BACKGROUND OF THE INVENTION

Field of the Invention

The following invention specification relates to the process for the preparation of black tea made from yerba mate (ilex paraguariensis), and the respective end product.

Description of Related Art

It is known that the use of yerba mate as food is restricted to some regions of South America, where its largest consumption is in the form of mate, a cultural habit. The present product has the potential to compete for consumers worldwide, as it does theCamellia sinensisgreen tea and the black tea, and reach consumers who the mate would not be able to reach.

In order to use the yerba mate, several drying processes are known, for example, those described in PI 9504075-7 comprising a construction having a heat draft system through modular upper outlets with a butterfly valve on each chimney. Inside the oven, two belts are moved in series, in the opposite direction, being one upper belt and one lower belt, and the belts are unloaded by means of load dumpers, consisting of a bladed shaft rotating in the same direction as the belts. A deflector plate directs the yerba mate from the upper belt to the lower belt and to a discharge outlet guiding the yerba mate from the lower belt to the outlet conveyor belt. The furnaces conduct the heat generated to the oven by means of ducts that split into two branches, where a distributor receives the yerba mate from a belt.

MU 7703102-4 describes an equipment for the industrial betterment of yerba mate, wherein it is fed by a vertical duct, and feeds a tilting horizontal chute for the action of two rows of cam-action S-shaped pestles alternating on their rollers, and motor-driven sequentials to grind and create the yerba mate gum, such equipment may be made up of a single row of pestles that, in turn, use wooden or steel beams as a guide, so that the pestles have a free action to reach the bottom of the lower chute provided at its end with a conveyor thread to take the yerba mate in its end form to usual bagging conveyors.

PI 1002236-8 describes a fractionation and scorching process for yerba mate leaves with hot water steam for eliminating toxicity. Briefly, it consists of passing the herb leaves through a water steam bath with controlled and previously calculated temperature in order to prepare the leaf for human consumption. The process is initiated by a primary equipment with saturated steam injection from a water-tube boiler, interconnected to the secondary equipment that receives, through the injectors, the injection of reheated steam at preset pressure and temperature.

An equipment for scorching and drying yerba mate leaves using hot water steam is described in MU 9001057-4, the purpose of which is to eliminate contamination of the yerba mate by PAHs (aromatic polycyclic hydrocarbons) from the scorching and drying process of the yerba mate leaves, the equipment consists of a primary processing module with herb feeding inlet and a secondary processing module with a total of twelve injecting nozzles, being six on each side, coming from the water-tube boiler by means of saturated steam piping and reheated steam piping interconnected to the secondary nozzles, being two on each side and one on the top.

Expanding a form of consumption of yerba mate means introducing into the people's diet the antioxidants contained in such species, which are superior to those ofCamellia sinensis.

From what is known from the prior art, the direct contact of yerba mate leaves with gases generated in the furnace during the scorching stage can contaminate the raw material with aromatic polycyclic hydrocarbons. They have a high carcinogenic potential, which may remain in the end product intended for the consumer. Not washing the leaves at the beginning of processing is also a problem. The vegetal material may be contaminated by environmental pollutants, microorganisms and small invertebrates.

Thus, the invention is intended to solve the abovementioned drawbacks by modifying how the leaves are processed. In the initial step of the proposed process for the production of black tea, the young leaves (buds) of yerba mate are withered for a certain time. Next, the already withered leaves are rolled, followed by fermentation, after such fermentation the drying and segregation steps are carried out.

