Preface

This odorant database is intended to aid in the structure assignment of odor-active compounds in food.

Odor-active compounds vitally contribute to the sensory profile of foods which is the key driver for consumers’ food selection. Thus, the knowledge on the crucial odor-active compounds is of high interest for analytical quality control as well as for targeted product development in the food industry.

To identify odor-active compounds among the bulk of odorless volatiles present in a food, gas chromatography-olfactometry (GC-O) is the method of choice. The volatiles isolated from the food material by mild, artifact-avoiding techniques are separated by gas chromatography (GC) and odor-active compounds are localized in the chromatogram recorded by a flame ionization detector (FID) or a mass spectral detector (MSD) by online evaluation of the column effluent odor at a heated exit, the sniffing port.

To assign the structures of the odor-active compounds perceived during GC-O analysis, direct mass spectral analysis is typically of little help. As the odor threshold values of typical food odorants cover a range of more than ten orders of magnitude, potent odorants rarely constitute major compounds in the food volatile isolate, but more often are present at minor or trace levels, at which co-eluted major compounds make their mass spectral identification impossible. At this point, a preliminary structure assignment based on odor quality and retention index is often much easier to achieve, because co-eluted odorless volatiles do not lead to interferences. Of course, these structure assignments must afterwards be confirmed by analysis of authentic reference compounds using GC-O as well as GC-MS which requires separation of the target compounds in the food volatile isolate from interfering matrix constituents by fractionation (e.g. using acid-base-extraction, liquid chromatography etc.) and GC-O to localize the target compounds in the individual fractions. Nevertheless, a preliminary structure assignment based on odor quality and retention index has a great potential to significantly speed up the approach. This, however, requires a dataset including the most abundant food odorants together with their odor properties and their retention indices on popular GC stationary phases. Therefore, we established the Leibniz-LSB@TUM Odorant Database.

In the past, the Leibniz-LSB@TUM Odorant Database has been used in numerous projects at the Leibniz-LSB@TUM and its predecessor Deutsche Forschungsanstalt für Lebensmittelchemie (DFA; German Research Center for Food Chemistry) to identify the odor-active compounds in different types of foods. The Leibniz-LSB@TUM Odorant Database has thus contributed to several hundred publications authored by scientists of DFA and Leibniz-LSB@TUM. After more than twenty years of exclusive in-house use, in 2019, we decided to make this data collection available to the scientific community free of charge on the internet.

We would be very happy, if the Leibniz-LSB@TUM Odorant Database could assist you in identifying odor-active compounds and your efforts were crowned with success.

Freising, October 2019

Dr. Johanna Kreissl
Dr. Veronika Mall
Dr. Petra Steinhaus
PD Dr. Martin Steinhaus

To the contents of the Leibniz-LSB@TUM Odorant Database

 

Further reading: For a review on the analysis of odor-active compounds in foods and beverages please consult Steinhaus M. Gas chromatography-olfactometry: principles, practical aspects and applications in food analysis. In: Advanced Gas Chromatography in Food Analysis. Tranchida P (ed.). The Royal Society of Chemistry: Cambridge, UK, 2020, pp. 337-399. Print ISBN 978-1-78801-127-3. eISBN 978-1-78801-899-9.