Improving the performance of an electronic nose by wine aroma training to distinguish between drip coffee and canned coffee.

Kouki Fujioka,Keiichi Ikeda,Yoshinobu Manome,Yasuko Tomizawa,Nobuo Shimizu

doi:10.3390/s150101354

Abstract

Coffee aroma, with more than 600 components, is considered as one of the most complex food aromas. Although electronic noses have been successfully used for objective analysis and differentiation of total coffee aromas, it is difficult to use them to describe the specific features of coffee aroma (i.e., the type of smell). This is because data obtained by electronic noses are generally based on electrical resistance/current and samples are distinguished by principal component analysis. In this paper, we present an electronic nose that is capable of learning the wine related aromas using the aroma kit “Le Nez du Vin,” and the potential to describe coffee aroma in a similar manner comparable to how wine experts describe wine aroma. The results of our investigation showed that the aromas of three drip coffees were more similar to those of pine and honey in the aroma kit than to the aromas of three canned coffees. Conversely, the aromas of canned coffees were more similar to the kit coffee aroma. In addition, the aromatic patterns of coffees were different from those of green tea and red wine. Although further study is required to fit the data to human olfaction, the presented method and the use of vocabularies in aroma kits promise to enhance objective discrimination and description of aromas by electronic noses.

Highlights

Coffee aroma has more than 600 components and is considered to be one of the most complex food/drink aromas [1]
We investigated the applicability of the method to other coffees, and compared the coffees with wine and green tea using an electronic nose trained by Le Nez du Vin
We first measured the resistances of the coffee aromas

Summary

Introduction

Coffee aroma has more than 600 components and is considered to be one of the most complex food/drink aromas [1]. It has been observed that the interaction between furfuryl mercaptan (a major component of coffee aroma) and short-chain carboxylic acids affects human olfaction [2,3], and that the peak areas of 40 important compounds in coffee volatiles were different for different sampling times [4] This has made it difficult to describe the features of total coffee aroma based on the components. Despite the successful use of electronic noses for coffee evaluation and discrimination, it is difficult to use the technique to describe the features of coffee aroma (i.e., the type of smell) directly This is because the data obtained by electronic noses are generally in the form of electrical resistance/current and the classification of samples is based on principal component analysis. We investigated the applicability of the method to other coffees, and compared the coffees with wine and green tea using an electronic nose trained by Le Nez du Vin

Experimental Section

Aroma Samples from Le Nez du Vin

Sample Measurements and Analyses Using FF-2A Electronic Nose

51. Vinaigre

Results and Discussion