10
1 Yerba Mate Tea, a Traditional South American …
The treatment is critical enough because the enzymatic denaturation can avoid
oxidation: in addition, moisture levels are lowered
(f) Trituration and drying of yerba mate leaves. Actually, these steps can be carried
out at the same time into continuous metallic cylinders, although a superior quality may be achieved if leavers are initially dried with hot air (and
low thermal values are required) and subsequently triturated. The drying or
barbaqua step (100 °C, eight to 24 h) is also named secado, reducing moisture
to 3–6%. Other alternative versions of the same process consider 30–180 min
(g) Milling step. It has to be noted that the raw material for this intermediate step,
triturated and dried leaves, is now defined yerba mate cancheada (in Brazil) or
canchada (in Argentina). The Portuguese and Spanish words cancheada and
canchada mean ‘thickly ground’. After this step, yerba mate can be obtained
in two different versions (steps h or i). It has to be noted that dried leaves may
be aged (9–12 months) in Argentina
(h) Production of roasted yerba mate. Milled leaves are roasted (120 °C, 15 min),
subjected to another milling step, and finally packed into teabag packages. This
product is used for maté cocido: a green yerba mate used for producing herbal
tea
(i) Production of loose yerba mate. Milled leaves are crushed, sieved, classified
according to grinding (coarse, medium, and fine degree), and finally: (1) packed
into loose packages (commercial names: mate, chimarrão, and tererê), or (2)
further aged (6–24 months) before packaging (as loose products).
Some considerations should be done here with relation to above-discussed steps
(Matta 2019; Prestes et al. 2014):
(1) The preferred harvesting period can vary. In general, Brazilian harvesters
prefer to carry out the first step between May and September, with the aim of
reducing plant damages. On the other side (Argentina), the preferred harvesting
period should be between April and September (with one additional month if
compared with Brazil). In this period, the quantity of harvested yerba mate
leaves should approximately surpass half of the total available I. paraguariensis
in both countries of 15%
(2) The storage step should be considered carefully because colorimetric modifications depend not only on storage conditions but also on the time: anyway, they
are irreversible and unavoidable, according to the Parisi’s First Law of Food
Degradation (Srivastava 2019). For this reason, Brazilian operators prefer to
receive intermediate yerba mate leaves constantly throughout the year, with the
objective of minimising colorimetric damages. In general, the most genuine
yerba mate would be intensely green, and excessive storage times can surely
modify this tint. On the contrary, Argentinean operators generally prefer an
additional 9–12 month storage (aging) before milling (yerba mate canchada)
with the aim of modifying the colorimetric appearance of green leaves and
improving the typical flavour. The same operation can be carried out before
packaging loose mate (in the final step)
1 Yerba Mate Tea, a Traditional South American …
The treatment is critical enough because the enzymatic denaturation can avoid
oxidation: in addition, moisture levels are lowered
(f) Trituration and drying of yerba mate leaves. Actually, these steps can be carried
out at the same time into continuous metallic cylinders, although a superior quality may be achieved if leavers are initially dried with hot air (and
low thermal values are required) and subsequently triturated. The drying or
barbaqua step (100 °C, eight to 24 h) is also named secado, reducing moisture
to 3–6%. Other alternative versions of the same process consider 30–180 min
(g) Milling step. It has to be noted that the raw material for this intermediate step,
triturated and dried leaves, is now defined yerba mate cancheada (in Brazil) or
canchada (in Argentina). The Portuguese and Spanish words cancheada and
canchada mean ‘thickly ground’. After this step, yerba mate can be obtained
in two different versions (steps h or i). It has to be noted that dried leaves may
be aged (9–12 months) in Argentina
(h) Production of roasted yerba mate. Milled leaves are roasted (120 °C, 15 min),
subjected to another milling step, and finally packed into teabag packages. This
product is used for maté cocido: a green yerba mate used for producing herbal
tea
(i) Production of loose yerba mate. Milled leaves are crushed, sieved, classified
according to grinding (coarse, medium, and fine degree), and finally: (1) packed
into loose packages (commercial names: mate, chimarrão, and tererê), or (2)
further aged (6–24 months) before packaging (as loose products).
Some considerations should be done here with relation to above-discussed steps
(Matta 2019; Prestes et al. 2014):
(1) The preferred harvesting period can vary. In general, Brazilian harvesters
prefer to carry out the first step between May and September, with the aim of
reducing plant damages. On the other side (Argentina), the preferred harvesting
period should be between April and September (with one additional month if
compared with Brazil). In this period, the quantity of harvested yerba mate
leaves should approximately surpass half of the total available I. paraguariensis
in both countries of 15%
(2) The storage step should be considered carefully because colorimetric modifications depend not only on storage conditions but also on the time: anyway, they
are irreversible and unavoidable, according to the Parisi’s First Law of Food
Degradation (Srivastava 2019). For this reason, Brazilian operators prefer to
receive intermediate yerba mate leaves constantly throughout the year, with the
objective of minimising colorimetric damages. In general, the most genuine
yerba mate would be intensely green, and excessive storage times can surely
modify this tint. On the contrary, Argentinean operators generally prefer an
additional 9–12 month storage (aging) before milling (yerba mate canchada)
with the aim of modifying the colorimetric appearance of green leaves and
improving the typical flavour. The same operation can be carried out before
packaging loose mate (in the final step)