Determination of the volatile acid content (Type II)
OIV-MA-VI-03 Determination of the volatile acid content
Type II method
- Definition
By convention, the volatile acidity of vinegar refers to the difference between the total acidity and the fixed acidity.
- Principle
Calculation of difference between total acidity and fixed acidity, expressed in grams of acetic acid per L.
- References
See the methods I (determination of total acidity content) and II (determination of the fixed acidity content).
- Results
4.1. Calculation
Considering:
- to be the total acidity content (expressed in grams of acetic acid per L of sample) and
- to be the fixed acidity content (expressed in grams of acetic acid per L of sample).
The volatile acidity content expressed in grams of acetic acid per L of sample is given by:
|
4.2. Presentation
The results expressed in grams of acetic acid per liter are given to the first decimal.
- Interlaboratory validation (Hitos et al.2000)
Units: % (m/V)
Sample |
r |
Sr |
RSDr |
R |
SR |
RSDR |
RSDR (Horwitz) |
Horrat Index |
1 – 8.24% (m/v) |
0.0445 |
0.016 |
0.19 |
0.1632 |
0.058 |
0.71 |
2.91 |
0.24 |
2 – 11.17% (m/v) |
0.0438 |
0.016 |
0.14 |
0.1967 |
0.070 |
0.63 |
2.78 |
0.23 |
3 – 11.20% (m/v) |
0.0595 |
0.021 |
0.19 |
0.2076 |
0.074 |
0.66 |
2.78 |
0.24 |
4 – 11.94% (m/v) |
0.0473 |
0.017 |
0.14 |
0.1652 |
0.059 |
0.49 |
2.75 |
0.18 |
5 – 11.16% (m/v) |
0.0518 |
0.019 |
0.17 |
0.3577 |
0.0128 |
1.14 |
2.78 |
0.41 |
- Bibliography
- Anonymous, 1993, Métodos Oficiales de Análisis, Tomo II, Ministério de Agricultura, Pesca y Alimentación, Madrid, Spain.
- AOAC, 1984, Official Methods of the Ass. Offic. Agric. Chem., 14th edit., Arlington USA.
- Hitos P., Pons A., Martin de la Hinojosa, I, Gomez R., Hernandez A. and Muñoz J., 2000. Validation of analysis methods for total, fixed and volatile acidity of non-volatile reducing substances, copper and zinc in wine vinegars, Green Sheet of OIV No. 115.