Geographical origin identification of pure Sri Lanka tea infusions with electronic nose, electronic tongue and sensory profile analysis

Abstract

a Tea quality used to be traditionally evaluated by sensory panels. Their expertise is considerably better than that of the average consumers. However, there can be definite subjectivity in the judgment of sensory panels. A new direction is advanced sensory study that integrates sensory assessment with instrumental evaluation. The aim of this paper is to distinguish five Sri Lanka black teas from plantations of different geographical origins. From the tea samples, infusions were prepared with standard procedure. Three different test methods were applied: electronic nose, electronic tongue and sensory assessment. In the case of the electronic nose only the volatile components were evaluated. The Alpha Astree II potentiometric electronic tongue analyzed the liquid phase, while in the sensory profiling all perceptible attributes were tested. Data were analyzed with principle component analysis (PCA), linear discriminant analysis (LDA) and in the case of sensory analysis with one-way ANOVA. The partial least square regression (PLS) was used to estimate the sensory attributes. As a final result, we found that LDA maps show the quality differences of teas grown at different altitudes and geographical location of growing regions.

Electronic Nose as a Tool for Monitoring the Authenticity of Food. A Review

“…Three most important tea growing countries are India, China, and Sri Lanka. In Sri Lanka, the tea quality is classified not only according to the plantation locations but also according to growing altitude (Kovács et al 2010). Five black teas originating from Sri Lanka were examined by Kovács et al (2010) using an e-nose based on 22 metal oxide semiconductor field-effect transistors (MOSFETs) and MOS sensors, potentiometric e-tongue, and sensory assessment.…”

“…In Sri Lanka, the tea quality is classified not only according to the plantation locations but also according to growing altitude (Kovács et al 2010). Five black teas originating from Sri Lanka were examined by Kovács et al (2010) using an e-nose based on 22 metal oxide semiconductor field-effect transistors (MOSFETs) and MOS sensors, potentiometric e-tongue, and sensory assessment. The tea growing regions were Kandy (the tea plantations located between 650 and 1300 m), Uva located 1200-1500 m, Dimbula located at 1200-1700 m, Nuwara Eliya located at 2000 m, and Ruhuna at 600 m. E-nose and e-tongue data were analysed with PCA and LDA.…”

Vision system and electronic tongue application to detect coffee adulteration with barley

“…All measurements were performed with a specifi c sensorarray (that includes SRS, GPS, STS, UMS, SPS, SWS, and BRS sensors according to the manufacturer). The detailed description of the instrument was presented in several previous publications (KOVÁCS et al, 2010).…”

The Feasibility and Stability of Distinguishing the Kiwi Fruit Geographical Origin Based on Electronic Nose Analysis

“…ANOVA was performed to examine whether there were significant differences of samples from different provinces. PCA is frequently used to reduce the dimensionality of original data by calculating several components that best describe the differences between objects and acquire visualization of cluters (Cynkar et al, 2010 (Kovács et al, 2010). The principle of SLDA for variables selection is the maximum contribution for group differentiation.…”