Matcha è una varietà di tè verde finemente macinato, noto per il suo utilizzo nella tradizionale cerimonia del tè giapponese. Originario del Giappone, il matcha è apprezzato per il suo sapore ricco e per i numerosi benefici per la salute.
Il matcha è prodotto dalle foglie di tè verde che sono state ombreggiate per diverse settimane prima della raccolta. Questo processo aumenta il contenuto di clorofilla e aminoacidi delle foglie, conferendo al matcha il suo caratteristico colore verde brillante e un sapore dolce e umami. Le foglie vengono poi essiccate e macinate in una polvere fine.
Habitat e Coltivazione
Il matcha è coltivato principalmente in Giappone, nelle regioni di Uji (Kyoto), Nishio (Aichi), Shizuoka e Kyushu. La coltivazione del matcha richiede particolare attenzione, soprattutto per quanto riguarda l'ombreggiatura delle piante prima della raccolta.
Processo di produzione industriale
Coltivazione. La produzione di Matcha inizia con la coltivazione delle piante di tè (Camellia sinensis) in condizioni specifiche. Circa 3-4 settimane prima della raccolta, le piante vengono coperte per ridurre l'esposizione alla luce solare diretta. Questo processo aumenta la clorofilla e il contenuto di aminoacidi nelle foglie, conferendo al Matcha il suo caratteristico sapore dolce e intenso colore verde.
Raccolta. Le foglie di tè, note come tencha quando destinate alla produzione di Matcha, vengono raccolte manualmente. Solo le foglie più giovani e di alta qualità vengono selezionate per la produzione di Matcha.
Vaporizzazione. Subito dopo la raccolta, le foglie vengono brevemente esposte al vapore per prevenire l'ossidazione e preservare il colore e i nutrienti.
Essiccazione. Le foglie vengono poi essiccate per rimuovere l'umidità residua.
Rimozione. Prima della macinazione, steli e venature vengono rimossi dalle foglie per garantire la finezza della polvere di Matcha.
Macinazione. Le foglie secche vengono macinate in un fine polvere utilizzando mulini di pietra. Questo processo lento e attento evita il surriscaldamento delle foglie, preservando il sapore e il colore del Matcha.
Confezionamento. Il Matcha in polvere viene confezionato immediatamente dopo la macinazione per preservarne freschezza, colore e proprietà nutrizionali.
Proprietà
Ricco di antiossidanti, in particolare catechine come l'EGCG (1), il matcha offre benefici per la salute, tra cui la riduzione del rischio di malattie cardiache (2) e il miglioramento del metabolismo. Contiene anche L-teanina, che promuove il rilassamento (3), la concentrazione e che funziona anche come antidepressivo (4).
Usi
Cerimonia del Tè: Il matcha è al centro della cerimonia del tè giapponese, dove viene preparato e servito secondo tradizioni secolari.
Alimentari e Bevande: Oltre al consumo tradizionale, il matcha è utilizzato in una varietà di prodotti alimentari e bevande, come latte al matcha, dolci, gelati e persino cocktail.
Salute e Benessere: Grazie ai suoi benefici per la salute, il matcha è anche utilizzato in integratori alimentari e prodotti per la cura del corpo.
Impatto ambientale
La coltivazione del matcha può avere un impatto ambientale, soprattutto se non gestita in modo sostenibile. Tuttavia, ci sono sforzi crescenti per produrre matcha biologico e pratiche agricole sostenibili in Giappone.
Conservazione
Il matcha deve essere conservato in un contenitore ermetico, al riparo dalla luce, dall'umidità e da odori forti, per preservarne il sapore e le proprietà nutrizionali.
Bibliografia_____________________________________________________________________
(1) Kochman J, Jakubczyk K, Antoniewicz J, Mruk H, Janda K. Health Benefits and Chemical Composition of Matcha Green Tea: A Review. Molecules. 2020 Dec 27;26(1):85. doi: 10.3390/molecules26010085. PMID: 33375458; PMCID: PMC7796401.
Abstract. Japanese matcha is a type of powdered green tea, grown in a traditional way. Shading of the plants during the growth period enhances the processes of synthesis and accumulation of biologically active compounds, including theanine, caffeine, chlorophyll and various types of catechins. Green tea contains four main catechins, i.e., (-)-epicatechin (EC), (-)-epicatechin-3-gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin-3-gallate (EGCG), of which the latter is the most active and abundant and matcha is their best condensed source. Due to its unique chemical composition and prized flavour, which sets it apart from other tea beverages, it is considered the highest quality tea. Its health-promoting properties are attributed to the high content of antioxidant and anti-inflammatory substances. Studies confirming the high antioxidant potential of tea beverages claim that it originates from the considerable content of catechins, a type of phenolic compound with beneficial effects on human health. Due to its potential for preventing many diseases and supporting cognitive function, regular consumption of matcha may have a positive effect on both physical and mental health. The aim of this review was to compile the health benefits of matcha tea. It is the first such review to be undertaken, and presents its main bioactive compounds in a systematic manner.
(2) Iwai R, Ishii T, Fukushima Y, Okamoto T, Ichihashi M, Sasaki Y, Mizuatni KI. Matcha and Its Components Control Angiogenic Potential. J Nutr Sci Vitaminol (Tokyo). 2021;67(2):118-125. doi: 10.3177/jnsv.67.118. PMID: 33952732.
Abstract. The brain needs the appropriate capillary networks to maintain normal brain function. Since previous studies showed age-related decrease in the cortical capillaries, it is suggested that protection against capillary aging is critical for maintaining brain function. Epidemiological studies have indicated that brain functions were protected from age-related decline by the long-term consumption of matcha. However, whether matcha has protective effects on capillary aging has not been studied yet. In this study, we utilized Flt1-DsR mice that expressed a red fluorescent protein in vascular endothelial cells to visualize cortical capillaries clearly. We found that cortical capillary density decreased in aging Flt1-DsR mice. Our results of the aortic ring assay and tube formation assay revealed that matcha and its components vitamin K1 and lutein, which are abundant in matcha powder, enhanced the angiogenic potential. Moreover, we evaluated the effect of long-term ingestion of matcha on mouse cortical capillary aging by using imaging experiments. The capillary density of the Flt1-DsR mice, which were fed matcha-containing food, indicated the protective effects of matcha ingestion on capillary aging in a limited cortical layer. These results suggest that biological regulation of matcha and its components affect the angiogenic potential, which is related to the prevention of capillary aging.
(3) Unno K, Furushima D, Hamamoto S, Iguchi K, Yamada H, Morita A, Horie H, Nakamura Y. Stress-Reducing Function of Matcha Green Tea in Animal Experiments and Clinical Trials. Nutrients. 2018 Oct 10;10(10):1468. doi: 10.3390/nu10101468.
Abstract. Theanine, a major amino acid in green tea, exhibits a stress-reducing effect in mice and humans. Matcha, which is essentially theanine-rich powdered green tea, is abundant in caffeine. Caffeine has a strong antagonistic effect against theanine. The stress-reducing effect of matcha was examined with an animal experiment and a clinical trial. The stress-reducing effect of matcha marketed in Japan and abroad was assessed based on its composition. The stress-reducing effect of matcha in mice was evaluated as suppressed adrenal hypertrophy using territorially-based loaded stress. High contents of theanine and arginine in matcha exhibited a high stress-reducing effect. However, an effective stress-reducing outcome was only possible when the molar ratio of caffeine and epigallocatechin gallate (EGCG) to theanine and arginine was less than two. Participants (n = 39) consumed test-matcha, which was expected to have a stress-reducing effect, or placebo-matcha, where no effect was expected. Anxiety, a reaction to stress, was significantly lower in the test-matcha group than in the placebo group. To predict mental function of each matcha, both the quantity of theanine and the ratios of caffeine, EGCG, and arginine against theanine need to be verified.
Shigeta M, Aoi W, Morita C, Soga K, Inoue R, Fukushima Y, Kobayashi Y, Kuwahata M. Matcha green tea beverage moderates fatigue and supports resistance training-induced adaptation. Nutr J. 2023 Jul 5;22(1):32. doi: 10.1186/s12937-023-00859-4.
(4) Kurauchi Y, Ohta Y, Matsuda K, Sanematsu W, Devkota HP, Seki T, Katsuki H. Matcha Tea Powder's Antidepressant-like Effect through the Activation of the Dopaminergic System in Mice Is Dependent on Social Isolation Stress. Nutrients. 2023 Jan 22;15(3):581. doi: 10.3390/nu15030581.
Abstract. Matcha tea powder is believed to have various physiological benefits; however, its detailed mechanism of action has been poorly understood. Here, we investigated whether the mental state of mice, due to social isolation stress, affects the antidepressant-like effect of Matcha tea powder by using the tail suspension test. Oral administration of Matcha tea powder reduced the duration of immobility in the stress-susceptible C57BL/6J strain, but not in BALB/c strain. In C57BL/6J mice, SCH23390, a dopamine D1 receptor blocker, prevented Matcha tea powder from exerting its antidepressant-like effect. Matcha tea powder also increased the number of c-Fos-positive cells in the prefrontal cortex (PFC) region and the nucleus accumbens (NAc) region in C57BL/6J mice, but not in BALB/c mice. In contrast, Matcha tea powder did not change the number of c-Fos-positive cells in the ventral tegmental area (VTA) region. Notably, C57BL/6J mice with a shorter immobility time had a higher number of c-Fos-positive cells in the PFC, NAc, and VTA regions. However, no such correlation was observed in the stress-tolerant BALB/c mice. These results suggest that Matcha tea powder exerts an antidepressant-like effect through the activation of the dopaminergic system including the PFC-NAc-VTA circuit and that mental states are important factors affecting the physiological benefits of Matcha tea powder.
