Sensory Evaluation Flashcards
What are sensory evaluations?
a scientific discipline that applies to principles of experimental design and statistical analysis to the use of human senses for the purpose of evaluating consumer products
sensory modes:
sight, odour/smell, taste, touch, sound
what does sight depend on?
size, shape, and colour primarily but also consistency, defects, and viscosity
which is the most important factor in food evaluations?
sight
what is one factor colour has been shown to influence even when there is no difference?
taste perception
what first detects odour?
olfactory epithelium
through what actions is odour detected?
sighing, swallowing, exhaling
How is odour detected?
volatile molecules make contact with the olfactory receptors which transmit electric impulses to to the brain, via the olfactory bulb
what is the name of the condition where total or partial sense of smell is lost? what causes it?
anosmia
head injury, infection, or blockage
what are the three methods of how to classify smells?
6 groups, 4 groups, or 2 groups
what are the group names for the 6 group classification of smells?
spicy, flowery, fruity, resinous, burnt, and foul
what are the group names for the 4 group classification of smells?
fragrant, acidic, burnt, and caprylic
what are the group names for the 2 group classification of smells?
inedible and edible
how do we sense taste?
substance is dissolved in saliva and seeps into the taste buds which initiate nerve impulses to the brain
What parts of the body sense taste?
papillae, upper esophagus, soft palate, cheek, and epiglottis
how long does it take taste buds to die and regenerate?
2 weeks
how many taste buds do humans have and what are the exceptions to this?
~10 000
smokers, elderly, super tasters
what are the categories of taste?
bitter, sweet, sour, salty, umami
what is the taste threshold?
concentration of taste needed to elicit a taste response
primary tastes ___ sense with equal ease, what does sensing them depend on?
are not
time, concentration, texture, temperature
flavour = ___ + ___
taste/aroma
what factors affect taste?
genetics, age, sex, degree of hunger, temperature of food, colour of food, time of day, medications
adding salt to food does what?
decreases sour or bitter tastes and enhances sweet
adding sweetener to food does what?
decreases sour, bitter, and salt tastes
What is touch?
the tactile characteristics of food determined by shape, form, and feel (things which cause kinetic sensations)
What are feelings of resistance from food detected by? what are the assessed by?
nerves
mouth, tongue, and jaw
What are the characteristics of touch?
texture, consistency, astringency, chemesthesis, and temperature
mouthfeel
a products physical and chemical interaction in the mouth
What is sound used to determine?
freshness based on the presence or lack of crunch/crispness
What perceptions are changed by enriching the colour of milk?
higher fat, smoother texture, increased flavour
what are the two categories of sensory tests?
analytical and affective
What are the two types of analytical tests?
discriminative and descriptive
What are the two categories of affective tests?
hedonic and personal preference
What are the two categories of discriminative tests?
difference and sensitivity
what are the two categories of descriptive tests?
flavour and texture
analytical tests:
used to detect differences, usually done by smaller groups of people
affective tests:
acceptance/preference tests, usually individual results
discriminative tests:
used to detect discernible differences
difference tests:
differentiate between samples
sensitivity tests:
detect flavour threshold
descriptive tests:
used to quantify differences
flavour profile:
used to detect specific flavours
texture profile:
used to detect specific textures
hedonic tests:
related to pleasure, ranked on a scale for various characteristics
personal preference:
select the preferred sample
Duo-trio test:
a difference test, three samples are presented with one being the standard, tester is asked which matches the standard (50% chance of guessing correctly)
Triangle test:
a difference test, three samples are presented together and the tester is asked to identify which two are the same (33% chance of guessing correctly), not good for strong samples
Paired comparison test:
a difference test, two samples are presented and the tester is asked which has more of a certain characteristic (50% chance of guessing correctly), doesn’t indicate extent of difference
threshold test:
a sensitivity test to determine the smallest amount of detectable solution (tasted low to high)
dilution test:
a sensitivity test to determine the smallest amount of test material detected when mixed with another material
