By Sara Lara Abia
Popular Science Article
According to numerous reports by the United Nations Food and Agriculture Organization (FAO), consumption of fruits and vegetables may reduce the risk of chronic degenerative, carcinogenic, and cardiovascular diseases, among others, given the bioactive compounds found in these foods.
A bioactive compound is a type of chemical substance found in small amounts in plants and foods such as fruits, vegetables, oils, and whole grains. This type of compounds performs certain health-promoting functions in the body. Some examples of these are carotenoids, like lycopene (tomatoes), phenolic acids (red, black, or green tea), flavonoids (cranberries, blueberries, and plums), other carotenoids (Spanish persimmon, papaya), and resveratrol (red grapes, berries).
Because people’s modern lifestyle is increasingly hectic, they often have no time to eat properly, which has caused the average intake of fresh fruits and vegetables to fall short of the recommended level. That’s why the consumption of juices and beverages with the necessary amount of nutrients and extra benefits for the body has grown popular among the population in recent years.
However, the biological activity of bioactive compounds stems from their solubilization and bioaccessibility in the gastrointestinal tract. This means that the biological efficacy of bioactive compounds depends upon the amount of substance that is available for absorption in the human body. In fact, releasing these compounds from the food matrix is not always easy. Some substances even need carrier molecules to be absorbed in the gastrointestinal tract, as is the case with carotenoids.
To enhance the bioaccessibility of bioactive compounds, researchers from Tec de Monterrey and the Food Sciences Research Institute (CIAL-CSIC) in Madrid are working in the development of a means to preserve these beneficial substances without compromising the sensory quality (unpleasant smell or taste) of the products containing them.
Being, as it is, a collaborative project between Mexico and Spain, research has focused on fruits and other natural food products (and the byproducts obtained from industrial transformation) deemed relevant for both countries, like Spanish persimmon, a fruit from Spain, and papaya, a fruit from Mexico and Spain.
On the one hand, we have Spanish persimmon (Diospyros kaki), a fruit produced mainly in the Spanish region of Valencia and exported to different countries in the European Union.
According to a report released by FAO in 2016, Spain grows 4.7 percent of the world production of Spanish persimmon. This fruit of Chinese origin contains numerous bioactive compounds known for their health-promoting benefits, which are mainly due to their antioxidant properties. The Phytochemistry and Vegetable Functionality Research Group from CIAL has studied this food matrix for many years, which has led to the characterization of the bioactive compounds found in it. This work has also helped assess the usefulness of new technologies (high hydrostatic pressure and ultrasound) in enhancing the extraction of the phenolic and carotenoid compounds of interest with the least possible impact in order to increase the health-promoting benefits of the by-products.
On the other hand, papaya (Carica papaya) is a very popular fruit in Mexico and the United States. According to a report by SAGARPA (Mexican Department of Agriculture and Rural Development) released in 2017, Mexico is the largest exporter of papaya in the world with 168.7 thousand tons/year, followed by Guatemala, with 49.6 thousand tons/year. Papaya exports in Mexico account for 17.72 percent of total papaya availability in the country. This fruit is a rich source of bioactive compounds (carotenoids and flavonoids, among others), which produce positive effects on people’s health by way of their antioxidant properties and their potential to guard against cardiovascular diseases, respectively.
Work in the Research Laboratory
The Nutriomics and Emerging Technologies Research Group led by Dr. Jorge Welti Chanes from Tecnológico de Monterrey partnered with the Phytochemistry and Vegetable Functionality Research Group led by Dr. M. Pilar Cano Dolado from CIAL to conduct studies that have led to the characterization of both the Mexican and Spanish varieties of prickly pears. This work has also helped establish the usefulness of these fruits as natural sources of functional and nutraceutical (medicinal substances of natural origin that, given their health-promoting benefits, can be used for the prevention and treatment of disease) ingredients.
Studies of this kind have also been carried out on Spanish persimmon in order to elucidate its potential for the production of functional foods and ingredients rich in bioactive compounds, mainly phenolic acids and carotenoids.
So far, the researchers have been able to characterize the bioactive compounds found in these fruits. To achieve this goal, the experts improved the extraction yields with conventional solvents and used advanced chromatographic techniques. The next step is to improve substance extractability from tissues through green technologies (sustainable and environmentally friendly), which involves the use of innovative extraction techniques and solvents that cause minimum impact on the environment.
It is also important to address the issues concerning the improvement of bioactive compound bioaccessibility during digestion in the GI tract and stability during physiological processes. Not all bioactive compounds are available for use in the body.
In recent years, the use of nanoemulsions as food matrices has been proposed in order to improve the encapsulation, absorption and transport processes of bioactive compounds. Studies have shown that nanoemulsions could provide an ideal means to encapsulate and protect the bioactive compounds until they reach the tissues where they are supposed to be released. Nanoemulsions are systems made up of two liquids that do not blend (usually water and oil). In nanoemulsions, small droplets of one liquid are dispersed in the other liquid. The droplets in nanoemulsions are 20-500 nanometers in diameter. To get a better idea of their minute size, consider a single strand of human hair, which is 70-100 microns in diameter.
Currently, these research groups are conducting studies to assess how the use of innovative, environmentally friendly technologies (ultrasound and high pressure with green solvents) could improve the extraction of health-promoting substances to be used as functional ingredients in the production of foods with more readily bioavailable bioactive compounds.
About the Author
Sara Lara holds a master’s degree in agricultural chemistry and new foods from Universidad Autónoma de Madrid, Spain. She is currently pursuing a Ph.D. degree in biotechnology at the Tecnológico de Monterrey School of Engineering and Sciences (Monterrey Campus, Mexico).
Dr. Jorge Welti Chanes holds a Ph.D. degree in chemistry from the University of Valencia, Spain. He is a research professor at the Tecnológico de Monterrey School of Engineering and Sciences, his research areas of interest being biotechnology and foods. He is a member of the National System of Researchers (Level III) and Mexico’s National Academy of Sciences. He is an elected member of both the World Academy of Food Sciences and the International Union of Food Science and Technology (IUFoST).
Dr. M. Pilar Cano Dolado holds a Ph.D. degree in chemistry from Universidad Autónoma de Madrid, Spain. She is a research professor (CSIC-UAM) and leader of the Phytochemistry and Vegetable Functionality Research Group at CIAL. She is also a Distinguished International Professor at Tecnológico de Monterrey, where she is a member of the Emerging Technologies and Molecular Nutrition Strategic Research Group.
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