South African Weather Service Act, 2001
R 385
Agricultural Product Standards Act, 1990 (Act No. 119 of 1990)RegulationsRegulations relating to the Grading, Packing and Marking of Wheat Products intended for sale in the Republic of South AfricaMethods of Anaylsis for Wheat Products18. Determination of the bran content of brown wheat flour |
The bran content of brown wheat flour shall be determined as set out below.
| (1) | The apparatus used for the determination of the bran content of brown wheat flour is as follows: |
| (a) | An electrically driven laboratory plansifter fitted with an automatic time switch. This sifter must have a throw of 75-77 mm and the drive must run at a speed of 180-190 r.p.m. The sieving motion must be horizontal and circular when sieving and the sieves must not have a precession action; |
| (b) | A round sieve, 200 mm in diameter covered with a 212 micron stainless steel wire mesh. The sieve must be fitted with a tight-fitting lid and receiver in order that no material is lost during sieving; and |
| (c) | Nylon cubes with 13 mm to 18 mm sides. |
| (2) | The method that is used in the determination of the bran content of brown wheat flour is as follows: |
| (a) | Fit the 200 mm round sieve into the receiver. Place 200 g (with a variation not exceeding 0,1 g) of a representative sample of brown wheat flour and two nylon cubes into the sieve. Cover the sieve with the lid and mount in the plansifter. Sieve for five minutes. Remove the sieve, lid and receiver from the plansifter. Remove the lid and brush any material adhering to it back into the sieve. Tap the sieve lightly five to ten times with the palm of the hand so that any material adhering to the bottom of the sieve will drop back into the receiver. Remove the sieve from the receiver and determine the mass of the material remaining above the sieve to the nearest 0,1 g. Record this mass (A grams). Measure the mass of the material in the receiver to the nearest 0,1 g. Record this mass (B grams). The total mass of the material recovered (A + B) must equal 200 g (with a variation not exceeding 0,2 g). If the total mass of the material recovered falls outside the tolerance of 200 g (with a variation not exceeding 0,2 g) the test must be repeated; and |
| (b) | Calculate the percentage material which remains on the sieve as follows: |
|
Bran percentage |
= |
A 2 |
Take the average of the duplicate percentages thus obtained as the bran percentage (m/m) of the brown wheat meal and report it to the nearest 0,1. Repeat the determination if the duplicate percentages differ by more than 0,4.
