Browsing Department of Chemistry by Issue Date
Now showing items 1-20 of 337
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Optimising fermentation time in black tea manufacture
(Elsevier, 1986)A comparative study using in-line theaflavins analysis (ILTF), theaflavins of made-tea analysis (TFMT) and tasters' evaluations, to optimise fermentation during tea manufacture, was carried out. All methods obeyed a quadratic ... -
Correlation of theaflavins content and valuations of Kenyan black teas
(John Wiley & Sons, Ltd, 1986-05-01)Correlation between theaflavins content and tasters' valuations of Kenyan black teas generally give positive but statistically non-significant correlation coefficients. In 105 correlations using 12 samples each, only ... -
Flavour volatiles of Assam CTC black teas manufactured from different plucking standards and orthodox teas manufactured from different altitudes of Darjeeling
(John Wiley & Sons, Ltd, 1988-01-01)Biochemical correlations between volatile flavour constituents (VFC) of CTC bluck teas manufactured from fine and coarse plucking of Assam tea and orthodox teas fiom three different altitudes were carried out by GC-MS. ... -
Effects of Geographical Area of Production on the Composition of the Volatile Flavour Compounds in Kenyan Clonal Black CTC Teas
(Cambridge University Press, 1988-04)The contents of the volatile flavour compounds and the flavour index of black teas vary with localities. The magnitude and order of the variations are clonally dependent, the relative performance of clones varying with ... -
Flavonoids from Tephrosia interrupta and T. linearis.
(CABI DIRECT, 1990)In east Africa, medicinal uses have been reported for the roots of T. interrupta (coughs and treatment of women after childbirth) and the leaves of T. linearis ([unspecified] diseases in infants). Flavonoid analyses are ... -
The effects of altitude on the chemical composition of black tea
(John Wiley & Sons, Ltd, 1990-01-01)Changes in quality parameters of crush, tear and curl (CTC) black clonal teas due to variations in altitude within a radius of 10 km were determined. There were significant (P= 0.05) changes in all the quality parameters ... -
Isolation and chemical characterisation of pyrrolisidine alkaloids from some senecio
(University of Calgary, 1991) -
Errata. Pyrrolizidine Alkaloids from Senecio hadiensis
(American Chemical Society, 1991-09)17-Oxosparteine (1 mg), -isolupanine (3 mg), and N-methylcytisine (2 mg) were iden- tified by ms and tic comparisons with authentic samples (6,8). Catalytic reduction (2 mg) of 5,6-dehydrolu- panine (4 mg), oil, ms (9) ... -
Tea Aroma
(Chapman and Hall, London, 1992)Tea is manufactured by a variety of processes producing a range of beverages from green, non-fermented tea through to black, fermented tea. The consumer acceptability of these beverages is largely dependent on the flavor ... -
Comparison of gas chromatographic volatile profiling methods for assessing the flavour quality of kenyan black teas
(John Wiley & Sons, Ltd, 1992-01-01)A comparison is made of the various ratios used to quantify black tea aroma such as the ratio of the sum of gas chromatographic peak areas of compounds eluting before linalool (3,7-dimethyl-1,6-0ctadien-3-01) to those ... -
Ruwenine and ruzorine: Pyrrolizidine alkaloids of Senecio ruwenzoriensis
(Pergamon, 1992-09-01)A reinvestigation of Kenyan Senecio ruwenzoriensis reported to contain two alkaloids of unknown structures, ruwenine and ruzorine, resulted in the isolation of the pyrrolizidine alkaloid isoline, accompanied by what appeared ... -
The pyrrolizidine alkaloids of Senecio syringifolius and S. hadiensis from Kenya
(Pergamon, 1993-01-01)Angularine, rosmarinine and 12-O-acetylrosmarine, together with their N-oxides were isolated from epigeal parts of S. syringifolius, while -
Changes in theaflavin composition and astringency during black tea fermentation
(Elsevier, 1994-01-01)Both theaflavins and sensory evaluations vary in a quadratic manner with fermentation duration in the process of black tea manufacture. The rate of formation of total (Flavognost) theaflavins varies with clones, and within ... -
Response of some black tea quality parameters to nitrogen fertiliser rates and plucking frequencies
(John Wiley & Sons, Ltd, 1994-12-01)The effects of the rate of application of nitrogenous fertiliser and frequency of plucking (harvesting) on various black tea quality parameters and yields were compared on done 6/8. High rates of nitrogen application and ... -
Clonal variation in the individual theaflavin levels and their impact on astringency and sensory evaluations
(Elsevier, 1995-01-01)Clonal variation in the individual theaflavin levels and their impact on astringency and sensory evaluations -
Flavanol composition and caffeine content of green leaf as quality potential indicators of Kenyan black teas
(1997)The Ñavanol composition and ca† eine content of green tea leaf, black tea quality parameters of theaÑavins, thearubigins, liquor brightness and total colour varied more among clones than with time of the year. In green ... -
Flavanol Composition and Caffeine Content of Green Leaf as Quality Potential Indicators of Kenyan Black Teas
(1997)The Ñavanol composition and ca†eine content of green tea leaf, black tea quality parameters of theaÑavins, thearubigins, liquor brightness and total colour varied more among clones than with time of the year. In green ... -
Chinchona Alkaloid from Dendrosenecio kilimanjari subsp. cottonii
(Georg Thieme Verlag Stuttgart· New York, 1997-02)Investigation of the Tanzanian Dendrosenecio kilimanjari subsp. cottonii resulted in the isolation of the cinchona alkaloid, cinchonidine (2). Conversion of cinchonidine to deoxy-cinchonidine was achieved in high yield ...
