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2019Journal articleFree to read

Gas chromatographic Analysis of Organic Acids in Japanese Green Tea Leaves.

Shirai N

Journal of oleo science

Read at the publisher →Free full text →PubMed

Abstract

Herein, gas chromatography is used to determine and quantify organic acids in Japanese green tea leaves, and the established method is employed to profile the acid components of Matcha, Gyokuro, Sencha green teas, and green tea varieties and thus acquire data needed to ensure the high quality and safety of green tea. The tea leaves were esterified with 10 vol% sulfuric acid in 1-butanol at 100℃ for 2 h. Oxalic acid contents were high in Asatsuyu and Okuyutaka samples and were low in Sofu, increasing in the order of Sencha < Gyokuro < Matcha, while citric acid content increased in the order of Sencha < Matcha < Gyokuro. Moreover, the oxalic acid content of Gyokuro only slightly increased with increasing tea grade. The relative contents of the different fatty acids did not strongly vary between the different green tea varieties. However, the n-3 to n-6 ratio was found to be low in Sofu. The progressing maturity increased the n-3 to n-6 ratio of Yabukita. The n-3 to n-6 ratio was low in high-grade Matcha, Gyokuro, Sencha green teas, and was related to the green tea quality. The developed method was concluded to be suitable for the evaluation of green tea quality.

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Study type

Chemical / analytical

Measuring what is in matcha, or how to detect it.

Assigned automatically from the title, abstract and subject terms.

Topics

Processing, milling and qualityAuthenticity and analytical methods

Matcha is a main subject here (named in the keywords).

Keywords and subject terms

fatty acidgas chromatographygreen teaorganic acidoxalic acidorganic acidsmatchasenchacitric acidfatty acidsn-6/n-3 ratiotea gradeAcids, AcyclicChromatography, GasMolecular StructurePlant LeavesTea

Cite this study

Shirai N. (2019). Gas chromatographic Analysis of Organic Acids in Japanese Green Tea Leaves. Journal of oleo science. https://doi.org/10.5650/jos.ess19208

DOI: 10.5650/jos.ess19208 · PubMed ID: 31787675 · Cited by 18 (OpenAlex)

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