Analysis of lipophilic compounds of tea coated on the surface of clay teapots

The surface of a clay teapot tends to be coated with a waterproof film after constant use for tea preparation. The waterproof films of two kinds of teapots (zisha and zhuni) used for preparing oolong tea and old oolong tea were extracted and subjected to gas chromatography–mass spectrometry analysis. The results showed that comparable constituents were detected in these films; they were primarily fatty acids and linear hydrocarbons that were particularly rich in palmitic acid and stearic acid. To explore the source of these two abundant fatty acids, the fatty acid compositions of fresh tea leaves, granules, infusion, and vapor of infusion were analyzed by gas chromatography. Fresh tea leaves were rich in palmitic acid (C-16:0), unsaturated linolenic acid (C-18:3), linoleic acid (C-18:2), and oleic acid (C-18:1), which were presumably from the phospholipid membrane. During the process of manufacturing oolong tea, the three unsaturated fatty acids may be substantially degraded or oxidized to stearic acid (C-18:0), which was enriched with palmitic acid in the tea granules and in the infusion. The vapor of the tea infusion is primarily composed of palmitic acid and stearic acid. Thus, the coated films of teapots mostly originated from the lipophilic compounds of the tea infusions

Effect of teapot materials on the chemical composition of oolong tea infusions

The flavor and quality of tea are widely believed to be associated with the pot in which the tea is made. However, this claim is mostly by experiences and lacks solid support from scientific evidence. The current study investigated and compared the chemical compositions of oolong tea made with six different teapot materials, namely Zisha, Zhuni, stainless steel, ceramic, glass and plastic

Article Sinulariolide Induced Hepatocellular Carcinoma Apoptosis through Activation of Mitochondrial-Related Apoptotic and PERK/eIF2α/ATF4/CHOP Pathway

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養壺－紫砂壺表面的附著物質

Tea is a traditional beverage with beneficial health functions, and widely consumed in Chinese society. To enhance the aroma, color and taste of tea, infusion is traditionally prepared by immersing tea granules with hot water in zisha teapots. For the tea consumers, it is part of enjoyment to observe the gradual change of surface coating in zisha teapots, and the practice of this teapot maintenance is regarded as an art of tea culture called ＂Yang Hu＂. Waterproof films of zisha teapots were formed by preparing oolong tea and Tzen oolong tea, and found to be mainly fatty acids and linear hydrocarbons, particularly rich in plamitic acid and stearic acid. The two abundant saturated fatty acids, palmitic acid and stearic acid, coated on the surface of teapots were presumably originated from membrane phospholipids of tea leaf cells that were disintegrated during the heating and shaping processes of manufacturing oolong tea. Palmitic acid and stearic acid might be partially dissolved in tea infusion and evaporated to the surface of teapots for deposition via the cavities within the zisha teapots.茶是華人傳統的養生飲品。以紫砂壺泡茶，有助於突顯茶的香氣、色澤與滋味。養壺，顧名思義是紫砂壺體表面光亮潤澤的養成；透過長期反覆茶葉沖泡，紫砂壺體表面會逐漸累積防水物質，而此附著表面的防水層會讓壺體擁有溫潤的光澤。以烏龍茶及熷烏龍茶進行養壺實驗發現，茶壺表面的附著物質主要為脂肪酸，其中以棕櫚酸和硬脂酸為最主要成分。推測脂肪酸來源應為製作烏龍茶過程中因高溫與揉捻破壞茶葉細胞，導致細胞膜主要結構成份－磷脂質裂解所產生，當以熱開水泡茶時，部分脂肪酸會釋出於茶湯中，並藉由紫砂壺體的微小氣孔間隙揮發至壺體表面而附著