61B-11 |
Identification of aroma characteristics of various black tea infusions using electronic nose technology |
O. TOKUSOGLU1, M. K. Unal1, and M. O. Balaban2. (1) Dept. of Food Engineering, Ege Univ., Bornova, Izmir, 35100, Turkey, (2) Food Science & Human Nutrition Dept., Univ. of Florida, Gainesville, FL 32611 Current quality assessment of black teas relies on sensory inspections. These were not always reproducible and there is a necessity of quick, simple, and inexpensive method for reliable detection in black tea manufacturing. Electronic noses have potential in the food industry as quality control and screening tools. The objectives of this study were 1) to determine the aroma characteristics of black tea infusions using EN 2) to correlate e-nose readings with odor sensory evaluations 3) to develop sensory method for aroma quality of these teas 4) to determine the influences of phenolic compounds quantities on odor quality. Twenty-three commercial black teas (Camellia Sinensis L.), manufacturing pure samples and tea bags were obtained from Turkish Tea Board Çaykur, Lipton, Ulusoy Company and Seylan black teas obtained from Hey Gida A.S. in Turkey. Replicate tea infusions ( 7g/100ml water) were used for E-nose (model 4000,EEV). Phenolic compounds were determined by chromatographic and spectrophotometric methods, 8- member trained sensory panel judged black tea infusions for aroma evaluations. E-Nose readings (n=5) were correlated with sensory data using Discriminant Function Analysis (DFA) and gave correct classification rates (CCR) of 96%,100%, 100%, 98% for four group of black teas. Black teas were placed into similar clusters for both the sensory and the electronic nose data. DFA yielded black tea aroma differentiation that was consistent between electronic nose and sensory data. EN can be used to differentiate black teas in a similar manner to descriptive sensory analysis. The correlation between EN sensors data and total(catechins + tanen + gallic acid) of these teas was determined (y=-6.114 + 0.980 * Sensors) (p< 0.05). This study is a step towards objective determination of aroma quality of black tea , EN is an important quality tool for end product application. Phenolic compounds has been influenced the odor quality.
Session 61B, Food Chemistry: Flavor and aroma chemistry
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