OPERATIONAL TECHNIQUE REDUCING MATTERS (Sugars-AAZ)
Very interesting, easy and fast method.
TOTAL REDUCING MATTERS:
1- Dump in the flask 10.00 mL COPPER SOLUTION, 5.00 mL ALKALI, 2.00 mL of the SAMPLE to be analyzed and a pinch of pumice.
2- Warm up the GAB heater plate about twenty minutes earlier. Stopper the flask with a watch glass, place it on the plate and wait til boiling. From this moment are exactly one and a half minutes. Elapsed time, withdraw and cool under running tap water.
3- Add 10 mL of iodide, 10 ml of starch and 10 ml of ACID.
4- Then it is placed under the GAB BURET, that will be filled in advance and make up with LIQUID ON VALUATION. At the same time that the liquid is poured, shaking the flask until it obtains a cream color. Read directly in the burette, the concentration in gr/L. Total reduction of substances (sugars).
SUGAR ON INVESTMENT:
1- Pour 10.00 mL COPPER SOLUTION in the flask, 2.00 mL of the sample, and a pinch of pumice.
2- Cover and place the flask in the heater plate and from the moment it starts to boil, count exactly two minutes, then without removing from the heater plate, 5 mL of ALKALI are added, and are count again exactly a minute and a half. Elapsed time, remove and cool under running tap water.
3- Proceed as point 3 above.
4- Proceed as point 4 above.
The graduation of the GAB burette is given in gr/L.
It is desirable to follow the order of addition of reagents as indicated.
Respect the boiling times.
Due to the action of polyphenols, results in red wines are higher. Proceed to bleachingt according to winemaker.
CONTROL OF SOLUTIONS:
El ensayo en blanco se efectúa igual como el análisis de la muestra de vino, pero en su lugar se utilizan 2 mL de agua destilada y se procede como en MATERIAS REDUCTORAS TOTALES. The blank test is the same as the analysis of the sample of wine, but instead it is used 2.00 mL of distilled water and proceed as in TOTAL REDUCING MATTERS.