Study at FEA focused on in vitro analysis of the four most consumed varieties in Brazil
White, black, green and mate teas contain polyphenols, bioactive compounds present in abundance in the human diet and which have beneficial effects in reducing overweight and obesity and their complications such as type 2 diabetes mellitus. However, many polyphenols are not absorbed in the form in which are found in food because they are linked to other molecules, mainly sugars, which reduces their absorption and bioavailability. To overcome the problem, the molecular groups in which polyphenols participate need to be broken, that is, transformed into smaller chains, with structures more easily absorbed by tissues. This biotransformation can be achieved by adding glycosidic enzymes to food processing, thus creating polyphenols that the body recognizes better, which increases bioaccessibility, bioavailability and bioactivity, increasing its functional activity.
The aim was to characterize the bioactive phenolic compounds present in the mentioned teas, both in your conventional way and after biotransformation, which Bruna Sampaio Roberto carried out doctoral research at the Department of Food Sciences, of the Faculty of Food Engineering (FEA) at Unicamp, supervised by professor Gabriela Alves Macedo. The author, who has a degree in pharmacy and a master's degree in food science from the Federal University of Santa Maria (RS), also completed a seven-month internship at The James Hutton Institute, in Dundee (Scotland).
From the above it can be seen that not everything that is natural is better. Certain interventions in natural products can enhance some of their functional capabilities, such as those that offer health benefits and contribute to reducing the risk of certain diseases. The focus of this work on four widely consumed teas in Brazil – white, black, green and mate – is justified by the fact that the impacts of polyphenols on human health still require clarification.
Bruna Roberto's objective was to evaluate vitro the possibility of biotransforming tea polyphenols into their most active form; its bioaccessibility in gastrointestinal conditions; and its anti-obesity and anti-diabetes potential by measuring the inhibitions of digestive enzymes, fat deposits in cells, in order to compare them with conventional products.
To break down (hydrolysis) the polymer chains, the researcher used the tannase enzyme as a catalyst, immobilized by the microencapsulation process in sodium alginate, which facilitates its use and recovery at the end of the process, and eliminates possible allergenic effects that the enzyme may have. offer the product. The extracts obtained from each type of tea, before and after processing, were dried and the powder subjected to analysis.
The polyphenol molecules present, their antioxidant capacity and their potential to inhibit the gastric enzymes α-amylase, α-glucosidase and lipase, responsible for the absorption of carbohydrates and fats, were then determined. Research shows that inhibiting these enzymes and reducing the absorption of these nutrients can contribute to reducing the effects of certain foods in relation to obesity and diabetes. In this sense, the potential of biotransformed teas to reduce fat deposits in cells was also determined, through methods vitro using pre-adipocytes (cells that store fat).
Bruna also stopped to verify the best operational conditions of the bioreactor used for enzymatic biotransformation using tannase immobilized in sodium alginate. The research invitro, evaluating the inhibition of enzymes responsible for human digestion, showed inhibition mainly of α-amylase and lipase, while studies in cells indicated a reduction of around 20% in the fat index stored by adipocytes, when compared to conventional tea, and a reduction in up to 64% compared to cells that did not receive any type of treatment.
Another concern in the study was to verify whether the polyphenols resulting from the process resulting from stomach simulations have the potential to reach the intestine. Based on the study vitro, the author concluded that, in fact, some of them actually do so, with the potential to carry out functional activities, in which the attack on free radicals stands out.
Bruna Roberto concludes: “Teas subjected to the action of microencapsulated tannase certainly have a more functionally effective action than those consumed conventionally. This is due to the possible increase in the bioavailability of polyphenols, enhancing the fight against obesity, diabetes and antioxidant activities.”
Importance
The importance of research is highlighted when it is known that obesity and excess body mass are risk factors for several chronic non-communicable diseases, such as type 2 diabetes mellitus, high blood pressure, cardiovascular diseases, strokes, hyperlipidemia, musculoskeletal disorders and various types of cancer, and which are among the five main risk factors for mortality.
Although there are multiple factors that contribute to obesity, studies are focused on biological factors related to lifestyle, mainly the binomial diet and physical activity. In this regard, the inclusion of foods with antioxidants that attack free radicals or that act on lipid and glucose metabolism has been positive to prevent obesity complications – and several epidemiological studies have demonstrated the beneficial effects of tea and its bioactive compounds in this regard.
