Application of Hot Water Extraction Techniques and the Principal Component Analysis to Study the Influence of Cultivation of Commercial Yerba Mate Samples on Their Mineral Profiles

Abstract

Consumption of organic food has grown much around the world in the last 20 years. Change in the profile of consumers who have increasingly sought a healthy diet is the major contributor to this phenomenon. In scientific literature, some studies have already shown the nutritional superiority of organic food in the individual evaluation of metabolites. However, few studies have assessed interaction among metabolites, especially the one between minerals and the food matrix. This information may have great relevance in determining the extractability of minerals, especially in food consumed through infusion, such as yerba mate, since this interaction can directly influence their solubility. Thus, this study aimed to use hot water extraction techniques (infusion and decoction) and the principal component analysis (PCA) to evaluate the differences between organic and conventional cultivation systems in absorption and availability of Ca, Mg, Fe, Mn, and Zn in yerba mate leaves and stems. The PCA showed that cultivation influences total mineral contents found in both leaves and stems. Results of extractability only showed differences in conventional leaf samples, from which all minerals under study were better extracted. Results point out a different interaction between minerals and the matrix, depending on the cultivation, and to the stronger interaction between the matrix and minerals in organic samples, a fact which leads to low availability of minerals for consumption.

Leaves, Infusion, and Grounds—A Three–Stage Assessment of Element Content in Yerba Mate (Ilex paraguariensis) Based on the Dynamic Extraction and Mineralization of Residues

“…In the case of the main components (above 100 mg kg −1 ), the only exception was observed for Brazilian yerba mate (Si > Fe). The same order was also reported [4,6], or single exceptions were observed, i.e., Rb > Sr [5] and Cu > Ti [8]. In the case of moderate concentrated elements (1-100 mg kg −1 ), the mutual orders of B, Rb, and Sr (as the median) were characteristic for countries of origin, i.e., Argentina (B > Sr > Rb), Paraguay (Sr > B > Rb) and Brazil (Sr > Rb > B).…”

“…The extraction percentages (as median) were sorted in descending order: K (61%) > Na (58%) > Ni (56%) > Rb (53%) > As (52%) > B (51%) > P (49%) > S (47%) > Cu (46%) ≥ Co (46%) > Se (45%) > Pb (39%) > Cr (38%) > Zn (34%) > Mg (31%) > Si (29%) > Mn (24%) > Al (15%) > Cd (8.4%) > Sr (8.3%) > Ca (7.4%) > Fe (1.0%) > Ti (0.2%). On the one hand, different percentages of water-extractable contents were reported in the literature [4][5][6][7][8][9][10]. On the other hand, it must be noted that most of these authors proposed their own procedures for water extraction (brewing) due to a lack of standardization in preparing infusions.…”

“…Due to this, there is a lot of freedom in the procedures for preparing infusions. Although various yerba mate producers recommend using a 1:10 ratio (50 g of leaves and twigs to 500 mL of water at a temperature of 70-80 • C), the authors use different proportions, e.g., 25 g to 200 mL [4], 1 g to 50 mL [6], 0.5 g to 20 mL [7,8], 10 g to 80 mL [9]. Nevertheless, these are examples of the use of the 1:10 ratio, i.e., 1 g to 10 mL [5] and 10 g to 100 mL [9].…”

“…Nevertheless, these are examples of the use of the 1:10 ratio, i.e., 1 g to 10 mL [5] and 10 g to 100 mL [9]. When it comes to water temperature, boiling water dominates (100 • C) [6][7][8][9], although this is contrary to the correct procedure for brewing yerba mate. There are also a few studies comparing the content of elements extracted in cold and warm Foods 2024, 13, 509 2 of 13 water [5,10].…”