IDF Standards

This document specifies a method for the determination of β-galactooligosaccharides (GOS) in infant formula (both powder and liquid) containing 0,2 g/100 g to 3,0 g/100 g of GOS in the product as prepared ready for consumption.The method has been validated in a multi-laboratory study with reconstituted infant formula at levels of 0,236 g/100 g, 0,594 g/100 g, 0,616 g/100 g and 0,688 g/100 g and infant formula RTF at levels of 0,316 g/100 g and 0,858 g/100 g. During the single laboratory validation study[1] spike-recovery experiments were performed up to 3 g/100 g in reconstituted infant formula powders (milk-based, partially hydrolysed milk-based and soy-based), and reconstituted adult nutritional powders.

This document specifies a method for the quantitative determination of total amino acids using 6-aminoquinolyl-N-hydroxy-succinimidyl carbamate (ACQ) derivatization followed by ultra-high-performance liquid chromatography (UHPLC) separation and ultraviolet (UV) detection. It specifies a method for the determination, in one single analysis, of the following amino acids: alanine, arginine, aspartic acid (combined with asparagine), cystine (dimer of cysteine, combined with cysteine), glutamic acid (combined with glutamine), glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tyrosine and valine.

This method does not apply to the determination of tryptophan.

This method is applicable to infant and adult/paediatric nutritional formulas, dairy products and other matrices such as cereals. It was validated in infant formulas (milk- and soy-based, including partially hydrolysed and elemental products), toddler formula, adult nutritional powder, UHT skimmed milk, whey powder, sodium caseinate, whole milk powder, bran pet food, dry pet food and breakfast cereal.

This document gives guidance on the sample preparation of fresh cheese, (semi) soft cheese, (semi) hard cheese, processed cheese and whey cheese for physical and chemical analysis, including analysis by applying instrumental methods.

This document describes the (sub)sampling, and sample preparation steps carried out after sampling according to ISO 707 | IDF 50 and prior to method-specific sample preparations, e.g. as with analytical methods listed in References [2] to [22].

This document specifies a method for the determination of melamine and cyanuric acid with liquid chromatography in combination with tandem mass spectrometry (LC-MS/MS). The method has been validated in an interlaboratory study via the analysis of spiked samples of milk-based infant formula, soy-based infant formula, milk powder, whole milk, soy drink and milk chocolate ranging from 0,71 mg/kg to 1,43 mg/kg for melamine and 0,57 mg/kg to 1,45 mg/kg for cyanuric acid. The limits of quantification (LOQ) for melamine and cyanuric acid in food are 0,05 mg/kg and 0,25 mg/kg, respectively. The upper limit of the working range is up to 10 mg/kg for melamine and up to 25 mg/kg for cyanuric acid.

This document specifies a method for the determination of the fat content of all types of cheese and processed cheese products containing lactose of below 5 % (mass fraction) of non-fat solids, and all types of caseins and caseinates.

The method is not applicable to fresh cheese types containing, for example, fruits, syrup or muesli. For such products, the Schmid-Bondzynski-Ratzlaff (SBR) principle is not applicable due to high concentrations of sugars. For these products, the method using the Weibull-Berntrop principle (see ISO 8262-3 | IDF 124-3[4]) is appropriate.

This first edition cancels and replaces ISO 1735 | IDF 5:2004 and ISO 5543 | IDF 127:2004, which have been merged and technically revised.

The Bulletin of the IDF No. 235/1988 - Interlaboratory collaborative studies (second series) – FIL-IDF (page 55) contains the reports of the collaborative studies on cheese, caseins and caseinates referred to in annexes C and D.  

This document specifies the method for the determination of fat content.

The method is applicable to:

1. a) raw milk (cow, sheep, goat), reduced fat milk, skimmed milk, chemically preserved milk and processed liquid milk;
2. b) dried milk products (e.g. whole, partially skimmed, skimmed milk powder; dairy permeate powder; whey powder; blend skimmed milk powder and vegetable fat; milk based infant formula powder);
3. c) raw, processed and sour cream.

For the following products, the precision figures are given in Annex H. These precision figures are derived from interlaboratory studies not conforming to the requirements from ISO 5725-2 in terms of number of samples (< 6) and number of participating laboratories (< 8).

1. d) evaporated milk and sweetened condensed milk (e.g. liquid sweetened and unsweetened concentrated milk);
2. e) whey cheese as defined in CODEX CXS 284‑1999;
3. f) liquid whey and buttermilk;
4. g) milk-based edible ices and ice mixes;
5. h) liquid concentrated infant foods.

The method does not apply in the following cases:

This document gives guidelines for using infrared spectrometry in in-line and on-line applications for dairy processing. These applications are distinct to those covered in ISO 21543 | IDF 201.
It is applicable, but not limited, to:
— the determination of protein, fat and total solids in liquid milk and milk products using mid and near infrared spectrometry;
— the determination of protein, fat and moisture in solid or semi-solid products, such as milk powder, and butter and liquid dairy streams using near infrared spectrometry.

This document specifies a method for the determination of the whey to casein protein ratio, ranging from 20:80 to 80:20 in cow milk-based infant formula powders.

This method does not apply to the analysis of infant formulas containing hydrolysed protein or proteins from other sources (e.g. plants or milk from other mammals).

This document specifies a liquid chromatography tandem mass spectrometry (LC–MS/MS) method for the quantification of the inhibitory substance, nitrofurazone, in milk and milk products.

The method has been validated for measuring trace levels of intact nitrofurazone to levels down to 1 ng/g in fluid milk and powdered dairy products on a whole product (i.e. powder) basis. While the method is expected to apply to other dairy matrices, additional validation will be required to demonstrate this.

This document specifies the quantitative liquid chromatographic determination of specific sugars (galactose, glucose, fructose, sucrose, lactose and maltose) in various milk and milk products, applying arabinose as an internal standard. The method is applicable to the following dairy matrices: milk, sweetened condensed milk, milk powder, cheese, whey powder, infant formula, milk dessert and yoghurt. The method does not apply to dairy products containing soy or to the determination of the lactose content in low-lactose milk products at levels below 1 mg/g.

This document specifies a method for the quantitative determination of calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), phosphorus (P), potassium (K), sodium (Na), zinc (Zn), chromium (Cr), molybdenum (Mo) and selenium (Se) using inductively coupled plasma and mass spectrometry (ICP-MS).

The method is applicable for the determination of all 12 elements in infant formula and adult nutritional products. The method is also applicable for milk, milk powder, whey powder, butter and cheese excluding the determination of Cr, because all Cr results were below the quantification limit and reproducibility could not be determined in these matrices. The present method is an extension of ISO 20649 | IDF 235 (AOAC 2011.19) which was validated only for Cr, Mo and Se in infant formula and adult nutritional products.

This document specifies a method for the determination of chloride in milk, milk products, infant formula and adult nutritionals by potentiometry with an analytical range of 0,35 mg chloride/100 g to 711,6 mg chloride/100 g product, or ready-to-feed products.

This document specifies a method for the determination of inulin-type fructans (including oligofructose, fructooligosaccharides) in infant formula and adult nutritionals (both powder and liquid) containing 0,03 g/100 g to 5,0 g/100 g of fructans in the product as prepared ready for consumption.
The method has been validated in a multi laboratory study[1] with reconstituted standard reference material (SRM), infant/adult nutritional formula at a level of 0,204 g/100 g, adult nutritionals ready-to-feed (RTF) at levels of 1,28 g/100 g and 2,67 g/100 g, infant formula RTF at a level of 0,300 g/100 g, reconstituted follow-up formula at levels of 0,209 g/100 g to 0,275 g/100 g, reconstituted infant formula at levels from 0,030 8 g/100 g to 0,264 g/100 g. During the single laboratory validation study[2], spike-recovery experiments were performed up to 5 g/100 g in reconstituted infant formula powders (milk-based, partially hydrolysed milk-based and soy-based), adult nutritional RTF and reconstituted adult nutritional powders.

This document specifies a method, the acido-butyrometric or “Gerber”, for determining the fat content of milk. It is applicable to whole milk and partially skimmed milk.
It is also applicable to milk containing authorized preservatives (potassium dichromate, bronopol). It does not apply to formalin milk, nor to milks that have undergone a homogenisation treatment.

This document specifies an acidobutyrometric method for determining the fat content of cream. The reference method remains the gravimetric method (by ammoniacal ether extraction) described in ISO 2450 | IDF 16.
This method is applicable to cream having a fat content between 20 % and 50 % inclusive:
— intended for manufacturing butter;
— sweet, unmatured and non-inoculated;
— raw or having undergone a heat treatment;
— non-homogenized;
— with or without preservatives (2-bromo-2-nitropropane, 1,3 diol or bronopol).

This standard specifies an enzymatic method for the determination of the lactose content of milk and reconstituted milk by measurement of the difference in pH (differential pH measurement).

Milk and milk products — Detection of Enterobacter sakazakii is withdrawn and replaced by the horizontal standard ISO 22964 Microbiology of the food chain -- Horizontal method for the detection of Cronobacter spp. The scope of the IDF/ISO method has been extended to Cronobacter spp. detection in food products for humans and feeding animals and environmental samples and the title changed accordingly;

Cheese - Determination of propionic acid level by chromatography - Part 1: Method by ion exchange chromatography

Cheese - Determination of propionic acid level by chromatography - Part 1: Method by gas chromatography

Milk and Milk products – Detection of Salmonella  is now replaced with ISO 6579 Microbiology of the food chain -- Horizontal method for the detection, enumeration and serotyping of Salmonella -- Part 1: Detection of Salmonella spp. This document describes a horizontal method for the detection of Salmonella spp. in food (including milk and milk products, originally described in ISO 6785), in animal feed, in animal faeces, and in environmental samples from the primary production stage.

Milk and Cheese - Determination of hen's egg white lysozyme content by high performance liquid chromatography

ISO 8968-1/IDF 20-1 – Milk and milk products – Determination of nitrogen content – Part 1: Kjeldahl principle and crude protein calculation

Infant formula and adultnutritionals - determination of chromium,  selenium and molybdenum

 Infant formula and adult nutritinals - determination of total iodine