Odor and nutrition, Part 3

Peer-reviewed | Manuscript received: March 18, 2016 | Revision accepted: September 19, 2016

Food odorants and their analysis

The first two parts in this series dealt with the physiological basis of smell and the chemical properties of odorants. In this third part, foods and their respective odorants are targeted. As part of this, the challenges are highlighted that arise when analysing the aroma of foodstuff. Thereafter, modern analytical approaches and methods are discussed. And in a concluding short outlook about the key food odorant research, possible fast detection methods and their applicability are outlined.

How are key food odorants identified?

For the research and evaluation of food aromas one can principally distinguish the sensory and instrumental analysis. Actually, both methods are tightly interconnected and are frequently combined, since the purely numeric and descriptive data from the instrumental analysis can rarely be interpreted without the accompanying sensory analysis. All required steps to unravel the full aroma profile of foods and to identify all relevant key food odorants (KFO) gear into each other as presented in • Figure 1 [1].

Abstract

Identifying those odorants in a food that actually contribute to the perceivable aroma requires a very elaborate and multi-step analytical procedure. As part of this analytical task, human sensory as well as instrumental analytical techniques are combined. Due to the large inhomogeneity of the possible odorants in the foods of interest, a specific strategy needs to be developed for each analysis. Usually, key food odorants are identified by first carefully processing the food samples and extracting the volatile fraction. These extracts are used in aroma extract dilution analyses to identify the most potent candidate substances. After quantification of the odorants, their odor thresholds are correlated to their actual concentration. In a matrix similar to the tested food, the identified odorants are recombined to model the aroma and to check whether they are sufficient. The odorants can only be proven to be required and thus be considered a key food odorant by omitting single odorants from this optimized combined mix. This elaborate process clearly shows which hurdles automatised high speed analytical tools on a microelectronic or biological basis will have to overcome.

Keywords: key food odorants, analytical chemistry, flavor analysis, sensory analysis

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