1. SENSORY EVALUATION

2. 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

3. THE CHEMICAL SENSES
SIGHT- VISION
TASTE - GUSTATION
SMELL - OLFACTION

4. MECHANICAL SENSES TOUCH - TACTILE SENSES HEARING - SOUND
KINESTHESIS - MOTION
EQUILIBRIUM - BALANCE

5. OTHER FACTORS Social and Family Cultural Religious beliefs
Nutrition and Health
Economic and Marketplace factors
Technological developments
Emotional and psychological factors

6. SIGHT - VISION Creates first impression Visual appeal - attractiveness
Used to judge quality - ripeness, freshness, concentration, defects, extent of cooking

7. VISUAL PROPERTIES OF FOOD
Color
Transparency or opaqueness
Dullness or gloss
Size
Shape
Amount
Defects, decay, infestation

8. 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

9. FIVE TASTES
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

10. 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

11. EFFECT OF SUB-THRESHOLD SUBSTANCES
Salt Increases sweet, decreases sour
SourIncreases salty, decreases sweet
SweetDecreases salt, decreases bitter

12. 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 F

13. 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)

14. OLFACTORY - SMELL Ability to detect chemicals dissolved in air
Aroma impacts on taste
Don’t taste greasy, chocolate, mint – smell, mouthfeel, or combination

15. TEXTURE - TACTILE Qualities felt with fingers, tongue, palate, teeth
Index of quality
Smoothness, stickiness, graininess
Crispness, crunch

16. 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

17. SENSORY TESTING
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
DESCRIPTIVE TESTS

18. DIFFERENCE TESTS 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

19. ACCEPTANCE/PREFERENCE
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

20. DESCRIPTIVE TESTS Trained panelists Difference between products
Highly specialized tests

21. ANALYTICAL EVALUATION
Uses equipment
Sprectrophotometer - color
Consistometer - consistency
Viscometer-viscosity

22. 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