Ingredienti
citronella
Cymbopogon citratus (DC.) Stapf
From the sun-drenched soils of Southeast Asia arises Cymbopogon citratus, the stately citronella, a botanical jewel whose slender, emerald blades carry the echo of ancient remedies and refined cuisines.
From the sun-drenched soils of Southeast Asia arises Cymbopogon citratus, the stately citronella, a botanical jewel whose slender, emerald blades carry the echo of ancient remedies and refined cuisines. Its vibrant, uplifting citrus scent, a symphony of nature\'s purest essence, invites a journey of discovery into a world where gastronomy and profound well-being merge in perfect harmony.
Taxonomy
| Species | Name | Distribution |
|---|---|---|
| Cymbopogon flexuosus (East Indian citronella) | Cymbopogon flexuosus (East Indian citronella) | Originating from the lush landscapes of India, Sri Lanka, Burma, and Thailand. This species is widely cultivated for its essential oil, which possesses an exceptionally high citral content. |
| Cymbopogon nardus (Citronella Grass) | Cymbopogon nardus (Citronella Grass) | Native to the tropical regions of Southeast Asia. Elevated to prominence for its essential oil, the famed citronella oil, which serves as a natural insect repellent and is a prized component in perfumery. |
| Cymbopogon martinii (Palmarosa) | Cymbopogon martinii (Palmarosa) | Finding its origins in the mountainous regions of India and Nepal. The essential oil of this plant is cherished in aromatherapy and for the creation of high-quality cosmetics. |
Biology & Habitat
Cymbopogon citratus, commonly known as citronella, is a tropical, evergreen, and perennial grass. The plant takes root in the soils of Southern India and Sri Lanka and has since spread widely throughout the warm regions of Southeast Asia, where it is now extensively cultivated. As a frost-tender species, it thrives exclusively in warm climates, where it develops into dense, well-formed, rounded clumps.
Voor een optimale groei verlangt het citroengras een standplaats in de volle zon, alhoewel het een lichte mate van schaduw kan verdragen. De plant toont zich aanpasbaar aan diverse grondsoorten, maar ontvouwt haar volledige potentieel in een organisch rijke, goed doorlatende leemgrond. Ze gedijt optimaal in tropische en subtropische klimaten (gemiddelde jaartemperatuur boven 18 °C); in koudere Europese regio's wordt ze als eenjarige plant geteeld of voor de winter naar binnen gehaald.
Il Cymbopogon citratus si trova tipicamente ad altitudini fino a 1.400 metri nelle regioni tropicali e subtropicali. Le temperature ideali per la crescita variano tra i 24 e i 30°C, con una tolleranza che si estende da 18 a 34°C; tuttavia, temperature inferiori a 10°C possono risultare fatali. La pianta prospera con una piovosità media annua compresa tra 1.500 e 3.000 mm, e può tollerare un intervallo che va da 700 a 4.200 mm. La propagazione avviene principalmente tramite la divisione di cespi maturi, poiché i semi sono notoriamente difficili da ottenere.
Morphology
Cymbopogon citratus, commonly known as citronella, manifests as a tropical, evergreen, perennial grass characterized by the formation of dense, rounded clumps. The plant can reach an impressive height of one and a half meters and achieve an equal spread, exhibiting rapid growth. Its habit is defined by an upright, clumping structure.
Le foglie sono la caratteristica più sorprendente del limonegrass. Sono elegantemente arcuate, con una struttura lineare a nastro, e possono raggiungere una lunghezza fino a novanta centimetri con una larghezza di due centimetri e mezzo. Queste foglie verde chiaro, quando vengono schiacciate, rilasciano un aroma distintivo di limone, una qualità che conferisce alla pianta un grande valore.
È raro che la citronella fiorisca, soprattutto quando coltivata al di fuori del suo habitat tropicale nativo. Se la pianta dovesse fiorire, le infiorescenze sono generalmente poco appariscenti e non costituiscono una caratteristica ornamentale principale. La strategia riproduttiva della pianta si basa quindi principalmente sulla propagazione vegetativa piuttosto che sulla produzione di semi.
Il fusto di Cymbopogon citratus non è legnoso, ma è costituito da guaine fogliari strettamente compatte che formano una sezione bulbosa, di colore verde pallido tendente al bianco, alla base. Questa parte è particolarmente raccolta per scopi culinari. Il sistema radicale è fibroso e denso, contribuendo alla capacità della pianta di migliorare la struttura del terreno e prevenire l’erosione.
Physiology & Chemistry
The essential oil of Cymbopogon citratus consists of 65–85% citral, a mixture of the geometric isomers neral (citral B) and geranial (citral A). Citral is responsible for the powerful limone aroma and possesses proven antimicrobial, antifungal and antioxidant properties. In addition to citral, the oil contains myrcene, linalool, geraniol and β-caryophyllene.
The leaves also contain flavonoids (luteolin, isoorientin, orientin), phenolic acids (chlorogenic acid, caffeic acid) and triterpenoids. Luteolin has demonstrated anti-inflammatory and neuroprotective activity in preclinical studies. The combination of citral and flavonoids contributes to the synergistic biological activity of the plant extract.
| Plant Part | Active Compounds |
|---|---|
| Stem base (pale section) | Citral (neral + geranial, 65–85%), myrcene, linalool, geraniol — primary source of essential oil |
| Leaves | Flavonoids (luteolin, isoorientin, orientin), phenolic acids (chlorogenic, caffeic acid), triterpenoids |
| Essential oil (distilled) | Citral 65–85%, myrcene 10–15%, linalool, geraniol, β-caryophyllene, citronellal |
| Root | Sesquiterpenoids, resinous compounds; limited culinary use |
Varieties & Cultivars
Cymbopogon citratus has no officially registered cultivars in the strict botanical sense, but in practice regional selections are distinguished by citral content, leaf colour and vigour. The most widely used selections for culinary and commercial cultivation are listed below.
| Cultivar | Characteristics | Use |
|---|---|---|
| Cymbopogon citratus — Standard cultivated selection | Most widespread selection for culinary use; high citral concentration (70–80%), broad leaves, robust growth. | Foundation of Asian cuisines (Tom Yum, curry, pho), herbal teas, syrups and essential oil distillation. |
| Cymbopogon flexuosus — East Indian citronella | Higher citral concentration (80–85%) than C. citratus; reddish stem base; better drought resistance. | Primarily for commercial essential oil distillation; also applicable in culinary use. |
| Cymbopogon nardus — Citronella grass | Contains citronellal and geraniol instead of citral; less limone aroma, more floral scent. | Essential oil for insect repellents (citronella candles, sprays), perfumery and cosmetics. |
| Cymbopogon martinii — Palmarosa | High geraniol content (75–95%); rose-like scent; no pronounced limone aroma. | Aromatherapy, skin care, high-quality cosmetics and perfumery. |
| Cymbopogon winterianus — Java citronella | Higher essential oil yield than C. nardus; higher citronellal concentration. | Commercial production of citronella oil for insect repellents and perfumery. |
Health Effects
The essential oil of citronella, with its high citral content, has demonstrated significant antimicrobial activity in multiple in vitro studies against Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus niger. It inhibits bacterial biofilm formation and disrupts the cell wall integrity of fungi.
Citral and flavonoids (particularly luteolin) in citronella inhibit the synthesis of pro-inflammatory cytokines (TNF-α, IL-6) in macrophages. Animal studies have shown that citronella oil inhibits the activity of COX-2 and lipoxygenase, enzymes involved in the arachidonic acid cascade.
Ethanol extracts of Cymbopogon citratus reduce blood glucose levels and improve insulin sensitivity in animal models. Epidemiological data from traditional medicine systems (Ayurveda, African phytotherapy) support its use in blood sugar regulation.
citronella oil exhibits anxiolytic and sedative effects in preclinical models, presumably through modulation of the GABAergic system. Inhalation of citral has shown a significant anxiolytic effect in mouse studies.
Citral and limonene in citronella oil have induced apoptosis in various cancer cell lines (breast, lung, colon carcinoma) in cell culture studies. These findings are exclusively preclinical; clinical evidence in humans is lacking.
Health Effects
- citronella essential oil must not be applied undiluted to the skin; always dilute in a carrier oil (1–2%) to prevent skin irritation or sensitisation.
- Use of citronella oil is not recommended during pregnancy and breastfeeding due to insufficient safety data for these groups.
- Individuals with a known allergy to grasses (Poaceae) or citrus terpenes should exercise caution when using citronella oil or extracts.
- Ingestion of large quantities of citronella oil (beyond usual dietary amounts) may be hepatotoxic; use as a dietary supplement only under the supervision of a healthcare provider.
Ethnobotany & History
La storia del Cymbopogon citratus, o limonegrass, è indissolubilmente legata alle tradizioni culinarie e medicinali del Sud-est asiatico, dove la pianta è coltivata da millenni. Antichi scritti provenienti dall’India e dalla Malesia attestano il suo lungo riconoscimento come erba di grande valore. Nella medicina ayurvedica e in altri sistemi tradizionali di guarigione, veniva utilizzata per il trattamento di un’ampia gamma di disturbi.
L'introduzione della citronella nel mondo più ampio seguì le rotte del commercio e dello scambio culturale del Sud-est asiatico. I mercanti arabi portarono l'erba in Africa e, successivamente, i coloni europei ne favorirono la diffusione in altre regioni tropicali. Nel XVII secolo, la citronella aveva raggiunto l'Europa, sebbene fosse principalmente considerata una curiosità botanica o un ingrediente esotico.
Durante il XX secolo, la popolarità della citronella ha conosciuto un'impennata a livello globale, in parte grazie al crescente interesse per le cucine thailandese e vietnamita. Il suo caratteristico e raffinato sapore e aroma di limone l'hanno resa un ingrediente indispensabile in piatti come la zuppa Tom Yum e il pho vietnamita. Questo apprezzamento culinario ha portato a una significativa espansione della sua coltivazione e a una maggiore disponibilità.
Oltre alle sue applicazioni culinarie, la citronella ha una ricca storia nella medicina tradizionale. Nelle Filippine, veniva utilizzata come agente antipiretico e diuretico. Nella medicina popolare brasiliana, era impiegata come rimedio calmante e ansiolitico. I suoi usi tradizionali includono anche il trattamento di disturbi digestivi, dolori e infiammazioni, evidenziando la versatilità di questa pianta come erba medicinale.
The cultural significance of citronella extends to ritual and ceremonial practices in certain communities, where it is used for purification and protection. Its fragrance is often associated with freshness and purity. The enduring presence of citronella in both the kitchen and the medicine cabinet of various cultures testifies to its lasting value and remarkable adaptability throughout the centuries.
Sources
Kew Gardens — Plants of the World Online; PFAF Plant Database; Missouri Botanical Garden; NCBI Taxonomy Browser; EMA Herbal Monographs; Wikipedia (verified).