Castagne d’acqua (Water Chestnuts)
Descrizione
Le castagne d’acqua (Eleocharis dulcis) sono cormi acquatici commestibili molto diffusi nella cucina asiatica.
Mantengono una croccantezza eccezionale anche dopo la cottura, caratteristica unica rispetto ad altri vegetali.
Presentano sapore delicato, leggermente dolce, e aroma neutro.
Disponibili fresche, pelate, in scatola, essiccate oppure trasformate in farina/amido.
Valori nutrizionali indicativi per 100 g
(Valori medi riferiti a castagne d’acqua fresche e pelate.)
Energia: 90–100 kcal
Carboidrati: 22–24 g
Zuccheri: 4–5 g
Fibre alimentari: 3–4 g
Proteine: 1–2 g
Lipidi: <0,5 g
Minerali: potassio (elevato), manganese, rame, magnesio
Vitamine: vitamina C (in parte ridotta dopo cottura), vitamina B6, riboflavina
Principali sostanze contenute
Carboidrati complessi: amido (amylose/amylopectin) e zuccheri solubili.
Antiossidanti fenolici: acido ferulico, catechine e derivati.
Minerali: potassio, rame, manganese.
Composti bioattivi: flavonoidi e saponine in tracce.
Processo di produzione
Raccolta: i cormi vengono raccolti a maturazione da coltivazioni acquatiche.
Lavaggio e pelatura: tramite macchine pelatrici e rifinitura manuale per qualità superiore.
Blanching: breve scottatura per inattivare enzimi e prevenire imbrunimenti.
Formati disponibili:
Controlli qualità: parametri microbiologici, fisici e sensoriali secondo protocolli GMP/HACCP.
Proprietà fisiche
Aspetto: bianco, liscio, dalla forma tondeggiante.
Texture: estremamente croccante, stabile alla cottura grazie alla particolare struttura della parete cellulare.
Umidità: 70–80% (fresche); <10% (essiccate).
pH: 5,8–6,5.
Stabilità: buona resistenza termica; la versione in scatola mantiene consistenza per lunghi periodi.
Proprietà sensoriali e tecnologiche
Impieghi alimentari
Piatti asiatici saltati in padella (stir-fry).
Curry, zuppe e wok.
Ripieni per involtini, ravioli, wonton.
Insalate e piatti freddi per aggiungere croccantezza.
Snack fritti (chips di castagne d’acqua).
Farina di castagne d’acqua:
prodotti da forno senza glutine
addensanti per salse e creme
dolci tradizionali asiatici
Nutrizione e salute
Basso contenuto di grassi e calorie.
Ricche di potassio, utile per la regolazione della pressione sanguigna.
Apporto di fibre benefiche per la digestione.
Fonte naturale di antiossidanti con potenziale attività antinfiammatoria.
Naturalmente prive di glutine.
Alto contenuto di acqua → alimento a bassa densità calorica.
Nota porzione
Allergeni e intolleranze
Non contiene allergeni principali.
Non contiene glutine, lattosio, soia o frutta a guscio.
Rarissime sensibilità individuali verso piante acquatiche.
In prodotti in scatola: verificare eventuali conservanti (es. acido citrico).
Conservazione e shelf-life
Fresche (non pelate): 1–2 settimane in frigorifero.
Pelate fresche: 3–5 giorni immerse in acqua (da cambiare quotidianamente).
In scatola: 1–3 anni sigillate; 2–3 giorni in frigorifero dopo apertura (in acqua pulita).
Essiccate/farina: 12–24 mesi in luogo fresco e asciutto.
Sicurezza e regolatorio
Ingredienti classificati come vegetali; nessun ADI specifico.
Devono rispettare limiti igienico–sanitari su contaminanti e residui.
Controlli standard: carica microbica, pesticidi, metalli pesanti (in base alla zona di coltivazione).
Processi conformi ai protocolli GMP/HACCP.
Etichettatura
Denominazione: “castagne d’acqua” oppure “water chestnuts (Eleocharis dulcis)”.
Per prodotti in scatola: indicare acqua/salamoia, eventuali acidificanti.
Può riportare il claim senza glutine se garantita l’assenza di contaminazioni.
Troubleshooting
Sostenibilità e filiera
Coltivate in sistemi acquatici a basso impatto ambientale.
Potenzialmente parte di rotazioni agricole che favoriscono biodiversità e uso efficiente dell’acqua.
Attenzione alla gestione delle acque di scolo e dei reflui (monitoraggio BOD/COD).
Scarti di lavorazione utilizzabili per mangimi o compost.
Principali funzioni INCI (cosmesi)
(Quando usate come “Water Chestnut Extract”)
Agente condizionante cutaneo.
Componente lenitivo e idratante.
Antiossidante di origine vegetale.
Leggera funzione astringente/tonificante.
Conclusione
Le castagne d’acqua rappresentano un ingrediente estremamente versatile, leggero e funcionalmente unico grazie alla loro capacità di mantenere croccantezza dopo la cottura. Offrono applicazioni in una vasta gamma di prodotti, dai piatti pronti agli snack, dai ripieni alle preparazioni senza glutine. Con un profilo nutrizionale equilibrato, buona sostenibilità produttiva e assenza di allergeni rilevanti, sono un ingrediente apprezzato sia nelle cucine tradizionali che nell’industria alimentare moderna.
Mini-glossario
SFA – Saturated Fatty Acids (acidi grassi saturi): l’eccesso nella dieta può alzare l’LDL; qui presenti in quantità minime.
MUFA – Monounsaturated Fatty Acids (acidi grassi monoinsaturi): associati a benefici cardiovascolari.
PUFA – Polyunsaturated Fatty Acids (acidi grassi polinsaturi): includono n-3 e n-6, con funzioni metaboliche e cardio-protettive.
TFA – Trans Fatty Acids (acidi grassi trans): le forme industriali sono sfavorevoli; nelle castagne d’acqua sono assenti.
GMP/HACCP – Good Manufacturing Practices / Hazard Analysis and Critical Control Points: sistemi che garantiscono sicurezza e tracciabilità nella produzione.
BOD/COD – Biological oxygen demand / chemical oxygen demand: indicatori dell’impatto ambientale dei reflui.
Bibliografia__________________________________________________________________________
Wei RR, Ma QG, Sang ZP, Dong JH. Studies on phenylpropanoids from Eleocharis dulcis and their hepatoprotective activities. Zhongguo Zhong Yao Za Zhi. 2021 Mar;46(6):1430-1437. doi: 10.19540/j.cnki.cjcmm.20200821.201.
Abstract. To study phenylpropanoids from Eleocharis dulcis and their hepatoprotective activities. The compounds were separated and purified from ethyl acetate part by conventional column chromatography and preparative liquid chromatography, and their structures were identified by various spectral techniques. The HL-7702 cells damage model of hepatocytes induced by APAP was used to screen and evaluate the hepatoprotective activities of these compounds. Sixteen compounds were isolated from ethyl acetate part of E. dulcis, and their structures were identified as 6'-(4″-hydroxy-3″-methoxy-phenylpropenyl)-1-(10-methoxy-phenylacetone)-1'-O-β-D-glucopy-ranoside(1), susaroyside A(2), clausenaglycoside B(3), clausenaglycoside C(4), clausenaglycoside D(5), emarginone A(6), emarginone B(7), thoreliin B(8), 4-O-(1',3'-dihydroxypropan-2'-yl)-dihydroconiferyl alcohol 9-O-β-D-glucopyranoside(9), 2-[4-(3-methoxy-1-propenyl)-2-methoxy-phenoxy]-propane-1,3-diol(10), 6'-O-(E-cinnamoyl)-coniferin(11), methyl 3-(2-O-β-D-glucopyranosyl-3,4,5,6-tetramethoxyphenyl) propanoate(12), clausenaglycoside A(13), 9-O-(E-cinnamoyl)-coniferin(14), 6'-O-(E-cinnamoyl)-syringin(15), 2'-O-(E-cinnamoyl)-syringin(16). Among them, compound 1 was a new compound. Compounds 2-16 were isolated from this plant for the first time. Among them, compounds 2 and 8 showed certain hepatoprotective activities.
Li G, Nie H, Huang S, Li X, Wu S, Tang X, Song M, Luo Y. Taste Compound Generation and Variation in Chinese Water Chestnut (Eleocharis dulcis (Burm.f.) Trin. ex Hensch.) Processed with Different Methods by UPLC-MS/MS and Electronic Tongue System. Foods. 2022 Nov 30;11(23):3869. doi: 10.3390/foods11233869.
Abstract. Chinese water chestnut (CWC) is popular among consumers due to its unique flavor and crisp and sweet taste. Thus far, the key substances affecting the taste compound of CWC are still unclear. In this study, we used UPLC-MS/MS and an electronic tongue system to study the effects of four typical steaming and cooking methods, cooking without peel for 10 min (PC), steaming without peel for 15 min (PS), cooking with peel for 30 min (WPC), steaming with peel for 30 min (WPS), on the taste compound generation and variation of CWC, and revealed the secret of its crisp and sweet taste. The results show that the electronic tongue can effectively identify the taste profile of CWC, and the effective tastes of CWC were umami, bitterness, saltiness, and sweetness. We screened 371 differential compounds from 640 metabolic species. Among them, nucleotides and their derivatives, carbohydrates, organic acids and their derivatives, and amino acids and their derivatives are closely related to the key taste of CWC, and these compounds affected the taste of CWC through six related metabolic pathways: oxidative phosphorylation and purine metabolism; alanine, aspartate, and glutamate; bile secretion; amino sugar and nucleotide sugar metabolism; the phenylpropane pathway; and toluene degradation. This study reveals the potential metabolic causes of taste compound generation and variation in the taste of CWC.
Gu Y, Yang X, Shang C, Thao TTP, Koyama T. Inhibition and interactions of alpha-amylase by daucosterol from the peel of Chinese water chestnut (Eleocharis dulcis). Food Funct. 2021 Sep 20;12(18):8411-8424. doi: 10.1039/d1fo00887k.
Abstract. The alpha-amylase inhibitory effect of daucosterol purified from the peel of Chinese water chestnut (CWC), a common Chinese vegetable, was assessed. The alpha-amylase inhibitory properties were elucidated by enzyme inhibition, fluorescence quenching and molecular docking experiments. It was found that three saponins from CWC peel exhibited potent inhibitory activity on alpha-amylase and daucosterol was found to be the main inhibitory factor against alpha-amylase with a mixed-type mode. Strong fluorescence quenching of alpha-amylase was observed under static fluorescence quenching with hydrophobic interactions with daucosterol. Molecular docking revealed that the conformation of daucosterol in the high-affinity sites I and II of alpha-amylase was optimum, and hydrophobic interactions were produced by daucosterol aglycone, and hydrogen bonding by the β-D-glucopyranosyl residue. Ingested daucosterol suppressed the elevation of blood glucose levels through inhibition of alpha-amylase in the small intestine in starch-loaded mice. This study provides data supporting the potential benefit of daucosterol from CWC peel in the treatment of diabetes.
Grassby T, Jay AJ, Merali Z, Parker ML, Parr AJ, Faulds CB, Waldron KW. Compositional analysis of Chinese water chestnut (Eleocharis dulcis) cell-wall material from parenchyma, epidermis, and subepidermal tissues. J Agric Food Chem. 2013 Oct 9;61(40):9680-8. doi: 10.1021/jf401863n.
Abstract. Chinese water chestnut (Eleocharis dulcis (Burman f.) Trin ex Henschel) is a corm consumed globally in Oriental-style cuisine. The corm consists of three main tissues, the epidermis, subepidermis, and parenchyma; the cell walls of which were analyzed for sugar, phenolic, and lignin content. Sugar content, measured by gas chromatography, was higher in the parenchyma cell walls (931 μg/mg) than in the subepidermis (775 μg/mg) or epidermis (685 μg/mg). The alkali-extractable phenolic content, measured by high-performance liquid chromatography, was greater in the epidermal (32.4 μg/mg) and subepidermal cell walls (21.7 μg/mg) than in the cell walls of the parenchyma (12.3 μg/mg). The proportion of diferulic acids was higher in the parenchyma. The Klason lignin content of epidermal and subepidermal cell walls was ~15%. Methylation analysis of Chinese water chestnut cell-wall polysaccharides identified xyloglucan as the predominant hemicellulose in the parenchyma for the first time, and also a significant pectin component, similar to other nongraminaceous monocots.
Castagne d'acqua 
