Overview
ISO 735:1977 specifies a laboratory method for the determination of ash insoluble in hydrochloric acid in oilseed residues. The procedure applies to residues produced by extraction of oil from oilseeds (pressure or solvent extraction), excluding compounded products. The method treats the total ash (see ISO 749) with hydrochloric acid to dissolve acid‑soluble material, then incinerates and weighs the remaining insoluble residue.
Keywords: ISO 735, oilseed residues, ash insoluble in hydrochloric acid, determination, total ash, incineration, HCl.
Key topics and technical requirements
Applications and users
- Quality control in oilseed processing (meal and cake quality).
- Chemical analysis laboratories in food/feed testing.
- Research laboratories studying mineral or silica content of residues.
- Commodity inspection and regulatory testing where ash composition affects grading or utilization (e.g., feed formulation, fertilizer use).
Related standards
- ISO 749 - Oilseed residues - Determination of total ash (method to obtain the total ash input to this procedure).
- ISO 771 - Oilseed residues - Determination of moisture and volatile matter (used for dry‑matter calculations).
This standard is practical for laboratories performing routine compositional analysis of oilseed residues and provides a reproducible, internationally recognized procedure for assessing the acid‑insoluble ash fraction.