ISO 11050:2020 PDF

Overview

ISO 11050:2020 - Wheat flour and durum wheat semolina: Determination of impurities of animal origin specifies a laboratory method to detect and quantify animal-origin contaminants in wheat flours (ash ≤ 0.75 %), with or without additives, and in durum wheat semolinas. The procedure separates contaminants such as insects (all life stages and fragments), rodent hairs and fragments, and mites, using acid hydrolysis, phase separation, filtration and microscopic examination.

Key topics and technical requirements

• Scope and purpose: Quantification of impurities of animal origin in wheat flour and durum semolina for food safety and quality control.
• Sampling: Laboratory sample of at least 600 g; store at 4 °C if analysis is delayed. (ISO 24333 is recommended for sampling procedures.)
• Test portion: 50 g ± 0.1 g taken after thorough mixing.
• Hydrolysis and separation:
  • Dilution in ~300 ml demineralized water and acid hydrolysis with concentrated HCl (20 ml).
  • Addition of paraffin oil (30 ml) and boiling with gentle stirring for 30 minutes to concentrate insoluble particles at the water/oil interface.
  • Phase separation in conical separating funnels and transfer to filtration.
• Filtration and examination:
  • Ash-free filter paper (90 mm) with 5 mm guide lines; Büchner-type filtration unit; vacuum pump capable of