Gas Chromatography and Olfactometry: Electronic Nose Analysis

9548 Words Apr 13th, 2013 39 Pages
Gas Chromatography/Olfactometry and
Electronic Nose Analyses of Retronasal Aroma of Espresso and Correlation with Sensory
Evaluation by an Artificial Neural Network
Tomomi Michishita, Masayuki Akiyama, Yuta Hirano, Michio Ikeda, Yasuyuki Sagara, and Tetsuya Araki

Abstract: To develop a method for evaluating and designing the retronasal aroma of espresso, sensory evaluation data was

correlated with data obtained from gas chromatography/olfactometry (GC/O, CharmAnalysisTM ) and from an electronic nose system α FOX4000 (E-nose). The volatile compounds of various kinds of espresso (arabica coffee beans from 6 production countries: Brazil, Ethiopia, Guatemala, Colombia, Indonesia, and Tanzania; 3 roasting degrees for each country: L
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The perceived quality of prepackaged chilled espresso beverages, which are packaged in a plastic cup with a straw and have gained growing popularity in the coffee beverage market in Japan, is affected by retronasal aroma rather than orthonasal aroma. In vivo measurements and model mouth systems such as breath-by-breath (Graus and others 2001), oral breath sampling (Roozen and Legger-Huysman 1995), and the retronasal aroma simulator (RAS) (Roberts and Acree 1995) have been developed to analyze retronasal aroma (van Ruth and others 1994; Elmore and Langley 1996). The RAS gives a good approximation of the flavor composition as defined by breath-bybreath measurements and shows higher odorant concentration and sensitivity compared with previous methods (Deibler and others
2001). GC/O analysis of the retronasal aroma of freshly brewed espresso using the RAS and the influence of milk addition have been reported (Akiyama and others 2009). However, the influence

Vol. 75, Nr. 9, 2010 r Journal of Food Science S477

S: Sensory & Food
Quality

(GC/O, CharmAnalysisTM ), retronasal aroma of espresso coffee, sensory evaluation

Retronasal aroma of espresso . . . of coffee origin or roasting degree on the aroma is not yet fully understood. GC/O and electronic nose (E-nose) have been developed as analytical techniques for the odor