Agglomeration of dried ilex paraguariensis for consumption purposes

Abstract

Nowadays, many products need to be transported long distances. The amount of material is in many cases limited by volume, especially if we take into account transport by sea. This way ready products or byproducts for beverages industry are imported from Asia, Africa or Southern America. The main streams seem to be tea and coffee, but there are other herbs. Such material is dried Ilex paraguariensis, which is used for brewing a special type of tea called Yerba Mate. Main countries, responsible for production are located in Southern America (Paraguay, Argentina and Brazil). Different than for coffee, the whole processing must be made on the place of cultivation. For transportation for long distances, densification of material seems to be a reasonable way to lower the cost of this operation. This paper presents a possibility of pressure agglomeration of Ilex paraguariensis for consumption. The impact of the agglomeration process has been analysed on the qualities of the drought product. The physical characteristics of the raw material have been determined, such as the grain size distribution and moisture content. Agglomeration tests were performed using different pressures and the study was conducted about absolute and envelope density, porosity and the Brazilian test to check the compressive strength of the pellets. As research material 4 blends available in the marked were used. The results presented in the paper show that there is a possibility of production of high quality granulates made from Ilex paraguariensis. What should be expected, the highest envelope density was obtained for the highest formation pressure. What needs to be mentioned, the pressure needed to achieve a good quality granule was even two times higher than in the case of other herbal materials. This was mainly due to stiff and tough structure of the material. Nevertheless, the results show that agglomeration of dried Yerba Mate can be an interesting form for long distance transportation.