Brewed Tea Research Articles

Processing of oolong tea from passion fruit buds of Passiflora edulis

The research aimed to create oolong tea products from passion fruit buds, diversifying this product line and improving the usage value of this bioactive material. The tea fermentation process was conducted at a temperature of 25 ± 2°C for 4 h, while the semi-drying and final-drying were performed at 50 ± 2°C for 4 h and 90 ± 2°C for 4 h, respectively. Tea product had a moisture content of 5.45%, a reducing sugar content of 1.21 mg/g, and a total polyphenol content of 22.38 mg/g. Tea was brewed at a tea to water ratio of 2.5% for 3 min at 95°C. In sensory evaluations of the brewed tea, color scored 4.93, clarity scored 3.91, smell scored 4.81, and taste scored 4.89. Thus, the product was graded as “good” according to TCVN 12713:2019.

Antioxidant analysis of protein from fresh and dry leaf of Orthosiphon aristatus (Blume) Miq.

Orthosiphon aristatus (Blume) Miq. is a folklore plant consumed as brewed tea for various health benefits. The white variety of the plants leaf and stem are predominantly sold in the market in dried form, blooming as a natural herbal product. To date, no proteomics and antioxidant studies are available on the fresh and dried leaf protein extract of O. aristatus since most studies take an interest in the crude extracts of plants. Thereupon, this study focuses on the One-dimensional (1D) electrophoretic pattern of the fresh and dry leaf determined via sodium dodecyl-sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Additionally, antioxidant proteins are currently being focused on for their link to controlling disease through their potential to destroy free radicals that are present in excess. Hence, an antioxidant assay was conducted for the fresh and dry leaf protein extract using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical assay and ferric reducing antioxidant power (FRAP) assay. The electrophoretic pattern obtained resulted in approximately 16 and 10 bands for the fresh and dry leaves respectively. As for the antioxidant activity, the dry leaf had higher radical scavenging activity and higher reducing power compared to the fresh leaf. The findings obtained provides insight in to the protein content and antioxidant activity found in the protein extract of fresh and dry leaves of O. aristatus. Hence, further detailed study of the protein extracts could further unveil their therapeutic potential.

Establishment of appropriate conditions for the efficient determination of multiple mycotoxins in tea samples and assessment of their drinking risks

Conditions were determined for rapid, convenient, and efficient determination of 16 common mycotoxins in tea samples. Mycotoxins in tea leaves and tea infusion samples were extracted using solid-liquid extraction/liquid-liquid extraction combined with ultrasonic-assisted extraction. The extraction solvent was 2-butanone/ethyl acetate (9/1 v/v) with 0.1 % formic acid. The established conditions enabled the analysis of these mycotoxins by ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) in 5.5 min. In addition, HPLC with a temperature-controlled fluorescence detector was able to simultaneously determine 8 mycotoxins with fluorescent properties in 10 min without derivatization. Aflatoxin M1 (2.15 and 3.01 μg/kg), fumonisin B2 (198.89 μg/kg), and zearalenone (87.54 μg/kg) could be detected in commercially available pu-erh tea, green tea, and black tea products, and their total transfer rates from the products to brewed tea infusions were 64.08–65.13 %, 90.59 %, and 25.99 %, respectively. The risks of drinking mycotoxins from these tea infusions mostly showed low levels of concern.

Microbead-Based Colorimetric and Portable Sensors for Polyphenol Detection.

Natural polyphenols found in health supplements and drinks have antioxidant and anti-inflammatory properties. In particular, to determine the beneficial qualities of antioxidant drinks and beverages, consumers demand precise quantification of the total amount of polyphenols as on-site detection. Herein, we developed a new concept of portable beads suitable for the field detection available: colorimetric quantification of polyphenols equipped with color converting software applications in a smartphone or tablet PC. The yellowish beads contain ferric ions to react with polyphenol to produce blackish metal-phenolic complexes. It is simple to perform the detection procedure: dipping the beads in the analytical sample and out-taking a photo-converting into RGB color values and quantification of the existed polyphenol. The overall process was completed within 5 min. Compared with the Folin-Ciocalteu assay, which is a representative optical sensor kit for total phenolic content, the bead-based sensor showed a better limit of detection of 0.0415 mM for tannic acid and comparable sensing capability for a polyphenol-containing plant extract and brewed tea. The beads conserved the shape and sensitivity after months of storage or under environmental interference such as a change in the temperature.

Optimization Design of Automatic Tea Ceremony Teacup Equipment Based on TRIZ Principle

With the development of science and technology and the accelerated pace of society, people are increasingly pursuing a convenient way of life. The art of making tea in traditional Chinese tea culture, although rich in deep cultural heritage, is difficult to adapt its cumbersome steps to the modern fast-paced life. In order to solve this contradiction, this paper applies TRIZ theory to optimize the design of fully automatic tea cup equipment, aiming to realize the automation of the tea brewing process, while retaining the cultural essence of traditional tea art. Through the automation design of the steps of blancher, tea brewing and aroma shaking, combined with modern mechanical design and intelligent control technology, this study proposes an innovative fully automatic tea ceremony teacup equipment program. The solution not only improves the efficiency of tea brewing, but also ensures the quality of tea soup and the experience of traditional tea ceremony through careful design. Ultimately, the feasibility and effectiveness of the proposed scheme are verified through kinematic analysis, prototype testing and user experience evaluation. This study is of great practical significance for the modernization and transformation of the traditional tea ceremony, and also provides a reference for the automation of other traditional processes.

Tea (Camellia sinensis) leaves accumulate higher levels of Aluminum: Potential Health Risk- Alzheimer’s disease (AD): An updated review of evidence

This review paper of literature highlights the role of accumulation of aluminum in tea leaves and its toxic effects on human health. Tea is the most consumed beverage in the world after water and contains heavy metals and trace elements that may cause potential negative effects on health. Tea is known to be a metal accumulator. However, drinking even a very high dietary amount of black tea or green tea would be unlikely to cause these adverse effects in humans. Thus, for the majority of heavy tea drinkers around the world, tea is likely to be the largest single source of aluminum intake. Addition of milk to tea can decrease or completely inhibit tea antioxidant properties. According to the literature survey, it is well known that the tea plant accumulates aluminum in its leaves to a greater extent than most other edible plants, and would be a potentially important source of dietary aluminum. Aluminum can be transferred into tea infusions through brewing tea, then enter the human body via tea drinking, thereby causing potential harm to human health. On the basis of literature survey, even though some epidemiological reports were contradictory, there was mounting scientific evidence suggesting a relationship between the neurotoxicity of aluminum and the pathogenesis of Alzheimer’s disease. In particular, the link between aluminum and Alzheimer’s disease has been the subject of scientific debate for several decades. The literature survey confirmed that aluminum hypothesis has been the subject of much debate and criticism for several decades. Evidence from human clinical trials suggested that moderate (1–6 cups/day) rather than excessive consumption of tea could bring diverse health benefits. The relationship between tea consumption and dementia has not been well established yet and other studies reported no significant association. The cause of Alzheimer's disease and any association with aluminum is still unknown. There have been conflicting findings in the scientific literature.

Analyzing the Effects of Rapid and Natural Cooling Techniques on the Quality of Hand-Shaken Green Tea Beverages.

This study compared the quality of hand-shaken green tea prepared through rapid and natural cooling methods. Cooling is crucial in preserving green tea's flavor, aroma, and nutritional components. In the rapid cooling method, green tea is freshly brewed at an initial temperature of 95 °C for 25 min, and then rapidly cooled to 18 °C for 25 min. Conversely, the natural cooling method involves brewing tea at the same initial temperature and time, but allowing it to cool gradually to 30 °C over approximately 4-5 h at room temperature. This study's findings indicate that the rapid cooling method produced green tea with a more vibrant color and improved clarity versus the natural cooling method. Sensory analysis revealed that the taste and aroma of the hand-shaken green tea prepared using rapid cooling were perceived to be more refreshing and invigorating. However, the natural cooling method preserved a higher level of chemical components, including individual catechin caffeine, total polyphenol, soluble solids, reducing sugar, and total tannins. The essential amino acid content of the rapidly and naturally cooled green tea infusions was 6.85 and 13.55 μg/mL, respectively. The γ-Aminobutyric acid (GABA) content was 439.82 and 457.31 μg/mL, respectively. This study's findings suggest that rapid cooling during the preparation of hand-shaken green tea enhances its overall quality. The vibrant color, improved clarity, refreshing taste, and invigorating aroma make it a preferable choice for tea enthusiasts who seek an enhanced sensory experience and excellent quality.

Storm Ciarán's effect on the boiling point of water in the southeast of the United Kingdom

AbstractThe spatial atmospheric pressure field due to Storm Ciarán is investigated in the south‐east of the UK at high temporal and spatial resolution using data from roadside sites. During Ciarán’s passage, a reduction in the boiling point of water was measured at Reading, from which a wider effect on the boiling point of water associated with Ciarán was calculated for the populated regions of the southeast and London. For many people in this region on 2 November 2023, the boiling point of water at breakfast time would have been below the recommended temperature range for optimal brewing of tea.

Nitenpyram in tea: Eco-friendly detection methodology and residue behavior

Studies on nitenpyram determination and behavior within tea remain limited despite its widespread use as a neonicotinoid. An organic-saving analytical approach tailored for the detection of nitenpyram in tea was established. Nitenpyram was extracted by boiling water and cleaned up by Cleanert PCX solid-phase. The average recoveries were 75.1–94.5 %, with relative standard deviations (RSDs) of 0.7–8.6 % for saving 34.5–88.6 % organic solvent. The limits of quantification (LOQs) were 0.002 mg·kg−1 in fresh tea shoots, 0.005 mg·kg−1 in made tea, and 0.001 mg·L-1 in tea brew, satisfying the current minimum Maximum Residue Limit (MRL). Nitenpyram dissipated rapidly with half-lives of 1.2–1.4 days at the recommended dosage (27 g a.i. ha−1) in two locations. Remarkably, 20–110 % of nitenpyram was leached out from made tea in different brewing modes. This work provides insights into nitenpyram’s rational application in tea cultivation and offers considerations to institutions tasked with unestablished MRLs in tea.

Optimisation of corn silk tea production, and its antioxidant profile

Following COVID-19 pandemic, functional foods and beverages continue to develop, especially those with high antioxidant activity. The functional beverage from corn silk can be processed into brewed tea. The critical points in the making process of corn silk tea are the drying equipment, drying temperature, and drying time. With efficient method, corn silk tea can produce high antioxidant activity. The present work optimised the temperature and drying method based on antioxidant activity. The results of the present work are expected to be used in micro/small/medium enterprises (MSMEs) to produce corn silk herbal tea. The present work used Randomised Block Design (RBD) with two factors; drying temperatures (45, 55, and 65°C) and drying equipment (cabinet and oven) for 5 h. The analysis carried out was antioxidant activity and profiling using LC-HRMS (liquid chromatography high-resolution mass spectrometry) that ran in a positive (+) mode. The processing of corn silk tea using cabinet drying at 65°C for 5 h produced antioxidant activity of 82.00 ± 0.75%. This was higher than commercial black tea (81.71 ± 0.15%) and commercial green tea (78.37 ± 0.43%). The analysis using LC-HRMS showed that the corn silk tea contained betaine (N,N,N-trimethylglycine) (RT 0.928), 6-methylquinoline (RT 4.741), hesperidin (3’,5,7-trihydroxy-4’-methoxyflavanone) (RT 302.07817), luvangetin (10-methoxy-2,2-dimethylpyrano[3,2-g]chromen-8-one) (RT 258.08837), embelin (2,5-dihydroxy-3-undecyl-1,4-benzoquinone) (RT 13.074), and eucalyptol (1,8-cineole) (RT 13.325).

Research on Aesthetic Education in Higher Vocational Colleges based on Traditional Tea Ceremony

Tea is a traditional Chinese drink, which is not only welcomed and loved by the older generation but is also enjoyed by certain popularity in the world. From tea making and tea brewing to tea tasting in tea culture and tea etiquette, the tea ceremony with rising popularity is the subject of this study. In this regard, this study starts with the tea ceremony, hoping to find some innovative strategies for its integration into the process of aesthetic education in higher vocational colleges. This paper specifically discusses the core meaning of the traditional tea ceremony and aesthetics and points out that the tea ceremony is not only an art of life but also a cultural practice with deep philosophy. The study also points out its positive effects on higher vocational aesthetic education, including cultivating students’ consciousness of civilization and understanding of etiquette and developing students’ interests, hobbies, and specialties. Furthermore, based on the research conclusions, a series of feasible and effective practical strategies for promoting aesthetic education through tea ceremonies are proposed, hoping to provide more references for educators.

Effects of different brewing conditions on acrylamide levels in Turkish black tea and health risk assessment

In this study, the effects of different brewing parameters (brewing method, teapot spout shape, brewing time, brewing water temperature) on acrylamide levels in black tea were investigated. Then, the level of acrylamide exposure from black tea consumption was evaluated in terms of carcinogenic and non-carcinogenic health risks. The average acrylamide level of all black tea samples brewed with 24 different methods was 53.2±17.1 µg/L. There was no significant difference in acrylamide levels (median) between brewing parameters except for the brewing water temperature value (p < 0.01). Individuals aged 15 years and over living in Türkiye were found to have an acrylamide exposure level in the range of 0.06−0.27 µg/kg bw/day. Consumption of brewed black tea according to different brewing parameters in light, normal and over-brewed forms was found to be safe in terms of non-carcinogenic health risks. However, acrylamide exposure levels indicate the presence of potential and significant health risks in terms of carcinogenic risks considering similar consumption patterns. When all the data are evaluated together, in order to reduce the acrylamide exposure level and potential health risks of acrylamide, black tea should be brewed with water at 95 ℃ and over-brewed tea consumption should be avoided.

Membrane capacitive deionization (MCDI): A flexible and tunable technology for customized water softening

There is a growing demand for water treatment systems for which the quality of feedwater in and product water out are not necessarily fixed with “tunable” technologies essential in many instances to satisfy the unique requirements of particular end-users. For example, in household applications, the optimal water hardness differs for particular end uses of the supplied product (such as water for potable purposes, water for hydration, or water for coffee or tea brewing) with the inclusion of specific minerals enhancing the suitability of the product in each case. However, conventional softening technologies are not dynamically flexible or tunable and, typically, simply remove all hardness ions from the feedwater. Membrane capacitive deionization (MCDI) can potentially fill this gap with its process flexibility and tunability achieved by fine tuning different operational parameters. In this article, we demonstrate that constant-current MCDI can be operated flexibly by increasing or decreasing the current and flow rate simultaneously to achieve the same desalination performance but different productivity whilst maintaining high water recovery. This characteristic can be used to operate MCDI in an energy-efficient manner to produce treated water more slowly at times of normal demand but more rapidly at times of peak demand. We also highlight the “tunability” of MCDI enabling the control of effluent hardness over different desired ranges by correlating the rates of hardness and conductivity removal using a power function model. Using this model, it is possible to either i) soften water to the same hardness level regardless of the fluctuation in hardness of feed waters, or ii) precisely control the effluent hardness at different levels to avoid excessive or insufficient hardness removal.

Determination of Element Concentration of Brewed Tea Consumed in Iran Using ICP-OES: A Risk Assessment Study.

Tea is a popular drink enjoyed by many people around the world. However, it is important to note that impurities and contaminants in tea can potentially threaten human health when consumed. The main objective of this research is to assess the concentration of 16 trace elements (As, Fe, Al, Co, B, Li, Cd, Ba, Pb, Cr, Zn, Hg, Ni, Mn, Sb, and Sn) present in different types brewed of tea by using the ICP-OES (the inductively coupled plasma optical emission spectrometer) device, and the human health risks related to its use were evaluated. In this study, manganese (Mn) indicated the highest mean concentration in black (917.64µg/kg) and green tea (912.89µg/kg), respectively. Our study showed that the highest mean concentration of element boron (B) was (44.36µg/kg) in Stachys lavandulifolia brewed tea. Among different packaging, tea bag samples had the highest concentration of Mn (1025.65µg/kg) and aluminum (Al) (396.63µg/kg). However, those unpacked posed the lowest content of Mn (188.13µg/kg) and Al (100.47µg/kg). The lead (Pb), mercury (Hg), and cadmium (Cd) concentrations in all samples were lower than the maximum limit of the Iranian standard and the WHO. In general, the amount of tea metal in Iranian samples was higher than in imported samples. Also, increasing the brewing time (10 min) can be effective in the solubility and extraction of metals such as B, Hg, cobalt (Co), iron (Fe), and lithium (Li). Further, the correlation between the amount of metals and type in tea samples was evaluated with principal component analysis. Based on the conducted non-carcinogenic risk assessment by the Monte Carlo simulation, the hazard index (HI), due to ingestion of heavy metals via tea in the 5-min brewing of tea, was 7.39E - 03 and 2.09E - 03, and in the 10-min brewing of tea, it was 3.20E - 02 and 9.07E - 03 for children and adults, respectively. Therefore, there was no significant non-carcinogenic risk from tea consumption.

The linguistic and cultural script "tea drinking" in Chinese communication

The article explores the cultural significance of tea drinking in Chinese communication by studying the corresponding linguistic and cultural script. The historical context and the current state of Chinese tea culture is considered; the language used to describe the tea drinking process, including individual lexemes, phrases and idiomatic expressions, is analyzed. Also, the article explores the norms of etiquette and traditions associated with tea drinking. A brief overview of tea idioms in the Chinese language reflecting the linguistic and cultural value of tea drinking is provided. The conclusion is made about the high importance of the considered linguistic and cultural script in Chinese culture, as well as the need to introduce this linguistic and cultural component into the process of teaching Chinese to foreign students. The subject of the study is linguistic and cultural scripts relevant within the framework of Chinese linguoculture using the example of the script "tea party". The novelty of the study lies in the fact that it provides a multidimensional analysis of the linguistic and cultural script "Tea Party" in Chinese linguoculture. In particular, the specialized tea vocabulary, phraseological units, as well as etiquette replicas that are related to tea drinking in Chinese linguoculture are considered. In Chinese culture, there is a complex and interesting tea etiquette to study. The linguistic and cultural script "Tea Party" in the framework of Chinese culture consists of three parts: the preamble of the event, the event and the result of the event. The preamble of the event includes a greeting and an order for tea (the latter is relevant if the tea party takes place in a tea room). An event (i.e., a tea party) involves brewing tea and drinking tea. The latter usually goes without words, because in Chinese culture it is customary to turn off all possible stimuli for the sake of enjoying a tea drink. Besides, the important part is gratitude for a good tea. The result of the event is the payment of the bill (if it happens in a tea shop) and farewell at the end of the tea party.

Co-gasification of lignite and spent tea waste for the generation of hydrogen-rich syngas in a fluidized bed gasifier

The co-gasification of high moisture and high volatile content low-rank lignite (LG) coal and a common waste generated from the brewed tea leaves was studied in a fluidized bed gasification unit. Multiple experiments were conducted at different temperatures, ranging from 800 °C to 900 °C, at fixed operating parameters to elucidate the catalytic thermo-chemical impact on the gasifier performance parameters. The catalytic effect of alkali and alkaline earth metals (AAEMs), especially CaO, K2O, and Na2O present in the spent tea waste (STW) sample, on the product gas composition and performance parameters during the co-gasification experiments with LG was demonstrated. Mixed blends of LG and STW showed enhancement in the overall reactivity of the steam gasification runs, compared to the LG-only feed, primarily due to the change in the surface morphology, textures, and pore structures of the solid product ash samples, as identified with the electron spectroscopy analysis. Liquid and product samples were analyzed using characterization techniques such as Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) analytical techniques, along with the proximate, ultimate, and X-ray fluorescence (XRF) analysis of the gasification feed samples. An optimized blend ratio of 20 wt % of STW with LG sample enhanced the volumetric gas composition of H2 and CH4 gases from 52.03 % to 61.32 % and 3.98 %–5.45 % (on a dry-N2-free basis) with a relatively constant CO gas composition. It showed a reduced CO2 composition from 28.64 % to 18.25 % (on a dry-N2-free basis) for the gasification temperature of 900 °C. Even at the lower gasification temperatures of 800 °C and 850 °C with LG + STW feed, steam gasification experiments showed relatively comparable or superior performance to gasification experiments at 900 °C with LG-only feed. The present study indicated a holistic way to utilize the spent tea waste generated from millions of homes and commercial establishments in various parts of the world with potential application towards synergistic gasification process with other conventional carbon-source materials.

ASIC Design and Implementation of Automated Coffee and Tea Brewing System with FPGA Validation

Abstract: This paper presents a pioneering approach to enhance the efficiency of automated coffee and tea brewing systems through the integration of an ASIC-GDSII and FPGA validation. Leveraging the power of 45nm CMOS Technology, the design achieves substantial reductions in area, power consumption, and delay. The Verilog HDL code undergoes meticulous verification using Cadence tools like Genus and Innovus, ensuring optimal design performance. Innovus validates timing constraints, ensuring adherence to acceptable delay parameters. The resulting compact design not only minimizes power consumption but also effectively addresses leakage issues. These comprehensive optimizations meet stringent performance, area, and power requirements, elevating the operational efficiency of automated brewing systems. Furthermore, the control algorithm is synthesized and implemented using Xilinx's ISE Design Suite, followed by validation on SPARTAN 6 FPGA, providing invaluable insights for future synthesis and implementation endeavors.

Analisis Strategi Pemasaran Teh Celup Walini Industri Hilir PTPN VIII Berdasarkan Perspektif Syariah

PT Perkebunan Nusantara (PTPN) VIII's downstream company is the Downstream Tea Industry (IHT). IHT makes two types of tea: tea bags and brewed tea. The trademark used is Walini. Every year, IHT in running its business increases. This makes the author interested in examining the methods used and whether these methods are in accordance with sharia principles. Qualitative descriptive research is used in this type of research. Both primary and secondary data were used. Primary data was obtained from the marketing division, sales division, tabin, general department employees, and head of production. Data collection methods are through interviews, documentation, and observation. The results showed that IHT uses a marketing mix strategy, which includes product, price, location, and promotion strategies. The product strategy is to maintain quality, increase flavor variety, and improve packaging. The price strategy is Cost-Plus, Premium, Dynamic, and Competition-Based. The place (distribution) strategy is e-commerce, general trade, and contemporary trade. She uses gimmicks, collaborating with private and public educational institutions, events, and social media to promote herself. IHT uses sharia marketing strategies by using attributes and values such as spirituality, shidiq, amanah, fathanah, and tabligh.

Dietary Flavonoid Intakes in France Are Linked to Brewed Tea Consumption and to Socioeconomic Status: Analyses of the Third French Individual and National Food Consumption (INCA3) Survey for Children and Adults.

Flavonoids from green and black tea may benefit cardiovascular health. Brewed tea consumption and flavonoid intake in France have not been previously explored. This study assessed the dietary intake of flavonoids among French children and adults, using 3 days' dietary recall for 3896 persons aged >4 y in the Third French Individual and National Food Consumption Survey (INCA3). Foods consumed by INCA 3 participants were manually matched with the flavonoid content of foods from the French PhenolExplorer database and the US Department of Agriculture expanded flavonoid database (2018 version). The six subclasses of flavonoids were flavan-3-ols, flavanones, anthocyanidins, flavonols, flavones, and isoflavones. Flavonoid intake was stratified by age subgroups (children and adults separately) and examined using socio-demographics and tea consumption patterns. Mean flavonoid intake was 210 mg/d. Flavonoids in the French diet were predominantly flavan-3-ols (147 mg/d), of which tea is the main source. The effects of age, education, income, and socio-professional category (SPC) on flavonoid intake were all significant (p < 0.0001). Brewed tea consumers were 31.88% of French adults and 3.79% of children. Brewed tea consumption and flavonoid intake were highly correlated. The highest brewed tea and flavonoid intakes were found among individuals with the highest SPC and education levels. Flavonoid intake in France was associated with brewed tea consumption and with higher education and income.

HS-SPME/GC×GC-TOFMS 방법으로 가루 녹차의 금속 냄새 화합물 특정 분석

Powdered green tea has a bright green color through shading cultivation. Moreover, people can intake all the active ingredients contained in the tea by directly drinking whisking powdered green tea instead of brewed tea water. This tea is loved by consumers worldwide under the name of “Green Tea Latte.“ Countries that produce powdered green tea compete fiercely for research and development to improve the color, flavor, aroma, and fine particles. This study analyzed the metallic odor compounds in the sensory evaluations of two powdered green teas using headspace-solid phase microextraction (HS-SPME)/ two-dimensional gas chromatography-time of flight mass spectrometry (GCxGC-TOFMS) methods. Alk-1-en-3-ols, alka-1,5-dien-3-ols, alk-1-en-3-ones, alka-1,5-dien-3-ones, (Z)- and (E)-alka-1,5-dien-3-ols, and corresponding ketones are the metallic odors identified in previous research. GC-TOFMS (1D) and GC×GC-TOFMS (2D) were conducted for qualitative analysis. The results of 2D qualitative analysis identified four compounds (1,5-hexadien-3-ol, 1-octen-3-one, 1-octen-3-ol, and benzophenone) in a sample with metallic odor and three compounds (1-octen-3-one, 1-octen-3-ol, and benzophenone) in the normal sample. A calculation of the peak areas showed that the amounts of compounds were more than three times higher in the metallic odor sample than in the normal sample with areas of 9×107 and 3×107 , respectively. Thus, 1,5-hexadien-3-ol, which was the most obvious difference between the two samples, may cause the metallic odor.