WVIT 442 Sensory Evaluation

What is the general aromatic descriptor of esters

Fruity

1) During our labs, many of the students have perceived in and out a certain level of spritziness (or fizziness if you want) on certain wines. What is the compound responsible for this perception and what sensory attribute this compound can potentially affect?

CO2, and increase perceived acidity

1) Familiarize yourself with the main AVA's within California we have covered so far during our wine labs (so far, Sauvignon Blanc, Chardonnay and to come are Riesling, Viognier and Pinot Grigio)

Chardonnay: North coast, Central Coast Sa

in general terms, Sauvignon blanc are not meant to aging and empirical observations indicate that new world Sauvingnon blanc wines do not age well and are thus meant to be consumers as young wines. Explain the chemical and or stylistic reason behind this trend?

Esters are apart of 2nd aromas, they are not made for age ability New world wines are less acidic in general than old world, creating less agreeability

3. What is a hedonic judgment? Can it be useful for wine assessment? Justify your answer.

Hedonic judgment encompasses the things you like and dislike, such as coffee with or without sugar. It can be used for wine tasting but it's not appropriate for sensory analysis because no one cares what you like and don't like when you're assessing wine

2.Within the human sensory system, what is the physiological function of proprioreceptors and how they may play a role during wine perception?

Their role is to detect movement and position, and this can help with fizz and effervescence and carbonation when tasting wine *physiological function is like how we all perceive bitterness different

1) Explain the different and distinctive sensory features of wine acids: tartaric, malic, citric, acetic, and lactic acid.

a. Acetic acid is the most important acid in wine... b. Tartaric: sour, tart c. Malic: sour apple, crisp d. Citric: citrus flavors e. Acetic: volatile, vinegar f. Lactic: milky and soft flavors-softens out a wine when MLF occur

1) What are exactly "Muscat" clones? In which varieties are these clones relevant?

a. Muscat clones - same vine parentage but different clones that have different characteristics (Muscat Alexandria and Frontignan)

1.In general, is the sense of hearing relevant to sensory perception? Why? Provide and example that may apply to wine sensory evaluation.

Yes effects the way you feel and how your going to interact with the wine by changing or effecting the mood. If you hear someone say this wine scored well and is very expensive it can affect your perception of the wine or champagne cork popping, you will associate the good experience/ celebrating with sparking wine and the cork popping

1) Explain the temporary aspects of taste sensation and how they may affect wine perception.

a. 5 basic taste perceived w/ more or less intensity throughout the entire tong (sweet, salty, acidic, bitterness, and umami)

1) The Ohio River Valley AVA is an American Viticultural Area centered on the Ohio River and surrounding areas, which includes portions of the states of Indiana, Kentucky, Ohio and West Virginia. You are the consultant winemaker for a 5,000-case winery in Indiana which also outsource wine in bulk from other local wineries to meet the winery's demand. You are confronted now with the potential purchase of a 2000-gallon lot of Cabernet Franc. Upon sensory analysis, you suspect that the wine has been blended with non-vinifera grapes (which sells for cheaper price as compared with vinifera grapes_. What analytical tool will you choose to back up your claim about a potential blending with non-vinifera grapes and for which compounds will you look for?

a. A GC-MS or HPLC analysis could be used to test for presence of Methyl-anthranilate look for artificial flavors or chewing gum or strawberry, no tannins

1) What factors may be at play for the increasing trend observed within US winemakers to produce oak-free Chardonnays?

a. ABC - anything but Chardonnay, a shift in the consumar demand curve and steering away from the oaky/buttery flavors

1) The perception threshold of sucrose in water has been found to be very variable, ranging from 2 to 5 to 22 mM. Explain why this may be so.

a. Adaption, people who's diets are relatively high in sucrose become desensitized and their threshold for sweetness perception increases. different cultures contain different diets and sugar consumption is variable

1) What are the main advantages and what are the main disadvantages of having super tasters as the sole components of a trained sensory panel?

a. Advantage = able to perceive more flavors than others Disadvantages = reach saturation more quickly when assessing wines and they could have a higher sensitivity to bitterness.

1) What are the general sensory descriptors associated with aldehydes? What are the main pathways through which they appear in wines?

a. Aldehydes = (rotten or over ripe apple) They can appear from the alcoholic fermentation or from oxidation (microbial oxidation of ethanol)

1) What is anosmia? How can this physiological disorder practically affect wine sensory evaluation? Provide examples.

a. Anosmia = loss of smell b. Effects your ability of evaluate wines because you will be unable to precieve certain aromatic compounds rotundone (peppery smell, like in syrah)

1) What is a tastant? Provide a definition.

a. Any chemical that stimulates the sensory cells in a taste bud.

1) Define with your own words, but with chemical terms, what is a tannin. What are the main sensory properties of tannins in red wines?

a. Any phenolic compound of sufficiently high molecular weight containing sufficient hydroxyls and other suitable groups (i.e. carboxyls) to form effectively strong complexes with protein and other macromolecules under the particular environmental conditions being studied A tannin is a polyphenol that is bitter tasting, but gives astringency in your mouth. Tannins feel dry and make you pucker. Gives a fuzzy feeling on the tongue and gums.

1) What is the physiological basis of the phenomenon known as "Asian flush"? is this or relevance for wine marketing and sales? Why?

a. Asians have a lower level of the ALDH enzyme which makes it harder for their body to breakdown wine/ metabolize alcohol and this causes their face/skin to appear more red.

1) Astringency, as a tactile sensation, develops slowly, whereas bitterness, a taste sensation develops relatively faster (relative to astringency, that is). Why this is so?

a. Astringency = is a sensation that is felt through nerve endings which are located mostly on our lips/tong/& fingers & much precipitate tannins to engage in a reaction before it's precieved Bitterness = is a taste that is felt through the pores in our tong that are connected to our frontal cortex in the brain so this is why we develop this feeling faster

1) Can the sensation of astringency show some adaptation/saturation with repeated ingestions? Discuss the consequences this may have for wine sensory analysis from a practical standpoint.

a. Astringency compounds bind to proteins in our saliva and become ingested. Once our mouth runs out of the proteins, the intensity of the wine will increase and it will seem more astringent than it did before.

1) Barrel fermentation is a common winemaking technique in Chardonnay winemaking. Explain the sensory profile that distinguishes barrel fermented Chardonnay wines from stainless steel fermented Chardonnay wines.

a. Barrel fermented = toasty, yeasty, bread crumbs, butter, vanilla, coconut, smokey ginger characteristics b. Stainless steel = more fruit forward/fresh notes, crisp, green apple, pear

1) Why is Chenin Blanc rarely used for production of still wines and, instead, preferentially used for production of sparkling wines?

a. Because its naturally high in acidity which translate well into CO2

1) Why we cannot effectively perceive flavors when we have a cold or flu? May that situation (being sick with a cold or flu) affect sensory perception?

a. Because of the mucus build up in these pathways and inhibits our ability to distinguish flavor

1) In Burgundy, Pinot Noir paintings outnumber Chardonnay on a 3 to 1 fashion. However, the volume of Chardonnay produced in Burgundy is very similar or even higher than the produced volume of Pinot Noir. Why this is so?

a. Because pinot noir clusters are much smaller so they rot much easier due to their tight cluster formation

1) Why, in general terms, Americans have higher perception thresholds for sucrose? Discuss the implications of this specific feature on hedonic acceptance by regular wine consumers of late-harvest wines (residual sugars > 50 g/L). Also, knowing that red wines are considered dry when residual sugars are < 5 g/L, what is to expect if some very pricy Cabernet Sauvignon from Rutherford have 9 g/L of residual sugars? Should we observe the same behavior or outcome should we give the same Cab to regular wine consumers from Finland? Why ?

a. Because there's more sucrose in our day to day diet compared to other nation/populations of people. b. Generally Americans will be more accepting of late harvest wines with a lot of extra sugars because we have become less sensitive to the taste of sugar due to the amount consumed in our diet You will most likely have a different outcome because different populations of people have different thresholds for certain tastes. Finland, Denmark, and Norway have a higher threshold for acidity

1) Why these G-G's compounds are not volatile?

a. Because they are bound to sugars and become too heavy, more than 300 DA

1) Why bitter compounds (and therefore bitter perception) takes longer than, say, the perception of saltiness? How this may affect wine perception?

a. Bitter compounds take longer because they're bigger and bulky so it takes more time to move through your mouth (awkward big bulky like Shac) * also genetics, some people can not perceive bitterness

1) Using as a basis what we learned (and discussed) during lab section # 3 (Chardonnay wines) how are Chardonnay wines from Burgundy and Chablis different, from a sensory perspective, from California Chardonnay wines?

a. Burgundy and Chablis are more fruity, earthy, mineral and citrus, high acid, style wine more after grape b. California are more buttery, vanilla, oak, has more oaky characteristics, aged in barrel

1) What are the main sensory features that distinguish California Chardonnay from Chardonnay wines produce from grapes grown in Burgundy? In addition to specific stylistic protocols followed during winemaking (which you can discuss as well on your answer), what other factors may be at play?

a. CA chard = more rich, buttery, w/ vanilla notes, and more oak aging Burgundy chard = more fruity, w/ mineral & earthy notes, sometimes citrusy or crisp

1) Name the main phenolic compounds responsible for bitterness in red wines. Additionally, explain why these compounds have the ability to elicit bitterness relative to other wine phenolics such as tannins.

a. Catechin, epicatechin, epigallocatechin, epicatechin-3-0-gallate tannins elicit astringency a tactile sensation rather than a taste b. These compounds elecicit bitterness rather than tannins because tannins are astringent which is not the same as bitterness

1) Successful growing of Sauvignon Blanc can be accomplished in climate conditions so diverse as coastal (or ocean) influence to continental climate conditions. Provide examples of both of such regions (ocean and continental) that successfully produce Sauvignon Blanc wines also mentioning how these two contrasting climate conditions impact the sensory profile of the resulting wines.

a. Coastal- new Zealand, Sonoma coast, chile—these are more grassy and herbaceous, tropical fruits, ( only harvest once) Continental-Argentina: minerality, cats pee and gun powder ( have to have multiple harvest dates.)

1) What are the main approaches one have available for evaluating the sensory properties of a wine? which one would you favor in the case of a big corporate winery?

a. Color, smell, and taste. I would favor taste because I believe that is the most important b. Bridget: There are experts and connoiseurs, there are panelists, and then there are scientific instruments. * corporate wineries would want taste as well, because you are trying to keep your product as consistent as the last.*

1) Explain the main sensory profiles of Chardonnay wines as a function of climate conditions (e.g. cold and continental; warm and continental; template and ocean influence).

a. Cool climate= pear, citrus, green apple, watermelon, pineapple, mineral (magic acid) b. Temperate= floral, nutty, tropical fruits, pineapple c. Warm=honey, banana, peachy, canned pineapple, roasted apple pie

1) How do esters influence wine style ? provide an example.

a. Esters (fruity/floral aromas) are great for young wines like whites or rosé. They are basically all you smell in rosé wines and it's true to the wine style because esters will disappear over time and are meant to be consumed ideally the year following the vintage.

1) Explain how ethanol influences the solubility of wine aromas and what is the practical impact of the involved chemistry on wine perceived aroma.

a. Ethanol decreases fruitiness. It traps wine aromas in hydrophobic pockets because it increases the solubility which means the volatility of the aromas decreases. Ethanol increases the solubility of aromas, (hydrophobic pockets) pockets surround/ trap the volatile components, keeping it trapped in solution, if it is in solution, not in headspace This is why we swirl the wine to release the volatile compounds

1) Of the total pool of esters present in wines, ethyl-acetate is the most abundant ester? Explain why.

a. Ethanol is produced during fermentation and acetate is naturally in grapes ethanol is the most abundant alcohol in wine, acidic acid most prevalent acid produced during fermentation, with both of them be available it creates more of an opportunity to create ethyl-acetate

1) Why the definition of threshold makes reference to a concentration "range" instead of just a single, specific concentration of a given stimuli?

a. Every persons recognition threshold could very and many factors can affect a threshold for a given person, like prior exposure

1) What is the general aromatic descriptor of terpenes?

a. Floral

1) You have been recently hired as the CEO of a worldwide wine company that focuses on mass production wines. Your company has several winemakers around the world and a director of winemaking that oversees them. During a board meeting, you learn that, traditionally, final decisions about blending for year-in/year out consistency are always on the hands of the director of winemaking. Provide ALL the physiological reasons that you, as a CEO, will present to the director of winemaking to convince him his course of action may not be a good idea.

a. For a company that's as diverse and large as this one, it would be ideal to appeal to the largest possible consumer base. In order to do this, a more diverse sensory panel will be needed to evaluate the wines so that a better representative sample of the general population is provided.

1) Esters are formed via a covalent reaction between an acid and an alcohol. For the most part, they share one particular sensory trait. Explain which sensory trait this is.

a. Fruity aromas

1) What is the general aromatic descriptor of higher alcohols?

a. Fusel, distilled beverages, brandy, whiskey Hexanol is herbaceous and phenyl-ethanol is rose-like

1) Define, from a chemical standpoint, glycosil-glycoside aroma compounds (G-G's for short) and their importance for wine chemistry and wine sensory properties.

a. GG is released during fermentation. It's an aromatic compound that's a primary aroma has to be attached to a glucose and becomes too heavy so we can spell it anymore technically from the variety but are brought out during fermentation and that is why it is a primary aroma bond and once it is broken you can smell it again in wine

1) What are the 4 classification levels, quality wine, one can find in Burgundy?

a. Grand cru b. Premier cru c. Village appellations d. Regional appellations

1) Explain in which way glass shape and the volume and potential exposed surface on the headspace of a glass can affect the molar partition coefficient of a given aroma compound.

a. Higher ratio of head space will increase the molar partition coefficient

1) Pyrazines are primary aroma compounds that are naturally present in certain grape varieties. Comment on what varieties the appearance of pyrazines is more common and name ALL the potential sources of these compounds in wines.

a. Most common in Sauvignon blanc, cabernet sauvignon, cab franc, and merlot. b. Plant vigor, nitrogen supply, maturity, and MOG are all potential sources of pyrazines in wine

1) In certain wine regions, Sauvignon Blanc is typically harvested at three or more consecutive maturity levels (e.g. 19, 22 and 24 Brix). In which regions this approach is more common and what goal a winemaker pursuing this approach is trying to accomplish?

a. In Mendoza Argentina and Central Valley ( warmer regions). Winemaker wants to include more acidic berries (younger betters) and more mature grapes with more esters to create a more complex wine. The purpose of this is to get different ripeness evels, thus different aromas and flavors, create more balance wine, different acid levels, difference flavors and aromas.

1) How is informal wine tasting different from formal sensory analysis?

a. Informal tasting = hedonic, decoding the wine in an informal way, "I like this." b. Sensory analysis = it's a formal way of describing the wine and has specific standards for wine.

1) Can a certain threshold determine wine rejection? Explain.

a. It depends on the situation (aroma/taste) and the person perceiving and the amount in the wine. Some compounds, like TCA, any recognition would cause wine rejection, but for most other compounds the rejection threshold will be different than the recognition threshold.

1) Discuss at least one practical implication (from a sensory perspective) regarding the fact that Saccharomyces cerevisiae preferentially metabolizes glucose over fructose.

a. It does this because the residual sugars in the wine are primarily made up of fructose and this makes it much sweeter. b. glucose is not as sweet as fructose, so when the yeast consume the glucose and leave behind any fructose

1) Why tastants need to be soluble in water?

a. It needs to be water soluble so that your spit can break down the wine and detect the phenolic compounds (chem. Composition that make up taste, color, and mouthfeel) b. Spit breaks apart wine then it moves to the taste bud then the pore, it must attach to a detector (protein made out of amino acids) and then generate an electronic action that travels to the orbital frontal cortex

1) Define the concept of Odor Activity Value (AOV). In addition, discuss ALL the advantages and ALL the pitfalls this concept has as it relates to wine sensory analysis.

a. It's a ratio: concentration / rejection threshold b. Advantages = can give a general sense for the intensity of an aroma and allows for quantification of an aroma Disadvantages = everyone's different recognition threshold, EtOH severely impacts the ability of compounds to be precieved, wine aromas are perceived w/in the wine matrix which severely impacts perception

1) How is stereochemistry and molecular shape of a given molecule important for sweetness perception?

a. It's important because the given molecule has to bind perfectly to the receptor so that sweetness can be perceived.

1) The main aroma compound (though not the only one) present in English lavender (Lavandula angustifolia) is linalool. This terpene also appear as a component of the aroma of orange blossoms and lemon peels. Furthermore, most Muscat wines (e.g. Muscat Canelli) own their aromatic sensory features to linalool as well. Why lavender, orange blossoms, lemon peels and Muscat wines do not smell similar, even though that they share linalool as main aroma compound?

a. Linalool can have different aromas based on it's concentration and the other compounds in the wines matrix

1) You are invited as a judge in a wine competition in San Francisco. You have just received a flight of 6 Cabernet Sauvignon from the Howell Mountain AVA in Napa Valley. You are told some of these Cabs have residual sugars, whereas some others are bone dry (residual sugars below 1 g/L). You ought to judge perceived bitterness, astringency, perceived sweetness and acidity. Explain with your own words what you expect to happen with these descriptors as you analyze the wines. Also, knowing these wines are particularly high in tannins and phenolics, in general, what measures would you follow to minimize sensory carry over?

a. Looking for astringency is simple because you will feel a dry mouthfeel on the upper lip and tongue as if the moisture was sucked out. While bitterness is a sharp and harsh flavor, as a super taster I describe it as like drinking chemicals that lingers in your mouth and throat. Sweetness can be perceived by the viscosity (syrup/thick sweet) of the wine and if there is more sweetness then is masks the acidity which would give the wine a perceptions of tartness and crispness. Knowing these wines are high in tannins and phenolics I would rinse my mouth with water and eat a cracker after each oe to clear my palate, and possibility even give it some time in between each one to regenerate saliva and such back to normal. b. Minimize sensory carry over = drink lots of water and chew on unsalted crackers to cleanse the palate and refresh saliva.

1) What is monosodium glutamate and how this compound is perceived? Explain its potential relevance (if any) for wines.

a. MSG is umami. This compound is perceived as savory, creamy, rich mouthfeel, and rounds out acidity and bitterness. It is thought to synergize saltiness, sweetness, and acidity. It is not particularly relevant in wines, however you may perceive certain sensations from wines as umami even if it is not actually there.

1) From the perspective of the basic tastes, and based on what we learn (and taste) about the sensory features of wine and grape acids: what is the sensory consequence (emphasis on taste) of the occurrence of malolactic fermentation? What sensory featrues may allow you to suggest a wine as very little or no malolactic fermentation? What sensory features may allow you to suggest a given wine has full malolactic fermentation?

a. Malolactic fermentation is the process of taking malic acid and chemically changing it into lactic acid. This leaves the wine smooth buttery taste. You can tell if the wine has very little or no malolactic fermentation when it doesn't possess the smooth, buttery taste and it comes across as more fresh or acidic.

1) How the molar partition coefficient is related to the vapor pressure and what these two concepts practically mean?

a. Molar partition coefficient is related because it is the measurement of how volatile a compound is. High vapor pressure means the compound has a low boiling point and is easily volatile in the air. The higher the vapor pressure of a volatile compound, the higher the molar partition coefficient and in the end, how easily perceivable an aromatic compound can be Low mpc, aromas won't be intense and hard to detect, High mpc means aromas are strong and easily perceived

1) From a chemical standpoint, and, more precisely, from the perspective of their molecular weight, terpenes are classified as monoterpenes, sesquiterpenes and diterpenes. Provide an actual example of one important monoterpene and one important sesquiterpene known to occur in wines.

a. Mono- linalool (orange blossom or lavender ) b. Sesquiterpene- Rotundone (black pepper)

Explain the ways volatile compounds (something that free from being bound, you can smell these more) can potentially reach the olfactory epithelium

a. Olfactory epithelium is perceived through the nose and volatile compounds are free and not binded to anything in the wine so we can smell them. b. The volatile compounds can reach the olfactory through orthonasla or retronasal pathways, and are pushed up by the nasal turbinates to be able to reach the epithelium.

1) Where are G-G's compounds mostly localized within the grape cluster?

a. On the skins and in the mesocarp( pulp)

1) Explain the physiology of orthonasal versus retronasal perception. Which one (if any) of these 2 ways is more relevant for practical wine sensory analysis? Why?

a. Orthonasal through the nose, retronasal through the throat/palate Orthonasal is smelling an aroma with your nose and that aroma following the pathway to your olfactory epithiliumto be perceived, whereas retronasal is when the aroma compound travels to the epithelium via the back of your mouth once the wine or other item is in your mouth, and that constitutes flavor. They are both very relevant because the scents you receive orthnasal versus retronasalcan be completely different based on the pathway

1) Explain the evolutionary reason why we humans being have proline-rich-proteins (PRP's) in our saliva.

a. PRP's act as a defense barrier against anti-eating factors. This is because tannins are anti-feeding factors that affect digestions, so we need those proteins for our bodies to tell us not to eat these items

1) What are trigeminal sensations and which ones are especially important for wines?

a. Pain, temperature, irritation, and {astringency/body/acidity (important for wine)}

1) What are the main compounds responsible for textural aspects in wines?

a. Phenolic compounds

1) Explain and discuss the molecular basis of astringency.

a. Phenolic compounds bind with proline rich salivary proteins and cause them to precipitate out of solution which results in a decrease in saliva lubrication. b. Lack of spit in our mouth, proteins in the wine evaporate the lubrication spit c. Bridg: Astringency is when the tannins precipitate the proteins and amino acids from your mouth. The Proline rich proteins(PRPs) in our saliva react with the condensed tannins and create hydrogen bonds to precipitate the proteins out.

1) Explain how salivary flow rate affects the perception of astringency. In addition to that, answer the following as well: under which conditions human beings increase their salivary flow rate (the so-called stimulated saliva). Will a potential situation of increased salivary flow rate affect the perception of astringency when drinking wine ?

a. Phenolic compounds bind with proline rich salivary proteins and cause them to precipitate out of solution which results in a decrease in saliva lubrication. So the more saliva your body produces the less astringency you will perceive. b. You can increase your saliva flow rate by rinsing your mouth out with water, drinking lots of water, or chewing on non-salted/ nonfat crackers. c. Yes, the more spit you have the more proteins you will have in your mouth and more astringent compounds can bind to the proteins and you will feel less of the sensation

1) Define and explain the physiological and genetic basis of PROP status. Discuss what consequences PROP status may have for wine sensory evaluation.

a. Physical factor that determines how sensitive a person is bitterness PROP status is dependent upon the density of fungiform taste buds on someones tongue and how that plays into their ability to perceive bitterness. very low density of fungiform taste buds can cause a person to not perceive bitterness at all

1) The physiology of we human beings accommodates different types of taste buds. What are those types? Name them. Also: from the perspective of taste perception, what kind of taste buds is more relevant?

a. Physiology of taste: Anatomy of a taste bud papillae - cells are actually neurons that connect to brain b. FUNGIFORM - most abundant on tip of tong and we all have different amounts, most relevant c. Circumvallate - big and bulky not very functional d. Foliayte - located on the sides of the tongue. e. Filiform - don't have pores, only tactile receptors

1) There is no right or wrong answer for this question. I just want to tease your brain. You are in charge of a tasting room of a 20,000 case-winery in Paso Robles. Your tasting room traffic during weekends can be as high as 100-120 patrons on a good, sunny Saturday afternoon. Since you have learned the consequences and importance of knowing your own PROP status, and since you are pouring now a very tannic and full-bodied Petit Sirah, you come up with the geeky idea to have a portion of your patrons taking the PROP status test. What can be potential pitfalls and potential benefits of implementing this on a commercial tasting room?

a. Pitfalls = not everyone will be as interested in learning about their own PROP status as you are. You will need to be very careful about the ratio of bitterness you use in the sample because if you have a super taster in the group they could be very sensitive to the compound. Benefits = more educated wine drinkers. Customers feel like they are getting special treatment and walk away with a more memorable experience. Once you know your patrons PROP status you can make suggestion on specific wines that might accommodate their personal taste

1) Discuss the positive and negative sensory impacts esters can have in wines.

a. Positive = fruity, banana, pear, honey, floral, and apple characteristics b. Negative = ethyl acetate, smells like nail polish remover

1) Define primary aromas and expand on which varieties and wine styles, in particular, primary aromas are relevant.

a. Primary aroma = aromas directly from the specific grape varietal (skins), most relevant in young wines as free volatiles like rosé. Cab Sauv: has a bell pepper smell/taste Sauv Blanc: naturally have grassy/tropical fruit characteristic Muscat: floral characteristics (terpenes)

1) Why we human beings relate the perception of sensory odors/aroma with certain memories and/or emotions we have felt in the past?

a. Psychometric functions link a stimulus with a response The Frontal cortex processes sensory perception as well as memories

1) Define in your our word the concept of psychometrics.

a. Psychometrics function links a stimulus with a response. measurement of a psychological response A function that relates the concentration of a stimulus with a response

1) From the perspective of the physiology of smell, what is the role played by the turbinate bones?

a. Push aromas to your olfactory epithelium, the turbinate bone physically pushes up volatiles

1) If you were to grab an unripe Cabernet Sauvignon berry (say at véraison) chances are, irrespective of vineyard location, you should be able to perceived the typical genetal character of pyrazines. Where are pyrazines located on the berry?

a. Pyrazines = located in mostly the berry skins aromas - bell pepper, herbaceous, earthy, canned/green beans(sauvignon blanc)

1) You are in charge of a sensory panel for a large wine importer. You are in charge of several panels, but you have been assigned a new panel composed by 18 individuals, 80% of which are veterans which have shown, in the past, symptoms of PTSD (post-traumatic stress disorder). Your company is now closing a deal with a German producer to import about 10,000 cases of Riesling from the Mosel appellation. However, your company is concerned about the consumers' potential rejection due to the evident "kerosene" or "petrol" character of this Riesling wine (due to a compound called trimethyl dihydronaphthalene, in short TDN). You have been assigned the task to establish the rejection threshold for TDN in the Riesling wines to be potentially purchased with the panel composed of veterans. Answer the following: a) what is the rejection threshold? Provide a definition; b) explain, using physiological concepts, why it may be not a good idea to use the panel of veterans to establish this rejection threshold.

a. Rejection threshold = Magnitude of stimulus above which the product is rejected b. Because of their experiences and since emotions/memories are linked in the same area of our brain as aromas/flavors, they might be more sensitive to the kerosene compound because they are veterins with PTSD and could have a bias PROP status which would make them reject the wine more easily.

1) What is flavor?

a. Retronasal human sense, combination of ortho- and retronasal pathways.. nose and back of the throat

1) During lab section #2, we tasted some white wines from Bordeaux. What were the main varietals included there?

a. Sauvignon blanc, semillion, sauternes

1) Define secondary aromas and expand on which varieties and wine styles, in particular, secondary aromas are relevant.

a. Secondary aromas = Fermentative/ from freshly fermented juice. Used in mostly annual consumption or high rotation red& whites. whites/rose you are getting lots of secondary aromas because you have minimal skin contact which would give it primary aromas Most whites are not made for aging, no tannins, won't age well.

1) Esters are, by definition secondary aromas. Explain from a chemical and sensory perspective what secondary aromas are.

a. Secondary aromas are those released during fermentation, they give off fruity characters from the fermentation process. They are created from the reaction of an alcohol and an acid, which end up both being components of wine after fermentation

1) How is the variety known as Steen, grown in South Africa, relates to Chenin Blanc?

a. Steen is the same as chenin blanc, and most planted white in SA, Chenin is usually used for sparkling wines because it is high in acid, low in tannins,

1) Explain and describe the chain of sensory perception. In particular, indicate in which specific step of the chain a hedonic response is produced.

a. Stimulus (color or taste ~ chem basis) i. Sensory receptors {nose, eyes, toung, finger tips, etc} b. Sensation (neurological basis) i. Exposure, c. Perception (psychological basis) i. Exposure plays a role and can hinder your take on the wine if you haven't been exposed enough d. Response i. Decode in informal way (hedonic) wine tasting Formal (have standards) sensory analysis

1) What are residual sugars? What type of residual sugars are mostly found in late harvest wines and why?

a. Sugars left over in the wine after the fermentation process?... The primary sugars found in RS are fructose because fructose and glucose are the most primary sugars in grapes, but during fermentation the glucose is consumed by the yeast, leaving behind the fructose

1) Explain the basics of the winemaking technique known as sur-lies in Chardonnay winemaking adding what this technique brings about from a sensory perspective.

a. Sur lies is fermenting on the lees, or on the sediment. This brings out a more yeasty, bread crumb character

1) What are Sauternes wines? What are the main varieties involved in the production of Sauternes wines?

a. Sweet wines made from semillon Made from a blend of sauv blanc and muscadelle, semicolon

1) What are taste buds and how they are assembled and constituted?

a. Taste buds = it's a complex tissue that contains pores. They are assembled throughout the entire tongue but the tip of the tongue has more taste buds

1) When a sommelier makes reference to the "complex bouquet" of a given wine, to which aromas he/she is making reference ?

a. Tertiary aromas from aging and non-volatile factors that are GG released later on

1) Same context as question 18. You notice your tasting room manager is now pouring two wines in the following order. Your late-harvest Semillon, with about 80 g/L RS is being poured first, followed by your cool climate Petite Sirah. Discuss the implications, from the perspective of the consumers and their sensory impressions, of this action.

a. The Petite Sirah will taste more bitter because of cross-potentiation of sweet and bitter. (Increasing in sensitivity due to exposure to a contrasting diff stimulus) The Petit Sirah will be perceived as being more dry and the perception of acid will likely be affected as well b. Sweet wines should always go at the end of the flight because of this! If you start with sweet wines the other more bitter wines will come across as more bitter

1) Explain the different and distinctive sensory features of wine sugars: glucose and fructose.

a. The comparative sweetness difference between the two sugars is very different: i. Fructose = 1.73 Glucose = .74

1) Define the molar partition coefficient. In addition: what makes volatile sulfur compounds (such as dimethyl sulfide, scent of truffles) so pervasive?

a. The molar partition coefficient measures how volatile a compound is. This is why water cannot be smelled because the hydrogen bonds keep it locked in and any aromas are non volatile. VSC have a high molar partition coefficient thus, whatever solvent they are in, they easily escape which is why we are able to smell them so easil, readily, and strongly.

1) How can salivary flow rate affect the perception of astringency and what is the mechanism behind? How can one measure salivary flow rate?

a. The more saliva that a person produces, the more proteins they will have available to attach to the astringency compounds in the wine and they will perceive less of the sensation b. ? by the mount of astringency felt, or by how dry their mouth feels

4) What are electronic tongues and electronic noses? Are these devices useful for the wine industry? Are these devices useful for other industries? Why?

a. These are machines used to detect specific aromas and flavors in the wine. They could be beneficial in the wine industry but it is not a real person and everyone is different. They are used in the pharmaceutical industry to detect bitterness

1) Fruity esters, such as ethyl-octanoate (which we smell during lecture), do not have taste qualities (they are tasteless). Explain from a psychological perspective why some fruity esters are perceived as sweet via retronasal. Hint: this holds also true for terpeness and perceived sweetness.

a. This is a psychological notion because we know that fruity foods are usually sweet with sugar, such as a banana or ripe strawberry. However, their fruit characteristics and aromas, are actually technically not sweet, but because those two things are usually associated, we perceive esters as sweet.

1) Under practical sensory evaluation conditions, a disagreement between ortho- and retro-nasal perception is often observed. We experienced this also during lab #3, while tasting some Chardonnay wines. Indeed, some of you noticed some wines showed a specific aromatic profile orthonasally and a totally different aromatic profile on the flavor. Explain from a physiological standpoint why this is so.

a. This is because the volatile compounds have an affinity for different pathways, such as terpenes (floral) prefer orthonasal while furaneols{furfurol} (comes from freshly toasting barrels/freshly roasted coffee) prefer retronasal

1) How is fume Blanc similar and different to Sauvignon Blanc? Explain

a. This is because they are made in stainless steel tank so they do not pick up any oak tannins/proteins. Sauvignon blanc also are rich in pyrazines and esters and those will fade and diminish with time. Sauv is meant to be a more crisp ad acidic wine, and the acidity can be compromised if aged too long Fume blanc is renamed and a synonym for sauvignon blanc, this is barrel fermented

1) During lecture held on Monday 6-27, the instructor presented data showing that the recognition threshold for salty taste of our group was well below the published recognition threshold. Explain why that may be.

a. This means that our group is very used to salt and has become desensitized to the taste in a "normal" threshold level. We most-likely consume a lot of salt in our diets and have adapted to the taste causing our recognition threshold to increase. (we need more salt to recognize the flavor)

1) In general terms, repeated exposure to a given flavor and/or aroma is linked with equally increasing liking to that flavor or aroma. Why?

a. This occurs when a person becomes adapted to the flavor or aroma and they get used to the smell/taste once they have been exposed to it frequently.

1) It is a fact that the general population here in the US tends to like oak flavors and aromas (these compounds are know as oak-lactones). If this is the case, why is the use of barrel for fermentation and aging of Chardonnay imuch more common than the use of barrel fermentation in Sauvignon Blanc?

a. Tradition

1) From an evolutionary standpoint, it has been found that there are quantitative differences in the taste bud density between human males and females. Explain to what group (males or females) favors this difference and what may be the evolutionary reason beyond this favoritism.

a. Yes, females typically have a higher taste bud density than males and it has to do with evolution (making good choices while eating so they can get/stay prego)

1) Is the ester content of a given wine influenced by shelf-life?

a. Yes, they will disappear with aging

1) What are the 2 more important white varieties in Burgundy?

a. chardonnay & aligote

1) In your role as winemaker, you are responsible for the operation of a small winery (5,000 cases a year) in the Santa Barbara County. The winery also owns a small tasting room in downtown Santa Barbara. One Saturday morning you decide to stop by the tasting room. You notice there are several patrons(regular customers) tasting wine. You also notice that the tasting room manager is pouring your flag ship cool climate Sauvignon Blanc at 23 °C (you sneaked out with a glass of freshly poured Sauv. Blanc and measured the temperature with a thermometer). Discuss the implications, from the perspective of the consumers and their sensory impressions, of this situation.

a. usually at about 22 °C sensory of wine changes. as temperature increases sweetness perception increases and acidity decreases. increased perception of acidity also increases the perception of freshness which is culturally correlated

1) A hydrophobic mucous layer coats the olfactory epithelium. Conversely, water, as a molecule, is extremely hydrophilic due to extended H bonding. Why water is odorless?

a. water cannot be smelled because the hydrogen bonds keep it locked in and any aromas are non volatile. VSC have a high molar partition coefficient thus, whatever solvent they are in, they easily escape which is why we are able to smell them so easily, readily, and strongly.

1) Explain the chemical parallelism between the tanning of animal tissue to transform it into leather and the sensation of astringency upon ingestion of a red wine.

a.When you are tanning animal tissue, you add tannins to remove proteins from the skin, to help try it out and keep longer. the tannins interact with the proteins and precipitate them out. The same thing is happening in your mouth when you feel astringency.The tannins in the wine are stripping out the proline rich proteins from your saliva, leaving you with a very dry feeling mouth

1) By and large, how do pyrazines relate to canopy vigor?

more canopy more pyrazines,

1) You are now the head winemaker of a 10,000-cases winery in the Finger Lakes region of New York state. One of the flagship varietals your winery is known for is Cabernet Franc. The assistant winemaker, which is under your supervision and has been with the winery for the previous 6 years, has commented to you that pyrazines are an issue and that they need to be managed during winemaking. Harvest start at earnest and when revising the red wine program you found Cabernet Franc is typically made by doing first a prefermentative cold soak with dry ice for 5 days, following by a 15-day skin maceration period. In the context outlined above: is this winemaking program adequate or inadequate? Provide your rationale.

no if pyrazines are a problem you do not want to have a 15 day maceration period that would be extracting more of those components, you would want to have the least amount of skin contact time

this is a snap shot of a tongue we took during one of our labs, indicated the total number of fungiform papillae can you count in the snap shot.

see questions 54 in study guide.

1) Same winery and location as # 61. You have in front of you a very rainy and unseasonably cold year, which started with delayed bud break, then a cold snap during spring that lead to spring frost damage on some of the vines, which in turn affected berry set (thus ramping out canopy vigor and density), and then sugars levels not surpassing 21 Brix in Cabernet Franc. Explain why pyrazines are going to be a serious issue relative to more benevolent years. Also, as a head winemaker confronted with the issue of dealing with these compounds year-in year-out, can you recommend winemaking practices that may control or reduce the pyrazines content of the wine?

when grapes have higher brix there are less pyrazines. Pyrazines are thermo sensitive. if your picking something at 21 vs 28 brix, the 21 brix was exposed to less weather than the 28 brix. The 28 brix has more time for the pyrazines to break down compared to the 21 brix I would recommend thinning out the canopy and leaving the grapes out longer to the pyrazines can break down more