New Year’s eve is coming and people like to say good bye to the last year with a glass of whisky. For cyclodextrin researchers it might be interesting how cyclodextrin can be coupled with whisky. This post gives a summary on the related publications and patents.
Powdered whisky was obtained by complexation with cyclodextrin according to a Japanese patent filed in 1981 [1]. Palcohol (powdered alcohol) is a product produced by using cyclodextrin to complex both alcohol and flavor components. Four types were available in 2015 in the US: “V” made from vodka, “R” from rum, “Powderita” made from Margarita and “Cosmopolitan” made from whisky [2]. The flyer of Illinois Higher Education Center warns that:
- The product is so light and transportable, worries are it can easily be brought into venues. e. g. schools and sporting events.
- It could be put into someone’s food or drink without their knowledge.
- People will snort it to get drunk.
- Kids will be able to get a hold of it much easier.
There were various news in electronic press on Palcohol in 2014 and 2015. Now it seems to be not marketed at present.
Another application of inclusion complexation when cyclodextrin is added to liquor to mask the undesirable taste and odor as it was claimed in an early Japanese patent [3].
In addition, cyclodextrins are also used in the analysis of whisky:
- In a recent paper α-cyclodextrin-based separation of whisky flavor components, such as quaiacol and its analogs (4-ethylguaiacol (4-EG), three cresol isomers, and phenols) was reported [4]. These components form different inclusion complexes with α-cyclodextrin and can be detected on a Nafion-modified boron-doped diamond (BDD) electrode. The stable Nafion layer preconcentrates the analyte-α-CD complexes prior to electroanalysis by square wave voltammetry (SWV) to enhance detection sensitivities.
- Good enantioseparation was achieved for both whisky and cognac lactone (5-butyl-4-methyloxolan-2-one or 5-butyl-4-methyldihydro-2(3H)-furanone and (5-pentyl-4-methyloxolan-2-one or 5-pentyl-4-methyldihydro-2(3H)-furanone), found in oak wood) with high resolution using 6-O-tert.-butyl dimethylsilyl-2,3-dialkylated or 6-O-tert.-butyl dimethylsilyl-2,3-diacylated cyclodextrin derivatives as chiral selectors [5].
References:
[1] Shinjiyou, K.: Preparation of alcohol-containing solid substance. JPS57149238A (1981)
[2] Powdered alcohol. Illinois Higher education Center. (2015) https://www.eiu.edu/ihec/Powdered_Alcohol_Flyer.pdf
[3] Hara, S.; Nakamura, T.: Processing of liquor. JPS58146271A (1982)
[4] Hayes, P.E., Glennon, J.D., Buzid, A., Luong, J.H.T.: Simultaneous electroanalysis of guaiacol and its analogs based on their differential complexation with α-cyclodextrin on nafion modified boron-doped diamond electrode. Electroanalysis (in press) (2019)
[5] Schmarr, H.-G., Mathes, M., Wall, K., Metzner, F., Fraefel, M.: Enantiodifferentiation of whisky and cognac lactones using gas chromatography with different cyclodextrin chiral stationary phase. Journal of Chromatography A 1516, 135-141 (2017)