... 1380 ASHU GULATI*, ARVIND GULATI, SDRAVINDRANATH AND AKSHEY K. GUPTA Hill Area Tea Science Di... more ... 1380 ASHU GULATI*, ARVIND GULATI, SDRAVINDRANATH AND AKSHEY K. GUPTA Hill Area Tea Science Division, Institute of Himalayan ... vacuum, was extracted with 0 2 m Na # SO % and assayed spectrophotometrically with d( )catechin as substrate (Singh & Ravindranath ...
The aroma constituents of Kangra orthodox black tea were isolated by simultaneous distillation ex... more The aroma constituents of Kangra orthodox black tea were isolated by simultaneous distillation extraction (SDE), supercritical fluid extraction and beverage method. The aroma-active compounds were identified using gas chromatography-olfactometry-mass spectrometry. Geraniol, linalool, (Z/E)-linalool oxides, (E)-2-hexenal, phytol, β-ionone, hotrienol, methylpyrazine and methyl salicylate were major volatile constituents in all the extracts. Minor volatile compounds in all the extracts were 2-ethyl-5-methylpyrazine, ethylpyrazine, 2-6,10,14-trimethyl-2-pentadecanone, acetylfuran, hexanoic acid, dihydroactinidiolide and (E/Z)-2,6-nonadienal. The concentrated SDE extract was fractionated into acidic, basic, water-soluble and neutral fractions. The neutral fraction was further chromatographed on a packed silica gel column eluted with pentane and diethyl ether to separate minor compounds. The aroma-active compounds identified using gas chromatography-olfactometry-mass spectrometry were 2-amylfuran, (E/Z)-2,6-nonadienal, 1-pentanol, epoxylinalool, (Z)-jasmone, 2-acetylpyrrole, farnesyl acetone, geranyl acetone, cadinol, cubenol and dihydroactinidiolide. AEDA studies showed 2-hexenal, 3-hexenol, ethylpyrazine, (Z/E)-linalool oxides, linalool, (E/Z)-2,6-nonadienal, geraniol, phenylethanol, β-ionone, hotrienol and dihydroactinidiolide to be odour active components.
Recently anthocyanin-rich purple tea varieties have been developed. The quality of these new purp... more Recently anthocyanin-rich purple tea varieties have been developed. The quality of these new purple tea varieties developed in Kangra valley was assessed, and compared with the quality of tea from standard Kangra clone. Purple tea shoots (PL) recorded higher amount of polyphenols compared to standard green tea shoot (GL) while epigallocatechin gallate (EGCG) recorded higher levels in GL. Higher levels of theaflavins were recorded in orthodox black tea from purple shoots (BTP) compared to black tea (BT) made from green shoots. Both theanine and caffeine recorded higher levels in GL. Volatile flavour profiles of these teas showed qualitative and quantitative differences. Aroma extract dilution assay showed higher dilution factors in BTP than BT. Orthodox teas from purple shoots exhibited higher antioxidant activity compared to standard black tea. Strong correlation of total quality scores with aroma and infusion colour was observed. Tea from anthocyanin-rich cultivars can become speci...
Physiological and biochemical attributes were studied in different developmental stages from unop... more Physiological and biochemical attributes were studied in different developmental stages from unopened bud (stage 1) to full bloom (stage 5) of flowers of tea (Camellia sinensis). The proteins recorded higher levels in stages 1 and 2 and decreased thereafter with development of flowers. Like the tea shoots, flavan-3-ol EGCG and EC were present in highest and lowest amounts, respectively in
Journal of the Science of Food and Agriculture, 1996
Abstract Periodic seasonal variations in infusion quality of orthodox Kangra tea over various gro... more Abstract Periodic seasonal variations in infusion quality of orthodox Kangra tea over various growth flushes are reported. Theaflavins, thearubigins and caffeine recorded maximum content during early flush and gradual decline with progress in season, showing a ...
... 1380 ASHU GULATI*, ARVIND GULATI, SDRAVINDRANATH AND AKSHEY K. GUPTA Hill Area Tea Science Di... more ... 1380 ASHU GULATI*, ARVIND GULATI, SDRAVINDRANATH AND AKSHEY K. GUPTA Hill Area Tea Science Division, Institute of Himalayan ... vacuum, was extracted with 0 2 m Na # SO % and assayed spectrophotometrically with d( )catechin as substrate (Singh & Ravindranath ...
Volatile flavour components of tea flowers (Camellia sinensis) were isolated by two methods viz. ... more Volatile flavour components of tea flowers (Camellia sinensis) were isolated by two methods viz. simultaneous distillation extraction (SDE), supercritical fluid extraction (SFE), analyzed by GC and GC/MS and compared with headspace analysis (HS). The composition of the volatile components extracted by the three methods differed considerably. In SFE, phenylethanol (14.7%), linalool (7.9%), (E)-linalool oxide furanoid (3.5%), epoxy linalool (1.6%), geraniol (2.3%) and hotrienol (1.5%) were major components. m-Xylene (2.6%), (E)-linalool oxide pyranoid (5.4%), p-myrcene (5.2%), alpha-cadinol (4.3%) and methyl palmitate (2.9%) were major compounds isolated by SDE. 3-hexenol (2.1%) (E)-4,8-dimethyl-1,3,7-nonatriene (20.9%) and linalool (35.1%) are major components in headspace analysis. Acetophenone and pheromone germacrene D is detected in tea flowers by all the methods studied. Floral, fresh and fruity odour of tea flowers is retained by SFE as there is very little loss of heat sensiti...
2012 Sixth International Conference on Sensing Technology (ICST), 2012
ABSTRACT Theaflavins (TF) and thearubigins (TR) are the important chemical compounds, which contr... more ABSTRACT Theaflavins (TF) and thearubigins (TR) are the important chemical compounds, which contribute to the colour and brightness of tea liquor. Estimation of TF and TR in black tea is generally done using a spectrophotometer. But, the analysis technique undergoes rigorous time consuming effort for sample preparation; also the operation of costly spectrophotometer requires expert manpower. To overcome above problems an electronic vision system (E-Vision system) based on image processing has been developed, which is faster, low cost, repeatable and can estimate the amount of Total Colour (TC), Brightness (TB), Theaflavins (TF) and TF/TR ratio for orthodox tea liquors. This paper describes the newly developed E-Vision system, experimental methods using orthodox black tea sample, data analysis algorithms and finally, the performance of the E-Vision system as compared to the results of traditional spectrophotometer. The data analysis is done using Principal Component Analysis (PCA) and Multiple Linear Regression (MLR). A correlation has been established between colour of tea liquor images and TC, TB, TR and TF/TR ratio.
Two major iridoid glucosides, namely plantarenaloside, a neurotrophic compound, and boschnaloside... more Two major iridoid glucosides, namely plantarenaloside, a neurotrophic compound, and boschnaloside, an antibacterial iridoid glucoside, have been isolated from the shoots of Incarvillea emodi (a wild ornamental plant). The compounds are characterised by NMR spectral data and ESI mass spectrometery. This is the first ever report on the isolation of iridoid glucosides from I. emodi (Bignoniaceae).
ABSTRACT Effect of extraction temperature and pressure on the removal of caffeine from Kangra ort... more ABSTRACT Effect of extraction temperature and pressure on the removal of caffeine from Kangra orthodox black tea using supercritical carbon dioxide was investigated. Maximum caffeine as well as volatile flavor components was extracted at 35 degrees C/170 bar using 60 g/min flow rate for 90 min extraction in dynamic mode. Satisfactory decaffeination and quality retention were achieved at extraction at 60 degrees C/90 bar. The quality of extracts reduced at higher extraction temperature and pressure combinations. Maximum amounts of theaflavins (88.88%), thearubigins (81.18%) and catechins (73.53%) were retained at these extraction conditions. Volatile components in original (caffeinated) and decaffeinated black teas were isolated by simultaneous distillation extraction (SDE), and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). 2-Hexenal, 3-hexenol, phenylacetaldehyde, cis-linalool oxide, linalool, trans-geraniol, nerolidol, methyl salicylate, alpha- and beta-ionones decreased in decaffeinated black teas compared to untreated control. beta-ionone (1.77%), trans-linalool oxide (5.36%), linalool (7.84%), trans-geraniol (4.32%) and methyl salicylate (1.90%) were retained in satisfactory amount in decaffeination at 60 degrees C/90 bar. Application of aroma extract dilution analysis revealed 11 odor active compounds with flavor dilution (FD) factor ranging from 8 to 512 and odor quality investigated by GC-FID, GC-MS. Some unknown compounds quantitatively reduced or disappeared during decaffeination process. Although there was considerable loss of theaflavins and thearubigins as well as volatile flavor components, SFE extraction at 60 degrees C/90 bar for 90 min appears as the method suitable for selective removal of caffeine from the Kangra orthodox black tea.
ABSTRACT Processing of apple fruits for juice/cider production generates large volume of pomace a... more ABSTRACT Processing of apple fruits for juice/cider production generates large volume of pomace at industrial scale. This biomass (cell wall material and pulp tissues) is rich in array of nutrients, especially dietary fiber and polyphenols. Apple fruits confront various processing conditions at industrial level, influencing the biochemical composition of generated pomace, including its phenolic profile. In present study, a simple, fast and reproducible reversed-phase high-performance liquid chromatography method using diode array detector was developed and validated for separation of different phenolics present in industrial apple pomace. The present method showed reliable and reproducible intraday (0.2–4.0 % RSD) and interday (3.7–8.1 % RSD) precision with limits of detection and quantification values in range of 0.14–0.58 and 0.48–1.95 μg ml−1, respectively, for all the phenolics. Different solvent-mediated extraction of dried pomace powder was also performed to evaluate its total antioxidant potential using standard spectrophotometric assays. The major phenolics found in industrial apple pomace extracts were quercetin (1.4–10.3 μg mg−1), phloretin (1.1–9.3 μg mg−1) and phloridzin (0.62–2.0 μg mg−1).
... 1380 ASHU GULATI*, ARVIND GULATI, SDRAVINDRANATH AND AKSHEY K. GUPTA Hill Area Tea Science Di... more ... 1380 ASHU GULATI*, ARVIND GULATI, SDRAVINDRANATH AND AKSHEY K. GUPTA Hill Area Tea Science Division, Institute of Himalayan ... vacuum, was extracted with 0 2 m Na # SO % and assayed spectrophotometrically with d( )catechin as substrate (Singh & Ravindranath ...
The aroma constituents of Kangra orthodox black tea were isolated by simultaneous distillation ex... more The aroma constituents of Kangra orthodox black tea were isolated by simultaneous distillation extraction (SDE), supercritical fluid extraction and beverage method. The aroma-active compounds were identified using gas chromatography-olfactometry-mass spectrometry. Geraniol, linalool, (Z/E)-linalool oxides, (E)-2-hexenal, phytol, β-ionone, hotrienol, methylpyrazine and methyl salicylate were major volatile constituents in all the extracts. Minor volatile compounds in all the extracts were 2-ethyl-5-methylpyrazine, ethylpyrazine, 2-6,10,14-trimethyl-2-pentadecanone, acetylfuran, hexanoic acid, dihydroactinidiolide and (E/Z)-2,6-nonadienal. The concentrated SDE extract was fractionated into acidic, basic, water-soluble and neutral fractions. The neutral fraction was further chromatographed on a packed silica gel column eluted with pentane and diethyl ether to separate minor compounds. The aroma-active compounds identified using gas chromatography-olfactometry-mass spectrometry were 2-amylfuran, (E/Z)-2,6-nonadienal, 1-pentanol, epoxylinalool, (Z)-jasmone, 2-acetylpyrrole, farnesyl acetone, geranyl acetone, cadinol, cubenol and dihydroactinidiolide. AEDA studies showed 2-hexenal, 3-hexenol, ethylpyrazine, (Z/E)-linalool oxides, linalool, (E/Z)-2,6-nonadienal, geraniol, phenylethanol, β-ionone, hotrienol and dihydroactinidiolide to be odour active components.
Recently anthocyanin-rich purple tea varieties have been developed. The quality of these new purp... more Recently anthocyanin-rich purple tea varieties have been developed. The quality of these new purple tea varieties developed in Kangra valley was assessed, and compared with the quality of tea from standard Kangra clone. Purple tea shoots (PL) recorded higher amount of polyphenols compared to standard green tea shoot (GL) while epigallocatechin gallate (EGCG) recorded higher levels in GL. Higher levels of theaflavins were recorded in orthodox black tea from purple shoots (BTP) compared to black tea (BT) made from green shoots. Both theanine and caffeine recorded higher levels in GL. Volatile flavour profiles of these teas showed qualitative and quantitative differences. Aroma extract dilution assay showed higher dilution factors in BTP than BT. Orthodox teas from purple shoots exhibited higher antioxidant activity compared to standard black tea. Strong correlation of total quality scores with aroma and infusion colour was observed. Tea from anthocyanin-rich cultivars can become speci...
Physiological and biochemical attributes were studied in different developmental stages from unop... more Physiological and biochemical attributes were studied in different developmental stages from unopened bud (stage 1) to full bloom (stage 5) of flowers of tea (Camellia sinensis). The proteins recorded higher levels in stages 1 and 2 and decreased thereafter with development of flowers. Like the tea shoots, flavan-3-ol EGCG and EC were present in highest and lowest amounts, respectively in
Journal of the Science of Food and Agriculture, 1996
Abstract Periodic seasonal variations in infusion quality of orthodox Kangra tea over various gro... more Abstract Periodic seasonal variations in infusion quality of orthodox Kangra tea over various growth flushes are reported. Theaflavins, thearubigins and caffeine recorded maximum content during early flush and gradual decline with progress in season, showing a ...
... 1380 ASHU GULATI*, ARVIND GULATI, SDRAVINDRANATH AND AKSHEY K. GUPTA Hill Area Tea Science Di... more ... 1380 ASHU GULATI*, ARVIND GULATI, SDRAVINDRANATH AND AKSHEY K. GUPTA Hill Area Tea Science Division, Institute of Himalayan ... vacuum, was extracted with 0 2 m Na # SO % and assayed spectrophotometrically with d( )catechin as substrate (Singh & Ravindranath ...
Volatile flavour components of tea flowers (Camellia sinensis) were isolated by two methods viz. ... more Volatile flavour components of tea flowers (Camellia sinensis) were isolated by two methods viz. simultaneous distillation extraction (SDE), supercritical fluid extraction (SFE), analyzed by GC and GC/MS and compared with headspace analysis (HS). The composition of the volatile components extracted by the three methods differed considerably. In SFE, phenylethanol (14.7%), linalool (7.9%), (E)-linalool oxide furanoid (3.5%), epoxy linalool (1.6%), geraniol (2.3%) and hotrienol (1.5%) were major components. m-Xylene (2.6%), (E)-linalool oxide pyranoid (5.4%), p-myrcene (5.2%), alpha-cadinol (4.3%) and methyl palmitate (2.9%) were major compounds isolated by SDE. 3-hexenol (2.1%) (E)-4,8-dimethyl-1,3,7-nonatriene (20.9%) and linalool (35.1%) are major components in headspace analysis. Acetophenone and pheromone germacrene D is detected in tea flowers by all the methods studied. Floral, fresh and fruity odour of tea flowers is retained by SFE as there is very little loss of heat sensiti...
2012 Sixth International Conference on Sensing Technology (ICST), 2012
ABSTRACT Theaflavins (TF) and thearubigins (TR) are the important chemical compounds, which contr... more ABSTRACT Theaflavins (TF) and thearubigins (TR) are the important chemical compounds, which contribute to the colour and brightness of tea liquor. Estimation of TF and TR in black tea is generally done using a spectrophotometer. But, the analysis technique undergoes rigorous time consuming effort for sample preparation; also the operation of costly spectrophotometer requires expert manpower. To overcome above problems an electronic vision system (E-Vision system) based on image processing has been developed, which is faster, low cost, repeatable and can estimate the amount of Total Colour (TC), Brightness (TB), Theaflavins (TF) and TF/TR ratio for orthodox tea liquors. This paper describes the newly developed E-Vision system, experimental methods using orthodox black tea sample, data analysis algorithms and finally, the performance of the E-Vision system as compared to the results of traditional spectrophotometer. The data analysis is done using Principal Component Analysis (PCA) and Multiple Linear Regression (MLR). A correlation has been established between colour of tea liquor images and TC, TB, TR and TF/TR ratio.
Two major iridoid glucosides, namely plantarenaloside, a neurotrophic compound, and boschnaloside... more Two major iridoid glucosides, namely plantarenaloside, a neurotrophic compound, and boschnaloside, an antibacterial iridoid glucoside, have been isolated from the shoots of Incarvillea emodi (a wild ornamental plant). The compounds are characterised by NMR spectral data and ESI mass spectrometery. This is the first ever report on the isolation of iridoid glucosides from I. emodi (Bignoniaceae).
ABSTRACT Effect of extraction temperature and pressure on the removal of caffeine from Kangra ort... more ABSTRACT Effect of extraction temperature and pressure on the removal of caffeine from Kangra orthodox black tea using supercritical carbon dioxide was investigated. Maximum caffeine as well as volatile flavor components was extracted at 35 degrees C/170 bar using 60 g/min flow rate for 90 min extraction in dynamic mode. Satisfactory decaffeination and quality retention were achieved at extraction at 60 degrees C/90 bar. The quality of extracts reduced at higher extraction temperature and pressure combinations. Maximum amounts of theaflavins (88.88%), thearubigins (81.18%) and catechins (73.53%) were retained at these extraction conditions. Volatile components in original (caffeinated) and decaffeinated black teas were isolated by simultaneous distillation extraction (SDE), and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). 2-Hexenal, 3-hexenol, phenylacetaldehyde, cis-linalool oxide, linalool, trans-geraniol, nerolidol, methyl salicylate, alpha- and beta-ionones decreased in decaffeinated black teas compared to untreated control. beta-ionone (1.77%), trans-linalool oxide (5.36%), linalool (7.84%), trans-geraniol (4.32%) and methyl salicylate (1.90%) were retained in satisfactory amount in decaffeination at 60 degrees C/90 bar. Application of aroma extract dilution analysis revealed 11 odor active compounds with flavor dilution (FD) factor ranging from 8 to 512 and odor quality investigated by GC-FID, GC-MS. Some unknown compounds quantitatively reduced or disappeared during decaffeination process. Although there was considerable loss of theaflavins and thearubigins as well as volatile flavor components, SFE extraction at 60 degrees C/90 bar for 90 min appears as the method suitable for selective removal of caffeine from the Kangra orthodox black tea.
ABSTRACT Processing of apple fruits for juice/cider production generates large volume of pomace a... more ABSTRACT Processing of apple fruits for juice/cider production generates large volume of pomace at industrial scale. This biomass (cell wall material and pulp tissues) is rich in array of nutrients, especially dietary fiber and polyphenols. Apple fruits confront various processing conditions at industrial level, influencing the biochemical composition of generated pomace, including its phenolic profile. In present study, a simple, fast and reproducible reversed-phase high-performance liquid chromatography method using diode array detector was developed and validated for separation of different phenolics present in industrial apple pomace. The present method showed reliable and reproducible intraday (0.2–4.0 % RSD) and interday (3.7–8.1 % RSD) precision with limits of detection and quantification values in range of 0.14–0.58 and 0.48–1.95 μg ml−1, respectively, for all the phenolics. Different solvent-mediated extraction of dried pomace powder was also performed to evaluate its total antioxidant potential using standard spectrophotometric assays. The major phenolics found in industrial apple pomace extracts were quercetin (1.4–10.3 μg mg−1), phloretin (1.1–9.3 μg mg−1) and phloridzin (0.62–2.0 μg mg−1).
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