ISO/TS 17996:2006

Cheese — Determination of rheological properties by uniaxial compression at constant displacement rate

ISO/TS 17996|IDF/RM 205:2006 describes a method for the determination of rheological properties by uniaxial compression at constant displacement rate in hard and semi-hard cheeses. The method provides standard conditions for sampling and testing, for data representation and general principles of calculation.

Fromage — Détermination des propriétés rhéologiques par compression uniaxiale à vitesse constante de translation

General Information

• Status: Withdrawn
• Publication Date: 28-Aug-2006
• ICS: 67.100.30 - Cheese
• Technical Committee: ISO/TC 34/SC 5 - Milk and milk products
• Drafting Committee: ISO/TC 34/SC 5 - Milk and milk products
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 06-Feb-2023

Relations

• Revised: ISO/TS 17996:2023 - Cheese — Determination of rheological properties by uniaxial compression at constant displacement rate
• Effective Date: 11-Jun-2022

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 17996
IDF/RM
205
First edition
2006-09-01

Cheese — Determination of rheological
properties by uniaxial compression at
constant displacement rate
Fromage — Détermination des propriétés rhéologiques par
compression uniaxiale à vitesse constante de translation




Reference numbers
ISO/TS 17996:2006(E)
IDF/RM 205:2006(E)
©
ISO and IDF 2006

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ISO/TS 17996:2006(E)
IDF/RM 205:2006(E)
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©  ISO and IDF 2006
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ii © ISO and IDF 2006 – All rights reserved

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ISO/TS 17996:2006(E)
IDF/RM 205:2006(E)
Contents Page
Foreword. iv
Foreword. v
1 Scope. 1
2 Terms and definitions. 1
3 Principle. 1
4 Apparatus. 1
5 Sampling. 2
6 Procedure. 2
6.1 Thermal equilibration of test samples. 2
6.2 Test portion . 2
6.3 Test conditions . 3
7 Analysis of the compression curves . 4
7.1 Data representation and calculation. 4
7.2 Parameters characterizing the compression curves . 5
7.3 Expression of results . 8
8 Precision. 8
8.1 Interlaboratory test . 8
8.2 Repeatability. 8
8.3 Reproducibility. 9
9 Test report. 9
Annex A (normative) Figures . 10
Annex B (normative) Non-standard sample conditions. 13
Annex C (informative) Examples of compression curves. 15
Annex D (informative) Results of interlaboratory trial with one sample . 17
Bibliography . 18

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ISO/TS 17996:2006(E)
IDF/RM 205:2006(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has
been established has the right to be represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
In other circumstances, particularly when there is an urgent market requirement for such documents, a
technical committee may decide to publish other types of normative document:
— an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in
an ISO working group and is accepted for publication if it is approved by more than 50 % of the members
of the parent committee casting a vote;
— an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical
committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting
a vote.
An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a
further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is
confirmed, it is reviewed again after a further three years, at which time it must either be transformed into an
International Standard or be withdrawn.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO/TS 17996|IDF/RM 205 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee
SC 5, Milk and milk products, and the International Dairy Federation (IDF). It is being published jointly by ISO
and IDF.
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ISO/TS 17996:2006(E)
IDF/RM 205:2006(E)
Foreword
IDF (the International Dairy Federation) is a worldwide federation of the dairy sector with a National
Committee in every member country. Every National Committee has the right to be represented on the IDF
Standing Committees carrying out the technical work. IDF collaborates with ISO in the development of
standard methods of analysis and sampling for milk and milk products.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the Action Teams and Standing Committees are circulated to the National Committees for voting.
Publication as an International Standard requires approval by at least 50 % of IDF National Committees
casting a vote.
In other circumstances, particularly when there is an urgent market requirement for such documents, a
Standing Committee may decide to publish an other type of normative document which is called by IDF:
Reviewed method. Such a method represents an agreement between the members of a Standing Committee
and is accepted for publication if it is approved by at least 50 % of the committee members casting a vote. A
Reviewed method is equal to an ISO/PAS or ISO/TS and will, therefore, also be published jointly under ISO
conditions.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. IDF shall not be held responsible for identifying any or all such patent rights.
ISO/TS 17996|IDF/RM 205 was prepared by the International Dairy Federation (IDF) and Technical
Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products. It is being published
jointly by IDF and ISO.
All work was carried out by the Joint ISO-IDF Action Team on Physical properties and rheological tests, of the
Standing Committee on Minor compounds and characterization of physical properties, under the aegis of its
former project leader, Mrs Y. Noël (FR), who performed most of the work, and its present project leader,
Mr P. Watkinson (NZ).

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ISO/TS 17996:2006(E)
TECHNICAL SPECIFICATION
IDF/RM 205:2006(E)

Cheese — Determination of rheological properties by uniaxial
compression at constant displacement rate
1 Scope
This Technical Specification describes a method for the determination of rheological properties by uniaxial
compression at constant displacement rate in hard and semi-hard cheeses.
The method provides standard conditions for sampling and testing, for data representation and general
principles of calculation.
NOTE Sampling might be difficult with some cheese varieties, for example caused by shortness, brittleness,
stickiness and soft consistency. In these cases, reliable results cannot be achieved.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
rheological properties
deformation under compression of the test sample by the procedure specified in this Technical Specification
3 Principle
A cylindrical test sample, of defined dimensions, is compressed at a constant crosshead speed with a
compression tool up to a relative deformation sufficient to determine the apparent fracture point. The force,
which is the resistance of the cheese sample during compression, is measured with a load cell. The
displacement may be measured either from the position of the cross head or calculated from the elapsed time
multiplied by the displacement rate.
A schematic representation of the principle of the test is given in Figure A.1.
4 Apparatus
Usual laboratory apparatus and, in particular, the following.
4.1 Cork-borer, such as that shown in Figure A.4 as an example.
It is recommended to mount the cork-borer on a drill-stand in order to drive it slowly and steadily through the
test sample.
4.2 Parallel-wire cutting device, with a wire of diameter less than or equal to 0,4 mm and with a system to
keep the two wires parallel to each other and perpendicular to the plug. It should also include a mechanically
driven cutting system to cut the test sample to the required height.
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ISO/TS 17996:2006(E)
IDF/RM 205:2006(E)
4.3 Measuring cell, with a support and compression plate of the same stiff material, with smooth and
parallel surfaces (e.g. stainless steel, aluminium or Teflon), of diameter larger (by 20 %) than that of the
deformed test portion when at maximum compression. The load cell capacity shall have a reasonable
relationship to the expected maximum force.
5 Sampling
A representative sample should have been sent to the laboratory. It should not have been damaged or
changed during transport or storage.
Sampling is not part of the method specified in this Technical Specification. A recommended sampling method
is given in ISO 707|IDF 50.
6 Procedure
6.1 Thermal equilibration of test samples
If the storage temperature of the loaf of cheese is above that of the measuring temperature, then the loaf of
cheese shall be equilibrated at the measuring temperature for at least 50 h before further preparation of the
test sample because of the slow crystallization of milk fat in the cheese.
If the storage temperature of the loaf of cheese is below that of the measuring temperature, before any
preparation store the loaf of cheese at the measuring temperature for at least 12 h. If there are specific
difficulties that can occur during the sample preparation at the measuring temperature, then sample at the
lower storage temperature and then equilibrate the test samples to the measurement temperature. In this case,
the sample thermal equilibration time may be less than 12 h.
NOTE Examples of specific sampling difficulties are that the cheese is hard to cut, or a heated loaf of cheese
changes the storage regime and therefore stops the use of the unsampled portions of the loaf of cheese for future
measurements.
The following shall be avoided:
a) dehydration of the test sample during the period of thermal equilibration;
b) deformation of the test sample due to its own mass.
6.2 Test portion
6.2.1 Location
Take the test portion from the loaf of the cheese with a plug about half a radius, either along a circle of a
cylindrical cheese, or along one side of a rectangular cheese (see Figure A.2).
Cut the test portion in the plug in the area representing around half of the length (see Figure A.3, plug A). If
the height of cheese is sufficient, two portions can be taken as shown in Figure A.3, plug B and plug C.
6.2.2 Direction
The standard direction for taking the test portion is parallel to the pressure axis in cheese making. See
Annex B for non-standard sampling conditions.
6.2.3 Geometry
The shape of the test portion shall be a cylinder with initial height/diameter ratio (h /d ) of between 1,1 and 1,5.
0 0
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ISO/TS 17996:2006(E)
IDF/RM 205:2006(E)
The initial height, h , of the test portion shall range from 12,5 mm to 25 mm. The diameter, d , for a given
0 0
height follows the above-mentioned ratio.
6.2.4 Cutting
Remove the rind or the plastic cover. Take a test portion using a cork-borer (4.1) with shapes shown in
Figure A.4. For sticky cheeses, samples are easier to take with corer A than corer B. For cheese varieties
showing shortness or brittleness, form B shown in Figure A.4 is more appropriate than form A. It is
recommended to use a cork-borer mounted on a drill-stand in order to drive it slowly and steadily through the
test sample.
If it is difficult to obtain a good cylindrical form, it is recommended to use mineral oil of low viscosity (e.g.
Vaseline oil) to lubricate the cork-borer. Do not test samples with cracks, holes or other visible defects.
Use a parallel-wire cutting device to cut the test sample to the required height. The wire diameter shall be less
than or equal to 0,4 mm. It is essential to have a system that keeps the two wires parallel to each other and
perpendicular to the plug. Preferably, use a mechanically driven cutting system. Taking these precautions into
account reduces the lack in parallelism between the sample surface and the compression plate.
6.2.5 Delay
A delay between the taking of a test portion and its testing allows stress relaxation of the test portion. The
recommended delay is between 10 min and 15 min. The upper limit is not strictly fixed but it should not
exceed 2 h. This recommendation is not relevant when sampling is done at a lower temperature than the
measuring temperature.
Store the test samples at the measuring temperature (6.3.5) and see Annex B for non-standard conditions.
Store samples in a pill-box or wrapped in plastic film to avoid dehydration during the delay between sampling
and testing.
6.3 Test conditions
6.3.1 Relative deformation
Perform the compression to just beyond the apparent fracture point (Figure A.5, curve 1) or to a predefined
maximum deformation (Figure 5, curve 2).
6.3.2 Crosshead speed
The standard value of the crosshead speed or displacement rate is 50 mm/min (or 0,83 mm/s) for initial height
12,5 mm u h u 25 mm.
0
6.3.3 Number of compression cycles
Perform one compression cycle.
6.3.4 Number of test portions
Measure at least four test portions, but preferably carry out more than this.
6.3.5 Measuring temperature
Measure at the standardized measuring temperature of 15 °C ± 1 °C.
NOTE Although the chosen test temperature of 15 °C is a good compromise for a single temperature, the challenge
remains that many studies will use other temperatures for good reasons, as outlined in Annex B.
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ISO/TS 17996:2006(E)
IDF/RM 205:2006(E)
See Annex B for non-standard conditions.
6.3.6 Nature of the interface between test portion and plates
Use a low viscosity mineral oil as lubricant between the test portion and the plates. Apply the oil as a very thin
layer on the plates.
7 Analysis of the compression curves
7.1 Data representation and calculation
7.1.1 Data representation
Raw data files contain data pairs (s , F ) with displacement data, s , of the compression plate and force data, F ,
i i i i
in units depending on the system. If the displacement of the plate is recorded right from the beginning of the
test (i.e. before the plate is in contact with the sample) then compute the absolute deformation data, |∆h |, of
i
the sample before any other calculation is performed. Let |s | be the absolute displacement of the plate when
0
the force becomes significantly different from zero (indicating the start of the compression of the sample).
Then calculate the absolute sample deformation data, |∆h |, using the following equation:
i
∆=hs−s (1)
ii 0
where
|s | is the absolute displacement of the plate when the force becomes significantly different from zero;
0
|s | is the absolute displacement of the plate.
i
The correct sample deformation data, ∆h , is then found using the following equation:
i
∆=hh−∆ (2)
ii
For further processing, it may be useful to remove data from the free precontact displacement of the
compression plate.
If the measuring system automatically records the absolute deformation |∆h| of the sample (starting with zero
as soon as the contact force becomes significant), then |s | is equal to |∆h | and no correction has to be
...