Starch - Determination of spot
1 Scope
This standard specifies the method of measuring starch spots by naked eye observation.
This standard is applicable to dried powdered starch and modified starch.
2 Term and definition
For the purposes of this standard, the following term and definition apply:
2.1
spot
mixed color spot observed with naked eyes under specified conditions
3 Principle
Read the number of spots by observing the sample with naked eyes.
4 Apparatus
4.1 Transparent plate: colorless transparent plate engraved with 10 square grids (1 cm × 1 cm). It shall be clean and contamination-free.
4.2 Flat plate: it shall be white, clean, and free of contamination to distribute the sample evenly.
5 Operating procedures
5.1 Sample pretreatment
Samples shall be well mixed.
5.2 Test portion
Weigh 10 g of sample (5.1) and distribute it evenly on the flat plate (4.2).
5.3 Counting
Cover the transparent plate (4.1) over the evenly distributed sample and gently flatten it. Under better light, with the distance between the eye and the transparent plate maintained at 30 cm, the spots in the samples shall be observed with the naked eye and counted,
Foreword i
1 Scope
2 Term and definition
3 Principle
4 Apparatus
5 Operating procedures
6 Calculation of result
7 Test report
