Acidulants

Specification for Ascorbic acid (Food Grade) as per IS:5342-1996

1.Identification

(a) To 2 ml of a 2 percent solution add a few drops of sodium nitroferricyanide followed by 1 ml of 0.1N sodium hydroxide. A transient blue colour shall be produced immediately.

(b) When to 2 ml of 2 percent solution in water are added, 2 ml of water,0.1 g of sodium bicarbonate, and about 0.02 g of ferrous sulphate, mixture is shaken and allowed to stand, a deep violet colour shall be produced which shall disappear on the addition of 5 ml of dilute sulphuric

acid.

 (c) Solution of ascorbic acid in ethanol shall decolourize a solution of 2,6- dichlorophenol indophenol.

2. Specific rotation of 2 % m/v solution in water at 20°C under sodium light +20.5°-+21.5 °

3. pH of 2 % (m/v) solution                                                                             2.4-2.8

4. Purity (as C6H8O6), % by mass                                                                     99 Min.

5. Loss on drying over sulphuric acid for 24 h, % by mass                            0.4 Max.

6. Sulphated ash, % by mass                                                                            0.1Max.

7. Arsenic (as As), mg/kg                                                                                  3 Max.

8. Heavy metals (as Pb), mg/kg                                                                        20 Max.

Specification for Lactic acid (Food Grade) as per IS:9971

1.Description : Lactic acid shall be yellowish to colourless syrupy liquid with an acidic taste and no odour. It consists of a mixture of lactic acid and lactate (C6H10O5). It is obtained by lactic fermentation of sugars or is prepared synthetically (50-90 percent).

2. Identification

(a) Solubility : Lactic acid shall be miscible with water and ethanol.

(b) Test for acid : Ten percent solution in water shall be acidic to litmus paper.

(c) Test for lactate : The material shall give positive test for lactate.

3. Purity (as C3H6O3), % by mass of the 95.0-105.0 labeled concentration

4. Sulphated ash % by mass                                                            0.1 Max.

5. Chlorides, % by mass                                                                    0.2 Max.

6. Sulphates (as SO4), % by mass                                                      0.25 Max.

7. Citric, oxalic, phosphoric and tartaric acids                         Conform to test

8. Sugars                                                                                   Conform to test

9. Readily carbinizable substances                                         Conform to test

10. Volatile fatty acid                                                             Conform to test

11. Cyanide                                                                            Conform to test

12. Methanol, % by mass                                                               0.2 Max.

13. Iron (as Fe), mg/kg                                                                  10 Max.

14. Heavy metals (as Pb), mg/kg                                                  10 Max.

15. Arsenic (as As), mg/kg                                                           3 Max.

Specification for Phosphoric acid (Food Grade) as per IS:10508-1983

1.Description: It is a clear, colourless, odourless and viscous liquid.

2. Identification

(a) Solubility: Miscible in water and ethanol.

(b) Test for acid: Phosphoric acid is strongly acid, even in high dilution.

(c) Neutralize a few ml of phosphoric acid and add dilute nitric acid.

Then add an equal volume of ammonium molybdate solution and warm. A bright canary-yellow precipitate is obtained.

(c) Test for phosphate: A 10% percent solution gives positive test for phosphate.

3. Purity (as H3PO4), % by mass                                                           85 Min.

4. Fluoride, mg/kg                                                                            10 Max.

5. Total heavy metals (as Pb), mg/kg                                               10 Max.

6. Lead (as Pb), mg/kg                                                                      5 Max.

7. Arsenic (as As), mg/kg                                                                 3 Max.

Specification for Citric acid (Food Grade) as per IS:13186-1991

1.Description: The material shall be in the form of white or colourless, odourless, crystalline solid with a strongly acid taste. The monohydrate effloresces in dry air.

2. Identification

(a) Solubility: The material is very soluble in water, freely soluble in ethanol and soluble in ether.

(b) Boil a neutralized solution of the sample with an excess of mercury sulphate test solution and filter, if necessary. Add a few drops of potassium permanganate. The violet colour disappears and a white precipitate forms.

(c) Add a neutralized solution of the sample with dilute sulphuric acid test solution and a few drops of 1 % potassium permanganate. Warm until the violet colour disappears and then add an excess of bromine test solution. A white precipitate forms either immediately or on cooling.

3. Purity (as C6H6O7), % by mass (on anhydrous basis)                99.5 Min.

4. Moisture, % by mass

(a) Anhydrous                                                                                 0.5 Max.

(b) Monohydrate                                                                             8.8 Max.

5. Sulphated ash, % by mass                                                          0.05 Max.

6. Total heavy metals (as Pb), mg/kg                                             10 Max.

7. Arsenic (as As), mg/kg                                                               3 Max.

8. Oxalates (as C2H2O4)                                                                 To pass the test

9. Readily carbinizable substance                                                 To pass the test