The determination of starch moisture can be carried out by the following steps:
Sample preparation: Take an appropriate amount of starch sample, use a paper towel or a desiccant to blot the moisture on the outer surface, then crush it and sieve it through a 40-mesh sieve.
Drying: Weigh 2-3 grams of the sieved starch sample, put it into an oven that has been dried to 105°C in advance, keep the temperature constant, and dry it to a constant mass (that is, the mass does not change).
Record the mass of the sample: remove the sample, cool it in a desiccator, and weigh it (referred to as the "dry weight").
Drying the sample: put the sample into an oven preheated to 130°C, keep the temperature constant, and dry it for 30 minutes.
Cooling the sample: Remove the sample, cool it to room temperature in a desiccator, and weigh it (called the "wet weight").
Calculate moisture content: Calculate the moisture content of starch samples using the following formula:
Moisture content (%) = (wet weight - dry weight) / dry weight × 100%
NBCHAO reminds you: use precision balances and ovens during drying and weighing, and strictly control the experimental conditions to avoid the influence of humidity and impurities in the air on the measurement results.