Survey: Revalidation of ICC Standards

Approval year: 1982 / Revision: 1984

Scope: This international standard specifies a method for the mechanical determination of the wet gluten content of wheat flour. This method is applicable to different wheat flours (commercial and experimental flours) but not to wheatmeal.

Principle: A dough is prepared from a flour sample by adding a buffered sodium chloride solution; the wet gluten is isolated by washing this dough with sodium chloride solution. The residual water adherent to the gluten is removed by centrifugation and the remainder weighed.

Definition: Wet gluten in wheat flour is a plastic-elastic substance consisting of gliadin and glutenin and obtained by the method specified in this international standard.

QUESTION: Do you use this method?

Approval year: 1972

Scope: Applicable to whole wheat

Principle: The test is based on the production of a "break" flour whose composition depends strongly on the moisture content of the wheat when it is ground; this dependence is least with soft, low protein wheats and is greatest with hard, high protein wheats.

Definition: The Sedimentation Test for wheat requires a special grinding method; wheat samples at a standard moisture content are ground by crushing through corrugated rolls followed by sieving through a standard sieve.

QUESTION: Do you use this method?

Approval year: 1980

Scope: This standard specifies general conditions relating to sampling for the assessment of the quality and condition of milled products from cereals in powder, particulate or agglomerated form and milling byproducts.

This standard does not apply to whole unprocessed cereal grains, to seed grains or to partially milled cereals which retain the form of the original material1). Starches and oils obtained from cereals or pulses are also excluded from the scope of this Standard.

1) For the sampling of cereals as grain, see ICC No. 101/1, Cereals Sampling (as grain). This method is also suitable for the partially milled cereals mentioned.

Definitions: Terms used in this standard have the following definitions:

    Consignment: The quantity of product despatched or received at one time and covered by a particular contract or shipping document.
    Lot: A stated portion of the consignment assumed to be of uniform characteristics which will allow the quality and condition to be assessed.
    Primary sample: A small quantity of product taken from a single position in the lot. A series of primary samples is drawn from different parts of the lot which when bulked will be representative of the lot.
    Bulk sample: The quantity of product formed by combining and mixing the primary samples drawn from any one particular lot.
    Final lot sample: A sample representing the quality and condition of the lot, obtained by reduction of the bulk sample and intended for analysis or other examination.
    Laboratory sample: A small quantity obtained by careful sub-division of the final lot-sample on which analyses will be performed by processes which are described in the relevant methods of analysis.

QUESTION: Do you use this method?

Approval year: 1990

Scope: Applicable to durum wheat wholemeal.

Principle: The swelling capacity of the gluten proteins of durum wheat wholemeal affects the rate of sedimentation of a meal suspension in the SDS medium. Better quality gluten gives rise to slower sedimentation and higher SDS-values.

Definition: The degree of sedimentation of a durum wheat meal suspended in a lactic acid-sodium dodecyl sulfate (SDS) medium during a standard time of settling. The SDS-value depends on the protein quality providing an indication of durum wheat gluten strength.

QUESTION: Do you use this method?

Approval year: 1994

Scope: This description specifies a method for the mechanical preparation of wet gluten and the subsequent determination of the Gluten Index according to Perten, as a measure of gluten characteristics. The method is applicable to whole wheat meals and wheat flours.

Principle: Gluten separated from whole wheat meal or wheat flour by the Glutomatic equipment is centrifuged to force wet gluten through a specially constructed sieve under standardized conditions. The total weight of the gluten is defined as gluten quantity. The percentage of wet gluten remaining on the sieve after centrifugation is defined as the Gluten Index. If the gluten is very weak all of the gluten may pass through the sieve, the Gluten Index is 0. When nothing passes through the sieve, the Index is 100.

Definition: Wet gluten in wheat flour is a visco-elastic substance made of gliadin and glutenin, which is obtained by means of the specified method contained in this international standard. The Gluten Index is a measure of the gluten characteristics, which indicates whether the gluten is weak, normal or strong.

QUESTION: Do you use this method?

Approval year: 1996

Scope: Applicable to wheat and wheat products. The method is applicable to the determination of ochratoxin A in wheat and wheat products at concentrations of 0.4 m g/kg up to 5.0 m g/kg in vegetable material and foodstuffs.

References:
    ICC-Standard No. 101/1, Sampling of grains
    ICC-Standard No. 130/1, Sampling of milling products
    ICC-Standard No. 110/1, Determination of moisture contents of cereals and cereal products

Definition: According to the method described below, ochratoxin A is determined after extraction and acidification using high performance liquid chromatography (HPLC).

QUESTION: Do you use this method?

Approval year: 1980/ Revision: 1994

Scope: This method is envisaged for the determination of crude protein content in cereals and cereal products.

Principle: The organic matter of the sample is oxidized with concentrated sulfuric acid in the presence of a catalyst: the product of the reaction (NH4)2SO4 is treated by alkali; free ammonia is distilled and titrated.

Definition: Crude protein is a conventional expression for the total content of nitrogenous compounds of the analysed product, calculated by multiplying the corresponding total nitrogen content by an conventional factor.

QUESTION: Do you use this method?

Approval year: 1968/ Revision: 1995

Scope: The method is applicable to meal and flour of wheat, rye, barley, as well as to other grains and to starch containing and malted products. In this standard the word "flour" also means meals and ground grains (wholemeal).

By converting the Falling Number into the Liquefaction Number it is possible to calculate the composition of flour mixtures of desired Falling Number.

Principle: The Falling Number is defined as the time in seconds required to stir and to allow a viscometer stirrer to fall a measured distance through a hot aqueous meal, flour or starch gel undergoing liquefaction due to alpha-amylase activity.

References:
    ICC-Standard No. 101/1, Sampling of Grain
    ICC-Standard No. 130/1, Sampling of Milling Products (semolina, flours, agglomerated flours and by-product)
    ICC-Standard No. 110/1, Determination of the Moisture, Content of Cereals and Cereal Products (Practical Method)
    ICC Recommendation No. 203, Statistical Analysis of the Results of Collaborative Studies
    ISO 3696, Water for analytical laboratory use - Specification and test methods

QUESTION: Do you use this method?

Approval year: 1960/ Revision: 1976

Scope: This method can be taken as the standard for the development of methods which are specifically suited to the practical determination of the moisture content of wheat, rice (hulled paddy), barley, maize or whole maize meal, millet, rye and oats, as grains, ground grains, semolina and flour. It is not to be used for the settlement of commercial disputes.

Principle: Measurement of moisture loss when the material, ground if necessary without change of moisture content, is equilibrated in an anhydrous atmosphere at a temperature between 45 and 50 °C and at a pressure of 1.3 ... 2.7 KPa (10 ... 20 mm Hg).

In the case of maize (and whole maize meal) the method for the determination of moisture content differs in some respects from the method for other cereals (and cereal products). In the Standard the variations are indicated by two columns in the description of the method; the right-hand column applies to maize and the left-hand column to other cereals and cereal products. Cereals and Cereal products (+) Maize and whole maize meal (+) For the sake of simplicity, in following paragraphs the word "product" is used to mean a cereal as well as a cereal product

Definition: The moisture content of a product is defined as the loss in weight sustained by the material under the conditions specified in this Standard, expressed as a percentage of the weight of the original sample.

QUESTION: Do you use this method?

Approval year: 1960/ Revision: 1976

Scope: This method is applicable specifically to: wheat, rice (hulled paddy), maize grains or flour from barley, millet, rye and oats, whole grain, ground grains, semolina and flour. This method gives unsatisfactory results for brewing barley. Because of the very high moisture content which can be found in maize sample (Sometimes more than 40 %) and because of the size and structure of the grains, problems arise in the pre-drying and grinding of maize for moisture determination. For this reason both the practical and the basic reference methods can in this case only be carried out by specialized laboratories.
Principle: Determination of the weight loss suffered by the sample when dried at a temperature of 130 to 133 °C under precisely fixed conditions so that a result is achieved which corresponds to the result is achieved which corresponds to the result obtained using the basic reference method (ICC Standard No. 109, Determination of the moisture content of cereals and cereal products).

In the case of maize (and whole maize meal) the method of determining moisture content differs in some points from the method for other cereals (and cereal products). In the description of the method in the Standard, the variations are given side by side in two columns: the right-hand column applies to maize and the left-hand to other cereals and cereal products.
Definition

Moisture content is taken to be the loss in weight, expressed as a percentage of the weight of the original sample, which the product undergoes under the conditions specified in the present ICC Standard No. 110.

QUESTION: Do you use this method?