## 2 Materials and Methods  
### Plant Material  
The _IP_ samples were obtained from a cultivated _IP_ field located at the Department of San Ignacio in the Province of Misiones, Argentina. This agro-ecological region has a subtropical climate without a dry season [2]. This region is particularly conducive for commercial exploitation of _IP_ culture [20]. _IP_ samples were withdrawn from a plantation containing a clay-sandy soil known as lateritic soil. This soil is rich in K and Fe oxides, and the local relief of the plantation permits rain waters to flow without stalling in the soil [1].  
The collection of samples was carried out according to the following procedure: four parts of 500 g each were taken from different places in a pile of material containing just-harvested, ripe green leaves. Subsequently, these four parts were mixed together to obtain a homogeneous and representative sample of the entire pile of ripe green leaves. Three aliquots of 500 g were withdrawn from the homogenized sample of ripe green leaves. Then, each of these aliquots were submitted to a different process:  
S1: Ripe green leaves were harvested, were naturally dried at room temperature under open-air conditions for two weeks, and were grounded. The fraction trapped between the sieves of a rectangular aperture of 5 \(\times\) 70 mm\({}^{2}\) and 1 \(\times\) 20 mm\({}^{2}\) was recovered for subsequent studies.  
S2: Ripe green leaves were harvested, were dried under direct fire for a few seconds, and were grounded. The fraction trapped between the sieves of a rectangular aperture of 5 \(\times\) 70 mm\({}^{2}\) and 1 \(\times\) 20 mm\({}^{2}\) was recovered for subsequent studies.  
S3: Ripe green leaves were harvested, were dried under direct fire for a few seconds, and were grounded. The fraction trapped between the sieves of a rectangular aperture of 5 \(\times\) 70 mm\({}^{2}\) and 1 \(\times\) 20 mm\({}^{2}\) was recovered and aged for 6 months at 21 \(\pm\) 5 \({}^{\circ}\)C and at a maximum of 60% relative humidity.  
All treated samples were homogenized and size reduced using a cyclonic mill (UDY, USA) equipped with a 1 \(\times\) 1 mm\({}^{2}\) sieve mesh. The resulting materials were hermetically sealed in plastic bags and stored at 4 \({}^{\circ}\)C until use.  
S1, S2, and S3 are three industrial processes currently applied in the production of _IP_ products. They must be understood as alternative paths to achieve marketable _IP_ products. The selection of the optimal path is carried out with a number of considerations, including the weather condition during harvest time, the urgency level of the customers regarding the delivery of products, production costs, and different quality ranges of _IP_ products, among many others. For example, S1 can be appropriate if the weather is dry during the harvest time and if there are no urgent demands from customers. S1 would not be appropriate if the weather was very humid during the harvest time. In this case, natural drying would demand too much time with certain risks of fungus proliferation. In this case, S2 and S3 would be more appropriate. Conversely, S2 is recommended in case of humid weather and urgent product demands. S3 is recommended in case of humid weather and no urgent demands.  
The S1 process can be considered an almost unaltered control sample. S1 processing is a very soft treatment. The great majority of phytochemical studies treat the plants according to S1. Drying in open-air conditions is the usual method for chemical stabilization and the conditioning of plants for scientific studies. Moreover, drying at 25 \({}^{\circ}\)C showed to be comparable to freeze-drying for the preservation of plant properties carried out during experimental studies to assess biomass composition [21; 22].