Principles of Sensory Science
Clips
Sensory evaluation
Position of sensory science:
Food science and technology is a analytical aspect of sensory science. Marketing and consumer
behavior is an psychological aspect of sensory science. Nutrition and health focuses more on biology
of sensory science.
Definition: “Sensory evaluation has been defined as a scientific method used to evoke, measure,
analyze and interpret those responses to products as perceived through the sense of sight, smell,
touch, taste and hearing.
The basic test methods:
Class Question Type of test Panel
Discrimination Are products Analytic Screened or trained
different? (n=10-12)
Descriptive How do products Analytic, more Screened or trained
differ? descriptive (n=25-40)
Affective How well are products Hedonic Screened for product
liked? use, untrained (n=75-
150)
Analytical sensory tests
- Intensity, amount, duration
- Strong control over the product and environment, high internal validity often done in
testing booths
- Reliability, sensitivity
- Few subjects, many samples
Hedonic sensory tests
- Predictive of real life
- As a whole, integrated instead of a few sips or bites
, - Weaker control, high external validity
- Many subjects, few samples otherwise the participants will get distracted
Why collect sensory data
- Food industry
o Taste, smell, texture, vision determine liking
o Liking is the most important determinant of choice
o Not possible to measure instrumentally
- Research and public health
o Sensory signals play major role in food intake
o Increase acceptability of healthy foods
o Low fat/sugar maintaining good taste!
Food perception
Psychophysics and psychohedonics
Psychophysics: relation between the physical, chemical properties of a food and the perception of it
by a panelist. Analytical field or research
Psychohedonics: physico-chemical properties and the pleasantness/liking of a product.
Psychophysics
Psychophysics: the higher a concentration of something the higher the perceived intensity. This
relationship is linear on a logarithmic scale.
Psychohedonics
,The relation between a concentration and liking has a bliss point, the concentration that is most
liked. For beverages this is found at a 10% amount of sugar for the overall population. However,
there are individual differences.
Individual differences in perception
- Age, gender, satiation, etc.
- Thresholds
- Suprathreshold sensitivity
- Identification ability
- Liking/preferences
Replication and reliability
- Order effect: fatigue may arise. So, samples presented later will be rated differently than
those rated in the beginning
- Frame of reference: when first given a high concentration and then a low concentration. The
second sample will be rated differently than when that sample was given first.
Introduction to descriptive analysis
Definition
A method aiming to provide a quantitative measure of the sensory properties of a set of products.
Sensory properties are also often called sensory attributes, can be sight, taste, etc.
Applications
Food industry
- Product reformulations
- New product development
- Quality control
o Acceptability to target
o Calibration of instruments
- Brand mapping
- Consumer preference mapping
Research
- Understanding relationships:
o Product/process/production properties
o Perceptible properties
, Adaption, mixtures and suppression
Adaption – smell
Continuous exposure adaption
E.g. after a while you won’t notice the perfume that you put on in the morning
Adaption – taste
- Adaption: when the perceived intensity decrease with continued exposure
- Cross adaption
(De)sensitization – trigeminal system
- (Cross)sensitization/desensitization depending on:
o Time-course stimulation
o Frequency stimulation
- In a short period of time: sensitized for the feeling (e.g. chewing on a chili pepper for a short
period of time). However continuously eating this will cause desensitization.
Zingerone: stinging part of ginger
Mixtures – smell
Difficult to detect individual components: coffee is not one odorant in itself. Makes it difficult to
detect the separate components.
Intensity suppression:
