General Provisions Standard for Manufacturing and
Preparation General Standards for Food
Additive use in Foods Specification and Standards General Test Methods Reagent, Solution, Standard Solution
for Quantitative Analysis and
Standard Solution Appendix
Permitted Use Level
A. Synthetic Additives
B. Natural Additives
C. Mixture Additives
Standard and Specification > Synthetic Additives > Propylene Glycol Alginate
157. Propylene Glycol Alginate  
[Compositional Specifications of Propylene Glycol Alginate]
Description Propylene Glycol Alginate occurs as a white to yellowish~white coarse or fine powder. It is almost odorless. 
Identification To 1 g of Propylene Glycol Alginate. add 100 ml of water to produce a pasty solution. Use this solution as the test solution.

(1) To 5 ml of the test solution, add 5 ml of lead acetate solution. It immediately solidifies into a gelatinous state.

(2) To 10 ml of the test solution, add 1 ml of sodium hydroxide solution, heat in a water bath for 5~6 minutes, cool, and add I ml of diluted sulfuric acid. It immediately solidifies to a gelatinous state.

(3) To 1ml of the test solution, add 4 ml of water, and shake vigorously. Effervescence persists. 
Purity (1) Arsenic and Heavy Metals : Should follow the procedures in Purity (3) and (4) for [Sodium Alginate].

(2) Degree of Esterification : Esterification of Propylene Glycol Alginate is calculated by the following equation and its value should not  less than 75%.
               Degree of Esterification (%) = 100 - (a+b+c)
   a, b, and c are obtained from (1), (2), and (3).
   A : content of free alginic acid (%)
   b : content of sodium alginate (%)
   c : content of insoluble ash (%)

(A) Free alginic acid : Weigh accurately about 0.5 g of Propylene Glycol Alginate (dried for 4 hours at 105°), dissolve in 200 ml of freshly boiled and cooled water, add 2 drops of phenolphthalein solution, and titrate with 0.02 N sodium hydroxide until the pink color persists for about 20 seconds. Calculate the content by the following formula. Perform a blank test in the same manner, and make any necessary correction.

  Content of free alginic acid (%)

         Volume of 0.02N sodium hydroxide consumed(ml)×0.00352
  = ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ x 100
                                Weight of the sample(g)

(B) Sodium alginate : Weigh accurately about 1 g of Propylene Glycol Alginate Alginate (dried for 4 hours at 105°) and follow the Procedure in Assay for alkaline salt of organic acid. I N this case, 20 ml of 0.1 N sulfuric acid and 0.1 N sodium hydroxide solution are used instead of 50 ml of 0.5 N sulfuric acid and 0.5 N sodium hydroxide solution. The content of sodium alginate is calculated by the following equation (indicator : 3 drops of methyl red solution).

Content of sodium alginate (%)
         Volume of 0.1N sulfuric acid consumed(ml)×0.0198
  =  ━━━━━━━━━━━━━━━━━━━━━━━━━━━ x 100
                              Weight of the sample(g)                  

(3) Insoluble ash : Dry the residue on the filter paper obtained in (B) of (1). ignite to constant weight, cool, and weigh accurately. Not more than 1.5%. 
Loss on Drying When Propylene Glycol Alginate is dried for 4 hours at 105°, the loss should not be more than 20%. 
Permitted Use Level of Propylene Glycol Alginate and Ingredients Containing it Usage should not be more than 1% of the food item as Propylene Glycol Alginate.