Vitamins and Antioxidants Not Necessarily Absorbed by the Body, Expert Explains
Many people have long assumed that food is healthy because it contains high levels of vitamins, antioxidants, or bioactive compounds. However, this assumption is not necessarily correct because not all of these compounds can be absorbed and utilised by the body.
Professor Endang Prangdimurti, a professor at the Faculty of Agricultural Engineering and Technology at IPB University, explained that a high nutrient content in a food does not automatically provide maximum benefits to the body. “Not all of these compounds can truly be utilised by the body,” she said.
For this reason, a research team has applied an in vitro digestion method, a simulation of the human digestive process in the laboratory, to determine how much of the beneficial content in food is actually available for absorption by the body, known as bioaccessibility.
Professor Endang said the simulation is designed to resemble the human digestive process, from the stages in the mouth, stomach, to the small intestine. Through this method, researchers can observe changes in bioactive components during digestion.
“During the digestive process, bioactive compounds can undergo various changes due to the influence of digestive enzymes, changes in acidity levels (pH), and interactions with proteins, fats, fibre, and the food matrix,” she said.
As a result, some compounds may degrade, change form, or instead become more easily released so that they are available for absorption by the body.
Since 2022, Professor Endang’s research has focused on using the in vitro digestion method to examine various functional foods. One of her studies investigated the effect of the drying process on the bioaccessibility of bioactive components in pulai leaves.
The results showed that the flavonoids dominating the boiled water of pulai leaves were not entirely stable during the digestive process. This means that although the initial content was high, not all of it could be utilised by the body after consumption.
In contrast, different results were found in whole foods. In several vegetables commonly consumed as fresh salads, the levels of phenolic compounds and antioxidant activity actually increased after passing through the digestive process.
Professor Endang believes this occurs because some bioactive compounds in whole foods are still bound within the food matrix. During digestion, these compounds are released, so the amount available for absorption by the body becomes greater.
“In whole foods, the content may initially appear lower because the compounds are still bound in the food matrix. After digestion, more of these compounds can be released and become available,” she explained.
The in vitro digestion method has also been used to test the potential of foods as antidiabetic agents. In green tea extract, for example, the activity of inhibiting carbohydrate-digesting enzymes was found to increase after passing through the digestion simulation.
In addition, this technique is used to test the allergenicity level of proteins as part of food safety assessment, including in the development of hypoallergenic food products.
Professor Endang said the in vitro digestion method can serve as an initial screening stage before further research is conducted on animals or humans. She hopes this approach can accelerate the development of functional foods based on local biological resources that are not only rich in vitamins and bioactive compounds, but also proven to be absorbable and provide real health benefits after consumption.