Characterization of Key Aroma Compounds in a Commercial Rum and an Australian Red Wine by Means of a New Sensomics-Based Expert System (SEBES)—An Approach To Use Artificial Intelligence in Determining Food Odor Codes

Abstract

Although to date more than 10 000 volatile compounds have been characterized in foods, a literature survey has previously shown that only 226 aroma compounds, assigned as key food odorants (KFOs), have been identified to actively contribute to the overall aromas of about 200 foods, such as beverages, meat products, cheeses, or baked goods. Currently, a multistep analytical procedure involving the human olfactory system, assigned as Sensomics, represents a reference approach to identify and quantitate key odorants, as well as to define their sensory impact in the overall food aroma profile by so-called aroma recombinates. Despite its proven effectiveness, the Sensomics approach is time-consuming because repeated sensory analyses, for example, by GC/olfactometry, are essential to assess the odor quality and potency of each single constituent in a given food distillate. Therefore, the aim of the present study was to develop a fast, but Sensomics-based expert system (SEBES) that is able to reliably predict the key aroma compounds of a given food in a limited number of runs without using the human olfactory system. First, a successful method for the quantitation of nearly 100 (out of the 226 known KFOs) components was developed in combination with a software allowing the direct use of the identification and quantitation data for the calculation of odor activity values (OAV; ratio of concentration to odor threshold). Using a rum and a wine as examples, the quantitative results obtained by the new SEBES method were compared to data obtained by applying an aroma extract dilution analysis and stable isotope dilution assays required in the classical Sensomics approach. A good agreement of the results was found with differences below 20% for most of the compounds considered. By implementing the GC × GC data analysis software with the in-house odor threshold database, odor activity values (ratio of concentration to odor threshold) were directly displayed in the software pane. The OAVs calculated by the software were in very good agreement with data manually calculated on the basis of the data obtained by SIDA. Thus, it was successfully shown that it is possible to characterize key food odorants with one single analytical platform and without using the human olfactory system, that is, by "artificial intelligence smelling".

The occurrence, enzymatic production, and application of ethyl butanoate, an important flavor constituent

“…41 In some types of wines, ethyl butanoate concentration is higher and contributes to a distinctive wine aroma; thus, it has been recognized as a key aroma compound. Nicolotti, Mall, and Schieberle 42 developed a sensomics-based expert system to reliably predict the key aroma compounds in foods. In this system, the computer system predicted the ethyl butanoate as an odor-active compound without using human olfactometry and found 185 µg/L of ethyl butanoate in commercial Rum, and 61.9 µg/L in Australian Cabernet Sauvignon red wine.…”

“…Later in the olfactometry analysis, it was also detected as a key aroma compound. 42 Marselan wine is made from Marselan variety of grape that is a cross between Cabernet Sauvignon and Grenache, where ethyl butanoate is found to be a key aroma compound with a concentration of 400 µg/L. 43 The concentration of ethyl butanoate in some other wines, where it is found as a key aroma compound, is as follows: Cabernet Franc wine 265.8 µg/L, 44 Cherry wine 393.0 µg/L, 45 and Chinese rice wine (Chinese Huangjiu) 424.3 µg/Kg.…”

Characterization of the Key Aroma Compounds in Marselan Wine by Gas Chromatography-Olfactometry, Quantitative Measurements, Aroma Recombination, and Omission Tests

“…Furthermore GC × GC-TOF-MS, with an excellent ability to separate and enhanced detector capabilities, has been shown to have the advantage in the quantitation of a set of key odorants over foods [24,25]. It can avoid complicated sample pretreatment and simultaneously quantify compounds with large differences of concentration in one run [26].…”

Role of gas chromatography and olfactometry to understand the wine aroma: Achievements denoted by multidimensional analysis

“…The use of the Odor Activity Value (OAV) is another approach to elucidate the contribution of each volatile compound to the wine aroma, as shown in three studies in Table 4 [7,73,118]. OAV is calculated from the ratio between the concentration of a compound and its odor threshold, which is usually obtained from the literature [7,118].…”

“…Odor threshold is defined as the lowest concentration capable of producing an olfactory sensation and that can be detected by 50% of the assessors [145,146]. Considering the compounds found at concentrations higher than their odor thresholds (OAV > 1), 24, 25, and 43 compounds showed potential to contribute to aroma of Nebbiolo [118], Cabernet Sauvignon [73] and Chardonnay wines [7], respectively. The highest OAV were obtained for ethyl octanoate, ethyl hexanoate, isoamyl acetate, ethyl butanoate, and β‐damascenone in Nebbiolo [118] and Chardonnay [7] wines, while methylpropanol and four ethyl esters (methylbutanoate, octanoate, ethyl hexanoate and propanoate were among the compounds of Cabernet Sauvignon wine with higher OAV [73].…”