak Choy without the cold chain,” explains Marelli.
Under refrigerated conditions of approximately 40 degrees Fahrenheit, the yellowing of the plants was delayed by about five days on average, the plants treated remain relatively green until day 25.
“The spectrophotometric analysis of the plants indicated that the plants treated had a higher antioxidant activity, while the analysis of the genes has shown that melatonin has triggered a protective chain reaction inside the plants, preserving chlorophyll and adjusting the hormones in slow senescence,” Temasek Life Science Laboratory.
“We studied the effects of melatonin and we saw that it improves the response to the stress of the plant after being cut, it therefore essentially decreases the stress that the experience of the factory, and this extends its duration of conservation,” explains Yangyang Han, co-author and interdisciplinary research researcher of the prohibiting and durable research group.
Towards post-harvest preservation
Although micro-actors can make it possible to minimize waste compared to other application methods such as spraying or soaking crops, researchers say that more work is necessary to deploy large-scale microseedles. For example, although researchers have applied micro-lightening patches in this experience, patches could be applied using tractors, autonomous drones and other agricultural equipment in the future.
“For this to be widely adopted, we would need to reach a performance and cost threshold to justify its use,” explains Marelli. “This method should become cheap enough to be used by farmers regularly.”
In the future, the research team plans to study the effects of a variety of hormones on different crops using its micro-lint delivery technology. The team believes that the technique should work with all kinds of products.
“We will continue to analyze how we can increase the impact that this can have on the value and quality of cultures,” explains Marelli. “For example, this could allow us to modulate the nutritional values of the harvest, how it is shaped, its texture, etc.? We will also continue to study the technology so that it can be used in the field.”
The work was supported by the Singapore-Mit Alliance for Research and Technology (Smart) and the National Research Foundation of Singapore.