Detection of optimum fermentation time for black tea manufacturing using electronic nose

Bhattacharyya, Nabarun; Seth, Sohan; Tudu, Bipan; Tamuly, Pradip; Jana, Arun; Ghosh, Devanita; Bandyopadhyay, Rajib; Bhuyan, Manabendra; Sabhapandit, Santanu

doi:10.1016/j.snb.2006.07.013

Cited by 119 publications

(37 citation statements)

References 9 publications

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“…[3]. In the previous studies by the authors [4,5], electronic nose-based monitoring of volatile emission patterns during black tea fermentation process and detection of the optimum fermentation time on the basis of peaks in the sensor outputs have been successfully achieved. Various methodologies such as singular value decomposition (SVD) and Mahalanobis distance computation have been made use of to evolve aroma index at any particular sniffing cycle.…”

Section: Introductionmentioning

confidence: 99%

Preemptive identification of optimum fermentation time for black tea using electronic nose

Bhattacharya

Tudu

Jana

et al. 2008

Sensors and Actuators B: Chemical

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Section: Introductionmentioning

confidence: 99%

Preemptive identification of optimum fermentation time for black tea using electronic nose

Bhattacharya

Tudu

Jana

et al. 2008

Sensors and Actuators B: Chemical

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“…Plant extracts have been widely used as topical applications for wound-healing, anti-aging, and disease treatments. Teas are classified into three major categories based on how they are manufactured as follows: (a) unfermented green tea, (b) partially fermented Oolong tea, and (c) fully fermented black tea [7,8]. Catechins (EGCG) and alkaloids (caffeine), the main active ingredients in green tea, have been proven to have a variety of physiological functions, such as protecting against cancers of the duodenum, colon, skin, lung, breast, esophagus, pancreas, and prostate.…”

mentioning

confidence: 99%

Extraction behavior of caffeine and EGCG from green and black tea

Lee

Lee²

2008

Biotechnol Bioproc E

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A dipping method was developed to extract the catechins (EGCG) and alkaloids (caffeine) from green tea (Korea) and black tea (Sri Lanka). The effects of the solvent composition (water vs. ethanol), extraction time, temperatures, and solvent pH on the amount of catechins (EGCG) and alkaloids (caffeine) extracted from green and black tea were investigated. Reversedphase high-performance liquid chromatography (RP-HPLC) was used to analyze the catechins (EGCG) and alkaloids (caffeine) extracted. The content of EGCG and caffeine in green tea extracts was in the range of 2.04~0.30 and 10.22~0.85 mg/g, respectively. The amount of EGCG and caffeine in black tea extracts was in the range of 0.32~0.24 and 5.26~1.01 mg/g, respectively. The amount of caffeine extracted from green and black tea was greater than the amount of EGCG. Pure water is the best solvent for extracting EGCG and caffeine from green tea. The amount of caffeine extracted from green and black tea increased as the temperature, extraction time, and hydrogen ion concentration of the solvent increased. Although the amount of EGCG extracted from green tea increased as the temperature increased, the amount of EGCG extracted from black tea was not affected by temperature. The extraction of EGCG from both green and black tea was not affected by the hydrogen ion concentration of the solvent. © KSBB hÉóïçêÇëW=Éñíê~ÅíáçåI=Å~ÑÑÉáåÉI=bd`dI=ÖêÉÉå=íÉ~I=Ää~Åâ=íÉ~I=emi`= = = = = Tea, the most popular beverage in the East, has attracted much interest from scientists due to its beneficial health effects [1-6]. Plant extracts have been widely used as topical applications for wound-healing, anti-aging, and disease treatments. Teas are classified into three major categories based on how they are manufactured as follows: (a) unfermented green tea, (b) partially fermented Oolong tea, and (c) fully fermented black tea [7,8]. Catechins (EGCG) and alkaloids (caffeine), the main active ingredients in green tea, have been proven to have a variety of physiological functions, such as protecting against cancers of the duodenum, colon, skin, lung, breast, esophagus, pancreas, and prostate.Catechins (EGCG) and alkaloids (caffeine) also show some anti-mutagenic, anti-carcinogenic, and anti-clastogenic effects [9][10][11][12]. EGCG and caffeine are usually isolated by extraction with organic solvents, and the extraction conditions (solvent, temperature, duration of extraction, pH, and composition ratio of solvent to material) can have a variety of effects on the extraction efficiency of EGCG and caffeine [13].In this paper, we studied the extraction behavior of catechins (EGCG) and alkaloids (caffeine) using green tea (Korea) and black tea (Sri Lanka) in order to obtain basic data on the process for extracting both materials. The effect of different extraction configurations on the extraction efficiency of catechins (EGCG) and alkaloids (caffeine) from green tea leaves and black tea leaves was investigated using various aqueous and pure solvents (ethanol composition of 40, 60, 80 vol%, pure ...

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“…Bhattacharya and colleagues used an array of eight MOX sensors for detection of optimum fermentation time for black tea manufacturing (Bhattacharya et al, 2007). A total of 81 samples were measured and analysed using the PCA technique.…”

Section: Electronic Noses In the Food Industrymentioning

confidence: 99%