香水檸檬可抗炎 促進益生菌護腸

 

天氣炎熱，酸甜解渴的檸檬茶是不少人的心頭好。傳統的港式檸檬茶多以錫蘭紅茶配黃檸檬，酸甜中帶點醇厚回甘。近年亦從內地興起「鴨屎香暴打檸檬茶」，以特色烏龍茶種「鴨屎香」(只因這種茶種在看似鴨屎的泥土中，與鴨屎毫無關係)，配以被捶打至完全釋放香味的廣東香水檸檬，味道酸甜清新之餘亦帶有獨特香氣。當中的香水檸檬對大家來說看似是新興食材，其實它比我們常見的黃檸檬更有歷史。

 

香水檸檬非檸檬    富含多酚好處多

香水檸檬(Citron)又名枸櫞，是芸香科柑橘屬的植物，和佛手柑、香櫞果等同種為Citrus medica，不同品系。它和柚子及橘子被稱為「柑橘屬祖先物種」，現代DNA及基因分析發現，常見的檸檬(Lemon)其實是枸櫞和柚子/橘子雜交而成的後代。香水檸檬外表和檸檬相近，但外皮多為綠色，皮厚清甜芳香、果肉較少無核。香水檸檬多生長在亞熱帶地區，東南亞、印度、中東、廣東等都有種植。

香水檸檬和其他柑橘類一樣，都是水份超過85%的水果。因其皮厚而汁肉較少，故膳食纖維及油份較黃檸檬高，但維他命C含量却較低。香水檸檬的營養及芳香化合物主要來自其外皮，果肉無籽而苦澀味較少，故在製作檸檬茶時，香水檸檬可以簡單整顆「暴打」釋放香味(主要來自外皮精油)而不帶苦澀。除了香水檸檬茶外，以香水檸檬製作的糖漿更是中東的傳統頭痛藥方。中東有研究發現，每天服用香水檸檬糖漿四週，受試偏頭痛患者的發病次數、時長及強度都比服用普通糖漿的對照組少，效果甚至可媲美預防偏頭痛的乙型阻斷劑藥物普潘奈(Propranolol)。

 

柑橘多酚增益菌   改善腸道抗炎症

香水檸檬的外皮含有相當多的柑橘多酚類黃酮(Flavonoids)化合物，如橙皮素(Hesperidin)、柚皮素(Naringenin)、葡萄糖苷(Glucoside)等。 英國研究發現，飲用柑橘汁後，當中88%的多酚都被腸道菌轉化吸收，只有一成多直接被人體利用。細菌培植研究指出，益生菌如長雙歧桿菌(Bifidobacterium longum)和鼠李糖乳桿菌(Lactobacillus rhamnosus) 分泌的酶能轉化利用柑橘多酚，因此有助益生菌於腸道中生長。另有研究指出，香水檸檬精油對害菌如大腸桿菌的殺滅能力比乳酸菌高十倍以上，有選擇性殺滅害菌的能力。

除了增加益菌、減少害菌外，柑橘多酚亦對腸道本身有好處。有研究以柚皮素培植模擬腸道屏障的人體細胞，發現柚皮素能增加細胞緊密連接蛋白(Tight junction protein)在細胞間的互相連接，而這些連接蛋白的基因表達亦被柚皮素激活。另有不少動物研究以不同的柑橘多酚如橙皮素和柚皮素等，餵食以藥物引發腸炎的小鼠，發現小鼠的腸炎症狀、發炎狀況，以至腸道屏障結構等都有所改善。

荷蘭有研究以柑橘提取物，在模擬腸道中與有代謝症狀受試者的腸道菌一同培植。發現柑橘提取物能增加模擬腸道中的短鏈脂肪酸如丁酸(Butyrate) 、乙酸(Acetate)和戊酸(Valerate)。團隊再邀請50名中年肥胖人士，分組每天服用柑橘提取物或安慰劑12週。結果發現服用柑橘提取物組別的腸道炎症指數較低，而製造丁酸的腸道菌數目則有所上升，使短鏈脂肪酸中丁酸比例明顯較高。

 

柑橘多酚烏龍茶     抗炎護腸促健康

前文曾介紹，腸道菌利用人類腸道中肉類的過剩營養素轉化成TMAO，增加心血管疾病、中風、癌症等風險。有研究以肉鹼(carnitine)餵飼小鼠，令其血液中的TMAO含量明顯增加，再分組餵飼小鼠烏龍茶或柑橘多酚提取物六週。結果發現這兩組小鼠的血液TMAO水平及血管炎症指標都有明顯下降。團隊指出這或因烏龍茶和柑橘多酚提取物能降低肝臟細胞中的黃素單氧化酶(Flavin Monooxygenase, FMO)水平，從而減少TMAO的產生。

香水檸檬與烏龍茶對腸道健康各有益處，這種新穎飲品配搭是街頭手搖飲品中健康的選擇。但大家亦要注意飲品的含糖量，建議盡量選擇低糖(甚至無糖)，兼顧美味與健康。

 

參考資料/延伸閱讀:

＜益生第一關＞2019/07/19--『大熱的冰凍甜飲』

https://hskgene.com/blogs/probiolife-first/summerdrink?_pos=9&_sid=56d7eff66&_ss=r

 

＜益生第一關＞2020/09/25--『多色茶食伴中秋 健康滋味同兼收』

https://hskgene.com/blogs/probiolife-first/tea_mid_autumn?_pos=1&_sid=88e5b5c7e&_ss=r

 

＜益生第一關＞2021/03/19--『益菌短鏈脂肪酸 整腸抗炎又補腦』

https://hskgene.com/blogs/probiolife-first/short-chain-fatty-acid?_pos=2&_sid=7d7a51781&_ss=r

 

＜益生第一關＞2022/02/24--『紅肉食用需適量 TMAO水平低護心血管』

https://hskgene.com/blogs/probiolife-first/tmao_cardiovascular-diseases_red-meat?_pos=1&_sid=30f02dc44&_ss=r

 

Easy Reading:

Lemon Vs Citron: What's The Difference?|Tasting Table |01-11-2022

https://www.tastingtable.com/1080948/lemon-vs-citron-whats-the-difference/

 

檸檬萊姆怎麼分？黃金檸檬跟香水檸檬也要分 | 上下游|27-08-2017

https://www.newsmarket.com.tw/blog/99579/

 

檸檬茶食譜--鴨屎香手打檸檬茶|Yahoo News |07-09-2023

https://hk.news.yahoo.com/%E9%B4%A8%E5%B1%8E%E9%A6%99%E6%89%8B%E6%89%93%E6%AA%B8%E6%AA%AC%E8%8C%B6-180001109.html?guccounter=1&guce_referrer=aHR0cHM6Ly93d3cuZ29vZ2xlLmNvbS8&guce_referrer_sig=AQAAAKAhSSAD6hTXAYyp-fYDupI_S4QYrCcFa-CaAjv-aKWv2gU1ZLXkb3VvoQRTBpE3PwG-y17qaFd9f6iRHRdNoyBvVO0rxfFujAE7BRiwij1jO9w-5GpQM8MU7NuqTtDFSxCcA9BA2Spp2gJjXOWzerdGtjan3N2sjCDR5WcAwTxh

 

飲料店最常用「四季檸檬」！農業部介紹4種常見檸檬一次看|中天新聞網|28-08-2023

https://tw.news.yahoo.com/%E9%A3%B2%E6%96%99%E5%BA%97%E6%9C%80%E5%B8%B8%E7%94%A8-%E5%9B%9B%E5%AD%A3%E6%AA%B8%E6%AA%AC-%E8%BE%B2%E6%A5%AD%E9%83%A8%E4%BB%8B%E7%B4%B94%E7%A8%AE%E5%B8%B8%E8%A6%8B%E6%AA%B8%E6%AA%AC-%E6%AC%A1%E7%9C%8B-093000639.html

 

Google Images:

香水檸檬 健康益處   citron health benefits

 

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