Dipartimento di Scienza e Tecnologia del Farmaco

Descrizione del progetto

In order to assess the quality of tea, it is necessary to know the amount and effect of biologically active substances and of potentially toxic elements. Furthermore, it must be pointed out that the quality of tea strongly depends on the soil in which the Camellia Sinensis plants are grown. For these reasons, the following topics will be addressed in the project:

- the study of the extent and mechanism of transfer of some potentially toxic elements from the soils where tea plants are grown to the leaves and finally to the infusions. Attention will be focused on arsenic, lead, copper, aluminium and fluorides (which at high concentrations have adverse effects on health); a method for the determination of some of these elements (arsenic, lead and copper) in the field will also be developed;

- study of the effect of applying organic materials on the release of these elements from the soil. In particular, the soils will be treated with tea pruning waste and with a biochar prepared separately from these materials. The application will be carried out with two different procedures;

- analysis of tea samples purchased from various commercial channels (supermarkets, health shops and the Internet) in Italy, Portugal and India;

- determination of the antioxidant, antimicrobial, anti-inflammatory and cytotoxic properties in the tea samples grown in the framework of the project, to study how soil treatments influence the amount of functional compounds, and in teas purchased from different commercial channels. These studies will allow us to evaluate the effects of tea on human health;

- testing of the effects of gastrointestinal digestion on the functional compounds existing in tea. The digested samples will be evaluated in terms of the total phenolic content and of its antioxidant activity, in order to study the bioacessibility of the functional compounds present in the tea. Also the bioaccessibility of potentially toxic elements will be evaluated. 

- testing of the bioaccessibility of such functional compounds and potentially toxic elements when tea is mixed with other food matrices An in vitro digestion model will be used: an homogenized sample will be digested in three steps (1) oral phase; (2) gastric phase, where gastric fluid will be added and incubated; and (3) intestinal phase, where duodenal fluid and bile fluid will be added and incubated. At the end of the digestion process, the bioaccessible fractions will be separated from sample residues (non-bioaccessible fraction) and will be analysed. 

- the valorization of agroindustrial residues of Camellia Sinensis as ingredient for the cosmetic industry, including their efficacy and safety assessment, in the framework of circular economy;

- comparison between the quantities of potentially toxic elements present in the analysed tea samples and the tolerable levels issued by international bodies, such as the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the Agency for Toxic Substances and Disease Registry (ATSDR). A calculation of the exposition to potentially toxic elements will be made assuming a daily consumption of one or more cups of tea;

- estimation of the risk of exposure to potentially toxic elements upon tea consumption. First, an evaluation will be made in Portugal, Italy and India on the amount of tea consumed on a daily basis, built on national statistics data and other data that can be useful. A dietary risk exposure will be assessed based on the comparison between the estimated daily intake of contaminants, calculated using theier concentration in tea and the tea daily consumption,  and limits of those contaminants imposed by law (national legislation, European legislation) and the tolerable levels issued by international bodies, such as the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the Agency for Toxic Substances and Disease Registry (ATSDR). The exposure risk will be studied for the different population (Portuguese, Italian and Indian), and different age and gender groups groups.

- processing of the experimental results obtained with multivariate statistical techniques.