Midterm Flashcards

Question

Sweet, umami, bitter * Requires _____ __ _____ coupled receptors (GPCR

Answer 1

Type II G-Protein Taste 1 receptor family (TAS1) – Taste 2 receptor family TAS2) – Sweet: 2 subtypes of type 1 - TAS1R2, TAS1R3 – Umami: 2 subtypes of type 1- TAS1R1, TAS1R3 – Bitter: 25 subtypes of type 2

Answer 2

This activates G-protein coupled receptor (GPCR) which initiates release of gustducin. which causes various compounds to release and thus releases ATP which then activates receptors on nerve fibres that leads to taste perception

Answer 3

Cation and anion Sodium chloride is the salt taste we recognize as salty

Answer 4

- An influx of cations (Na+) through sodium channels in taste cell membranes – Anions (Cl-) modulate the taste quality – The larger the anion (eg acetate vs chloride), the lower the saltiness perception

Answer 5

Strong acids (compounds with an H+) enter taste cells through a proton-elective ion channel – Cause cell depolarization and neurotransmitter release

Answer 6

Ligand – long chain fatty acids – Eg - linoleic acid and oleic acid * Challenges understanding fat taste because Fat has a smell – need to wear nose clips so odour isn’t a factor – Fat has a texture – made in emulsions so that texture isn’t a factor

Answer 7

Ageusia – “bitter blindness” is most common – Worst is taste blindness for all tastes * Could be: – Hypoageusia – Hyperageusia * Dysgeusia/Parageusia

Answer 8

Smell Very powerful and sensitive sense – 10,000 different compounds can be differentiated based on aroma * Strong memory link – Tip of the tongue phenomena

Answer 9

Warning, Attraction, It Evokes strong emotions due to previous experience

Answer 10

Odour compounds enter the nose – Retronasally – Orthonasally * Make contact with the olfactory epithelium * In the epithelium are neurons and receptors on cilia embedded in mucus * Receptors have specifically shaped proteins that bind with specific odour molecules * Leads to neuronal activation

Answer 11

Aproximately 400 and all 400 receptor responds to several odorants – Each receptor is encoded by a different gene – Every person has a different genetic makeup for odour sensitivity (unless you have an identical twin)

Answer 12

Anosmia (cold, mucus build up) * Hyposmia - high * Hyperosmia - low * Parosmia - altered

Answer 13

Burn Sensitivity to direct chemical stimulation of touch, pain and thermal receptors in the skin and mucous membranes Could be: * Irritation, pungency, cooling, warmth or burning * In mouth chemesthetic perception is due to stimulation of the trigeminal nerve. Large differences in eating enjoyment of spicy food among the population – Desensitization – a reduction/loss in sensitivity to a chemical irritant – Due to frequent exposure to the irritant – Desensitization occurs after the stimulation has stopped and can last for up to a day – People who eat a lot of spicy food appear to build up tolerances over time – probably due to the amount of spicy food they eat

Answer 14

- Desensitization – a reduction/loss in sensitivity to a chemical irritant – Due to frequent exposure to the irritant – Desensitization occurs after the stimulation has stopped and can last for up to a day – People who eat a lot of spicy food appear to build up tolerances over time – probably due to the amount of spicy food they eat

Answer 15

Need to combine all sensory processes together – Odour + Taste + Chemesthesis * Odour is a significant contributor – Precisely how much is not clear

Answer 16

- Individual variation Within an individual – time of day/interactions with other foods (demographics) - Experimental protocols Amount of oral cavity exposed Training of subjects - Choice of compound like sucrose vs aspartame or citric vs tartaric acid - method of rating Magnitude estimation vs visual analogue scale vs labelled magnitude scale

Answer 17

genetic testing The bitter receptor gene Homozygous - AA,PP or Heterozygous - PA sensory testing - Test sensitivity to PROP or PTC

Answer 18

- More fungiform papillae that are larger than a regular tasters tongue - Have PP or PA gene - Experience more chemical irritation (burn is strong) - Typically smoke and drink less than non-tasters - Bitterness is strong Fischer things that supertasters tend to be tall and lean while non are soft, round and fat

Answer 19

Genetic influences are modified by age (kids prefer carbonated drinks over milk or water when they have that bitter receptor genotype If you have the bitter receptor genotype, as you age, you seem to lose ability to detect bitter

Answer 20

Exposure to different flavours (breastmilk, amniotic fluid) may explain individual differences in food acceptability later in life

Answer 21

Female smokers – higher sucrose thresholds Maybe because: * Poor oral hygiene * Nicotine inhibits gustatory neural pathways * Maybe it’s not related to smoking but related to other factors * PROP sensitivity – smokers are more likely to be PROP sensitive therefore different in sucrose thresholds No clear answer but we know it does impact

Answer 22

Sweet, salt, and bitter taste also impact their olfaction

Answer 23

People who did not vape liked vanillin odour more than those who vaped Maybe due to sensory specific satiety for people who vape (vape users typically choose sweet vape flavours)

Answer 24

Yes, a test was done, testing for PROP, quinine, citric acid, sucrose and sodium chloride infused on filter paper, and DM2 patients showed identification impairment in salt taste and smell recognition. Those who were impaired showed higher fasting blood glucose levels (suggesting a possible relationship between glycemic levels and impairment in smell and taste.

Answer 25

Sweet taste intensity, sensitivity, and preference were increased by acute physical exercise, but sweet preference was reduced by chronic physical activity. Salty taste - perceived intensity and sensitivity decreased but an increased preference was noted during/following exercise. Sour taste intensity ratings were decreased following exercise and preference was enhanced. Umami taste intensity and sensitivity increased following exercise and preference was decreased. No significant results were obtained for bitter taste.

Answer 26

Running affects nasal air flow and saliva because they increase in the beginning then decrease causing perception change. Sweet, fruit sweet, floral and fresh decrease over time and sour, salty and astringent increase over time

Answer 27

describing food and its tastes/flavours used for beer, wine, olive oil, and bottled water.

Answer 28

Adaptation which is common in odours and tastes causes a decrease in responsiveness under conditions of constant stimulation Mixture interactions (occur with both tastes and odours) this can be due to suppression and enhancement

Answer 29

Oral physiological interactions and cognitive interactions

Answer 30

One compound interferes with the receptor cells or with taste transduction mechanism of another compound * Example - sodium salts and bitterness or sucrose and sodium chloride Like adding sugar to watermelon to bring out sweetness

Answer 31

* Mixture suppression - when two or more taste stimuli are mixed together, the perceived intensity is less than the sum of the individual taste intensities * Example – sweet and bitter Like adding sugar to bitter coffee

Answer 32

This is called a binary solution and there's a low medium and high intensity which can be impacted and Taste perception in binary solutions varies depending on intensity

Answer 33

1. Visual 2. Initial ingestion – first bite 3. Incision and repeated chewing – mastication 4. Swallowing 5. After “mouthfeel”

Answer 34

* Visual * Auditory * Tactile

Answer 35

* Air conduction * Bone conduction (fizz of soda)

Answer 36

* Astringency * Cooling * Burning

Answer 37

* Creaminess * Viscosity * Sticky

Answer 38

Dry puckering-like sensation in the mouth due to shrinking, drawing or puckering of the oral epithelium following consumption of polyphenolic compounds * Due to aggregation and precipitation of salivary proteins (mucins) when interacting with polyphenols * Polyphenols are found in: * Plant based products * Tea (tannins) * Whey protein * Red wine * Alum

Answer 39

* Due to the trigeminal system * Most well known compound for cooling is menthol * Activates both the olfactory region (it smells minty) and the trigeminal system (it is cooling and may also be painful) * When combined with xylitol you have sweetness and cooling (they are often together in chewing gum

Answer 40

* Also due to the trigeminal system * The most common compound is capsaicin

Answer 41

Texture is a sensory property that is based on food structure * Manifests itself with applied force * Forms the basis of the texture profile analysis (TPA) * Geometrical properties: * Size, shape orientation of particles * Mechanical properties: * Response to applied force * “Other” properties * Fat and moisture

Answer 42

texture profile analysis instrument 2- bite compression tested (most famous) tests how food breaks in mouth People use figure 8 when chewing and jaw comes up the machine goes down and uses same pressure every time which humans don't do

Answer 43

* Hardness * Cohesiveness - sticks to itself * Viscosity * Springiness * Adhesiveness - sticks to you

Answer 44

* Chewy * (hard x cohesive x springy) * Gummy * (hard x cohesive

Answer 45

1. Stimulus error 2. Logical error 3. Expectation error 4. Error of habituation 5. Halo effect 6. Order of presentation of samples 7. Mutual suggestion

Answer 46

Irrelevant criteria are used to assist with the evaluation (ie, packaging) Minimize by: * Blind tasting * Avoid external cues (nothing impacting the evaluation)

Answer 47

When 2 or more characteristics of the sample are associated in the minds of the panelist Minimize by: Masking any differences – serve in coloured glasses, serve under red light

Answer 48

Expectation error : Panelists expect what they are looking for (know what to look for) Error of habituation: You habituate your response (goes down) Minimize by Providing no details about samples Randomizing samples mixed ingredient lists

Answer 49

Halo effect – One positive attribute affects all others (if something is bad then everything is bad about that product) “Horns” effect – If a negative characteristic is evaluated, it will influence other attributes in a negative direction

Answer 50

– Pretesting the number of questions asked – Make sure you use the correct type of panel for the evaluation of products

Answer 51

Biases that may occur * Idiosyncratic scale use * Error of central tendency * Contrast effect (comparing and making decisions based on first sample)

Answer 52

Panelists respond to others around them Minimize by: * Separate sensory testing booths * Discouraging facial expressions and vocalizing of opinions

Answer 53

– Labelled with a 3-digit code – Randomized during presentation – All packaging/identifiers removed – Served under red light if required – Tested in sensory booths with people distanced from others

Answer 54

* Randomization – samples are evaluated by each person in a random order (not as good as cb) * Counterbalanced – each serving sequence occurs an equal number of times during testing

Answer 55

Completely randomized designs (CRD) * Samples are randomized across subjects – Randomized complete block designs (RCBD) * Samples are randomized across subjects within a block (every person sees each sample but only once, used for trained samples)

Answer 56

– Waiting area/room – Neutral colours – Positive air pressure (no smell in booth) – Temp of 20-22C, 50-55% humidity – Standardized illumination

Answer 57

- You want to make a healthier product but not lose customers. - You want to change ingredients (maybe you found a cheaper supplier) and you don’t want people to notice a difference. - You want to change production lines. - You want to change packaging.

Answer 58

simple difference – Only tells you if there is a difference, not what the difference is

Answer 59

directional difference – Does the product differ in X? which is sweeter, which is more lemony??

Answer 60

Simple difference test You present 3 samples where 2 are of the same products and one is a different product and you need to find which one is different. (would test around 60-70 ppl) 6 orders randomly presented to panelists like (aba, aab, abb, bab, bba, baa)

Answer 61

Simple difference test There are 3 samples and 1 same is a reference and then 2 test samples. The panellist has to match one test sample to the reference sample. 1st way to do this is always to use 1 sample as a reference making a constant ref test 2nd way is to use both samples as references making balanced reference test samples 1 and 2 always randomized

Answer 62

triangle duo and trio

Answer 63

Simple difference test It's a duo trio with two references so two references and two samples making the probability of guessing 50 % (matching test

Answer 64

Simple difference test Two samples that don't have obvious differences is useful when product differences are small. each panellist get 4 samples and you have to group them into two groups count a number of correct responses and find statistical differences

Answer 65

Simple difference test “gold standard” product that you want to compare other samples. - Before the session, familiarize panellists with sample “A” and sample “not A” - Panelists are presented only one sample at a time

Answer 66

Simple difference test Panelsts get 2 samples and have to indicate if they are different, useful when they are strongly flavoured.

Answer 67

attribute test Find difference between samples and how intense the difference Ie, which is sweeter analysis involves Conducting an ANOVA to determine if there is a significant difference between the samples

Answer 68

attribute test How do two samples differ in a specific characteristic? – For determining attribute differences between two samples just two samples and circle what is sweeter

Answer 69

attribute test Three samples and given as a triangle test but they determine specific attributes and only differ in that attribute ie, which is sweeter

Answer 70

Everyone can smell and taste at a certain level. if she sprays something some can pick it up others cant same for taste. Below a certain threshold people can't detect or taste and above a certain one people can

Answer 71

Detection (also known as absolute): Below this point, there is no sensation and above this point you perceive something * Recognition (important) * Terminal: point at which perception does not increase minimum amount needed to notice diff * Difference: the minimal amount needed to produce a noticeable increase in the sensation

Answer 72

* Aromas * Tastes * Flavours * In: – Water – Oil – Wine – Whatever you are interested in studying

Answer 73

To determine how groups of individuals perceive different odours/flavours/tastes – Health – Age – Gender * To compare to instrumental assessments * To measure taints in foods * To identify the compounds that are most contributing to a flavour

Answer 74

1. Method of limits (method of least noticeable difference, method of minimal changes, method of serial exploration) 2. Method of average error (method of adjustment)

Answer 75

Error of anticipation

Answer 76

– Fatigue/adaptation occurs – Error of habituation can also occur

Answer 77

have 2 (2AFC) or 3 (3AFC)

Answer 78

* Categorical – Nominal – Ordinal * Continuous – Interval – Ratio

Answer 79

Observations fall into groups – Groups are NOT related – independent – You are identifying or classifying an object – Data is qualitative – Example: Question: Are you happy today? Response options: Yes, No, I don’t know

Answer 80

Count the frequency of responses. * The easiest way to analyze the frequencies is to conduct at χ2 analysis. * This will tell you if there are significant differences between the groups. * After that the analysis can sometimes get complicated

Answer 81

– Observations fall into groups * Can identify the “order” that something appears * But can’t tell the magnitude of the difference * Data is quantitative

Answer 82

Used with one or more products * Can be used for intensity and like/dislike responses * Simple * well suited to consumers * Speed and accuracy of data coding and tabulation (when data tabulated manually

Answer 83

* You only know which sample is more (or less) of an attribute * You do not know anything about attribute intensity

Answer 84

either interval or ratio scales * Observations that are measured along a continuum * These scales provide the most comprehensive information of all scales used in sensory testing * You get an understanding of the order of the differences as well as the magnitude of the differences

Answer 85

Used with one or more products * Can be used for intensity and like/dislike responses * Relatively simple for people to understand how to use

Answer 86

The number of alternative responses is limited. * Labels or integers may be biased to subjects. * Tendency to distribute their judgments along most of the scale range or avoid the end categories.

Answer 87

Advantages * Panelists create their own scale * No endpoint bias * Can be used for intensity and like/dislike responses Disadvantages * The data needs to be normalized to get rid of outliers * Hard to explain to panellists * Cannot be used for children

Answer 88

trained panel has line scale consumer uses hedonic scale

Midterm Flashcards

(114 cards)