Lecture 1-sensory evaluation Flashcards
What is the defintion of Sensory Evaluation?
It is the scientific discipline that is used to measure, evaluate and interpret reactions to characteristics of food perceived by the 5 senses
What are the purposes of sensory evaluation? (6)
Evaluate the property of specific food ingredients alone or within a product
Quality control
Population specific product development
Evalution of differences and similarities between food products
Determine consumer acceptability of new food products
Evaluation of effectiveness of food modifications of products
What are factors that affect sensory perception and evaluation and give examples/ explain (8)
Environment-room, serving containers
Product attributes-color(red=sweeter), brand, packaging, cutlery
Microbes-more exposure the more we like it like chocolate
Demography/culture
Mood/emotions
Diease
Age
Gentic factors-polymorphisms
What are the 6 steps for the procedure of a sensory evaluation?
Define the scope/objectives of the sensory evaluation
Screen and select the samples for the evaluation
Select the evaluation method that best tests the project objectives
Select the test subjects based on the method chosen
Conduct evaluation in a controlled environment
Collect, analyze and report data
What are the 5 parameters to be aware of when conducting an evaluation and give a brief description of each.
Visual: pacakge/product appearance
Taste: sensation when food interacts with tatse receptors in mouth
Touch: product feel/texture
Smell: product smell/aroma when consumed
Sound: when consumed
What are important things to consider when chosing subjects:
If they will be trained or not by ASTM/ISO
Follow guidelines like volunteer, no conflict of interest, good sensory acuity, no allergies or anything that affects taste or smell, average users of product, can provide repeatble descriptions
What are the types of sensory evalutions?
Analytical methods (product oriented)
Discriminative method
Directional
Non directional
- non directional
Descriptive method
Affective methods (people oriented)
Paired preferance
9 point hedonic scale
Just about right scale
Likert scale
Describe the 3 discriminitive methods, (analytical).
Directional
-paired comparison test to see if the 2 samples are precitabily different, normally used to evaluate new/improved product
Non-directional
-traingle test/3 sample test
-asked to see which sample is different from the 2
2 non-directional
-duo-trio test/3 sample test
-one is reference and asked to say which is similar
ANALYTICAL METHOD: describe the descriptive method
-describe the differences and magintude of differences between products to see why consumers prefer one over the other
-Use the QDA scale and QDA spider plot to report findings
-use small trained number of subjects
AFFECTIVE METHODS: describe paired preference
-subjecrs are instructed to taste 2 samples one after another and then say which one they like using a score card
AFFECTIVE METHODS : describe 9 point hedonic scale
-subjects taste a product and select from scale the option that best represents their liking
-statements are converted to numerical values
AFFECTIVE METHODS : describe just about right scale
-presented as a 3-point/ 5-point scale
-mainly done by Profesionales
-hard to interpret
AFFECTIVE METHODS: describe likert scale /agree/disagree scale
- used in large scale consumer testing
What is the most used palate cleanser and what are other ones?
-water and crackers
-milk for spicy foods or foods with garlic -warm water for oily foods -bread and apples
