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NMKL PROCEDURE

No. 31 (2015)

Guidelines for sensory evaluation of bread

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Date: 15 December 2015

Approved: Franklin Georgsson

Nordic Committee on Food Analysis

GUIDELINES FOR

SENSORY EVALUATION OF BREAD

CONTENTS

1. Fore word

2. Purpose and scope

3. Facilities for sensory evaluation

3.1 Test rooms

3.2 Testing equipment

3.3 Staff of a sensory evaluation laboratory

4. Assessors

5. Sensory evaluation of bread

5.1 Bread samples

5.2 Sensory evaluation method

6. Evaluation of results and reporting

7. References

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No. 31 (2015) Guidelines for sensory evaluation of bread

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1. Foreword

Bread is an important part of the daily diet in the Nordic countries because of its generally good

nutritional value. However, the Nordic bread culture encompasses a wide assortment of bread types,

each with different characteristics. Therefore, local bread associations have collected bread

information in Sweden (Brödinstitutet), in Finland (Finnish Bread Information, Leipätiedotus) and in

Norway (Brød & Korn) for this procedure. Most bakery recipes include different cereals such as

wheat, rye, barley, oats, linseed and spelt, which are usually ground into various grades before

baking. Wholemeal flour, coarse flour, bran and flakes are also widely used in breads. Different

dried breads such as crisp-breads and rye crisps are popular in Finland and Sweden. Every Nordic

country, and almost each province, has its own specialities. One example is "tunnbröd", thin

unleavened, soft and crisp bread from the northern part of Sweden. In other parts of Sweden, the most

popular bread is the traditional Swedish wheat-rye loaf with syrup added. In recent years, many new

bread varieties – often pre-cut into slices – have entered the market, and they are quite similar in all

the Nordic countries. For instance, Finnish bakeries now bake black rye bread, multigrain breads,

leavened bread, and sweet-sour soft breads. It is also possible to add various flavourings to bread,

such as herbs, fish, blood, malt, berries, and vegetables. Norway has a strong bread culture, and a

tradition for eating bread for breakfast, and especially for lunch. Therefore, the consumption of bread

is very high, and most of the bread consumed is wholemeal bread.

Bread can be classified based on the raw materials of which is it made, and especially the type of

flour used in it, examples being oat bread, wheat bread, rye bread or multigrain bread. In addition, the

water content will determine the variation in hardness from soft to dry classes. Bread flavour, texture

and colour are the main sensory properties affecting consumer acceptability, but there are a lot of

individual differences in food perception protocol and food choice. The multi-dimensional nature of

Nordic bread results in a wide variation of critical sensory attributes in the different bread categories.

Based on EA-4/09: Sensory analysis is a scientific discipline used to evoke, measure, analyse and

interpret reactions to those characteristics of foods and other materials as are perceived by the

senses of sight, smell, taste, touch and hearing. This definition embraces both qualitative and

quantitative approaches and does not discriminate between the sensory attributes being assessed by

consumers or trained sensory assessors, or objective or subjective sensory questions being asked

about products and materials.

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Based on General vocabulary (ISO 5492): Sensory analysis is the science involved with the

assessment of the organoleptic attributes of a product by the senses.

This NMKL procedure has been elaborated by a project group consisting of:

Mari Sandell, University of Turku (project leader)

Saara Lundén, University of Turku, Finland

Hilkka Terho, University of Turku, Finland

Iwona Kihlberg, University of Uppsala, Sweden

Kristín Halldórsdóttir, Mjólkursamsalan Akureyri, Iceland

Mats Carlehög, NOFIMA, Norway

NMKL: Nordic Committee on Food Analysis, Members of Subcommittee 4 – Sensory Analysis

© NMKL www.nmkl.org

2. Purpose and scope

In sensory evaluation of bread, all five senses are equally important, as bread samples offer

experiences for all of them. In general, all ingredients of the dough, such as flour, salt, sugar and

yeast, as well as the production conditions, e.g. kneading, and parameters for leavening and baking in

the oven, contribute to the sensory properties of the bread. There is a need for a standardised method

to measure bread qualities, including freshness. This procedure points out the sensory properties

contributing to bread quality, and describes the main steps of the protocol, which need to be applied

in sensory evaluation of bread. The procedure describes analytical sensory evaluation of bread

carried out in a sensory laboratory with a trained panel. It does not explain the protocol used for

testing consumer acceptance of bread. This NMKL Procedure can be used as general guidelines for

all bread consumers, but is especially targeted at bakeries and the education of staff in bread making.

Flavour is the combination of retronasal odour, taste and chemesthesis properties (e.g. irritation or

pungency), and is perceived with chemical senses simultaneously (ISO 5492, Meilgaard et al 2006,

http://www.nmkl.org/

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Lawless & Heymann 2010). By retronasal odour we mean a smell sensation that is activated by odour

compounds, which have travelled through the mouth and throat to the nose and olfactory bulb.

Various chemical compounds can be activators in bread. As regards odour active compounds, more

than 540 different volatile aroma compounds have been measured from different kind of breads,

although only part of them will contribute to the final aroma (Callejo 2011). Taste properties such as

bitterness, saltiness and sourness are important flavour components of bread. Flavour properties such

as rye-like, flour-like or roasted-like depend on the raw material used, but also the production process

of the bread. In the grain itself, sugars, phenolic compounds, free fatty acids, lipids, volatile

compounds, free amino acids and small peptides are known to influence perceived flavour (Heiniö

2007). The extraction rate of the flour or the milling techniques (Kihlberg et al. 2004) and stages in

dough fermentation also contribute to the flavour, as does the texture of the bread. Aroma refers to

orthonasally perceived odour with the sense of smell. The aroma varies in the different parts of the

bread – on the outside or inside, on the slice cutting surface or crust. A typical off-odour of bread is

burnt odour.

Bread texture properties such as softness and hardness are perceived with the sense of touch. In

general, it is easy to notice differences in bread softness with the fingers by touching it, or with the

lips, teeth and tongue by biting into it. However, analytical sensory evaluation of different textural

attributes of bread is much more complicated. There are dozens of different texture attributes used in

the sensory evaluation of bread (Callejo 2011, Heiniö 2007, Salmenkallio-Marttila et al 2004,

Pohjanheimo et al 2006, 2010 Kihlberg 2004).

Appearance properties are those we perceive with the sense of sight, but also with the sense of touch.

In bread, these properties include attributes such as crumb colour, crust colour or crumb structure

(Salmenkallio-Marttila et al 2004, Callejo 2011). Crust colour is formed during baking in an oven

when the components of the dough react and change due to heating, and moreover due to Maillard

reaction and caramelisation. Crumb cell number, crumb cell size and homogeneity of cell size

distribution and porosity are all factors, which influence the crumb structure.

When it comes to bread, sensory properties describing sound or noise perceived with the sense of

hearing when bread is chewed and crushed in the mouth, are also vital for the sensory evaluation. A

classic example is the sound of crisp bread, a factor that can be very important to consumers.

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Freshness of bread may also be a critical quality factor to the average consumer. As a sensory

property it is a very complex and multisensory experience. It is mainly related to storage time and

conditions. A suitable standard for the measurement of freshness of bread is needed, but it does not

yet exist.

Examples of different sensory properties and definitions for Nordic bread that have been studied and

published are listed in Tables 1-8. Because of the complexity of bread as a research object and the

diversity of bread types within the Nordic countries, it is very difficult to define a standard procedure

for sensory evaluation of bread.

3. Facilities for sensory evaluation

3.1 Test rooms

There is an international standard (ISO 8589 Sensory analysis – General guidance for the design of

test rooms, EN ISO 8589) for the design and construction of a sensory laboratory. According to this

standard, analytical sensory evaluation needs to be carried out in a sensory laboratory built following

these specific guidelines. Research institutes and food companies with R&D departments usually

have such facilities. Special rooms for sensory evaluation are also preferred for smaller food

companies and quality control departments, but if this is not possible, the testing area should

resemble a sensory lab as closely as possible. A silent, clean and neutral environment with a high

level of hygiene, possibilities for individual testing, natural light and a very low level of different

smells or other sensory contaminants are the minimum requirements for a testing area used for

sensory evaluation purposes.

3.2 Testing equipment

All the equipment used in sensory analysis of bread should be suitable for food quality purposes, and

only used in the sensory laboratory. It is essential to ensure that assessors participating in sensory

testing are not exposed to any health risks. The equipment must be free of odours and colours in order

to avoid disturbing sensory stimuli, as well as practical to use and preferably washable and reusable.

White ceramic plates or plastic trays are well suited for serving samples. Cardboard/disposable plates,

though they are easy to use, may cause problems with odours deriving from the cardboard. All the

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materials need to be clean and suitable for edible products. When plates or trays are used, the samples

should be protected by e.g. plastic cling-film to avoid dryness of the product or contamination.

3.3 Staff of a sensory evaluation laboratory

Detailed guidance on the staff responsibilities in sensory evaluation laboratories can be found in ISO

13300-1 and ISO 13300-2. Based on EA-4/09, personnel working in a sensory laboratory should

undergo a comprehensive training program covering at least:

a) selection of test procedure, experimental design and analysis

b) product preparation and implementation of testing

c) data input and processing

d) preparation of reports

e) maintenance of records

f) maintenance of all necessary supplies and services

g) sensory assessor screening, selection, training and monitoring procedures

h) understanding the importance of the assessor's health and safety

All personnel in a sensory laboratory should adhere to strict rules of confidentiality and ethics. When

storing records about sensory panels or sensory evaluation, all the personal information concerning

assessors must be kept confidential. The identity of the assessors should not be revealed when

reporting results. Every member of staff in a sensory laboratory should be qualified for the job, and

show a thorough understanding of how to use different sensory methods, and how to prepare and

serve samples. The staff members are responsible for preparing the sensory sessions, including

selecting and preparing samples, and must ensure suitable conditions for the sensory panel by

following good laboratory practises at all times. They should be aware of the importance of good

housekeeping always maintaining the cleanliness of the test and preparation areas.

4. Assessors

In analytical sensory evaluation, the main instrument is a high quality sensory panel composed by

highly qualified assessors. Assessors are persons participating in sensory evaluation tasks on a

voluntary basis. There is an international guideline for the selection, training and monitoring of

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selected assessors and expert sensory assessors (ISO 8586). Before starting the actual sensory

analysis, it is important to test the functionality and skills of the senses of every potential assessor in a

sensory laboratory (ISO 8589). If any of the senses of an assessor is not working satisfactorily, the

results will be defective.

Sensory evaluations can be conducted using different evaluation methods (ISO 6658), and the choice

of method depends on the task and the aim of the study. When trying to detect very small differences

in bread samples, it is important to have highly sensitive assessors in the sensory panel (ISO 13301,

ISO 3972). When evaluating sensory profiles for bread samples, it is helpful to have creative

assessors with strong verbal skills, in addition to acute sensory skills, in the sensory panel. However,

in every case the assessors need to be able to repeat the evaluation in different sessions. This means

not just being available, but also being able to focus on their task in the sensory laboratory. The more

precise the sensory panel is, the more accurate and repeatable results will be gained. It is also

important to keep in mind that assessors are not machines or physical instruments. The senses will get

tired if the number of samples is too high. The motivation of the panel is very important, and should

be kept high at all times. Laboratory personnel are responsible for maintaining the motivation of the

assessors, and are recommended to organise various activities for the panel, such as “Getting-to-

Know-You games” and fun tasks in addition to the actual analysis work (Meilgaard 2006).

The number of assessor in each test depends on the evaluation method used. In discrimination testing,

the number of assessors in the panel should be higher than in a panel working with descriptive

analysis (5.2). In general, the number of recommended assessors is around 30 in discrimination test,

and 8-12 in profile test.

It is important to monitor the evaluation of every sensory panel (ISO 11132, PANEL CHECK). If the

results of a single assessor in repeated sessions are very varying, extra attention should be paid to

training tasks and motivation. NOTE! According to the ethical rules for sensory evaluation, an

assessor is allowed to stop his/her work in a sensory laboratory at any time, without explanation

(please check the rules of the central ethical board/committee in your respective country).

NMKL Procedure under elaboration: Recruiting / training and control of analytical panels. Training

of assessors.

NMKL Procedure No. 6 Yleiset ohjeet aistinvaraisten laboratorioiden laadunvarmistukseen (1998)

(General guidelines for quality assurance of sensory laboratories)

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NMKL Procedure No. 6 Generelle retningslinier for kvalitetssikring av sensoriske laboratorier

(1998) (General guidelines for quality assurance of sensory laboratories)

NMKL Procedure No. 28 Guidelines for reporting sensory data (2014)

5. Sensory evaluation of bread

5.1 Bread samples

Preparing bread samples for sensory evaluation is a challenging task. The samples are sensitive to

quality changes within a few days after baking. The process starts directly after the temperature has

gone down, and the recrystallisation of starch sets in. Storage time and conditions, and also the type

of packaging, are all critical factors for the sensory quality of bread. In sensory evaluation of bread, it

is important to ensure that all the samples maintain their freshness throughout the testing session.

The time between baking and sensory evaluation needs to be optimised. If the bread is to be evaluated

as fresh samples, one has to determine the acceptable level of freshness with preliminary tests in the

sensory laboratory. Typical questions should be: How fresh is fresh bread? When is the bread not

fresh anymore? How much is needed to have a representative sample in sensory evaluation? How can

one take into account the repeatability and the effect of different sessions?

If the bread samples are pre-cooked or “bake-off” type products, which are to be baked in the sensory

laboratory, the preparation protocol should be carried out according to the procedures recommended

by the producer. In every case, formalised preliminary tests should be carried out to ensure the proper

functioning of the oven, including stability of heat. The protocol for the presentation of bread samples

(temperature, serving, sample size and shape) should be tested before the actual analysis is carried

out.

If it is not possible to evaluate samples in the optimum time after baking, the bread samples should be

frozen before testing. In this case, it is necessary to understand the quality changes, e.g. in structure or

taste, caused by freezing. It is important to test the optimum storage time. How big are the quality

changes during storage? These changes depend on the type of bread, and the recipe from which it is

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made.

The shape of the bread samples that are served to the sensory panel needs to be standardised during

every session, if the bread samples in their intact state represent very different sizes and shapes. The

evaluated samples could be slices, strips or cubes, but they should be similar both within the same

bread type and between different testing breads. It may be necessary to remove the crust before

sensory evaluation to mask the effect of bread brand or manufacturer. It may be easy to recognise the

original bread label by seeing the whole slice, depending on the bakery, and this information may

influence the evaluation process. However, it may also be important to include the crust in testing

samples, to understand its role in critical sensory properties.

In sensory evaluation, the samples should always be presented to the assessors blind coded (e.g. with

three digit codes from random number tables or with computer programs). The order of the samples

should be randomised and balanced. The number of samples presented to the sensory panel in one

session depends on the sensory evaluation method and the type of product. However, the number of

different bread samples should not exceed 8 within one session. Depending on the sensory evaluation

protocol and the complexity of the evaluation task, even six different bread samples may be too

demanding for the senses of the assessors during one evaluation session.

5.2 Sensory evaluation method

The selection of method depends on the task and the goal of the analysis. In general, the sensory

methods in analytical sensory evaluation are divided into discrimination tests, ranking tests and

descriptive analyses. Instructions for using these methods and conditions are described in various ISO

standards (see below).

Discrimination tests (ISO 10399, ISO 4120, ISO 5495) are useful when two different bread types are

to be compared, and the differences may be small. For example, when one ingredient in a recipe

needs to be changed for some reason and the influence of this change on the sensory qualities of

bread needs to be checked. There are several different methods to be used in discrimination testing,

the most common being triangle test, duo-trio test and paired comparison test. The final result will

show if the differences between the samples are notable enough to be perceived by the senses or not.

However, a more detailed evaluation needs to be carried out if there is such a difference, to be able to

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understand its meaning and influence on consumer acceptance. The higher the number of assessors in

a discrimination test, the more reliable the result will be (Lawless and Heymann 2010).

With ranking tests (ISO 8587) it is possible to rank the samples after a named specific attribute, e.g.

based on their overall sensory quality or odour, or bitterness or sweetness.

Descriptive analysis (ISO 13299, ISO 11035, ISO 11036, ISO 11037) should be used when the goal

is to create a sensory profile of attributes, and moreover to evaluate the differences in intensities of

sensory attributes in bread samples. The sensory profile can include attributes for odour, appearance,

texture, sound and taste, taking into account all five senses. The more complex the profile is, the

more demanding the task is for the sensory assessors. In general, different sensations are divided into

details (attributes), and the intensity of each attribute is evaluated with a sensory scale. Examples of

such scales are a continuous unstructured line scale (0 = no sensation, 10 = very strong sensation), or

a categorised 9-point verbally anchored scale (1-9). If the sensory attributes are not available for

samples beforehand, they need to be created before the testing begins. The sensory attributes should

be carefully selected. The sensory panel may work on generating the descriptors for the sensory

attributes together with panel leader. For an assessor, it is important to learn and understand how to

evaluate each attribute and how to use the scale in the evaluation of the sensory attributes during the

training period before the actual sensory testing begins (ISO 5496, ISO 4121). The panel leader is

responsible for giving the right instructions on how to evaluate the attributes. For example, if there

are two different textural properties, every assessor should properly understand not only both

definitions, but also how to evaluate them in two different ways.

The panel leader is responsible for monitoring the quality of the assessors during training and

evaluation sessions. It is always helpful to use different reference samples to establish the definition

of sensory attributes and the dimensions of the attribute scale. The reference samples and their

definitions should also be available to every assessor during sensory sessions. To receive more

reliable results, it is always important to apply replicates in descriptive analysis. Every sample needs

to be evaluated at least twice by every assessor, and in a randomised order throughout the sessions.

The minimum size of a sensory panel for descriptive analysis is 8 persons. However, the optimum

number of assessors is 12-15. The duration of each sensory session depends on the sensory profile. If

the number of different attributes is high, the number of samples should be low in every session.

Sessions lasting longer than 2 hours is not recommended. The total time needed for training depends

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on the panel (e.g. their experience), the task at hand, type of samples, etc., but the main criterion is

consensus of the panel.

Sensory profiles of different types of bread samples manufactured in the Nordic countries have been

reported in many scientific publications (Kihlberg et al 2004, 2005, 2006, Heiniö 2003, Pohjanheimo

et al 2006, 2010), and a number of general lists of different sensory attributes related to bread have

been reviewed (Callejo 2011, Elia 2011, Heiniö 2007). NOTE! The attributes depend on bread type,

and the suitability of the attributes for bread samples other than those reported, should be tested

carefully before the sensory analysis. Frequently used properties are classified and reviewed in Tables

1-8.

It is also possible to use a quality scale, especially in quality control of manufacturers. A typical scale

is a 5-point scale ranging from a clear fail with major quality flaws (1) to excellent quality (5). When

using a quality scale, it is very important to understand the meaning of every single score on this

scale. The assessor needs to know the acceptable variation within each score. When does the sample

fulfil the minimum requirements for acceptable quality? Which properties should be taken into

account when measuring the quality of a specific product? As a minimum, these two questions should

be adequately answered before starting a sensory quality control testing with a new assessor. If the

product will not pass the sensory quality control, the personnel of the sensory laboratory should be

aware of the course of action in the event of failure. More information about quality control can be

found in NMKL Procedure No. 16: Sensory quality control (2005).

6. Evaluation of results and reporting

Discrimination test results only show if a difference exists; they do not indicate the direction of a

difference.

Descriptive test results are usually reported with bars or figures such as spider diagrams. Results can

include the mean evaluation of the panel together with the standard deviation (SD), ranging between

a minimum and maximum value. Showing correlations between sample and session, or session and

subject will add quality to the results. Statistical methods used are typically variance analyses

(ANOVA), principal component analyses (PCA), and applied regression methods such as preference

mapping. It is important to report the number of assessors and number of actual evaluations for each

sample and attributes. Results should show if there is difference between the samples in any of the

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evaluated attributes. More information about results can be found in NMKL Guideline No 28

Guidelines for reporting sensory data (2014) or in Sensorisk studiegruppe (“Sensory study group”)

(1997).

7. References

Callejo MS (2011) Present situation on the descriptive sensory analysis of bread, Journal of sensory

studies 26: 255-268.

EA-4/09 Accreditation for Sensory Testing Laboratories, European co-operation for Accreditation

2009

Elia M (2011) A procedure for sensory evaluation of bread: protocol developed by a trained panel.

Journal of sensory studies 26: 269-277.

Heiniö RL (2007) Sensory attributes of bakery products, in Bakery products: science and technology.

Hui Y.H. Corke H, De Leyn I, Nip WK, Cross N (eds.) Ames, Iowa, Blackwell Publishing, 285-298.

Heiniö RL (2003). Influence of processing on the flavor formation of oat and rye. VTT Publications

494.VTT Technical Research Centre of Finland.

Heiniö R.-L., Liukkonen, K.-H., Katina K., Myllymäki O. and Poutanen K. (2003). Milling

fractionation of rye produces different sensory profiles of both flour and bread. Lebensm.-Wiss. U.-

Technol. 36(5), 577-583.

Heiniö RL, Katina K, Wilhelmson A., Myllymäki O., Rajamäki T, Latva-Kala K, Liukkonen K. and

Poutanen K. (2003) Relationship between sensory perception and flavour-active volatile compounds

of germinated, sourdough fermented and native rye following the extrusion process. Lebensm.-Wiss.

U-Technol. 36(5), 533–545.

Kihlberg I. (2004). Sensory quality and consumer perception of wheat bread: Towards sustainable

production and consumption. Effects of Farming System,Year, Technology, Information and Values.

Acta Universitatis Upsaliensis. Comprehensive Summaries of Uppsala Dissertations from the Faculty

of Social Sciences 139. 86 pp Uppsala.

Kihlberg I., Johansson L., Kohler A. and Risvik E. (2004) Sensory qualities of whole wheat pan

bread – influence of farming system, milling and baking technique. J. Cereal Sci. 39(1), 67–84.

Kihlberg I., Johansson L., Langsrud Ø . and Risvik E. (2005). Effects of information on liking of

bread. Food Qual. Prefer. 16(1), 25–35.

Kihlberg I., Öström A. Johansson L. and Risvik E. (2006) Sensory qualities of plain white pan bread:

Influence of farming system, year of harvest and baking technique. J. Cereal Sci. 43(1), 15–30.

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Meilgaard MC, Carr BT, Civill GV (2006) Sensory Evaluation Techniques, 4th Edition

Lawless & Heymann (2010) Sensory evaluation of food; Principle and Practices, 2nd Edition,

Springer

Pohjanheimo T, Paasovaara R, Luomala H,

Sandell M (2010) Food choice motives and bread liking

of consumers embracing hedonistic and traditional values, Appetite, 54: 170-180.

Pohjanheimo T, Hakala M, Tahvonen R, Salminen S, Kallio H. (2006) Flaxseed in Bread-Making:

Effects on Sensory Quality, Aging and Composition of Bakery Product. J. Food Sci. 71(4):343-348.

Sensorisk studiegruppe. (1997) Sensorisk analyse – bedømmelse av nӕringsmidler.

Universitetsförlaget AS ISBN: 8213027388

Salmenkallio-Marttila M, Roininen K, Lindgren JT, Rousu J, Autio K, Lähteenmäki L (2004)

Applying machine learning methods in studying relationships between mouthfeel and microstructure

of the oat bread. J. Texture Stud. 35: 225-250.

http://www.brodinstitutet.se/allt-om-brod/brodkultur-i-sverige/

http://www.brodogkorn.no/

http://www.leipatiedotus.fi/

ISO standards published for sensory analysis

ISO 8589:2007 Sensory analysis – General guidance for the design of test rooms (EN ISO

8589:2010)

ISO 13300-1:2006 Sensory analysis – General guidance for the staff of a sensory evaluation

laboratory – Part1: Staff responsibilities

ISO 13300-2: 2006 Sensory analysis – General guidance for the staff of a sensory evaluation

laboratory – Part 2: Recruitment and training of panel leaders

ISO 8586:2012 Sensory analysis – General guidelines for the selection, training and

monitoring of selected assessors and expert sensory assessors

ISO 4121:2003 Sensory analysis – Guidelines for the use of quantitative response scales

ISO 6658:2005 Sensory analysis – Methodology – General guidance

ISO 11132:2012 Sensory analysis – Methodology – Guidelines for monitoring the

performance of a quantitative sensory panel

ISO 13301:2002 Sensory analysis – Methodology – General guidance for measuring odour,

flavor and taste detection thresholds by a three-alternative forced-choice (3-AFC) procedure

http://www.brodinstitutet.se/allt-om-brod/brodkultur-i-sverige/

http://www.leipatiedotus.fi/

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ISO 3972:2011 & ISO 3972:2011/Cor 1:2012 Sensory analysis – Methodology – Method

of investigating sensitivity of taste

ISO 5496:2006 Sensory analysis – Methodology – Initiation and training of assessors in the

detection and recognition of odours

ISO 8587:2006 Sensory analysis – Methodology – Ranking

ISO 10399:2004 Sensory analysis – Methodology – Duo-trio test (EN ISO 10399:2010)

ISO 4120:2004 Sensory analysis – Methodology – Triangle test (EN ISO 4120:2007)

ISO 5495:2005 & ISO 5495:2005/Cor1:2006 Sensory analysis – Methodology – Paired

comparison test (EN ISO 5495:2007)

ISO 13299:2003 Sensory analysis – Methodology – General guidance for establishing a

sensory profile (EN ISO 13299:2010)

ISO 11035:1994 Sensory analysis - Identification and selection of descriptors for

establishing a sensory profile by a multidimensional approach

ISO 11036:1994 Sensory analysis - Methodology - Texture profile

ISO 11037:2011 Sensory analysis – Guidelines for sensory assessment of the colour of

products

ISO 5492:2008 Sensory analysis - Vocabulary

NMKL Procedures

No. 6 (1998) General guidelines for the quality assurance of sensory laboratories (available

in Danish and Finnish)

No. 16 (2005) Sensory quality control (available in Norwegian, Finnish and English)

No. 27 (2013) Measurement uncertainty in sensory analysis (available in English and

Finnish)

No. 28 (2014) Guidelines for reporting sensory data (available in English)

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Table 1: Most common words used to describe appearance in Nordic bread.

Attribute Definition Type of

bread

Scale Ref

Appearance

Intensity of crust colour Degree of perceived

brown colour

characterising the crust

Wheat

bread

Continuous,

unstructured 10 cm long

scale (0-100)

Kihlberg et

al. 2004,

Kihlberg et

al. 2006

Colour (crumb) Scale from low:

yellow/beige, to high:

beige/grey

Wheat

bread

Continuous,


scale (0-100)

Kihlberg et

al. 2005

Colour tone (yellow/red)

(crumb)

Assessed according to

the NCS colour system,

Swedish standard

Wheat

bread

Continuous,


scale (0-100)

Kihlberg et

al. 2004

Whiteness/blackness

(crumb)

Assessed according to

the NCS colour system,

Swedish standard

Wheat

bread

Continuous,


scale (0-100)

Kihlberg et

al. 2004

Raw streak (crumb) Degree of perceived raw

dough streak at the

bottom of the loaf

Wheat

bread

Continuous,


scale (0-100)

Kihlberg et

al. 2004

Colour intensity

(crumb)

Degree of darkness in

crumb

Rye

bread

Continuous,


scale (0-10)

Heiniö et al.

2003

Colour (crust) Colour of bread crust Rye

bread

Unstructured 10 cm long

scale (0-10)

Pohjanheimo

et al. 2010

Porosity (crumb) Amount and size of

holes in sample

Rye

bread

Unstructured 10 cm long

scale (0-10)

Pohjanheimo

et al. 2010

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Table 2: Most common words used to describe appearance in other types of bread. Attribute Definition Type of

bread

Scale Ref

Appearance

Intensity of

crust colour

Degree of perceived brown colour

characterising the crust

Wheat bread continuous, unstructured

10 cm long scale (0-

100)

Elia

2011

Shininess (crust) Reflection of light on the crust Wheat bread continuous 10 cm long

scale

Elia

2011

Crookedness

(crust)

Presence of cracks on the surface

of the sample

Wheat bread continuous 10 cm long

scale

Elia

2011

Flouryness

(crust)

Quantity of flour on the surface of

the sample


scale

Elia

2011

Colour intensity

(crumb)

Intensity of colour Wheat bread continuous 10 cm long

scale

Elia

2011

Pore size

(crumb)

Size of holes in the crumb Wheat bread continuous 10 cm long

scale

Elia

2011

Pore regularity

(crumb)

Homogeneity of pores in the

crumb


scale

Elia

2011

Crust darkness Degree of colour darkness in the

crust ranging from light brown to

dark brown

Different

types of

bread

Callejo

2011

Thickness

(crust)

Thickness of crust of side part Different

types of

bread

Callejo

2011

Crumb darkness Degree of colour darkness in the

crumb ranging from white to dark

brown

Different

types of

bread

Callejo

2011

Crumb cell

number

Crumb cell number per cm2 Different

types of

bread

Callejo

2011

Crumb cell

homogeneity

Homogeneity of the size of the

crumb cells

Different

types of

bread

Callejo

2011

NMKL PROCEDURE


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Table 3: Most common words used to describe odour in Nordic bread. Attribute Definition Type of

bread

Scale Ref

Odour/Aroma

Overall

aroma

(crumb)

Degree of perceived overall

aroma of the sample

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)

Kihlberg et al. 2004,

Kihlberg et al. 2006

Wheat

(crumb)

Aroma typical of wholemeal

flour of wheat mixed with

boiling water 1:2

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)




Cereals

(crumb)

Aroma typical of cereals

(oats, rye, barley, wheat)

mixed with boiling water 1:3

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)



Whey

(crumb)

Aroma typical of whey Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)


Hay (crumb) Smell typical of fresh hay Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)


Rancid

(crumb)

Aroma typical of rancid nut

oil

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)


Earthy

(crumb)

Aroma typical of earth or raw

earthy potatoes

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)


Roasted

cereals

(crust)

Aroma typical of roasted

cereals

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)


Intensity of

odour

Perceived first impression of

odour intensity after the bread

has been opened

Rye

bread

Unstructured 10 cm

long scale (0-10)

Pohjanheimo et al. 2010

Sourness Sour odour Rye

bread

Unstructured 10 cm

long scale (0-10)

Pohjanheimo et al. 2010

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Table 4: Most common words used to describe odour in other types of bread. Attribute Definition Type of

bread

Scale Ref

Odour/Aroma

Lactic acid

(crumb and

crust)

Aroma associated with sour milk Wheat bread Continuous 10

cm long scale

Elia

2011

Butter (crumb

and crust)

Aroma associated with butter Wheat bread Continuous 10

cm long scale

Elia

2011

Lactic fat (crumb

and crust)

Aroma associated with milk fat Wheat bread Continuous 10

cm long scale

Elia

2011

Wood (crumb

and crust)

Aroma associated with dry wood Wheat bread Continuous 10

cm long scale

Elia

2011

Caramel (crumb

and crust)

Aroma associated with toasted sugar Wheat bread Continuous 10

cm long scale

Elia

2011

Smoke (crumb

and crust)

Aroma associated with dust and fire Wheat bread Continuous 10

cm long scale

Elia

2011

Mouldy (crumb

and crust)

Aroma associated with damp closed air

spaces

Wheat bread Continuous 10

cm long scale

Elia

2011

Wheat aroma Aroma typical of wholemeal flour of

wheat mixed with boiling water 1:2

Different

types of bread

Callejo

2011

Cereals Aroma typical of cereals (oats, rye,

barley, wheat) mixed with boiling water

1:3

Different

types of bread

Callejo

2011

Malty Sweet aroma typical of condensed milk,

toffee, and/or malt

Different

types of bread

Callejo

2011

Fermented Characteristic aroma of fermented

dough

Different

types of bread

Callejo

2011

Nutty Aromatic characteristics of mixed nuts,

e.g. walnuts, hazelnuts, brazil nuts and

pine nuts

Different

types of bread

Callejo

2011

Butter-like Aroma of butter with slightly rancid

overtones

Different

types of bread

Callejo

2011

Toasted (crust) Aroma associated with wheat grain that

has been roasted/burnt

Different

types of bread

Callejo

2011

NMKL PROCEDURE


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Table 5: Most common words used to describe texture in Nordic bread. Attribute Definition Type

of

bread

Scale Ref

Texture (by finger)

Compressibility

(crumb)

Resistance to moderate

pressure applied to the centre

of the slice

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)



Springiness

(crumb)

Swiftness of returning to the

initial shape after moderate

pressure applied to the centre

of the slice

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)


Deformability

(crumb)

Degree to which the sample

returns to initial shape after

moderate pressure applied to

the centre of the slice

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)




Elasticity (crumb) Response to stretching Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)



Softness (crumb) Force required to compress

sample between fingers

Rye

bread

Unstructured 10 cm

long scale (0-10)

Heiniö et al. 2003,

Pohjanheimo et al.

2010

Springiness

(crumb)

Speed with which a

compressed sample returns to

its original state after the

deforming force is removed

Rye

bread

Unstructured 10 cm

long scale (0-10)


Pohjanheimo et al.

2010

Moistness (crumb) Degree of moistness in crumb

perceived by pressing with

fingers

Rye

bread

Continuous,

unstructured 10 cm

long scale (0-10)

Heiniö et al. 2003

Texture (by mouth)

Smoothness

(crumb)

Degree of perceived

smoothness of the bread slice

surface by lips

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)


Mastication

resistance (crumb)

Degree of perceived

resistance to chewing the

sample

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)


Juiciness (crumb) Degree of perceived juiciness Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)




Compactness

(crumb)

Degree of perceived

compactness

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)


Toughness (crust) Degree of perceived

toughness of the crust

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)


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Crispiness (crust) Degree of perceived

crispiness of the crust

Wheat

bread

Continuous,

unstructured 10 cm

long scale (0-100)


Toughness

(crumb)

Amount of mastication

needed before swallowing

Rye

bread

Unstructured 10 cm

long scale (0-10)

Pohjanheimo et al.

2010

Moistness (crumb) Feeling of moisture on the cut

surface of the sample when

pressed against lips

Rye

bread

Unstructured 10 cm

long scale (0-10)


Pohjanheimo et al.

2010

Coarseness

(crumb)

Degree of coarseness of

crumb in mouth

Rye

bread

Continuous,

unstructured 10 cm

long scale (0-10)

Heiniö et al. 2003

Table 6: Most common words used to describe texture in other types of bread. Attribute Definition Type of

bread

Scale Ref

Texture (by finger)

Crumb

firmness

Resistance to crumb pressure on the

finger (this is from the original

publication)

Different

types of

bread

Callejo

2011

Tactile

elasticity

Ability of the sample to return to starting

position after compression

Different

types of

bread

Callejo

2011

Texture (by mouth)

Mastication

resistance

(crumb)

Degree of perceived resistance to

chewing the sample

Wheat bread Continuous,

unstructured 10 cm

long scale (0-100)

Elia

2011

Crustiness

(crumb)

Noise made by the first bite of the

sample between the molars

Wheat bread Continuous 10 cm

long scale

Elia

2011

Hardness

(crumb)

Force required by first bite through the

sample with the molars


long scale

Elia

2011

Elasticity

(crumb)

Sample recovery after the first bite Wheat bread Continuous 10 cm

long scale

Elia

2011

Friability

(crumb)

Ease with which the sample is broken

into smaller particles during chewing


long scale

Elia

2011

Graininess

(crumb)

Size of the particles once the sample has

been masticated until disintegrated and

then formed to a homogenous bolus


long scale

Elia

2011

Doughy

(crumb)

Pasty feeling (flour and water) which is

perceived in the mouth during chewing


long scale

Elia

2011

Mouth

residue

(crumb)

Amount of residual particles attached to

the mouth after chewing


long scale

Elia

2011

Toughness

(crust)

Degree of perceived toughness of the

crust

Wheat bread Continuous,

unstructured 10 cm

Elia

2011

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long scale (0-100)

Crustiness

(crust)

Noise made by the first bite of the

sample between the molars


long scale

Elia

2011

Hardness

(crust)

Force required by first bite through the

sample with the molars


long scale

Elia

2011

Elasticity

(crust)

Sample recovery after the first bite Wheat bread Continuous 10 cm

long scale

Elia

2011

Friability

(crust)

Ease with which the sample is broken

into smaller particles during chewing


long scale

Elia

2011

Moistness of

bread crumb

Amount of saliva secreted in the oral

cavity during sample chewing

Different

types of

bread

Callejo

2011

Adhesiveness Analysis after compression between the

tongue and palate; degree to which the

product adheres to the palate

Different

types of

bread

Callejo

2011

Cohesiveness Extent to which a material can be

deformed before it ruptures

Different

types of

bread

Callejo

2011

Crust

crispiness

Degree of perceived crispiness of the

crust

Different

types of

bread

Callejo

2011

NMKL PROCEDURE


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Table 7: Most common words used to describe flavour in Nordic bread. Attribute Definition Type of

bread

Scale Ref

Flavour

Sweetness

(crumb)

Degree of perceived sweet taste, as

a basic taste

wheat

bread

continuous,

unstructured 10-cm

long scale (0-100)


Saltiness

(crumb)

Degree of perceived salty taste, as

a basic taste

wheat

bread

continuous,

unstructured 10-cm

long scale (0-100)


Sour (crumb) Flavour typical of sour milk wheat

bread

continuous,

unstructured 10-cm

long scale (0-100)


Cereals

(crumb)

Taste typical of cereals (oats, rye,

barley, wheat) mixed in hot water

1:3

wheat

bread

continuous,

unstructured 10-cm

long scale (0-100)

Kihlberg et al.

2004, Kihlberg et

al. 2005

Wheat

(crumb)

Flavour typical of wheat kernel

mixed with boiling water 1:2 and

left overnight

wheat

bread

continuous,

unstructured 10-cm

long scale (0-100)

Kihlberg et al.

2005, Kihlberg et

al. 2006

Nuts (crumb) Taste typical of freshly ground

hazelnuts

wheat

bread

continuous,

unstructured 10-cm

long scale (0-100)


Earthy

(crumb)

Flavour typical of raw beetroots wheat

bread

continuous,

unstructured 10-cm

long scale (0-100)


Rancid

(crumb)

Flavour typical of rancid nut oil wheat

bread

continuous,

unstructured 10-cm

long scale (0-100)


Astringent

(crumb)

Dry feeling in the mouth with a

coarse puckering of the oral tissue

typical of old carrot, strong tea,

unripe banana

wheat

bread

continuous,

unstructured 10-cm

long scale (0-100)


Overall

flavour

(crumb)

Degree of perceived intensity of

overall flavour, after chewing the

sample

wheat

bread

continuous,

unstructured 10-cm

long scale (0-100)


Aftertaste

(crumb)


aftertaste, after chewing the sample

wheat

bread

continuous,

unstructured 10-cm

long scale (0-100)


Aftertaste

(crust)



wheat

bread

continuous,

unstructured 10-cm

long scale (0-100)


Flavour

intensity

(crust)

Intensity of overall flavour in crust rye

bread

continuous,

unstructured 10-cm

long scale (0-10)

Heiniö et al. 2003

Brownness

(crust)

Intensity of browned flavour after

biting into a crust piece before

rye

bread

unstructured 10-cm

long scale (0-10)

Pohjanheimo et al.

2010

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swallowing

Flavour

intensity

(crumb)

Intensity of overall flavour in

crumb

rye

bread

continuous,

unstructured 10-cm

long scale (0-10)

Heiniö et al. 2003

Intensity

(crumb)

Perceived impression of flavour

intensity in mouth after chewing

rye

bread

unstructured 10-cm

long scale (0-10)

Pohjanheimo et al.

2010

Sourness

(crumb)

Sour taste, evaluated after

swallowing

rye

bread

unstructured 10-cm

long scale (0-10)

Pohjanheimo et al.

2010

Bitterness

(crumb)

Degree of bitter taste in crumb rye

bread

continuous,

unstructured 10-cm

long scale (0-10)

Heiniö et al. 2003

Rye (crumb) Intensity of rye flavour after

swallowing

rye

bread

unstructured 10-cm

long scale (0-10)

Pohjanheimo et al.

2010

Freshness

(crumb)

Degree of fresh flavour in crumb rye

bread

continuous,

unstructured 10-cm

long scale (0-10)

Heiniö et al. 2003

Cereal flavour

(crumb)

Degree of rye-like flavour in

crumb

rye

bread

continuous,

unstructured 10-cm

long scale (0-10)

Heiniö et al. 2003

Aftertaste

intensity

(crumb)

Flavour of crumb staying after

tasting

rye

bread

continuous,

unstructured 10-cm

long scale (0-10)

Heiniö et al. 2003

NMKL PROCEDURE


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Table 8: Most common words used to describe flavour in other types of bread. Attribute Definition Type of

bread

Scale Ref

Flavor/Flavour

Toasted (crust) Aroma associated with toasted notes wheat bread continuous 10-cm long

scale

Elia

2011

Sweetness

(crumb)

Degree of perceived sweet taste, as a

basic taste

wheat bread continuous,

unstructured 10-cm

long scale (0-100)

Elia

2011

Saltiness

(crumb)

Degree of perceived salty taste, as a

basic taste


unstructured 10-cm

long scale (0-100)

Elia

2011

Sour (crumb) Flavour typical of sour milk wheat bread continuous,

unstructured 10-cm

long scale (0-100)

Elia

2011

Bitter (crumb) Bitter basic taste wheat bread continuous 10-cm long

scale

Elia

2011

Straw (crumb) General taste associated with fields of

ripe cereals

wheat bread continuous 10-cm long

scale

Elia

2011

Toasted (crumb) Aroma associated with toasted notes wheat bread continuous 10-cm long

scale

Elia

2011

Pungent (crumb) Itchy trigeminal sensation on the tip

of the tongue

wheat bread continuous 10-cm long

scale

Elia

2011

Yeasty (crumb) Fermented, yeast-like flavour wheat bread continuous 10-cm long

scale

Elia

2011

Oily (crumb) Overall flavour of oil wheat bread continuous 10-cm long

scale

Elia

2011

Overall flavour

(crumb)


overall flavour, after chewing the

sample


unstructured 10-cm

long scale (0-100)

Elia

2011

Aftertaste

(crumb)




unstructured 10-cm

long scale (0-100)

Elia

2011

Sweetness Having or denoting the characteristic

taste of sugar. Standard solution:

sucrose 16 g/L

different

types of

bread

Callejo

2011

Saltiness Perception of salinity. Standard

solution: sodium chloride 5 g/L

different

types of

bread

Callejo

2011

Sourness Degree of sour (odour and) taste different

types of

bread

Callejo

2011

Wheaty Flavour typical of wheat kernel

mixed with boiling water 1:2 and left

overnight

different

types of

bread

Callejo

2011

Whole bread Taste typical of bread made with different Callejo

NMKL PROCEDURE


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wheat and whole wheat flour, and/or

wheat fiber, and/or wheat bran

types of

bread

2011

Malty Aromatic sensation that produces a

taste or smell reminiscent of toasted

grains

different

types of

bread

Callejo

2011

Rye Characteristic aroma of rye flour different

types of

bread

Callejo

2011

Roasted flavour Degree of roasted/burnt odour and

taste of bread crust

different

types of

bread

Callejo

2011

Nutty Taste typical of freshly ground

hazelnuts

different

types of

bread

Callejo

2011

Yeasty Flavour associated with natural yeast

as a leavening agent

different

types of

bread

Callejo

2011

Intensity of

pungent flavour

(crumb)

Degree of pungent (sour, vinegar-

like) odour and taste of bread crumb

different

types of

bread

Callejo

2011

guidelines for sensory evaluation of bread - …nmkl.org/dokumenter/prosedyrer/en/proc31eng.pdf ·...

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