Workshop #2: Sensory Food Assessment, Herbs and Spices Familiarization Flashcards
Define sensory evaluation.
Scientific discipline used to evoke, measure, analyse and interpret reactions to those characteristics of foods and materials as they are perceived by the senses of sight, smell, taste, touch and hearing.
What does food evaluation evaluate?
- Appearance
- Texture
- Flavour
Define mouth feel.
Composite of tactile stimulation, temperature and pain
What does flavour involve?
Taste, odour, mouthfeel
Which sense is the most influential?
Sight
Which sense decrease with age? Why?
The ability to taste, due to an increase in detection threshold for taste and smell
Define detection threshold.
The point at which a person can sense that a solution is different than water
Why is it important to taste concentrations from low to high, rather than high to low?
Because of adaptation of taste receptors
What factors must be considered when conducting a taste panel?
- Taste panelists must be chosen carefully
- Food samples must be presented in an environment that would not influence the panelists’ sensory evaluation
- The appropriate tests need to be chose
- The results must be analyzed to determine statistical significations
Name the 3 tests commonly used in taste panels.
1) Preference and acceptance tests
2) Difference/Discriminative tests
3) Descriptive tests
Which type of test requires many panelists?
Preference and acceptance tests
Name the 3 preference and acceptance tests and explain them.
1) Comparative (which sample is preferred)
2) Monadic (rank liking on a standard scale of 5 or 9 points)
3) Consumer Ranking Tests
Name the 4 types of difference/discriminative tests.
1) Paired comparison
2) Triangle
3) Duo-trio
4) Ranking tests
What are difference/discriminative tests used for?
To determine whether or not a difference can be detected between samples
Describe duo-trio tests.
- Employs 3 samples
- Two are the same and one is different
- One sample is designated as the reference and is presented first
- Out of the other two samples, only ONE is the same as the first presented
What is the probability of selecting the correct sample by chance in the duo-trio test?
50%
What is the probability of selecting the correct sample by chance in the triangle test?
1/3
What is the probability of selecting the correct sample by chance in the paired comparison test?
50%
Describe the triangle test.
- 3 samples
- Two are the same, one is different
- NO SAMPLE as reference
- Panelist has to determine which of the 3 is different
Describe the paired comparison test.
- 2 samples
- Panelist has to determine which sample has the greater amount of a particular characteristic
The ranking test is an extension of which test?
Paired comparison
Why are samples numbered with different 3-digit codes?
To control for bias
Define texture.
The sensory manifestation of the structure of foods and is perceived by the skin and muscles of the lips, tongue, mouth, jaw and throat.
Name the 3 classes of textural characteristics.
1) Mechanical
2) Geometrical
3) Others.
Define mechanical characteristics (texture).
Characteristics related to the reaction of food to stress (hardness, viscosity, elasticity, brittleness, chewiness, gumminess)
Define geometrical characteristics (texture).
Characteristics related to the arrangement of physical constituents of a food product (size, shape, orientation, arrangement of particles in a food)
Define other characteristics (texture).
Properties related to the moisture and fat content of a food product
Which characteristic of texture is the most important in determining the manner in which the food handles and behaves in the mouth?
Mechanical
Name the 5 primary parameters of mechanical characteristics.
1) Hardness
2) Cohesiveness
3) Viscosity
4) Elasticity
5) Adhesiveness
What is adhesiveness related to?
Surface properties
What are hardness, cohesiveness, viscosity and elasticity related to?
Forces of attraction acting between particles of food and opposing disintegration
Name the 3 secondary parameters of mechanical characteristics.
1) Fracturability
2) Chewiness
3) Gumminess
Define hardness.
The force required to compress a substance between the molar teeth (for solids) or between the tongue and palate (for semi-solids) to a given deformation or to penetration
Define cohesiveness.
The extent to which a material can be deformed before it ruptures
Define viscosity.
The rate of flow per unit force
Define elasticity.
The rate of which a deformed material goes back to its undeformed condition after the deforming force is removed
Define adhesiveness.
The work necessary to overcome the attractive forces between the surface of the food and the surface of other materials with which the food comes in contact
Define fracturability.
The force with which a material crumbles, cracks or shatters: the horizontal force with which the fragments move away from the point where the vertical force is applied.
Fracturability is a product of what?
high degree of hardness and low degree of cohesiveness
Define chewiness.
The length of time or the number of chews required to masticate a solid food to a state ready for swallowing.
Chewiness is a product of what?
Hardness, cohesiveness and elasticity
Define gumminess.
The energy required to disintegrate a semi-solid food to a state ready for swallowing: a denseness that persists throughout mastication
Gumminess is a product of what?
Low degree of hardness and a high degree of cohesiveness
What is another word for elasticity?
Springiness
How do you evaluate mechanical characteristics?
It is both qualitative and quantitive
What has been devised to provide a defined, quantitative method of texture evaluation?
Standard rating scales, which encompass the entire range of textural characteristics in foods
Name the 3 factors considered when selecting foods to be used as standards.
1) Major brands of good quality control
2) Products requiring minimum amount of preparation to eliminate recipe variables
3) Products that do not change radically with small temperature variations
How do you measure hardness for solids?
Place food between the molar teeth and bite down evenly
How do you measure hardness for semi-solids?
Compressing the food against the palate with the tongue
What are the ranges of the hardness scale?
Soft, Firm, Hard
Name the 3 components of the fracturability scale.
1) Crumbly
2) Crunchy
3) Brittle
Define crumbly samples.
Low resistance to force (low hardness) and very low deformation before fracturing (low cohesiveness)
Define crunchy samples.
Fairly high resistance to force (moderate hardness) and very low deformation before fracturing (low cohesiveness)
Define brittle samples.
Very high resistance to force (high hardness) and very low deformation before fracturing (low cohesiveness)
Why is it best to rinse the mouth with water prior to each adhesiveness evaluation?
Since the amount of saliva in the mouth affects the degree of adhesiveness
How many points does the viscosity scale contain?
6
Name some popular terms of the viscosity scale.
Thin, watery, very thick
How many points does the chewiness scale contain?
3
Name the popular terms of the chewiness scale.
Tender, Chewy, Tough
How is the degree of chewiness measured?
Average number of chews required to masticate
What test is used to determine the detection threshold?
Dilution tests
Which test is descriptive?
Paired comparison
