🍎 Fat content of cereals, cereal-based products and animal feeding stuffs (not oilseeds or oleaginous fruits) — procedure A: crude fat extracted directly; procedure B: total fat after 1 h boiling with 3 mol/l hydrochloric acid (with preliminary extraction at fat content ≥ 150 g/kg); test portion of 1–5 g ground < 1 mm, extraction with light petroleum (30–60 °C) in a two-stage Randall apparatus — 20 min in boiling solvent, 40 min rinsing, 10 min recovery — drying of cups for 2 h at (103 ± 2) °C and weighing to 0.1 mg; result in % by mass to 0.1 %; r = 0.25 (A) and 0.35 (B), R = 0.63 (A) and 1.10 (B) g/100 g; PN-EN ISO 11085:2015-10

Food chemistry PN-EN ISO 11085

Overview

WHAT THE STANDARD COVERS. We read the text of the standard in the iTeh sample of ISO 11085:2015 (second edition, English text) — PN-EN ISO 11085:2015-10 adopts EN ISO 11085:2015 and ISO 11085:2015 as identical (PKN search): foreword, clauses 1–9 and clause 10 (precision) up to 10.4.3 — the sample ends on page 7. We do not read the test report, Annex A (interlaboratory test, Tables A.1, A.2) or Annex B (comparison of procedures A and B).

ACCORDING TO THE TEXT OF ISO 11085:2015. The standard was prepared by ISO/TC 34 "Food products", Subcommittee SC 4 "Cereals and pulses"; the second edition replaces ISO 11085:2008, technically revised. Scope (1): procedures for determining the fat content of cereals, cereal-based products and animal feeding stuffs; not applicable to oilseeds and oleaginous fruits; the choice of procedure depends on the nature and composition of the material and the purpose of analysis; procedure A — directly extractable crude fat, for all materials except those within procedure B; procedure B — total fat, for materials from which oils and fats cannot be completely extracted without prior hydrolysis; note: most cereals, as well as feeds of animal origin, yeasts, potato protein, compound feeds with milk products, glutens and products subjected to extrusion, flaking and heating give significantly higher fat contents by procedure B than by procedure A (Annex B). References (2): ISO 3696, ISO 6498 (preparation of feed samples). Definitions (3): crude fat content — mass fraction of substances extracted by procedure A; total fat content — by procedure B; both in % by mass. Principle (4): fat is extracted with light petroleum by the Randall modification of the Soxhlet method — the test portion is submerged in boiling solvent before rinsing with cold solvent, reducing extraction time; the solvent dissolves fats, oils, pigments and other soluble substances; after extraction the solvent is evaporated and recovered by condensation, and the fat residue is determined gravimetrically after drying; for total fat the sample is heated with hydrochloric acid — hydrolysis makes chemically or mechanically bound fats accessible; the mixture is cooled and filtered, the residue washed, dried and extracted; for high fat content (at least 150 g/kg) a preliminary extraction is performed before procedure B. Reagents (5): water of at least grade 3; light petroleum mainly of C6 hydrocarbons, boiling range 30–60 °C, bromine value below 1, evaporation residue below 20 mg/l; glass beads 5–6 mm or silicon carbide chips; HCl 3 mol/l; filtration aid (e.g. diatomaceous earth boiled 30 min in 6 mol/l HCl and dried at 130 °C); acetone; defatted cotton wool; fat-free filter paper. Apparatus (6): two-stage Randall extraction unit with solvent recovery and fluoroelastomer or PTFE seals; hydrolysis apparatus I (multiple-position, compatible with the extraction unit) and II (400 ml beaker with watch glass or 300 ml flask with reflux condenser); oven (103 ± 2) °C; microwave oven with defrost setting; desiccator; filter cartridge; cellulose extraction thimbles; aluminium or glass extraction cups; glass thimbles for hydrolysis; analytical balance; mill with 1 mm screen, and for 15–20 % fat a water-cooled knife mill; Büchner funnel. Sampling (7) is not part of the method — ISO 24333 recommended. Preparation (8.1): grinding to < 1 mm; feeds according to ISO 6498. Test portion (8.2): 1–5 g to 1 mg; at fat content above 150 g/kg total fat starts with preliminary extraction (8.3), then hydrolysis (8.4) and extraction (8.5); otherwise total fat starts at 8.4, crude fat at 8.5. Preliminary extraction (8.3): cups with 5–10 glass beads dried for at least 30 min at 103 °C, weighed (m2); reflux 3–5 drops/s (about 10 ml/min), cooling water about 15 °C, 2 l/min; 40–60 ml light petroleum, rinsing 20 min and recovery 10 min; evaporating traces under a fume hood; drying 30 min at 103 °C — excessive drying may oxidize the fat and give high results; weighing (m3). Hydrolysis (8.4): with apparatus I — 130 ml HCl, 1 h boiling, filtration on the cartridge, washing with warm (60 °C) water until acid-free, wiping surfaces with cotton wool soaked in acetone, drying to constant mass (e.g. 1 h in a microwave oven on defrost), acetone must have evaporated before drying; with apparatus II — 100 ml HCl and silicon carbide, 1 h gentle boiling swirling every 10 min, cooling, filtration aid, filtration through moistened fat-free double filter paper on a Büchner funnel, washing with cold water to a neutral filtrate; caution: oil or fat on the surface of the filtrate means a possible error — repeat with a smaller test portion or, preferably, with preliminary extraction. Extraction (8.5): cups with beads dried 30 min or to constant mass at 103 °C (m4); light petroleum sufficient to cover the test portion; 20 min boiling, 40 min rinsing, 10 min recovery; evaporating traces; drying 2 h at (103 ± 2) °C; weighing (m5). Calculation (9): with preliminary extraction w1 = [(m3 − m2)/m1 + (m5 − m4)/m1] × 100; without it w2 = (m5 − m4)/m1 × 100; result to 0.1 %. Precision (10): procedure A for 0.48–25.77 g/100 g — r = 0.25, R = 0.63, CDr = 0.42, CDR = 0.57; procedure B for 1.07–27.08 g/100 g — r = 0.35, R = 1.10, CDr = 0.78, CDR = 1.07; when comparing means of two results the critical difference is used, not the repeatability limit.

STATUS (as of 03.10.2026). In the PKN search engine (query "PN-EN ISO 11085", 03.10.2026) PN-EN ISO 11085:2015-10 appears in Polish and English versions, "Introduces: EN ISO 11085:2015 [IDT], ISO 11085:2015 [IDT]", without a withdrawal note; PN-EN ISO 11085:2010 (English version) — "Withdrawn and replaced by PN-EN ISO 11085:2015-10 - English version".

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, load up to 17.09.2026, read 03.10.2026). The number 11085 appears in 4 records at 2 laboratories: AB 1179 (3) and AB 1616 (1). In the current PCA documents (read 03.10.2026; AB 1616 issue no. 13 of 14.10.2025, AB 1179 issue no. 21 of 08.07.2026) the number appears in 4 lines at the same 2 laboratories; in each document the number of page markers equals the number of PDF pages, without duplicates; searching all PCA documents downloaded from the BIP on 03.10.2026 found no laboratories outside the database copy. Forms: "PN-EN ISO 11085:2015-10" (AB 1179), at AB 1616 "PN-EN ISO 11085:2015-10 excluding clauses 8.3 and 8.4", at AB 1179 for feeds together with Commission Regulation (EC) No 152/2009, Annex III point H, excluding sampling. None of these items is suspended (the AB 1179 document has a footnote on suspension of part of the scope marked in bold italics, but the items with this standard are not so marked). The "Laboratories" tab (query "PN-EN ISO 11085") shows both laboratories — checked by a tab query on the labcoda.pl production server on 03.10.2026.

WHAT THE LABORATORIES TEST (PCA items). AB 1616: cereal grain, feeds — crude fat content (0.5–25.8) %, extraction-gravimetric method, excluding clauses 8.3 and 8.4. AB 1179: cereals, cereal products and bread and pulse seeds — total fat content (0.38–47) %; animal feeds — crude fat content (0.38–45) %; technique described as "extraction-gravimetric method (Weibull-Stoldt)".

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. Choice of procedure: crude fat (A) and total fat (B) are different quantities — most cereals and many feeds give a significantly higher result by procedure B (1, note); AB 1616 excludes clauses 8.3 and 8.4 (preliminary extraction and hydrolysis), so its item contains only procedure A. Scope: the standard does not apply to oilseeds and oleaginous fruits (1); bread and pulse seeds at AB 1179 are not named in the scope of the standard. Fatty samples: from 150 g/kg fat procedure B requires preliminary extraction, and oil on the filtrate after hydrolysis means a possible error (8.2, 8.4.3). Drying: excessive drying oxidizes the fat and raises the result (8.3.8, 8.5.8); acetone must evaporate before drying the hydrolysis residue (8.4). Numbering: clause 8.4 refers to "8.4.1 or 8.4.2", while in the sample text hydrolysis with apparatus I is numbered 8.4.2 and with apparatus II 8.4.3 — this is worth checking in the PN text when citing clauses. Precision: the data cover 0.48–25.77 g/100 g (A) and 1.07–27.08 g/100 g (B) (10.2) — the range of AB 1616 (0.5–25.8 %) matches them, the ranges of AB 1179 reach 45 and 47 %. Name of the technique: AB 1179 describes the technique as "Weibull-Stoldt"; this name does not appear in the text of the standard read — the standard describes Randall extraction as a modification of the Soxhlet method and, for total fat, hydrolysis with hydrochloric acid (4).

WHAT WE DO NOT GIVE. We do not reproduce the results of the interlaboratory test (Annex A) or the comparison of procedures A and B (Annex B) — they are outside the sample. We do not summarize Regulation (EC) No 152/2009, ISO 6498 or ISO 24333 in this entry.

Method principle

The ground sample in a thimble is first immersed in boiling light petroleum and then rinsed with cold solvent (the Randall modification of the Soxhlet method), which shortens extraction; the solvent is evaporated and recovered, and the fat residue is dried at 103 °C and weighed. For total fat the sample is first boiled for 1 h with hydrochloric acid to release chemically or mechanically bound fat, filtered, washed and dried, and only then extracted; very fatty samples are defatted beforehand before hydrolysis.

Applications

• Cereals and cereal-based products — crude fat (A) and total fat (B) (1)
• Animal feeding stuffs, including feeds of animal origin and compound feeds with milk products — usually procedure B (1, note)
• Extruded, flaked and heated products, yeasts, potato protein, glutens — procedure B (1, note)
• Cereal grain, cereal products, bread, pulse seeds and feeds — crude and total fat — 4 accreditation scope records of 2 laboratories in PCA

Key parameters

Standard

Standard number

PN-EN ISO 11085:2015-10

Title (PL)

Ziarno zbóż, produkty wytworzone na bazie ziarna zbóż i pasze — Oznaczanie zawartości tłuszczu surowego i tłuszczu całkowitego metodą ekstrakcji Randalla

Title (EN)

Cereals, cereals-based products and animal feeding stuffs — Determination of crude fat and total fat content by the Randall extraction method

Step-by-step procedure

1. Sample preparation

   Grinding < 1 mm; feeds according to ISO 6498; test portion 1–5 g (8.1, 8.2). PN-EN ISO 11085:2015-10 — no withdrawal note (PKN, 03.10.2026).

2. Preliminary extraction (fat > 150 g/kg, procedure B)

   Rinsing 20 min, recovery 10 min, drying 30 min at 103 °C (8.3).

3. Hydrolysis (procedure B)

   HCl 3 mol/l, 1 h boiling, filtration, washing until acid-free, drying (8.4).

4. Randall extraction

   20 min boiling, 40 min rinsing, 10 min recovery; drying cups 2 h at 103 °C (8.5).

5. Result

   w1 or w2 in % by mass to 0.1 %; assessment against r, R and critical differences (9, 10).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Light petroleum is evaporated from the cups under an operating fume hood until all traces of solvent are gone; acetone must evaporate before drying in the microwave oven (8.3.7, 8.4, 8.5.7)

Frequently asked questions