title: Spatial variability of theaflavins and thearubigins fractions and their impact on black tea quality.
abstract: The spatial distribution of theaflavin and thearubigin fractions and their impact on black tea quality were investigated using multivariate and geostatistics techniques. Black tea samples were collected from tea gardens of six geographical regions of Assam and West Bengal, India. Total theaflavin (TF) and its four fractions of upper Assam, south bank and North Bank teas were higher than the other regions. Simple theaflavin showed highest significant correlation with tasters' quality. Low molecular weight thearubigins of south bank and North Bank were significantly higher than other regions. Total thearubigin (TR) and its fractions revealed significant positive correlation with tasters' organoleptic valuations. Tea tasters' parameters were significantly and positively correlated with each other. The semivariogram for quality parameters were best represented by gaussian models. The nugget/sill ratio indicated a strong/moderate spatial dependence of the studied parameters. Spatial variation of tea quality parameters may be used for quality assessment in the tea growing areas of India.
authors.affiliation: Tocklai Tea Research Institute, Tea Research Association, Jorhat, Assam 785008 India.
authors.forename: Lakshi Prasad
authors.initials: LP
authors.lastname: Bhuyan
authors.affiliation: Tocklai Tea Research Institute, Tea Research Association, Jorhat, Assam 785008 India.
authors.forename: Paban
authors.initials: P
authors.lastname: Borah
authors.affiliation: Tocklai Tea Research Institute, Tea Research Association, Jorhat, Assam 785008 India.
authors.forename: Santanu
authors.initials: S
authors.lastname: Sabhapondit
authors.affiliation: Tocklai Tea Research Institute, Tea Research Association, Jorhat, Assam 785008 India.
authors.forename: Ramen
authors.initials: R
authors.lastname: Gogoi
authors.affiliation: Indian Statistical Institute, North-East Centre, Tezpur, Assam 784028 India.
authors.forename: Pradip
authors.initials: P
authors.lastname: Bhattacharyya
keywords: Black tea; Geostatistics; North-East India; Theaflavins; Thearubigins