Amendment to the Ordinance for Enforcement of the Food Sanitation Act  and the 
Specifications and Standards for Food s, Food Additives , Etc . 
 
The government of Japan will designate metatartaric acid  as an authorized food 
additive  and establish compositional specifications  and use standards for this 
additive . 
 
Background  
Japan prohibits the sale of food additives that are not designated by the Minister of 
Health, Labour  and Welfare (hereinafter referred to as “the Minister”) under Article 
12 of the Food Sanitation Act (Act No. 233 of 1947; hereinafter referred to as “the 
Act”). In addition, when specifications or standards for food additives are stipulated 
in the Specifi cations and Standards for Foods , Food Additives , Etc . (Public Notice of 
the Ministry of Health and Welfare No. 370, 1959) , Japan prohibits the sale of those 
additives unless they meet the specifications or the standards  pursuant to Article 1 3 
of the Act . 
 
In response to a request from the Minister, the Committee on Food Additives of the 
Food Sanitation Council under the Pharmaceutical Affairs and Food Sanitation 
Council (hereinafter referred to as “the Committee”)  has dis cussed the adequacy of 
the designation of metatartaric acid  as a food additive. The conclusion of the 
Committee  is outlined below.  
 
Outline of conclusion  
The Minister  should designate metatartaric acid  as a food additive unlikely to cause 
harm to human health  pursuant to Article 1 2 of the Act  and should establish 
compositional specificatio ns and use standards for this additive pursuant to  Article 
13 of the Act (see Attachment  for the details ). 
   
 
Metatartaric Acid  
メタ酒石酸  
 
Standards for Use (draft)  
Permitted for use in grape wine only. Shall be used at  not more than  0.10 g/kg in grape 
wine.  
 
Compositional Specifications (draft)  
Substance Name  Metatartaric Acid  
CAS Number   [39469 -81-3] 
Definition  Metatartaric Acid consists mainly of molecule s obtained by heating L-
tartaric acid under atmospheric or vacuum pressure and esterifying the resulting fused 
substance.  The molecule s are of various chain lengths.  
Content   Metatartaric Acid  contains the equivalent of  99.5–113% of L-tartaric acid 
(C4H6O6 = 150.09 ). 
Description    Metatartaric Acid  occurs as  deliquescent,  white to yellowish white 
crystals or powder. It has a slight odor like caramel.  
Identification  Metatartaric Acid responds to all tests for Tartrate in the Qualitative 
Tests.  
pH  1.4–2.2  (1.0 g, water 100 mL).  
Purity  
(1) Clarity of solution   Almost c lear (1.0 g, water 10 mL).  
Almost c lear (1.0 g, ethanol (95) 30 mL ). 
(2) Degree of esterification   Not less than 32%.  
Calculate the esterification value of Metatartaric Acid  by the formula:  
Degree of esterification (%) = (20 − b)
(a + 20 − b) × 100  
Determine a and b according to the procedure given in the Assay.  
a = volume  (mL) of 1 mol/L sodium hydroxide consumed,  
b = volume  (mL) of 0.5 mol/L sulfuric acid consumed.  Attachment   
 
(3) Lead   Not more than 2 μg/g as Pb (2.0 g, Method 1, Control Solution: Lead 
Standard Solution 4.0 mL, Flame Method).  
(4) Arsenic   Not more than 3 μg/g as As (0.50 g, Method 1, Standard Color: Arsenic 
Standard Solution 3.0 mL, Apparatus B).  
Assay  Weigh quickly and accurately about 2 g of Metatartaric Acid, and dissolve it in 
water to make exactly 100 mL. Transfer exactly 50 mL of this solution into a flask, and 
immediately titrate with 1 mol/L sodium hydroxide (indicator: 10 drops of bromothymol 
blue TS). The endpoint is when the co lor of the solution changes to bluish green. Refer 
to the volume  of the sodium hydroxide consumed as a mL. Add 20 mL of 1 mol/L sodium 
hydroxide to the flask, stopper, allow to stand for 2 hours, and immediately titrate with 
0.5 mol/L sulfuric acid. The en dpoint is when the color of the solution changes to bluish 
green. Refer to the volume  of the sulfuric acid consumed as b mL. Calculate the content 
of metatartaric acid by the formula:  
Content (%) of metatartaric acid (as L-tartaric acid C 4H6O6) 
= (a + 20 − b) × 15.01
Weight  (g) of the sample 
Storage Standards   Store in a hermetic container, protected from moisture.  
 