🍎 Determination of the non-fat solids content of butter by the reference method — about 5 g of sample (warmed in a closed container to not more than 35 °C and mixed without breaking the emulsion) is dried in a dish at 102 ± 2 °C for at least 15 h (or about 30 min on a boiling water bath and 30 min in the oven), the fat is washed out with at least five portions of 15 ml of light petroleum (30–60 °C) or pentane through a sintered glass crucible of 16–40 µm, rinsed with 25 ml of solvent, and the dish with glass rod and crucible is dried at 102 °C to constant mass; result in % by mass to two decimal places, PN-EN ISO 3727-2

Food chemistry PN-EN ISO 3727-2

Overview

WHAT THE STANDARD COVERS. We read the text of the standard in the iTeh sample of ISO 3727-2:2001 | FIL 80-2:2001 in the French version (“Beurre — Détermination des teneurs en eau, en matière sèche non grasse et en matière grasse — Partie 2: Détermination de la teneur en matière sèche non grasse (Méthode de référence)”): title page, ISO and FIL forewords, Clauses 1–11 — the sample ends on page 5, before the informative Annex A with the results of the interlaboratory test. The heading of Clause 10 and part of the ISO foreword are missing in the text.

ACCORDING TO THE TEXT OF ISO 3727-2:2001. The standard was prepared by ISO/TC 34 “Food products”, Subcommittee SC 5 “Milk and milk products”, with the International Dairy Federation (FIL/IDF) in collaboration with AOAC International (also published by AOAC); the first edition, together with Parts 1 and 3, replaces ISO 3727:1977 (and IDF 80:1977), technically revised. The series ISO 3727 | IDF 80 “Butter — Determination of moisture, non-fat solids and fat contents”: Part 1 — moisture content (reference method), Part 2 — non-fat solids (reference method), Part 3 — calculation of fat content. Warning: the determination requires volatile, flammable solvents — electrical equipment must comply with the regulations for such hazards. Scope (1): reference method for determining the non-fat solids content of butter. Definition (2.1): non-fat solids content — the mass fraction of substances determined by the procedure of this part, in percent by mass. Principle (3): evaporation of water from a known mass of butter, extraction of fat with light petroleum and determination of the mass of the residue. Reagents (4): analytical grade; reagents shall not leave more than 1 mg of residue under the conditions of the determination; light petroleum with a boiling range of 30–60 °C or pentane (b.p. 36 °C). Apparatus (5): balance weighing to the nearest 1 mg, reading 0.1 mg; ventilated oven maintaining 102 ± 2 °C throughout the working space; desiccator with e.g. freshly dried silica gel with indicator; dishes of enamelled porcelain or corrosion-resistant metal, height 20–40 mm, diameter 50–70 mm; sintered glass filter crucible with pores of 16–40 µm with a suction flask; boiling water bath; straight glass rod. Sampling (6): not part of the method, recommended procedure in ISO 707; sample in a tightly closed container with a lid, filled from half to two thirds, stored at 2–14 °C until preparation. Preparation (7): warm in the closed container to not more than 35 °C, and when separation of fat may be expected (e.g. softer fractions), to the usual homogenization temperature of 24–30 °C; mix to a homogeneous mass without breaking the emulsion, avoiding loss of water; before weighing open and mix with a spoon or spatula for not more than 10 s. Procedure (8): dry the dish with glass rod and crucible for 1 h at 102 °C, cool in the desiccator to the temperature of the balance room (usually 45 min) and weigh (m0), remove the crucible and weigh the dish with the rod (m1) — with several test portions always the same set; about 5 g of butter to the nearest 1 mg into the dish (m2); dry for at least 15 h at 102 °C, or about 30 min on the boiling water bath (most of the bottom exposed to steam, frequent stirring with the rod) and then 30 min in the oven; cool; add 15 ml of light petroleum to the residue at about 25 °C, loosen the residue from the walls and bottom with the rod, decant the solvent through the crucible into the suction flask — repeat four times, at the fourth transfer as much of the residue as possible into the crucible; if fat is still visible in the dish, repeat until it is completely removed; rinse the residue in the crucible with 25 ml of light petroleum warmed to about 25 °C; dry the dish, rod and crucible for 30 min at 102 °C, cool in the desiccator and weigh to the nearest 1 mg; repeat drying until the difference between successive weighings is not more than 1 mg or until the mass increases — then take the lowest recorded mass (m3). Calculation (9): wnf = (m3 − m0) / (m2 − m1) × 100 %, to two decimal places. Precision (10): details of the interlaboratory test in Annex A — the values may not apply to other concentration ranges and matrices; repeatability — the difference between two results exceeds 0.15 % (m/m) in not more than 5 % of cases; reproducibility — 0.25 % (m/m). Test report (11): sample identification, sampling method (if known), reference to the standard, details not specified or optional and incidents, results or — when repeatability was checked — the final result.

STATUS (as of 03.10.2026). In the PKN search (query “3727-2”, 03.10.2026) PN-EN ISO 3727-2:2004 (Polish version, “Wprowadza: EN ISO 3727-2:2001 [IDT], ISO 3727-2:2001 [IDT]”) carries no withdrawal note; PN-EN ISO 3727-2:2002 (English version) — “Wycofana i zastąpiona przez PN-EN ISO 3727-2:2004 – wersja polska”. Card of PN-EN ISO 3727-2:2004: publication date 09.01.2004, 10 pages, KT 35 Mleka i Przetworów Mlecznych, no withdrawal note. In the iTeh catalogue (read 03.10.2026) ISO 3727-2:2001 has the status “Published”, stage 90.93 (International Standard confirmed).

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, data up to 17.09.2026, read 03.10.2026). The number 3727-2 appears in 3 records at 3 laboratories: AB 285, AB 705, AB 1334. In the current PCA documents (read 03.10.2026; AB 285 issue no. 28 of 13.01.2026, AB 1334 issue no. 31 of 04.05.2026, AB 705 issue no. 21 of 06.05.2026) the number appears in 3 lines at the same 3 laboratories; in each document the number of page markers equals the number of PDF pages, without repetitions; a search of all PCA documents downloaded from the BIP on 03.10.2026 found no laboratories outside the database copy. The form is always “PN-EN ISO 3727-2:2004”. None of these items is suspended. The “Laboratories” tab (query “PN-EN ISO 3727-2”) shows all 3 laboratories — checked by a tab query on the labcoda.pl production server on 03.10.2026.

WHAT THE LABORATORIES TEST (items in PCA). Object: butter (AB 285, AB 705), butter and fat blends, margarines (AB 1334). Characteristic: non-fat solids content. Ranges: (0.50–3.92) % (AB 285), (0.10–5.00) % (AB 1334), (0.05–6.00) % (AB 705). Technique: gravimetric method.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. Matrix: the scope of the standard is butter (1) — AB 1334 also applies it to fat blends and margarines; the precision data may not apply to other matrices and concentration ranges (10.1). Lower limit: the repeatability limit is 0.15 % and the reproducibility limit 0.25 % (m/m) (10) — ranges starting at 0.05 % (AB 705) and 0.10 % (AB 1334) lie below the permissible difference between two results. Sample: warming above 35 °C or breaking the emulsion and losing water during mixing change the mass of the test portion (7); the sample is stored at 2–14 °C in a tightly closed container (6). Extraction: at least five portions of solvent (four of 15 ml and a 25 ml rinse), until traces of fat disappear (8.3.2) — remaining fat raises the non-fat solids. Weighing: always the same set of dish, rod and crucible; constant mass — difference ≤ 1 mg, and if the mass increases the lowest value is taken (8.1.3, 8.3.5). Reagents: the solvent shall not leave more than 1 mg of residue (4).

WHAT WE DO NOT GIVE. The results of the interlaboratory test of Annex A are not quoted — they lie outside the sample. We have not read the content of Part 1 (moisture) and Part 3 (calculation of fat). We do not give legal requirements for butter.

Method principle

About 5 g of butter in a weighed dish with a glass rod is dried at 102 °C (at least 15 h, or 30 min on a boiling water bath and 30 min in the oven). The fat is washed out of the residue with light petroleum (30–60 °C) in 15 ml portions through a sintered glass crucible, transferring the residue to the crucible, and rinsed with 25 ml of solvent. The dish, rod and crucible are dried at 102 °C to constant mass; non-fat solids wnf = (m3 − m0) / (m2 − m1) × 100 %.

Applications

• Non-fat solids content of butter — reference method (1)
• Part 2 of the butter series; moisture — Part 1, calculation of fat — Part 3 (foreword)
• Butter, fat blends and margarines — items in the accreditation scopes of 3 laboratories in PCA

Key parameters

Standard

Standard number

PN-EN ISO 3727-2:2004

Title (PL)

Masło — Oznaczanie zawartości wody, suchej masy beztłuszczowej i tłuszczu — Część 2: Oznaczanie zawartości suchej masy beztłuszczowej (Metoda odwoławcza)

Title (EN)

Butter — Determination of moisture, non-fat solids and fat contents — Part 2: Determination of non-fat solids content (Reference method)

Step-by-step procedure

1. Sample preparation

   Warming in a closed container ≤ 35 °C (24–30 °C if fat separation is a risk), mixing without breaking the emulsion (7). PN-EN ISO 3727-2:2004 with no withdrawal note in PKN (03.10.2026).

2. Vessels

   Dish with rod and crucible 1 h at 102 °C, desiccator, weighing m0; without crucible m1 (8.1).

3. Drying of butter

   About 5 g (m2) ≥ 15 h at 102 °C, or water bath 30 min + oven 30 min (8.2).

4. Removal of fat

   4 × 15 ml of light petroleum through the crucible, until fat disappears; 25 ml rinse (8.3.1–8.3.3).

5. Weighing and result

   30 min at 102 °C, desiccator, weighing to constant mass (m3); wnf = (m3 − m0)/(m2 − m1) × 100 % (8.3.4, 8.3.5, 9).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Light petroleum and pentane — volatile and flammable; electrical equipment approved for such hazards, work in a fume hood (warning)
• Oven and boiling water bath — hot vessels

Frequently asked questions