SENSORY EVALUATION
SENSORY EVALUATION
Sensory - having to do with the
senses of sight, taste, smell, hearing,
touch - judgment of quality based on
sensory data
 Organolepsis - subject to judgment
by the senses
 Senses - the means of receiving all
information
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THE CHEMICAL SENSES
SIGHT- VISION
 TASTE - GUSTATION
 SMELL - OLFACTION
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MECHANICAL SENSES
TOUCH - TACTILE SENSES
 HEARING - SOUND
 KINESTHESIS - MOTION
 EQUILIBRIUM - BALANCE
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OTHER FACTORS
Social and Family
 Cultural
 Religious beliefs
 Nutrition and Health
 Economic and Marketplace factors
 Technological developments
 Emotional and psychological factors
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SIGHT - VISION
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Creates first impression
Visual appeal - attractiveness
Used to judge quality - ripeness,
freshness, concentration, defects,
extent of cooking
VISUAL PROPERTIES OF
FOOD
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Color
Transparency or opaqueness
Dullness or gloss
Size
Shape
Amount
Defects, decay, infestation
TASTE
Detects water soluble chemicals
 Tongue - taste “buds” located in
the papillae
 Substance must be dissolved in
water or saliva
 Flavor – combination of taste and
odor – complex mixture
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FIVE TASTES
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Sweet - Due to alcohol (OH) groups, detected
quickly, on the tip of tongue
Salty-Sodium ion modified by Chloride,
detected quickly, on tip of tongue
Sour-Acid, due to hydrogen ions, detected on
side of tongue
Bitter-taste buds at back of tongue
Umami-savory, glutamate that occurs
naturally in food. Some examples of these
foods are parmesan cheese, bacon bits, soy
sauce, meat, ketchup, from flavor enhancers
such as MSG
TASTE SENSITIVITY
Taste affected by other stimuli
 Time: Location of taste buds
 Threshold-Concentration required for
substance identification
 Sub-threshold-Substance not
identified, but will affect perception of
another taste
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EFFECT OF SUB-THRESHOLD
SUBSTANCES
Salt Increases sweet, decreases
sour
 SourIncreases salty, decreases
sweet
 SweetDecreases salt, decreases
bitter
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TEMPERATURE AND TASTE
Affects flavor, warm foods taste
stronger and sweeter than cold foods
 Salt stronger in warm foods
 Volatility of substances increase at
warm temperatures, so they smell
stronger-pungency
 Taste buds most receptive at
temperatures between 68-860F
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PSYCHOLOGICAL FACTORS
Flavor perceptions based on color,
color intensity, texture
(thickness)
 General health and well-being
 Time of day
 Adaptation-Previous exposure to
substance, especially salt tastes
(salt and resalt foods)
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OLFACTORY - SMELL
Ability to detect chemicals dissolved
in air
 Aroma impacts on taste
 Don’t taste greasy, chocolate, mint –
smell, mouthfeel, or combination
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TEXTURE - TACTILE
Qualities felt with fingers,
tongue, palate, teeth
 Index of quality
 Smoothness, stickiness,
graininess
 Crispness, crunch
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TASTE AND AGE
Varies over the lifespan
 Highest taste sensitivity occurs in
babies
 Number of taste cells in humans
declines with age
 Serious decline in taste cell numbers
begins ~45 y.o.
 By 70 greatly lowered ability to taste
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SENSORY TESTING
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Analytical -Laboratory evaluation,
used in early stages of product
development, objective evaluation
Affective - Consumer evaluation to
measure acceptance and preference
DIFFERENCE TESTS
ACCEPTANCE/PREFERENCE TESTS
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DESCRIPTIVE TESTS
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DIFFERENCE TESTS
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Determine perceivable difference between
products
Changing ingredients or source of
ingredient
Check quality of product over time
Check shelf life of a product
Triangle test-three samples, two alike,
determine the odd sample
Duo-trio test- match the reference product
ACCEPTANCE/PREFERENCE
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Paired Preference-choose preferred item
Ranking-rank preference
Rating Absolute Judgment
Hedonic – measures how much liked or
disliked
Food Action – would you eat or buy
DESCRIPTIVE TESTS
Trained panelists
 Difference between products
 Highly specialized tests
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ANALYTICAL EVALUATION
Uses equipment
 Sprectrophotometer - color
 Consistometer - consistency
 Viscometer-viscosity
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COMPARING SUBJECTIVE &
OBJECTIVE EVALUATIONS
Subjective/sensory
 Uses individuals
 Involves human
sensory organs
 Results may be
variable
 Determines human
sensitivity
 Determines customer
acceptance
 Time consuming,
expensive
 Essential for product
development
Objective analysis
 Uses equipment
 Uses physical,
chemical techniques
 Results are
repeatable
 Need to find
technique appropriate
for food
 Cannot determine
consumer acceptance
 Faster, cheaper, more
efficient
 Essential for routine
quality control