Analytical Strategy (529-0043-00 G)
http://www.zenobi.ethz.ch/
Fragrances
November 17, 2015
Fragrances
Susanne Kern
[email protected]
Givaudan Schweiz AG
Fragrances S&T / Ingredients Research Dübendorf
Off-note in a fragrance raw material
As a flavour and fragrance company, Givaudan develops and manufactures flavours for the food
industry and fragrances for the perfume (fine fragrance) and household/consumer product markets. For the fragrance side, manufacturing of fragrances is often based on natural or synthetic
raw materials that are chemically further processed to obtain the scented product. Sometimes,
minor impurities can also have a smell that affects the quality of the product. Therefore, the quality control does not only include analytical instruments but also the olfactive control by trained
people.
In the factory, at the beginning of the distillation process of menthone made from natural menthol
the production chemists are observing a “green/mossy” off-note which is expected to be an impurity that smells different from the wanted product. This is starting to affect the quality of the bulk,
so they would like to know what it is. They have sent now a sample for analysis of the first distillation fraction which should have the volatile impurity in a more concentrated form.
Interestingly enough, menthone made from artificial menthol does not have this issue, so the
natural menthol problem with impurities might be associated to originate from Mother Nature.
The reaction scheme for the production of menthone is shown below (Figure 1).
Figure 1 Reaction from menthol to menthone
Givaudan Schweiz AG Ueberlandstrasse 138 CH-8600 Duebendorf Switzerland
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A typical quality control measurement is done by GC-FID or GC-MS. A GC-MS chromatogram of a
typical raw material analysis of menthone is shown below (Figure 2).
RT: 0.00 - 20.00
NL:
3.06E6
m/z=
35.0-350.0 m/z=
39.5-40.5+
43.5-44.5
MS k92582e
8.35
100
90
80
Relative Abundance
70
60
50
40
30
20
10
8.45
0
0
2
4
6
8
10
Time (min)
12
14
16
18
20
Figure 2 GC-MS chromatogram of menthone
Tasks
1. What are the analytical strategies to identify the off-note?
We expect the off-note in very low concentration. With a GC-MS analysis there is no peak visible
which could explain the green/mossy smell.
2. Explain different headspace techniques.
3. What are odour threshold values and how can they be measured?
4. How would you analyse flavour compounds in peppermint chewing gum?
Literature
S. A. Haut, A convenient preparation of pure menthol and menthone isomers. J. Agric. Food Chem.
1985, 33, 278-280.
P.M. Müller, D. Lamparsky. Perfumes: Art, Science & Technology. Elsevier Applied Science. 1991.
Chapter 6: N. Neuner-Jehle, F. Etzweiler. The Measuring of Odors.
H. Surburg, J. Panten. Common Fragrance and Flavor Materials. Preparation, Properties and Uses,
5th completely revised and enlarged edition. Wiley-VCH. 2006.
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