Methional
Names | |
---|---|
Preferred IUPAC name
3-(Methylsulfanyl)propanal | |
Other names
3-(Methylmercapto)propionaldehyde; 3-(Methylthio)propionaldehyde; 3-(Methylthio)propanal
| |
Identifiers | |
3D model (
JSmol ) |
|
ChEBI | |
ChemSpider | |
ECHA InfoCard
|
100.019.893 |
EC Number |
|
PubChem CID
|
|
UNII | |
CompTox Dashboard (EPA)
|
|
| |
| |
Properties | |
C4H8OS | |
Molar mass | 104.17 g·mol−1 |
Appearance | Colorless liquid |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
Methional is an
Occurrence
In nature, methional is a thermally-induced volatile flavor compound. For instance, the heat-initiated Maillard reaction of reducing sugars and amino acids forms the initial basis of methional's composition. The formation of methional stems from the interaction of α-dicarbonyl compounds (intermediate products in the Maillard reaction) with methionine (Met) by the Strecker degradation reaction:[1]
- CH3SCH2CH2(NH2)CHCO2H + O → CH3SCH2CH2(HN=)CCO2H + H2O
- CH3SCH2CH2(HN=)CCO2H + H2O → CH3SCH2CH2CHO + NH3 + CO2
Methional easily degrades into methanethiol, which then oxidizes into dimethyl disulfide. Dimethyl disulfide is partly responsible for the "reactive sulfur" that contributes to the taste of potatoes. Furthermore, the methionine resulting from the Strecker degradation reaction produces alkyl pyrazines, which contribute to the flavors in roasted, toasted, or thermally processed foods. Due to the ease of its decomposition, a large portion of methional is lost during potato processing.
Similarly, in the presence of flavin mononucleotide (FMN) and light, methionine is nonenzymatically oxidized into methional, ammonia, and carbon dioxide.[2]
- CH3SCH2CH2(NH2)CHCO2H → CH3SCH2CH2CHO + NH3 + CO2
Preparation and reactions
Methional is synthesized commercially by the reaction of methanethiol and acrolein.[3]
- CH3SH + CH2=CHCHO → CH3SCH2CH2CHO
Using the
Methional is a versatile reagent in organic chemistry.[4]
Biological routes
Because of their high cost, methional or its precursor methionine are not added during potato processing.[1] In order to intensify flavoring of heat-processed potato foods, biotechnological approaches are used to increase methionine levels, and thus methional levels, in potato foods.
The enzyme
- CH3S(CH2)2CH(NH2)CO2H + O → CH3S(CH2)2COCO2H + NH3
- CH3S(CH2)2COCO2H → CH3S(CH2)2CHO + CO2
References
- ^
- ^ S. F. Yang, H. S. Ku & H. K. Pratt (1967) Photochemical Production of Ethylene from Methionine and Its Analogues in the Presence of Flavin Mononucleotide, The Journal of Biological Chemistry, 242, 5274-5280.
- ^ ISBN 978-3527306732.)
{{cite encyclopedia}}
: CS1 maint: multiple names: authors list (link - ISBN 978-0471936237.
- ^ María Del Carmen Martínez-Cuesta , Carmen Peláez & Teresa Requena (2013) Methionine Metabolism: Major Pathways and Enzymes Involved and Strategies for Control and Diversification of Volatile Sulfur Compounds in Cheese, Critical Reviews in Food Science and Nutrition, 53:4, 366-385.