HSP Application note #14
How to look at Flavor with Hansen Solubility Parameters(HSP)
HSPiP Team Senior Developer, Dr. Hiroshi Yamamoto
How to look at Flavor
We found very good home page of fragrance of flower.
(Unfortunately this site is written in only Japanese.)
There is one table in that page. This table means which flower contains which chemicals. ◎: this chemical is most important for that fragrance. □ : main component of that fragrance.
A: rose B: jasmine C: narcissus D: Ixora E: tuberose F: ilang-ilang G: orange-colored olive H: carnation I: Lavender J: Lilac K: majalis L: Common gardenia
At first, we calculate Hansen Solubility Parameter for the chemicals.
Hansen Solubility Parameters (HSP)
Hansen Solubility Parameters(HSP) were developed by Charles M. Hansen as a way of predicting if one material will dissolve in another and form a solution. They are based on the idea that "like dissolves like" where one molecule is defined as being 'like' another if it bonds to itself in a similar way.
What can perhaps be surprising is that one can assign HSP to so many different things. Gases like carbon dioxide, solids like carbon-60, sugar, and biological materials like human skin, depot fat, DNA, and even some proteins all have HSP. The list can be continued with drugs, polymers, plasticizers, and in fact any organic material and even many inorganic materials like salts. The only requirement for an experimental confirmation is that the material must behave differently in a sufficient number of test solvents upon contact.
Our basic concept is that we feel smell when some chemicals "Dissolve" to Olfactory Cell.
So, we believe Hansen Solubility Parameter will become very good descriptors to distinguish flavor of flower.
We use HSPiP software to calculate HSP.
HSPiP(Hansen Solubility Parameters in Practice)
The first edition of HSPiP that appeared in November, 2008, greatly enhanced the usefulness of the Hansen solubility parameters (HSP).
The HSP values of over 1200++ chemicals and 500 polymers are provided in convenient electronic format and have been revised and updated using the latest data sources in the second edition (March, 2009).
A third edition of the HSPiP appeared in March, 2010. There are now 10,000 compounds in the HSP file which also includes data on density, melting point, boiling point, critical parameters, Antoine constants and much more. The user is able to carry out many different sorts of optimisations of solubility, evaporation, diffusion, adhesion, create their own datasets (automatically if required) and explore the huge range of applications for HSP in coatings, paints, nanoparticles, cosmetics, pharma, organic photovoltaics and much more.
The 3rd Edition v3.1 was released on 12 December 2010. Current users can upgrade free (now v3.1.09) by downloading the latest .msi installer from http://hansen-solubility.com
The 4th Edition v4.0.x was released on 2 Jan. 2013. The Current users can upgrade with free charge.
2013.1.28 The Visual How to manual of HSPiP. You can understand what HSPiP can do.
If you have the Smiles structure, Y-MB calculate HSP of that molecule.
Smiles(Simplified Molecular Input Line Entry Syntax)
SMILES is a string obtained by printing the symbol nodes encountered in a depth-first tree traversal of a chemical graph.
Y-MB Properties Estimation
Y-MB break Smiles into correspponding Functional Groups and Estimate various Properties. These estimation schemes are come from Pirika technologies.
Then we analyze this vectors with SOM (Self Organization Map) method.
Every chemicals are mapped at 40*40 matrix.
If the HSP vectors are near, then mapped very near position.
SOM: Self Organization Map Neural Network
The most popular 5 flavor pattern become like this.
The pattern is so different.
Maybe our nose can distinguish these flavor. (We hope!)
Ixora, Narcissus, Jasmine patterns are similar.
Narcissus is very basic and Ixora and Jasmine are complicated composition.
Tuberose and ilang-ilang patterns are fairly similar.
And these flowers are not so familiar to us, maybe we can not distinguish.
Lavender and Common Gardenia have very strong flavor.
Basic pattern is similar.
Maialis, Rose, Jasmine are top 3 flavors in fragrance.
The patterns are very different.
Tuberose is something (Ixora+Rose+Jasmine)/3
So, every flower have their specific pattern.
If I can change the pattern to electric signal, I can make electric-Nose.
Such research is already done at CALTECH MSC.
They make sensors that change swelling rate to electric current.
So, if they use above 7 type HSP polymer sensor, that polymer swell effectively with covered chemicals. I searched corresponding polymer in HSPiP polymer database.
But, for the flavor, I need take into account RER effect.
Relative Evaporation Rate(RER) is very different for each chemicals.
HSPiP have the function estimate RER, and I append 1000*RER on SOM.
Some large RER molecules disturb small RER neighbor.
So, choosing polymer will more complicate.
If you want to know how to draw molecules, please refer to Power Tools applications.