|Home||Profile||Market Place||Sweeteners||Lab Methods||Glossary||Search|
|Master Index||Environment||Application||Starch||Statistics||Tables||Write us|
International Starch Institute
Science Park Aarhus, Denmark
ISI 09-2e Determination of Fibre in Starch by Weight
|1. Scope||The method is applicable to native potato and cassava starch
Rev. LT 11. Dec. 1997
|2. Principle||Starch is hydrolysed and filtered. Fibre defined as
non-soluble impurities are retained, dried and
determined by weight.
|Cornstarches do not filter properly.|
|3. Apparatus||3.1 Analytical balance weighing to the nearest 1 mg.
3.2 Shaking boiling water bath.
|3.3 Büchner funnel or Sartorius 250 ml glass vacuum filter funnel.
||Use a high flux filter. Do not use a glass frit filter support|
|4. Reagents||4.1 Dilute hydrochloric acid 0.1 N
|5. Procedure||100.0 g (w1) sample is slurried in a 1000 ml conical flask with 600 ml acid (4.1)|
|Place flask in boiling water bath (3.2) for 30 min||Shake min. until starch is gelatinised|
|Filter hot on filter (3.3). Flush flask and filter with 100 ml hot water.||Increase hydrolysis parameters if flux too low|
|Dry filter at 105 oC over night - min 12 hours. Weigh filter to nearest 1 mg (m1)|
|10.0 g (w0) sample is slurried in a 100 ml conical flask with
60 ml acid (4.1). Hydrolyse and filter as above. Weigh filter to nearest 1 mg (m0)
|6. Calculation||Calculate fibre of sample by averaging results of two samples with two
Fibre % = 100 * ((m1 - m0) / (1 - w0 / w1)) / w1
|Eventually correct to value on sample dry matter.
|7. Notes||Alternative: Substitute acid with heat stable alpha-amylase. It is essential
to hydrolyse to obtain high flux through filter. Use a filter holder with a screen filter
support or other non-clogging support.
|8. References||Similar AOAC method for crude fibre may be applied as more specific for residual plant fibre.||AOAC method detects lignin and cellulose|
|9. Image||Sartorius filter funnel(min 250 ml) with glass vacuum holder for 47 mm filters with PTFE-coated steel screen filter support|
| Top of Page | LabIndex |
Read Disclaimer notice. Copyright
All rights reserved. International Starch Institute, Science Park Aarhus, Denmark.
Keywords: laboratory method determination pulp fibre fiber starch