Sensory Evaluation Flashcards
Define sensory evaluation.
Sensory evaluation is a scientific discipline that applies principles of experimental design and statistical analysis to the use of human senses (sight, smell, taste, touch and hearing) for the purposes of evaluating consumer products.
Name some food selection criteria.
Appearance, odor/smell, taste, texture, sound, flavor
Name some food selection influences.
Sensory, nutritional, cultural, religious, psychological, sociological, budgetary
Name the 6 sensory aspects of food.
1) Sight
2) Odor
3) Touch
4) Taste
5) Sound
6) Flavour
Which sensory aspect of food MAY be the most important?
Sight
How is smell detected?
Volatile molecules are detected by the olfactory epithelium, which sends a signal to the olfactory bulb
Explain how smell is classified into groups.
They can be classified into 6, 4, or 2 groups.
Sometimes they overlap
Group 2: inedible vs. edible
Group 4: fragrant, burnt, acid, caprylic
Group 6: spicy, flowery, fruity, resinous, burnt, foul
How often do taste buds die and are regenerated?
Every 2 weeks
How many taste buds do humans have?
10 000, elderly and smokers have less
Name the 6 taste sensations.
1) Sweet
2) Salty
3) Sour
4) Bitter
5) Savoury
6) Oleogustus
Define taste threshold.
Concentration necessary to elicit a taste response.
How is the sweet taste sensation detected?
Chemical configuration of sweet molecules
How is the salty taste sensation detected?
Ionized salts
How is the sour taste sensation detected?
Acids in foods
How is the bitter taste sensation detected?
Certain compounds in foods
How is the savoury taste sensation detected?
Glutamate
How is the oleogustus taste sensation detected?
Fatty acids
Name some factors affecting taste.
Genetics, age, sex, degree of hunger, temperature of food, color of food, time of day, medications
How is touch detected?
Feeling of resistance to motion detected by nerves.
What is touch assessed by?
Assessed by mouth, tongue and jaw.
Name the 4 factors affecting touch
Texture
Consistency
Astringency
Chemesthesis
What is flavour composed of?
Aroma and mouthfeel
What is aroma?
Odor + taste
What is mouthfeel?
The way the foods feel in the mouth
Give an example of how our senses can be deceived.
The color of milk may result in perceiving it as: higher in fat
Compare sensory and objective tests.
Sensory: with people
Objective: physical and chemical tastes
Name some examples of sensory evaluations.
Difference tests, preference tests, acceptability tests
What are the food selection sensory modes?
- Sight
- Odour
- Taste
- Touch
- Sound
What is colour derived from?
- Radiant from object
- Receptor (retina) of the eye
- impulse in the optic nerve initiated when light bleaches pigment rhodopsin (vitamin A essential for its synthesis.)
- Brain
Where is the olfactory epithelium?
Upper part of the nasal cavity
What is anosmia?
Lack of ability to smell
How is taste sensed? What needs to happen?
- Sensed by taste buds
- Needs to be dissolved in liquid or saliva to seep into the taste bud to evoke a nerve impulse to the brain
What are sensory tests?
- Analytical (effective) tests
- Affective (acceptance or preference) tests
What are objective tests?
Physical and chemical
Do difference tests require trained or untrained consumers?
Trained evaluators or untrained consumers, depending on the goal
What are the two types of food evaluation?
Sensory (subjective) and objective tests
What are the two types of sensory tests?
- Analytical (differences)
- Affective (preference
Name 2 affective tests
Hedonic (9-point) and personal preference
Name the 2 types of analytical tests.
Discriminative and descriptive
Name 2 sensitivity tests.
Threshold and dilution
Name difference tests.
triangle, duo-trio, paired comparison, ranking, ordinal
Is nutrient analysis a chemical test or physical test? What about shortometer?
Physical: shortometer
Chemical: nutrient analysis
What tests measures the consistency of batters and other viscous foods?
Line-spread test
In what analytical sensory test is a tester asked to find the minimal detectable level of a substance?
Dilution
A food evaluation in which panelists responses range from “like extremely” to “dislike extremely” is best described as a ___ test.
Hedonic test
Which chemical test evaluates the degree of unsaturation in fats?
Iodine value test
What method is used to determine the protein, fat and carbohydrate content of foods?
Proximate analysis
What is the difference between threshold and dilution tests?
Threshold: increasing or decreasing concentrations until the substance can be recognized or not recognized
Dilution: find the smallest amount of test material detected when it is mixed with a standard material
