Interpretation of the new national standard for olive oil GB/T 46952-2025: How to identify pomace oil between fatty alcohols and triterpene alcohols

Olive oil is called "liquid gold", and the price difference between grades can reach several times. Passing off inferior products and using olive pomace oil as virgin oil is a long-standing regulatory problem in this category. One of the chemical bases for identifying the true identity of olive oil is hidden in itsFatty alcohol and triterpene alcohol fingerprintsinside.

On July 1, 2026, a new national standard specifically targeting these two types of components will be officially implemented. This article dismantles its technical logic, grade determination rules, and list of required standard products.

01 Quick overview of standards

STANDARD OVERVIEW · Who is in charge and when will it take effect?

On December 31, 2025, the State Administration for Market Regulation and the National Standardization Administration Committee issuedGB/T 46952-2025 "Determination of fatty alcohols and triterpene alcohols in olive oil and olive pomace oil - Capillary gas chromatography method", and atOfficially implemented from July 1, 2026. This standard is under the jurisdiction of the National Grain and Oils Standardization Technical Committee (SAC/TC 270), proposed and managed by the State Administration of Grain and Material Reserves. The Chinese Standard Classification Number is X04 and the International Standard Classification Number is 67.200.10.

Note: The second edition of ISO 12871:2019 was released in March 2019 and will continue to be valid after review in 2025. Its technical basis is the International Olive Council method COI/T.20/Doc. 26 Rev.2:2017.

02 Why measure these two categories?

WHY THESE MARKERS · Fingerprints from peel to pomace

The levels of fatty alcohols and triterpene alcohols in the non-glyceride components of olive oil are highly dependent on the processing method. Long-chain fatty alcohols are mainly concentrated in the surface layer of olive peel. The virgin oil obtained by pressing has a lower content; while pomace oil is extracted from the remaining pomace with a solvent, which will bring a large amount of waxes and fatty alcohols in the peel into the oil. This difference is the most stable chemical dividing line between the two.

Another group of compounds needs to be distinguished clearly:Erythrodiol and uvaol. Both are triterpenestwoAlcohols, which are also significantly enriched in pomace oil, are also the core indicators for the classification of IOC and the International Food Code (Codex Alimentarius, CXS 33-1981) - but they are separated and measured in the same fraction as sterols.Not within the scope of this standard.

When making actual judgments, the two sets of data must be viewed together.

03 Gray area of ​​wax content: why fatty alcohol is the key

THE GRAY ZONE · Dozens of mg/kg determines grade

The International Olive Council (IOC) trading standards set wax content limits for each grade:Lamp grade virgin olive oil < 300 mg/kg, crude olive pomace oil > 350 mg/kg. When the wax content falls between 300 and 350 mg/kg, it cannot be determined based on the wax content alone, and two other indicators need to be combined.

Note: Homoradiol + Ufaitol is expressed as a percentage of total sterols, so the calculation of this indicator is inseparable from the sterol composition data.

This means that if there is a deviation of tens of mg/kg in the measurement of fatty alcohols, it may directly change the grade determination of a batch of oil. The implementation of GB/T 46952-2025 provides a unified measurement basis for domestic laboratories.

This determination number comes from a complete internal standard method measurement: the sample is saponified by adding 1-eicosanol, the unsaponifiable matter is extracted with ether, the alcohol fraction is separated by thin layer chromatography or HPLC, and then silanized and then subjected to GC-FID - the content of each component is converted based on the peak area and amount of the internal standard.

In other words, whether the grade determination is accurate or not depends on two things:Are the purity and assignment of internal standards reliable?,as well asIs there any monomer reference substance to determine the peak position of C22~C28?. Merely comparing retention times with literature chromatograms is not enough - retention times will drift due to different column types, column lengths, and heating programs. Both of these things fall on the standard.

04 How to mix standard products

REFERENCE STANDARDS · Configuration by fraction

Once the unsaponifiable matter is prepared, two fractions are separated, and each fraction requires a set of reference substances. The laboratory needs to completely complete an olive oil grading, and the purchasing list is recommended to be prepared according to the following structure.

CATO can provide the following representative standard products, all produced under the ISO 17034 system and approved by CNAS (RM0030) and ANAB (AR-2832).

GB/T 46952-2025 List of supporting standard products

Determination of fatty alcohols and triterpene alcohols in olive oil and olive pomace oil

Remarks: ① Spot products will be shipped on the same day if ordered before 16:00; the item number, packaging specifications and supply status areCATO official website (www.cato-chem.com)Real-time information shall prevail. ② Click on the compound name to go directly to the CATO product details page to check the purity, specifications and price.

05 Frequently Asked Questions

FAQ

Q1: What is the relationship between fatty alcohol index and wax content?

Wax is an ester of fatty alcohols and fatty acids, both of which come mainly from fruit peels, but the wax content will be affected by processes such as refining. When the wax content is in the gray zone of 300-350 mg/kg, the total amount of fatty alcohols can provide a relatively independent evidence.

Q2: Why is 1-eicosanol used as internal standard?

The background content of C20-ol in olive oil is very low, and the peak position is before the target component, so it does not interfere with the peak to be measured, so it is suitable for use as an internal standard. Since all results are calculated based on the internal standard, it is recommended to use an internal standard with clear purity and a complete certificate, and check the response factor with a target component reference substance such as 1-octadecanol.

Q3: Are triterpene alcohol and triterpene diol the same thing?

no. Triterpene alcohols in this standard refer to 4,4-dimethylsterols, which are in the same fraction as fatty alcohols; erythrodiol and uranol are triterpene diols, which are in the same fraction as sterols, and are determined by the sterol method. The two belong to different branches in the analysis process and are used together when making judgments.

Q4: After testing fatty alcohols, do I still need to test for sterols?

need. The "high root diol + uriferol" index in the IOC standard is expressed as a percentage of the total sterols, which is inseparable from the sterol composition data; characteristic sterols such as β-sitosterol, campesterol, and Δ7-stigmasolenol themselves are also an important basis for judging whether to incorporate other vegetable oils. CATO can provide the above-mentioned sterol and ufatol monomer standards for peak positioning and system suitability confirmation.

GB/T 46952-2025 will be implemented on July 1, 2026. If you have any needs for establishing olive oil testing methods, standard configuration, or customized mixed control solutions, please feel free to contact the CATO technical team.

References

1. National Standard Information Public Service Platform, GB/T 46952-2025 standard registration information

2. ISO 12871:2019, Olive oils and olive-pomace oils — Determination of aliphatic and triterpenic alcohols content by capillary gas chromatography

3. International Olive Council. COI/T.20/Doc. No 26/Rev.5, 2020

4. International Olive Council. COI/T.15/NC No 3/Rev.20, 2024