International Research Conference of UWU-2020

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Browsing International Research Conference of UWU-2020 by Author "Abeywickrama, K.R.W."

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    Determination of Sucrose, Glucose and Fructose Levels in Low Grown Black Tea Using High Performance Liquid Chromatography Technique
    (Uva Wellassa University of Sri Lanka, 2020) Alwis, J.A.P.N.; Perera, G.A.A.R.; Abeywickrama, K.R.W.
    No extraneous matters are allowed to add during tea manufacture. Nevertheless, some of the manufacturers add sugar to withered tea leaves to develop better appearance in black tea. Sugar adulteration adversely affects the reputation of Ceylon Black Tea. As stipulated by the Tea Research Institute of Sri Lanka, maximum permissible levels of fructose, glucose, and sucrose for low grown black teas are 25 mg/g, 20 mg/g, and 35 mg/g respectively. The present study was conducted to determine whether the black tea manufactured in the low country in Sri Lanka was adulterated with sugar. Sample collection was done according to stratified random sampling keeping administrative districts; Galle, Matara, and Rathnapura as strata. Sixty-three black tea samples (Dust 1 grade) were collected during three consecutive weeks. Coldwater extracts of samples were prepared and their sugar levels were determined using a High-Performance Liquid Chromatograph fixed with a Zorbax NH2 column and a RI detector. The mobile phase comprised of 75% Acetonitrile and 25% de-ionized water. The average fructose, glucose, and sucrose contents of low grown tea were 6.3±2.7, 6.1±3.1, and 7.3±5.5 mg/g respectively. Fructose, glucose, and sucrose contents of all tea samples collected from Matara and Rathnapura districts were below the maximum permissible limits. Further, fructose and sucrose contents of Galle district’s black tea samples were also below the maximum permissible limits. The highest fructose, glucose, and sucrose contents were detected from the Rathnapura district’s black tea samples. It can be concluded that Matara and Rathnapura Districts’ black tea samples comply with the stipulated maximum permissible levels of fructose, glucose, and sucrose whereas Galle District’s black tea samples comply with the maximum permissible levels of fructose and sucrose. Keywords: Black tea, Fructose, Glucose, Sucrose, Adulteration