Overview
ISO 1443:1973 specifies a reference method for determining the total fat content in meat and meat products. The standardized procedure isolates occluded and bound lipids by boiling a test portion with dilute hydrochloric acid, followed by filtration, drying, and solvent extraction (n‑hexane or light petroleum). Results are expressed as a percentage by mass and reported as the mean of two determinations.
Keywords: ISO 1443, total fat content, meat and meat products, fat determination, hydrochloric acid extraction, Soxhlet, n‑hexane.
Key topics and technical requirements
- Scope: Reference method for total fat in meat and meat products; fat is defined as the fat extracted under the specified operating conditions.
- Sample preparation: Mince sample (mechanical meat mincer with ≤4 mm holes) and take a representative test portion (typically 3–5 g depending on expected fat content).
- Acid hydrolysis: Add ~50 ml of approximately 4 N hydrochloric acid and boil the test portion for 1 hour to free occluded/bound lipid fractions.
- Filtration & washing: Pour hot contents through a moistened fluted filter paper, wash until neutral to blue litmus, dry filter paper (103 ± 2 °C for 1 h), then transfer filter to extraction thimble.
- Solvent extraction: Extract fat retained on the filter using n‑hexane or light petroleum (40–60 °C distillation range) in a continuous or semi‑continuous extractor (e.g., Soxhlet) for about 4 hours. Solvent residue limits and solvent quality are specified.
- Drying & weighing: Dry and weigh extraction flask components at 103 ± 2 °C; calculate total fat (%) from mass differences using the standard formula. Report the arithmetic mean of two determinations, rounded to one decimal place.
- Quality criteria: Repeatability - the difference between two simultaneous determinations by the same analyst must not exceed 0.5 g fat per 100 g of sample.
- Limitations: The fat recovered by this method is for quantification only and is not suitable for determining fat characteristics.
Applications and users
- Food testing and analytical laboratories performing routine compositional analysis.
- Regulatory agencies and food safety authorities verifying labeled fat content in meat products.
- Meat processors and quality‑control teams monitoring product formulation and compliance.
- Research laboratories studying meat composition where a standardized reference method is required.
Related standards
- The procedure refers to a complementary meat sampling standard for obtaining representative samples (see ISO meat sampling standards). Laboratories should document any deviations or optional conditions in test reports.
Practical benefits: ISO 1443 provides a reproducible, internationally recognized reference method for accurate total fat determination in meat, supporting compliance, quality control, and comparability of test results.