Overview
ISO 8292-2:2008 specifies an indirect pulsed NMR method for determining the solid fat content (SFC) of animal and vegetable fats and oils. Using low-resolution pulsed nuclear magnetic resonance spectrometry, the standard defines measurement temperatures, thermal pre‑treatments, reference materials and practical test protocols. The indirect method is described as more accurate and more universally applicable to a wide range of fats (including polymorphic fats such as cocoa butter) though it is generally less easy to perform and less reproducible than the direct method (ISO 8292-1).
Key topics and requirements
- Principle: Measure the liquid-phase proton magnetization decay after thermal equilibration and reference to a liquid standard to calculate SFC.
- Thermal pre‑treatments: Two specified options - one for general fats stabilizing in the β′ polymorph and one for fats with pronounced polymorphism (β polymorph). Additional protocols are provided in an informative annex.
- Reference standard: Triolein reference sample (≥99% mass fraction; peroxide value < 5) used as the 100% liquid baseline; storage and replacement guidance included.
- Apparatus & conditions: Low-resolution pulsed NMR spectrometer (magnet uniformity ensuring reference sample half-life > 1 000 µs), 10 mm measurement probe/cell, glass measurement tubes (≈10 mm outer diameter), oven capable of ~80 °C, and water baths/temperature-controlled blocks (including 0 °C and 60 °C baths).
- Procedure & sampling: Test sample preparation per ISO 661; fill duplicate measurement tubes per sample and perform measurements following the chosen measurement protocol. Clauses define measurement repetition times, equilibration, crystallization/tempering and data expression.
- Quality data: Clauses on precision, repeatability and interlaboratory test results; guidance on test reporting and tube cleaning.
Applications
ISO 8292-2:2008 is used wherever solid fat content influences product quality, performance or regulatory compliance:
- Quality control and release testing for margarine, spreads, bakery fats, confectionery (cocoa and chocolate fats), dairy fats and frying oils
- Formulation and R&D to tune texture and melting profiles
- Process control during hydrogenation, fractionation or blending
- Comparative testing in forensic, regulatory or contract laboratory work
Who uses this standard
- Food and edible oil laboratories
- Manufacturers of fats, margarine and chocolate
- Research & development teams in food science
- Third‑party testing and certification laboratories
- Regulatory bodies monitoring food composition
Related standards
- ISO 8292-1 - Direct method for SFC by pulsed NMR
- ISO 661 - Preparation of test sample
- ISO 3960 - Peroxide value (triolein quality)
- ISO 5555 - Recommended sampling methods
Keywords: ISO 8292-2:2008, solid fat content, SFC, pulsed NMR, indirect method, triolein, thermal pre-treatment, fats and oils.
Open preview (PDF)Animal and vegetable fats and oils — Determination of solid fat content by pulsed NMR — Part 2: Indirect method