SOP: Determination of Nitrogen in Vinegar

GIFSQ — Global Institute for Food Safety & Quality

Principle

The vinegar is concentrated to a syrupy consistency to remove the water and volatile acids, and its nitrogen is then determined by the Kjeldahl method. Brewed vinegars contain appreciable nitrogen from the fermentation, while artificial vinegars contain almost none.

Procedure

Concentrate 50 to 100 ml of the vinegar to a syrupy consistency

↓

Determine the nitrogen by the Kjeldahl method (see page 16)

Precautions

Interpretation

• Total nitrogen (w/v): malt vinegars 404–840 ppm; artificial condiments 11–34 ppm.

References

Ranganna, S., Handbook of Analysis and Quality Control for Fruit and Vegetable Products, 2nd edition.