Designation of 2-Methylbutyraldehyde as Food Additive  
 
Purpose  
 
This is to newly designate  2-Methylbutyraldehyde as an authorized food 
additive.  
Under Article 10 of the Food Sanitation Law, food additives may be used or 
marketed only when they are authorized by the Minister of Health, Labour and 
Welfare. Where use standards or specifications are established for additives under 
Article 11 of the Law, those additives may be marketed only when they meet said 
established standards or specifications.  
In response to a request for opinion from the Minister, the Subcommittee on 
Food Additives under the Food Sanitation Committee which is established under 
the Pharmaceutical Affairs and Food Sanitation Council has discussed the 
adequacy of the designation of the substance as food additives. The report from the 
Subcommittee is outlined as below. 
 
 
Conclusion from the Subcommittee  
The Minister should designate 2-Methylbutyraldehyde , based on Article 10 of 
the Food Sanitation Law, as a food additive unlikely to harm human health and 
establish compositional specifications for the substance, based on Article 11 of the Law 
(see Attachment).  
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
Attachment 
 
2-Methylbutyraldehyde 
 
Standard for use  
It must not be used for purposes other than flavoring.  
 
Compositional specifications  
Substance name    2-Methylbutyraldehyde 
Structural formula 
CHO
H3C
CH3 
Molecular formula   C 5H10O 
Mol. Weight  86.13 
Chemical name, CAS number    2-Methylbutanal [96-17-3] 
Content 2-Methylbutanal contains not less than 95.0% of 2-methylbutanal (C 5H10O).  
Description   2-Methylbutanal occurs as a colorless to light yellow liquid having a 
characteristic odor.    
Identification   Determine the infrared absorption spectrum of 2-Methylbutanal, as 
directed in the Liquid Film Method under Infrared Spectrophotometry, and compare it 
with the Reference Spectrum. Both spectra exhibit absorptions having about the same 
intensity at the same wave numbers. 
Purity    
(1) Refractive index   n20
D: 1.388–1.396. 
(2) Specific gravity   d25
25: 0.799–0.815 
(3) Acid value   Not more than 10.0 (Flavoring Substance Tests).  
Assay   Proceed as directed in the Peak Area Percentage Method in the Gas 
Chromatographic Assay under the Flavor Substance Tests. Use operating conditions 
described below. Obtain the total area of the peaks of all components that appear within 
60 minutes after injection, and determine the peak area percentage of 
2-methylbutyraldehyde sought to the total area as the content. 
Operating conditions 
Detector: Hydrogen flame ionization detector or thermal conductivity detector. 
Column: Use a silicate glass capillary column (0.25–0.53 mm in internal diameter 
and 30–60 m in length), coated with a 0.25–1 mm thick layer of dimethyl  
 
 
polysiloxane or polyethylene glycol. 
Column temperature: Maintain the temperature at 50°C for 5 minutes, and raise 
to 230°C at a rate of 5°C/minute, and then maintain at 230°C  for 19 minutes. 
Inlet temperature: 125–175°C. 
Detector temperature: 250–300°C. 
Injection: Split (30:1–250:1). Adjust the column so that no component exceeds the 
capacity of the column.  
Carrier gas: Use helium or nitrogen. 
Flow rate: Adjust the flow rate so that  the  peak of the component to be 
determined appears within 5–10 minutes. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
 
 
Reference Spectrum 
2-Methylbutyraldehyde