Browsing Department of Chemistry by Issue Date
Now showing items 21-40 of 323
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The changes in black tea quality due to variations of plucking standard and fermentation time
(Elsevier, 1998)Catechin levels in green leaf, total theaflavins, brightness, thearubigins, colour, flavour index and sensory evaluation decrease with coarse plucking standard in clone 6/8. The sum of Group I volatile flavour compounds ... -
The changes in black tea quality due to variations of plucking standard and fermentation time
(Elsevier, 1998-04)Catechin levels in green leaf, total theaflavins, brightness, thearubigins, colour, flavour index and sensory evaluation decrease with coarse plucking standard in clone 6/8. The sum of Group I volatile flavour compounds ... -
The effects of blending clonal leaf on black tea quality
(Elsevier, 1999-08-01)Although most clones are selected for quality and yields, there are clones in production with superior yields but producing inferior black tea quality and vice versa. Some of these clones with superior yield give very poor ... -
Split application of nitrogen fertilizer rates in two tea cultivars grown in the Eastern and Western highlands of Kenya: I. Confirmatory results on yield effects.
(Tea Research Foundation of Kenya, 2000)Two experiments were conducted in Kericho and Kangaita, Kenya during 19991-98 to investigate the effects of nitrogen fertilizer rates (50, 100, 200, 400 and 800 kg/ha) and frequencies of application (1, 2 and 4 split ... -
Factors impeding tea production in smallholder sub-sector of the Kenya tea industry: an assessment extension staff awareness of existing technologies.
(Tea Research Foundation of Kenya, 2000)This study assessed the level of extension staff in the various technological packages when compared to the agronomic research recommendations. The survey covered 76 extension staff in Kirinyaga, Nyambene, Nandi and Nyamira ... -
Chlorophyll meter use on field grown tea: 1. The optimum leaf age and measuring positions on a leaf blade.
(Tea Research Foundation of Kenya, 2000)In a field experiment conducted in Kenya, a Hydro N-tester chlorophyll meter was used to determine the optimum age and reading position for the measurement of chlorophyll in leaves of tea (clone 6/8). Meter readings were ... -
Quality response of clonal black tea to nitrogen fertiliser, plucking interval and plucking standard
(John Wiley & Sons, Ltd., 2000)Variations in the black tea quality of high‐yielding clone S15/10 in response to rates of NPKS 25:5:5:5 fertiliser of 200 and 400 kg N ha−1 year−1, plucking intervals of 7, 14 and 21 days and a selective plucking standard ... -
A test for relative efficiency in the Smallholder Tea Sub-sector in Kenya
(Department of Agricultural Economics; University of Nairobi., 2001)Despite availability of tea growing technologies to all Kenya tea farmers, green leaf production in smallholder sub-sector remains low. Tea in Kenya is grown in the East of the Rift Valley and the West of the Rift Valley ... -
A Measure of Economic Rationality in the Smallholder Tea Sub-Sector in Kenya
(Department of Agricultural Economics; University of Nairobi., 2001)The smallholder tea sub-sector in Kenya is considered the largest and one of the most successful smallholder schemes in the world. However, tea productivity in this sub-sector has been persistently low when compared with ... -
Effects of fertilisers on tea yields and quality: A review with special reference to Africa and Sri Lanka.
(Tea Research Foundation of Kenya, 2001)Introduction the increase in world demand, consequently tea Camellia sinensis L. 0 . Kuntze plants are commercially grown under different climatic conditions with latitudes ranging from 49' N (Outer Carpathians) to 33' S ... -
Comparative responses in plain black tea quality parameters of different tea clones to fermentation temperature and duration
(Elsevier, 2001-02-01)The amounts of black tea theaflavins, brightness, and sensory evaluations varied with clones in the order clone 6/8>SC12/28>S15/10, while thearubigins and total colour changed in the reverse order. The rates of change of ... -
Química Inorgânica 1
(African Virtual University U i i Vi ll Af i i, 2001-02-07)O módulo começa com um olhar crítico à Tabela Periódica de elementos e a razão para a respectiva forma de classificação. A tabela torna mais fácil a compreensão e mais rápido, dos conceitos e factos da química dos elementos. ... -
Changes in the chemical and sensory quality parameters of black tea due to variations of fermentation time and temperature
(Elsevier, 2001-12-31)The changes in theaflavins and residual catechin compositions, thearubigins TRSI and TRSII, sensory characteristics of total colour, brightness and briskness of black tea were investigated. It was demonstrated that the ... -
Gender Analysis of Economic Efficiency in Smallholder Tea Production in Kenya
(Eastern Africa Agricultural Economics Society,1979, 2003)If the productivity of tea among the smallholders can only increase to about 2500 kg/ha/yr, the national projection of 300 thousand metric tones would be realized without the need to allocate more land to tea enterprise. ... -
Tea
(Oxford, 2003)This article focuses on the process of tea fermentation. Tea beverages are processed from the young tender shoots of Camellia sinensis L. O. Kuntze. Because of its subtle flavors and health benefits, tea has become the ... -
Changes in thearubigin fractions and theaflavin levels due to variations in processing conditions and their influence on black tea liquor brightness and total colour
(Elsevier, 2004-03-30)Increase in coarser plucking standards significantly (P< 0.05) depressed levels of theaflavin (TF; μmol/g), total colour and brightness (spectrophotometer) of black tea. But total thearubigins (TR) TRSI, TRSII and ... -
Reactions of Methyl Iodide and Halopropanes with Na0 Treated and Untreated NaX and NaY Zeolites
(Cambridge University Press, 2005)Products formed from reactions of methyl iodide, 1-chloropropane, 1-iodopropane and 1-bromopropane with Na0 treated and untreated NaX and NaY zeolites were studied using solid state 13C NMR and IR spectroscopy. At room ... -
Effects of Possible Spin-Spin Interactions on EPR spectra of Cu2+ exchanged Faujasite–X (I)
(Cambridge University Press, 2005)The interpretation of the continuous wave electron paramagnetic resonance (CW-EPR) spectra of Cu2+ exchanged in Faujasite zeolite is not straightforward. Recent literature points to the role of both Cu2+ zeolite sites and ... -
Long term effects of nitrogenous fertilizers on tea yields, nutrients uptake and some soil chemical properties
(Soil Science Society of East Africa, 2005)A field experiment was set up to determine long tenn responses of different rates of nitrogen fertilizers namely used in tea, N~KS 25:5:5:5 and NPK 20: 10: 10, on tea 'Ields, nutrient uptake and soil chemical properties. ... -
Assessment of Constraints in Technology Transfer System and Policies which Limit the Realisation of High Green Leaf Production in the Smallholder Tea Sector of the Kenya Tea …
(African Technology Policy Studies Network (ATPS), 2005-01-01)Technological recommendations for maximizing green leaf production have been made available to smallholder farmers by the Tea Research Foundation of Kenya (TRFK) through various publications. Indeed TRFK has released ...