Card Set Information
what is sensory analysis?
identification, sci measurement, analysis, interpretation of a product as it is percieved by the 5 senses
List the 5 senosry attribute of food products
visual, olfactory, kinaesthetic (tactile), gustatory, auditory
Could the multi-dimentional stimulus and human nerve system be imitated by machine?
No, this is why knowledge of sensory evaluation is important
why is it that human sense sensitivities hard to control?
they are variable over time and prone to bias
what is the role of the human in sensory analysis
the analyst instrument
what is the best model to predict consumer acceptance and food product consumption in real conditions
what makes sensory evaluation unique?
hard to describe, humans as analysis instrument, many variables that must be controlled to reduce error/ bias
list the uses of sensory evaluation
specification and quality control; shelf life studies; taint potential; product matching; product reformation; product mapping; product acceptability
what other fields does sensory evaluation directly tie in with?
market research, packaging/design, product research
what is the difference between olfactory and gustatory attribute?
olfactory is smell, gustatory is taste
what is the chain of sensory perception?
1)stimulus 2)sensation 3) perception 4) response
which organs do the stimulation part takes place at?
sense organ (nose, tongue, fingers, etc.)
where do the most part of the chain of sensory perception take place at?
color is a phenomena that involves both physical and psychological components, what is the wavelenght of blue, green, and red lights of the visible spectrum
400-500 nm for blue; 500-600 nm for green-yellow; 600-800 nm for red
what are the three characteristics of color?
hue, saturation, brightness
what is hue?
the degree at which a stimulus could be described as similar or different to red, green, blue, or yellow
what is saturation?
percieved intensity of a colour
What is brightness?
list three other visual attributes and give examples
size and shape - dimensions (l,w,h); surface texture - dull or shiny, rough or even, etc; clarity - haze, opacity, any particles?
Classify carbonation in volumes to their respective degree of effervescent
<=1,5 - no degree; 1,5-2,0 - light; 2-3 - medium; 3-4 - high
order these drinks in based on their degree of effervescent (ascending):beer/cider, fruit drinks, soft drinks/champagne, still drinks
still drinks - fruit drinks - beer/cider - soft drinks/champagne
What is the order of light being accepted into the eyes
light - lens - vitrous humor - focusing by lens - retina/receptor - nerve impulse (optical) - impression/response
what consists of the receptors?
rod and cone cells
what are rod cells?
detect weak light and no colour, 115 million cells
what are cone cells?
detect strong light, color, 6.5 million cells
what are three factos that impact color/visual evaluation?
lighting; decoration; size/form
what are the types of lighting that could influence color/visual evaluation
type and uniformity; free from shadow; daylight (it changes); normal conditions of consumer testing
what is flavor and what does it includes?
impression percieved via chem senses from a product in the mouth and includes aromatics; taste; chem feeling factor
what cause aromatics?
olfactory perception due to volatile substances being released from the product to the posterior nares
What cause taste?
Gustatory perception (sweet, salty, sour, bitter) - soluble substance in the mouth
Give examples of chemical feeling factor
astringency, spice heat, cooling, metallic flavor, bite, umami
what is chemical feeling factor
(look it up)
volatile substence detected thourgh nasal cavity and percieved by olfactory system
what is the difference between aroma and fragrance?
arome is for food; fragrance is for perfume or cosmetics
what is the difference between orthonasal and retronasal
orthonasal - volatil compound from food to nose through sniffing; retronasal - volatile compound from food by eating food (from mouth)
what are the factors of the amount of volatile compounds that escape?
temperature/ nature of product; surface condition
assuming the temperature is the same, which surface condition will be better to allow volatile compounds to escape?
soft, porous and humid surface
what is an odor?
an ezimatically reaction
how many odorous compounds are known and how much can an EXPERT perfumer differentiate?
17.000 known; can diff 150-200
what are the factos that impact sensitivty to smell?
1)hunger/ satisfaction; 2)mood; 3)concentration; 4)respitory infection; 5) menstruation cycle and pregnancy for women
Draw the area of taste receptors in the tongue!
How does tasting actually work? And look up taste buds
where does sweet taste come from?
sugars, proteins and other substances connected to ALDEHYDES and KETONES - both have CARBONYL GROUPS
What receptors detect sweetness?
G protein receptors coupled to G protein gusducin
What needs to be activated in order for the brain to activate sweetness?
Different variants of sweetness receptors
what tastes could a G-protein receptor coupled to the G-protein gusducin sense?
sweetness and bitter
what is the avg threshold of sucrose and lactose?
10 mM and 30mM
which sweet compuond has an average threshold of 2 μM?
What causes bitter taste and is there a reason why?
alkaloids (basic stuff) and it is thought to be an evolutionary response to toxins which are bitter
What causes umami taste?
Glutamate and its derivatives (MSG, IMP, 5'GMP)
where is umami taste found in?
aged foods like cheese
What increase the taste of umami?
Give two examples of cheeses that give umami taste
roquefurt and parmesan
list examples of unfermented umami tasting foods
nuts, brocolli, tomato, meat, grapes, walnuts, mushrooms (MEMORIZE)
What is sinergis effect in umami and what causes it?
when MSG, IMP, and 5GMP work together and enhances the exisiting taste of umami in food
what does glutamate bind to in stimulus and taste mechanism?
G protein coupled glutamate receptors
list the factors that affect sensitivity of taste
adaptation and fatigue; genetic; smoking
what is cross adaptation?
exposure to one taste substance have an adapting effect
what is the adapting effect?
causing a decrease in intensity of a second substance
what must be the same in full cross adaptation?
the decrease must be the same with exposre
what must be dome to claim no cross adaptation?
a test substance must have an intensity equivalent to its taste after a plain water adaptation
what is cross potentiation?
(look it up)