Commission Regulation (EC) No 273/2008 (repealed)Show full title

ANNEX IV (Article 4)

SENSORY EVALUATION OF BUTTER

1. SCOPE

The purpose of this procedure for sensory evaluation of butter is to provide a uniform method applicable in all Member States.

Refer to the current IDF International Standard for Milk and Milk Products, IDF 99 — Parts 1, 2, 3 on Sensory Evaluation, for further detail.

2. DEFINITIONS

‘Sensory evaluation’ (assessment) means the examination of the attributes of a product by the sense organs.

‘Panel’ means a group of selected assessors working, during the assessment, without intercommunication, and without influencing one another.

‘Assessor’ is defined as someone chosen for his/her ability to perform a sensory test. This type of assessor may have limited experience.

‘Expert Assessor’ is defined as someone with a high degree of sensory sensitivity and experience of sensory methodology, who is able to make consistent and reliable sensory assessments of various products. This type of assessor will have a good long term sensory memory.

‘Scoring’ means sensory evaluation by a panel, using a numerical scale. A nomenclature of defects must be used.

‘Grading’ means a quality classification which is performed on the basis of scoring.

‘Control documents’: documents used to record the individual scores for each attribute and the final grade of the product. (This document may also be used to record chemical composition.)

3. TEST ROOM

Refer to ISO 8589 and ISO/DIS 22935-2 | IDF 99-2 par 7 for more details.

Precautions must be taken in order that the assessors in the test room are not influenced by external factors.

The test room must be free from foreign odours and easy to clean. The walls must be of a light colour and non reflective.

The test room and its lighting must be such that the properties of the products to be scored are not affected.

The room must be equipped with appropriate thermostatic control to enable a constant temperature of butter to be maintained. Butter should have a temperature of 12 °C (±2 °C) at the time of grading.

4. SELECTION OF ASSESSORS

An assessor must be familiar with butter products and be competent to carry out sensory grading. His/her competence should be monitored on a regular basis (at least once a year) by the competent authority.

4.1. ISO/DIS 22935-1 | IDF 99-1 par 4 (recruitment) and par 5.1 should be consulted for details on general requirements and screening tests which may be used prior to official use of a new assessor.

It is essential that training is ongoing and general sessions should be held on a regular basis. Refer to ISO 8586-1 for information on panel training.

4.2. Initial training should cover the following:

• general theory and practical importance of sensory evaluation,

• methods, scales and description of sensory impressions,

• detection and recognition of sensory attributes and specific sensory terms,

• background training on the manufacture of butter,

• validated references and samples to help the assessor to identify specific flavours and flavour intensity within the product.

5. REQUIREMENTS FOR THE PANEL

The number of assessors in the panel should be uneven, the minimum number being three. The majority must be employees of the competent authority or authorised persons not employed by the dairy industry.

A panel Leader shall be responsible for the entire procedure and may participate in the panel.

A number of factors must be taken into account before evaluation in order to obtain optimal performances from the subjects:

• subjects must not be suffering from an illness which could affect their performance. In such a case, the assessor concerned should be replaced on the panel by another,

• subjects must be on time to take part in the evaluation and make sure that they have enough time to make their evaluation,

• subjects must not use strong-smelling substances like perfume, after-shave lotion, deodorant, etc. and should avoid eating strong-flavoured (e.g. highly spiced) food, etc.,

• subjects may not smoke, eat or drink anything other than water during the half hour before the evaluation.

6. PERFORMANCE

All Assessors should participate in regular sensory evaluation panels to maintain their competence. The frequency will depend on the volume and throughput of butter, and where possible, should be at least one panel per month.

Senior Assessors should also participate in a number of panels each year, and where possible, at least once per quarter.

7. SAMPLING AND PREPARATION OF THE SAMPLE

It is essential that the identity of the samples is concealed during the assessment so that any possible bias is avoided. The samples should be coded.

This should be organized prior to the evaluation. Requirement for temperature of butter during its transportation to the test room should be set (6 °C ± 2 °C).

When the sensory evaluation is carried out at a cold store, the sample is taken using a butter trier. If the sensory evaluation is carried out at another location other than the cold store, then at least a 500 g sample should be taken. During the evaluation, the butter should have the temperature of 12 °C (±2 °C) (refer: in ISO/DIS 22935-2 | IDF 99-2 the evaluation temperature of butter is 14 °C ± 2 °C). Large deviations should be avoided at all cost.

8. ASSESSMENT OF THE VALUE OF EACH ATTRIBUTE

8.1. The sensory evaluation is to be carried out in relation to the following three attributes: appearance, consistency and flavour:

‘Appearance’ involves the following features: colour, visible purity, absence of physical contamination, absence of mould growth and uniformity of water dispersion. Water dispersion is tested according to IDF-Standard 112A/1989.

‘Consistency’ involves the following features: Body, texture and firmness. Spreadability may be monitored using physical means should an Individual Member State so wish in order to satisfy customer requirements. The Commission may decide to harmonise methodology in the future.

‘Body’ is the term which refers to the cohesiveness of the product as it is being consumed. It is normally associated with firmness and spreadability, and should be uniform throughout the product. It is closely related to texture and is the ability of the product to stand up under its own weight. It is indicated by resistance during cutting and can be measured mechanically and by mouthfeel and fingerfeel.

‘Flavour’ is the characteristic as perceived in the mouth, predominantly by the taste buds of the tongue.

‘Aroma’ is the characteristic as perceived by the nose and sense of smell.

A significant deviation from the recommended temperature prevents a reliable evaluation of consistency and flavour. The temperature is of paramount importance.

Grading of butter must be deferred if the temperature is outside the recommended band.

8.2. Each attribute has to be sensory evaluated separately. The scoring has to be done according to table 1.

8.3. It may be desirable for the assessors to score together, before starting the assessment, one or more reference samples for appearance, consistency and flavour, in order to achieve uniformity.

8.4. Scoring for acceptance is as follows:

Refer to part 7 — Nomenclature, and description of criteria applicable to points, when scoring.

	Maximum	Required
Appearance	5	4
Consistency	5	4
Flavour/aroma	5	4

• Where the required score is not obtained, a description of the defect has to be given.

• The score given by each assessor for each attribute must be recorded in the control document.

• The product is accepted or rejected on the basis of a majority decision.

• Cases where differences between the individual scoring for each attribute are wider than adjacent points should not occur frequently (not more than once per 20 samples). Otherwise the competence of the panel should be checked by the panel leader.

9. SUPERVISION

A panel leader who must be an official employee of the competent authority and may be a member of the panel must be generally responsible for the entire procedure. He/she must record the individual scores for each attribute in the control document and certify whether the product is accepted or rejected.

10. NOMENCLATURE

Refer to the appended table 2.

11. REFERENCE

FIL-IDF 99C:1997 Sensory evaluation of dairy products by scoring — Reference method

ISO/DIS 22935 | IDF 99 International Standard for Milk and Milk Products — Sensory analysis — Parts 1-3

ISO 8586-1 Sensory analysis — General guidance for selection, training and monitoring of assessors — Part 1

ISO 8589 Sensory analysis — General guidance for the design of test rooms

FIL-IDF 112A:1989 Butter — Determination of water dispersion value

Table 1

Butter scoring

a Table 2.
b The defects mentioned under ‘good’ are only very small deviations from the ideal type.
Appearance			Consistency			Flavour + aroma
Points	Noa	Remarks	Points (quality class)	Noa	Remarks	Points (quality class)	Noa	Remarks
5		Very good ideal type highest quality (equal dry)	5		Very good ideal type highest quality (well spreadable)	5		Very good ideal type highest quality (absolutely pure finest aroma)
4		Good b no evident defects	4	17 18	Good b hard soft	4		Good b no evident defects
3	1 2 3 4 5 6 7 8	Fair (slight defects) loose (free), moisture not uniform, two coloured streaky mottled, marbled speckled oil separation overcoloured weak, open texture	3	14 15 16 17 18	Fair (slight defects) short, brittle, crumbly pasty, doughy, greasy sticky hard soft	3	21 22 25 27 33 34 35	Fair (slight defects) unclean foreign flavour acid cooked flavour, scorched flavour feed flavour coarse, bitter oversalted
2	1 3 4 5 6 10 11 12	Poor (evident defects) loose (free) moisture streaky mottled, marbled speckled oil separation foreign matter mouldy undissolved salt	2	14 15 16 17 18	Poor (evident defects) short, brittle, crumbly pasty, doughy, greasy sticky hard soft	2	21 22 23 25 32 33 34 35 36 38	Poor (evident defects) unclean foreign flavour stale acid oxidized flavour, metallic flavour feed flavour coarse, bitter oversalted musty-flat, putrid chemical flavour
1	1 3 4 5 6 7 9 10 11 12	Very poor (strong defects) loose (free) moisture streaky mottled, marbled speckled oil separation overcoloured granular foreign matter mouldy undissolved salt	1	14 15 16 17 18	Very poor (strong defects) short, brittle, crumbly pasty, doughy, greasy sticky hard soft	1	22 24 25 26 28 29 30 31 32 34 35 36 37 38	Very poor (strong defects) foreign flavour cheesy, lactic cheese flavour acid yeasty mould flavour rancid oily, fishy tallowy oxidized flavour, metallic flavour coarse, bitter oversalted musty-flat, putrid malty chemical flavour

Table 2

Table of butter defects

a This designation should be used as seldom as possible and only when the defect cannot be described more accurately.

I. Appearance

1. loose (free), moisture

2. not uniform, two coloured

3. streaky

4. mottled, marbled

5. speckled

6. oil separation

7. overcoloured

8. weak (open texture)

9. granular

10. foreign matter

11. mouldy

12. undissolved salt

II. Consistency

14. short, brittle, crumbly

15. pasty, doughy, greasy

16. sticky

17. hard

18. soft

III. Flavour and aroma

20. without flavour

21. uncleana

22. foreign flavour

23. stale

24. cheesy, lactic cheese flavour

25. acid

26. yeasty

27. (a) cooked flavour

(b) scorched flavour

28. mouldy flavour

29. rancid

30. oily, fishy

31. tallowy

32. (a) oxidized flavour

(b) metallic flavour

33. feed flavour

34. coarse, bitter

35. oversalted

36. musty-flat, putrid

37. malty

38. chemical flavour