Module.
1 Sensory evaluation…
Lesson-2
Factors Affecting Food Acceptance and Terminology Related to Sensory
Evaluation
2.1 INTRODUCTION
Acceptance of any Dairy/food products is based on, food attributes , sensory
perception, personal attitudes and human physiology, , the manner of serving, decor, social
grouping, cultural patterns, climatic conditions, consumer's psychology etc. Food acceptance
is regulated by
(1) Characteristics of the dairy/ food products.
These include
a. Purity & Safety
b. Convenience
c. Functional Properties
d. Nutritional Value
(2) Environmental surroundings
(3) Established Food Habits
(4) Intra- organic chemical conditions that may / may not be related to metabolic process.
Food preference, food choice and food habits are important terms which have
relationship with food acceptance. Food preference is particular food/s an individual likes or
dislikes, food choice is foods selected by an individual at a given time whereas food habits
are the sum of the food choices of an individual, constituting total diet. Food habits are
constantly changing because of increasing awareness towards nutrition, food safety and social
values.
2.2 FACTORS AFFECTING FOOD HABITS
The major factors affecting the dairy/food products habits are
1 Country and geography
2 Social values
3 Cultural patterns and religion
4 Groups of income and size of the family
5 Occupational groups
6 Age groups, anxiety, food as gratification of love
7 Emotions on food habits (taboos)
Factors affecting food acceptance and terminology related to sensory evaluation
8 Climate, specific environment - social psychology
9 Availability of food
10 Method of preparation & serving
11 Media Promulgation – radio, paper, TV
12 Personal aspirations & identifications
13 Education
14 Racial & moral prejudices
Our senses particularly taste & smell, are intimately associated with food habits and
have influence upon food selection & food habits. The ''eating quality'' of a food includes all
those sensations such as feel, taste & smell, experience by the consumer when the product is
taken in the mouth.
2.3.GENERAL TERMS RELATED TO SENSORY EVALUATION OF DAIRY
PRODUCTS
Today Sensory analysis of foods is gaining importance all over the world as it
provides information which helps in product improvement, quality maintenance, new product
development and analysis of market. In sensory evaluation, words and concepts serve as units
and means of communicating the results. The value of sensory test depends on terminology
which are used to reproduce and communicate the results. Different terms used in sensory
evaluation are described below
Absolute : A psychophysical method to estimate the absolute intensity of a
Judgment stimulus or a categorical judgment based on an observer's
experience. It does not include any external standard stimulus.
Acceptance : An experience or feature of experience characterized by a
positive (approaching a pleasant) attitude or Actual utilization
(Purchase, eating) may be measured by preference or liking for
specific food item. Both are not the same although, the two
definitions are often highly correlated.
Acuity : Ability to discern or perceive stimuli: sharpness or acuteness.
Adaptation : Loss of or change in sensitivity or response to a given stimulus
as a result of continuous exposure to that stimulus or a similar
Factors affecting food acceptance and terminology related to sensory evaluation
one.
Adequate stimulus : Normal stimulus sufficient to elicit a response from a given
sense.
Affective : Acceptance or avoidance responses. Hedonic scales measure
Response affective responses, that is, degree of pleasantness.
After – Taste : The experience which, under certain conditions, follows the
removal of a taste stimulus; it may be continuous with the
primary experience or may follow as a different quality after a
period, during which swallowing, saliva, dilution and other
influences may have affected the stimulus substances. (a) After
sensation, Negative After - image or after - taste in which the
qualities are complements of those originally and normally
induced by the stimulus. (b) After sensation, Positive After
image or after taste in which the qualities are the same as those
originally and normally induced by the stimulus.
Ageusia : It is a gustation abnormality which relates the lack or
impairment of sensitivity to taste stimuli.
Anesthesia : It is an olfactory abnormality which relates temporary
impairment of senses of smell and taste.
Anosmia : It is an olfactory abnormality which relates lack or impairment
of sensitivity to odor stimuli. i.e. temporary/ permanent loss of
smelling capacity.
Ante taste : A prior taste, or foretaste, usually of short duration, preceding
the main taste or flavour characteristics.
Appearance : The visual properties of a dairy/food products, including size,
shape, colour and conformation.
Appetite : Desire or inclination for anything, but more especially for food.
Factors affecting food acceptance and terminology related to sensory evaluation
Aroma : Sum of olfactory impression derived from the volatile
substances of a food product. Differs from odor in the respect
that many of these substances are first released through
chewing, warmth of the mouth, etc. and only then contribute to
the sensation via the throat - nose - duct.
Attribute : Classification of individual units as acceptable or unacceptable.
Autosmia : It is a olfactory abnormality which relates the odor sensation in
absence of odor stimuli.
Aversion : Dislike and avoidance of a of a stimulus; repugnance; antipathy
Body : The quality of a dairy/food products relating variously to their
consistency, compactness of texture, fullness, or richness.
Chewy : Tending to remain in the mouth without readily breaking up. or
dissolving. Requiring mastication.
Chroma : One of the three terms used in the Munsell notations to denote
colour referring to the saturation, or purity dimension.
Comparative : Direct Evaluation of one stimulus with another relative to a
Judgment specified dimension, such as intensity or degree of liking.
Compensation : The result of interaction of the components in a mixture of
stimuli in which each component is perceived as less intense
than it would be alone.
Composite : A method for evaluating quality of a product where specific
Scoring quality characteristics of a product are rated separately. The
rating scale is weighed for the individual quality characteristics
in relation to the relative importance of the individual
characteristics to the overall quality. Resulting scores are
Factors affecting food acceptance and terminology related to sensory evaluation
compounded for any one panelist to arrive at a composite score.
Conditioned : A response, which comes to be elicited by an originally neutral
Response stimulus, as a result of previous learning.
Confidence : A range of values, which has a given probability (usually 0.95
Interval or 0.99) of including the true value of the quality attribute being
(Statistical) rated.
Contrast : Juxtaposition of two different sensations which result in
intensifying or emphasizing their contrary characteristics. It may
be of two types (a) simultaneous or (b) successive.
Contrast Effect : A judgmental phenomenon which appears in evaluation of food
samples of different preference levels or quality, where the
presentation of one sample tends to make a following sample of
the opposite quality rate either higher or lower than it would if
they had been rated independently.
Cooling : A physical sensation in the mouth resulting from the presence of
a cold liquid or solid. Also a result of chemical action (menthol)
sensed by the skin.
Critical : Refers to a defect of most serious kind. In foods, it is usually
reserved for defects which may cause the food to be injurious to
health. Tolerance for critical defects is practically zero.
Dilution Index : Basically the method involves the determination of the
identification threshold for the material under study. The
dilution index is expressed in % dilution or as a ratio. The
dilution of 1% mean that the material was just identifiable when
made up in a 1% solution.
Discrimination : a) Perception of difference between two or more objects in
respect to certain characteristics. b) A differential response to
stimuli which differ quantitatively or qualitatively.
Factors affecting food acceptance and terminology related to sensory evaluation
Disguising : A testing method wherein various increments of a flavouring
Potential compound are added to a substance (usually distasteful) to mask
or disguise its sensory properties.
Evaluation Card : Wording questions used on semantic, sociological and
psychological aspects to obtain the information desired from the
penal
Expert : Generally, an individual acknowledged to be experienced and
skillful in a special practice in the food and beverage field, a
specialist with special powers of discrimination sensitivity and
perspicacity, who usually confines his diagnostic judgment to a
specific product under specific conditions.
Fatigue : Condition of organs or organisms which have undergone
excessive activity with resulting loss of power or capacity to
respond to stimulation.
Flavour : Total of sensory sensations perceived at the entrance of the
alimentary and respiratory tract, consequently mainly sum of
odour and taste, sometimes coupled with warmth, cold and mild
pain.
Flavouring : Any substance, such as an essence or extract, employed to give a
particular flavour.
Flavour Memory : As used in descriptive sensory analysis, an ability to recognize
and identify many individual odours and flavours.
Flavour Profile : A method of qualitative descriptive analysis of aroma and
Technique flavour. The method makes it possible to indicate degree of
difference between two samples on the basis of individual
character notes, the degree of blending and the overall
impression of the product.
Factors affecting food acceptance and terminology related to sensory evaluation
Forced Judgment : A reaction required by an experiment in which ''don't know'', or
other indeterminate answers are not permitted.
Fragrant : A pleasing olfactory quality, odours which are distinctly
pleasant smelling.
Grading : Sorting of products according to size or quality.
Gust : A unit of gustatory intensity relating to the threshold of a given
substance.
Gustation : The process of tasting.
Haptic : Pertaining to the skin or the sense of touch in its broadest sense.
Hedonic : Pertaining to pleasurable or unpleasurable experiences.
Inadequate : When a reaction is obtained by the application of energy which
Stimulus is not 'normal' to the sense system involved (such as an electrical
current applied to the tongue producing a taste), the non-normal
stimulus is termed inadequate.
Intensity : A quantitative attribute of a sensation approximately
proportional to the intensity of physical energy of the stimulus,
such as brightness of colours, loudness of sounds, and
concentration of taste or odour compounds.
Intensity Scale : Scaling method consisting of numbers of terms used to denote
the strength of a medium.
Interaction : A measure of the extent to which the effect of changing the level
of one factor depends on the level(s) of another or others.
Iso-hedonic : Equality in degree of pleasantness and unpleasantness.
Factors affecting food acceptance and terminology related to sensory evaluation
Judge : Examiner with some experience and / or training regarding the
test problem.
Just Noticeable : The smallest detectable difference between two stimuli.
Difference (JND)
Kinesthetics : Referring to the sense of feel by means of the mouth or fingers.
Masking : In taste, odour, or flavour application, it is a component quality
within a mixture which dominates or over - rides another quality
or other quality present, thus changing the quality of the
perceived resultant without benefit of chemical interaction of the
components themselves.
Matching : The process of equating or relating, pair by pair, for
experimental purposes, usually to determine the degree of the
similarity between a standard and an unknown, or two
unknowns.
Merosmia : A condition analogous to colour blindness in which odour are
not perceived.
MID : Minimum identifiable difference; difference threshold.
Mouthfeel : The original experience deriving from the sensations of the skin
in the mouth during and / or after ingestion of a good or
beverage. It relates to density, viscosity, surface tension and
other physical properties of the material being sampled.
Multiple : An unlimited number (usually more than three) of samples are
Comparison presented to the observer simultaneously in random arrangement
or in accordance with a predetermined statistical design.
Significance of result is usually calculated by the variance
method, or a rapid approximation thereof.
Factors affecting food acceptance and terminology related to sensory evaluation
Multiple Range : A test employing different significance values depending upon
Test the number of means being compared.
Objective : a) Capable of being recorded by physical instruments or as a
consequence of a repeatable operation. b) Not dependent upon
the observations and reports of an individual, and thus verifiable
by others.
Observer : One participating in a test, whose primary attention is directed
towards judge's response.
Odorant : A substance which stimulates the olfactory receptors.
Odour : Impression derived by smelling or sniffing. Positive hedonic
sensation (pleasing) is ''fragrance''. Negative hedonic sensation
(offensive) is ''stink''.
Olfactometer : An instrument for controlled presentation of odour stimuli, used
for measuring threshold and other quantitative values.
Olfactory : The smallest volume of vapour of a substance necessary for
Coefficient identification of its odour.
Organoleptic : Of the intrinsic quality of food which has an effect on the
senses.
Paired Preference : Paired comparison method using the preference criterion.
Palatable : Pleasing to the taste, and hence, acceptable.
Panel : A group of people (observers, subjects, judges) comprising a
test population, which has been specially selected or have
special knowledge or skills, or may merely be available and pre-
designated. a) Close Panel When judges work in individual
Factors affecting food acceptance and terminology related to sensory evaluation
booths and communication between them is forbidden. b) Open
Panel When judges sit and work in view of each other, even
perhaps commenting aloud and comparing notes.
Preference : (a) Expression of higher degree of liking. (b) Choice of one
object relative to other, (c) Psychological continuum of
affectivity (pleasantness - unpleasantness) on which such
choices are based. This continuum is also referred to as that of
degree of liking or disliking.
Primary Qualities : Within a specific sense, those qualities which are considered
basic and from which it is possible to compound all other
qualities. For example, salt, sweet, bitter and sour are primary
taste qualities.
Psychophysics : The study of the physical relations between stimulus variables
and psychological measures of sensory variables.
Psychophysical : A group of specific procedures used in psychophysical
Methods investigation.
Quality : (a) An aspect, attributes, characteristics, or fundamental
dimension of experience, which involves variation in kind rather
than in degree, (b) The composite of those characteristics that
differentiate among individual units of a product and have
significance in determining the degree of acceptability of that
unit by the user, (c) An aesthetic standard for a product usually
set by experienced users.
Rank order : A psychometric method that may be used in multiple
(Ranking) comparisons where the subject considers all of the samples in a
series at the same time and is required to rank them in order of
some designated dimension; such as preference, intensity and
quality.
Factors affecting food acceptance and terminology related to sensory evaluation
Rating Scale : A method for securing and recording a judgment concerning the
degree to which a stimulus material possesses a specific
attribute, for example, by placing a mark at an appropriate
position between the two extremes or a line that represents the
possible range of degrees of the attribute.
Reaction : In the behavioral sciences, action in response to known or
inferred stimulation.
Score : (a) Noun: A value assigned to specific response made to a test
item
(b) Verb: To rate the properties of a food on a scale or according
to some numerically defined set of criteria.
Screening : Pre-testing of possible samples, techniques of judges.
Sensitivity : Acuity; ability to perceive quantitative and / or qualitative
difference.
Sensory : Pertaining to the action of the sense organs.
Sequential : A procedure in which the sample number is not fixed in advance
Analysis but depends to some extent on the outcome of the sampling as it
proceeds.
Series effect : A tendency to over or underestimate a stimulus according to its
magnitude in relation to the series as a whole.
Method of Single : Any psychophysical or psychometric method in which a
Stimulus judgment follows the presentation of one stimulus only.
Smell : To perceive by excitation of the olfactory nerves.
Sniff : To evaluate an odor by drawing air audibly and abruptly through
nose.
Factors affecting food acceptance and terminology related to sensory evaluation
Sorting : A generic term for sensory tests that requires splitting of a
number of coded samples into a specified number of designated
subgroups: sorting involves both discrimination and matching
and in some cases ranking.
Standard : A sample presented as a model or example. The standard sample
conforms to a specified level or degree of quality.
Stimulus : That which excites a sense organ.
Subject : One participating in a test whose primary attention is directed
towards the samples.
Subjective : Pertaining to individual experience.
Subliminal : Blow the threshold; applied to stimuli which are not sufficiently
intense to arouse definite sensations but which, nevertheless,
have some effect upon the responses of the individual.
Supraliminal : Above the threshold, either absolute threshold or difference
threshold. See also subliminal.
Texture : Impression made by certain soluble substances in the mouth.
Salty, sour, sweet and bitter are basic tastes (a) Taste Inhibitor
Substance which renders taste organs less able to perceive
delicate taste reactions, (b) Taste Sensitizer Substance which
conditions the taste organs for keener perception.
Threshold : A statistically determined point on the stimulus scale at which
occurs a transition in a series of sensations or judgments.
Thresholds are of four kinds (a) Relative Threshold (RL) of
sensation, stimulus threshold, or absolute threshold, is that
magnitude of stimulus at which a transition occurs from no
sensation to sensation, (b) The Difference Threshold (DL) is the
least amount of change of a given stimulus necessary to produce
Factors affecting food acceptance and terminology related to sensory evaluation
a noticeable change in sensation, and the interval or units is
known as JND (Just Noticeable Difference). (c) Recognition or
identification threshold is that magnitude of stimulus necessary
for correct identification, (d) Terminal threshold is that
magnitude of a stimulus above which there is no increase in the
perceived intensity of the appropriate quality for the stimulus.
Time - Intensity : Measurement of the rate duration and intensity of stimulation by
Test a single stimulus.
Whiffing : A short, quick sniffing procedure.
Factors affecting food acceptance and terminology related to sensory evaluation
QUESTIONS
1. The process of tasting is known as
A. Olfaction
B. Gustation
C. Perception
D. Adoption
2. Just noticeable difference means
A. The smallest detectable difference between two stimuli
B. The detectable difference between two stimuli
C. The smallest detectable difference among more than two stimuli
D. The optimum detectable difference between two stimuli
3. The term Ageusia means
A. A gustation abnormality which relates blindness of taste stimuli
B A gustation abnormality which relates to lack of or impairment of sensitivity to
taste stimuli
C A gustation abnormality which relates to lack of or impairment of sensitivity to odour
stimuli
D A olfaction abnormality which relates to lack of impairment of sensitivity to touch
stimuli
4. Olfactometer is used for
A Measuring taste abnormality and other quantitative values
B Measuring reaction time and other quantitative values
C Measuring rheological properties and other quantitative values
D Measuring odour threshold and other quantitative values
5. Merosmia is a condition analogous to
A Colour blindness in which tastes are not perceived.
B Colour blindness in which colour are not perceived.
C Odour Colour blindness in which specific odours are not perceived.
D Taste blindness in which colour are not perceived.
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