Characterization of the Potent Odorants Contributing to the Characteristic Aroma of Matcha by Gas Chromatography–Olfactometry Techniques

Abstract

The odorants contributing to the characteristic aroma of matcha were investigated by analysis of the headspace samples and the volatile fractions prepared by a combination of solvent extraction and the SAFE techniques using three matcha powders of different grades (high, medium, and low). Gas chromatography-olfactometry of the headspace samples (GCO-H) and aroma extract dilution analysis (AEDA) applied to the volatile fractions revealed 16 (FD factor ≥1) and 39 (FD factor ≥4) odor-active peaks, respectively. Among them, 14 and 37 of the odorants, most of which were newly detected in matcha, were identified or tentatively identified by GC-MS and GC-O, respectively. By comparing the perceived odorants of three matcha powders, it was revealed that eight compounds with sweet, green, metallic, and floral notes showed high flavor dilution (FD) factors irrespective of the grades. In addition, some odorants were suggested to influence the characteristic aroma of each grade. Furthermore, trans-4,5-epoxy-(E)-2-decenal, one of the potent odorants of matcha, was revealed to exist as a racemic mixture in matcha. This result suggested that trans-4,5-epoxy-(E)-2-decenal is formed by a nonenzymatic reaction in matcha, different from that in black tea, and that the unique manufacturing process of matcha has a close connection with its formation.

Identification of Aroma Composition and Key Odorants Contributing to Aroma Characteristics of White Teas

“…It was roughly identical to previous reports that fatty acid-derived alcohols, aldehydes, and esters were the main components contribute to herbal-like scents (class A) of teas [16,19]. Among them, (E)-2-nonenal was reported as an important odorant contributing to the aroma characteristic of green tea [20,21] and matcha tea [28]; and hexanal was proven to be an important contributor to the aroma characteristic of green tea [21] and oolong tea [23]. It is worth noting that these odorants presented dual odor characteristics.…”

Gas chromatographic Analysis of Organic Acids in Japanese Green Tea Leaves

“…Polyunsaturated fatty acids are easily oxidized, and their derivatives are responsible for green tea aroma. Baba et al showed that Z -3-hexenal, Z,Z -3,6-nonadienal, and E,E -2,4-decadienal showed higher flavor dilution factors in medium-and low-grade Matcha than in high-grade Matcha 21 . In the present work, the n-3 to n-6 ratio was shown to be high in medium-and low-grade Matcha, and the change of this ratio was suggested to influence the aroma of this tea.…”

Comparison of Volatiles in Different Jasmine Tea Grade Samples Using Electronic Nose and Automatic Thermal Desorption-Gas Chromatography-Mass Spectrometry Followed by Multivariate Statistical Analysis

“…Here, all five aldehydes were negatively correlated with the grade of jasmine tea. Interestingly, these volatile compounds, which were harmful to the quality of jasmine tea, had been reported in green tea or originated from tea dhool [3,34,35]. Existing studies also demonstrated that hexanal and (E, E)-2,4-Heptadienal were negatively correlated with the grade of Japanese Matcha [34].…”

“…It was intriguing to find that most of these substances came from tea dhool [3,28]. Furthermore, according to existing research [16,34,35,42], most of them were negatively correlated to the quality of green tea.…”