Associate Professor Hirofumi Enomoto uses an analytical technique called mass spectrometry imaging to observe food at the molecular level.
By measuring the nutritional, functional and toxic components contained in food and visualizing their distribution,
Our goal is to expand the possibilities of food. We own analytical equipment that is rare in domestic and overseas facilities,
The center aims to develop cross-disciplinary research as a center for mass spectrometry imaging in the Kanto area.
"Strawberries have a sweet tip and are delicious"
Visualization of the distribution of its components for the first time
The foods we eat every day contain a variety of ingredients. Nutritional components such as the six major nutrients of proteins, lipids, carbohydrates (sugars), minerals, vitamins, and dietary fiber, and functional components such as polyphenols are important components that affect health.
The ingredients contained in each food can be measured by various analytical techniques. However, the conventional analysis method only reveals the type and amount of ingredients contained in the ingredients. It was not possible to measure even more detailed "where the ingredients are". This has become possible due to advances in imaging technology over the last few years.
Associate Professor Hirofumi Enomoto of the Department of Faculty of Science and Engineering, Department of Biosciences Technology, Teikyo University, is working on visualizing the distribution of food components using an analytical method called mass spectrometry imaging. For example, strawberries are known to be particularly sweet and delicious at the tip. By making full use of this analytical method, Associate Professor Enomoto was the first to successfully visualize the high concentration of sucrose, a sweet component, in the tip of a strawberry.
"If we can pinpoint the location and amount of nutritional and functional components in food, we can efficiently consume only those parts. At the same time, it is possible to analyze food safety and quality, such as pinpointing the location of substances harmful to humans, such as mycotoxins, in grains, and providing safe food with only those parts removed," says Associate Professor Enomoto.
From visualization of functional components for each tissue
Identify safe parts of pork
Associate Professor Enomoto's research covers a wide range of subjects, including grains, vegetables, and meat. For example, in his research on meat, he examined a phospholipid component called sphingomyelin in different tissues of pork. Behind this was a sense of crisis about the future of meat. In 2015, the World Health Organization (WHO) announced that processed meats such as bacon, ham, and sausages are carcinogenic. He mentioned that there is also a risk that pork and beef may be carcinogenic.
"While the WHO has announced the carcinogenicity of meat, they also acknowledge the health benefits of consuming meat. However, there are concerns that the image of meat has been deteriorating in recent years," says Associate Professor Enomoto.
Heme iron is considered to be one of the carcinogens of meat. On the other hand, sphingomyelin works to suppress carcinogenesis. Therefore, when we analyzed the location of sphingomyelin in each pork tissue, we found that loin contained a large amount of sphingomyelin in the muscle tissue. Moreover, there is little heme iron in that part. Pork loin may be a safe site with low carcinogenicity.
"If we evaluate the safety and functionality of each tissue in this way, we can see that pork as a whole is not harmful to health. This means that people can avoid the risky parts and eat pork safely. Furthermore, this method can be used to analyze a wide range of things, such as differences between breeds and changes in sphingomyelin content due to differences in feed," says Associate Professor Enomoto.
Elucidation of component deterioration at the molecular level
Realizing strawberries that can be distributed around the world
Recently, we are trying to clarify the function of polyphenols contained in strawberries. Flavonoids, one of the polyphenols, are known to have health effects such as oxidative stress relief and anti-aging, but in plants, they are substances for self-defense functions. It is a substance produced to protect the plant itself from active oxygen, pests, bacterial infections, etc. caused by ultraviolet rays, and may be related to quality deterioration.
Focusing on this point, Associate Professor Enomoto is attempting to elucidate the causes of strawberry spoilage. By examining the flavonoids contained in strawberries using mass spectrometry imaging, he believes that it may be possible to gain a deeper understanding of strawberry deterioration.
"Japanese strawberries are said to be delicious and are a fruit that can be enjoyed around the world. However, they are extremely susceptible to spoilage, which makes them difficult to transport over long distances. Therefore, we will first clarify the phenomenon of strawberry spoilage at a molecular level. In the future, if we can elucidate the causes of quality deterioration at a genetic level, we may be able to create strawberries that are less susceptible to spoilage through genome editing or other methods," says Associate Professor Enomoto.
In the Kanto area in the field of agriculture
At the Mass Spectrometry Imaging Research Center
Mass spectrometric imaging, which allows you to see invisible molecules, is a method of measuring the "mass" of a molecule in a substance and analyzing the type and amount of the molecule based on the difference in mass. Since there are no molecules without mass, it is a highly versatile analysis method that can measure everything, including small molecules that cannot be analyzed by other imaging techniques.
When measuring, a sample that has been instantly frozen while it is fresh is cut out to a thickness of about 10 micrometers, fixed to a slide glass, and then ionized. In other words, it turns the molecule into a gas with positive and negative charges. Then, it detects the gasified ions flying in the device and calculates the "mass" from the "mass-to-charge ratio (m / z)" for each ion. This work can be performed for each part in which the sample is divided into small pieces, and the distribution can be imaged.
Associate Professor Enomoto first encountered this method about 10 years ago. He wondered if this analytical method, which had been widely applied in the fields of medicine and pharmacy, could also be used for agricultural and livestock products, and so he worked at the Hamamatsu University School of Medicine Molecular Imaging Advanced Research Center, where he learned about the method.
"This technology was developed for use in disease diagnosis and biomarker searches, and 10 years ago it was virtually unknown outside of medicine. Over the past 10 years, mass spectrometry imaging technology has further improved, its recognition has risen, and we are receiving more inquiries about collaborative research. There are very few facilities in this field that can perform mass spectrometry imaging, so we would like to make this a research hub for mass spectrometry imaging in the agricultural field in the Kanto region." (Associate Professor Enomoto)
Associate Professor Enomoto says, "I want to make Teikyo University a research center for mass spectrometry imaging in the agricultural field in the Kanto region."
The next target is grains. Plant hormones are important substances that control plant growth and the biosynthesis of functional components. Having successfully "observed" the molecules of two plant hormones found in kidney beans—jasmonic acid-related oxylipins and abscisic acid—the researchers hope to investigate plant hormones in a variety of other beans and rice. The first step is to identify the locations where these plant hormones are present and to elucidate their physiological functions based on their distribution. Beyond that, the researchers hope to breed high-quality crops with excellent nutritional functionality and shelf life by controlling plant hormones, and furthermore, to visualize the pharmacokinetics of functional components in the body after consuming agricultural and livestock products, thereby clarifying their impact on human health. As a first step toward this goal, they are about to begin collaborative research with researchers from the Faculty of Faculty of Pharmaceutical Sciences within the framework of Advanced Comprehensive Research Organization, which is scheduled to be established at Teikyo University next year.
"By using mass spectrometry imaging, we can investigate food safety, nutritional functionality, and post-consumption phasing in the body in more detail. We would like to use the results to improve the quality and value-added of Japan's agricultural and livestock products," says Associate Professor Enomoto, talking about his outlook for the future. With food safety now a major priority due to growing health awareness, there are high expectations for mass spectrometry imaging.
