Definition

Sheryl HoffmannConcordia Collegeshoffmann@concordia.sa.edu.auTaste, Smell and the Other Senses1Summary of the WorkshopGoodie bag & ScorecardsTheory on SensesTheory on TasteActivitiesTheory on SmellWine Odour Quiz & Tabulation of ResultsResults & Australian Curriculum

11.20 12.00Goodie bag & ScorecardsTheory on SensesTheory on Taste12-12.30Activities12.30-12.45Theory on Smell12.45-1Wine Odour Quiz & Tabulation of Results1-1.25Results & Australian Curriculum

25 Traditional SensesTaste Smell TouchSightHearing

3ESP the 6th SenseExtrasensory perception involves reception of information not gained through the recognized physical senses but sensed with the mind. The term was adopted by Duke University psychologist J. B. Rhine to denote psychic abilities such as:TelepathyClairvoyancePrecognition

4Other Human SensesTemperature Pain Balance Acceleration

Part 15Other Human SensesVarious internal stimuli e.g. Chemoreceptors for detecting carbon dioxide concentrations in the bloodSensory receptors that sense fullness in the bladderKinesthetic sense relative position of the parts of the body

What constitutes a sense is a matter of some debate, leading to difficulties in defining what exactly a sense is.

6Animals Have Other Senses Gravity eg plantsElectroreceprtion detect electric fields eg sharks, platypusMagnetoception detect earths magnetic field eg birds7TasteThe sensation of taste can be categorized into four / five basic tastes: SweetSourSaltyBitter(Umami)PlusSpicyAstringentPiquantMetallic

8A Myth

The entire tongue can sense all of these tastes more or less equally

Try it yourself!9TasteTaste receptor cells are found in the taste buds, palate and early parts of the digestive system like the larynx and upper esophagus.

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Salty and sour taste sensations are both detected through ion channels.

Sweet, bitter, and umami tastes, however, are detected by way of G protein-coupled taste receptors.

Activity AWith a dry tongue we taste very little because the chemicals cant react with the receptors

10Taste budhttps://commons.wikimedia.org/wiki/File:Taste_bud.svg

Taste buds contain the receptors for taste. They are located around the small structures on the upper surface of the tongue, soft palate, upper esophagus and epiglottis, which are called papilla. Via small openings in the tongue epithelium, called taste pores, parts of the food dissolved in saliva come into contact with taste receptors. The taste receptor cells send information detected by the various receptors and ion channels to the brain

Average life of a taste bus is 10 days

4 types of papillae

In Activity C we will count one type of papillae as an indication of the number of taste buds that you have11SweetLots of chemical compounds are sweet: All of the simple carbohydratesSome aldehydes and ketonesSome of the amino acids are mildly sweet. A number of plant speciesEven some inorganic compounds are sweet, including Beryllium Chloride and Lead(II) Acetate

12SweetHundreds of synthetic organic compounds are sweet but also toxic: ChloroformNitrobenzeneEthylene glycol

Various artificial sweeteners including:SaccharinCyclamateAspartame

13A Sense of Sweetness

Radio National 5.50pm Monday 13th May 2013

Dr Norman Swan

Goodie bag 1 wrapped lolly14SourSourness is the taste that detects acidity.

Common sour foodsLemon, lime & grapefruitTamarindVinegarPickles Sour lolliesGoodie Bag 2 Citric Acid

Sour via ion channels15SaltySaltiness is a taste produced primarily by the presence of sodium ions, but other ions of the alkali metals group also taste salty.

lithium and potassium ions taste similar to sodiumthe larger rubidium and cesium ions do not taste as salty

16Hallstatt Salt Mine - Near Salzburg

oldest salt mines in the world

oldest wooden stairs in the world dated to BC 1344

17Iodised SaltTable salt mixed with a minute amount of various salts of the element iodine Prevents iodine deficiencyIodine is a micronutrient Naturally present in the food supply in some regions, especially near sea coasts, but is generally quite rare in the Earth's crustGoodie Bag 3 & 4 - iodised salt & Maldon salt

Dehlia Smith, How to Cook, Book 2, 1999, BBC Worldwide Ltd London. - TV Series & book

There have been two main sources for salt: sea water and rock salt. Rock salt occurs in vast beds of sedimentary minerals that result from the drying up of enclosed lakes, playas, and seas.18BitterCommon bitter foods includeCoffeeUnsweetened cocoaMarmaladeBeer (due to hops)Many plants in the Brassicaceae familyQuinine (found in tonic water)

Bitterness is the most sensitive of the tastes, and many perceive it as unpleasant, sharp, or disagreeable, but it is sometimes desirable and intentionally added via various bittering agents. Bitterness is of interest to those who study evolution, as well as various health researchers since a large number of natural bitter compounds are known to be toxic. The ability to detect bitter-tasting, toxic compounds at low thresholds is considered to provide an important protective function. Plant leaves often contain toxic compounds, yet even amongst leaf-eating primates, there is a tendency to prefer immature leaves, which tend to be higher in protein and lower in fiber and poisons than mature leaves. Amongst humans, various food processing techniques are used worldwide to detoxify otherwise inedible foods and make them palatable. G protein-coupled taste receptors, therefore genetically determined19PTCPTC - phenylthiocarbamide also known as phenylthiourea

Some people taste nothing. Some find it intensely bitter, and still others taste is as only slightly bitter.

On average, 75% of people can taste PTC, while 25% cannot.

Goodie Bag 5 PTC Paper

Because the characteristics of taste receptor cells are genetically determined, people vary in their ability to taste some molecules.

Today we know that the ability to taste PTC (or not) is conveyed by a single gene that codes for a taste receptor on the tongue. The PTC gene, TAS2R38, was discovered in 2003.There are two common forms (or alleles) of the PTC gene, and at least five rare forms. One of the common forms is a. tasting allele, and the other is a non-tasting allele. Each allele codes for a bitter taste receptor protein with a slightly different shape. The shape of the receptor protein determines how strongly it can bind to PTC. Since all people have two copies of every gene, combinations of the bitter taste gene variants determine whether someone finds PTC intensely bitter, somewhat bitter, or without taste at all.

Studies indicate that individuals with the "strong tasters" PTC gene variant were less likely to be smokers. This may indicate that people who find PTC bitter are more likely than non-tasters to find the taste of cigarettes bitter and may be less likely to smoke. Other studies suggest that there may be correlations between the ability to taste PTC and preferences for certain types of foods. This may be why some of us think that broccoli is just too bitter to eat

20UmamiJapanese word meaning good flavor" or "good tasteA pleasant savoury or meaty taste Subtle and blends well with other tastes to expand and round out flavors

occur naturally in many foods including meat, fish, vegetables and dairy products

is considered fundamental to many Eastern cuisines and was first described in 1908, although it was only recently recognized in the West as a basic taste

21Umami http://www.umami.org.au/

Green - fermented beans or grainsBlue - fermented fish or prawnsRed - other eg Australia vegemite from yeast extract

22MSGMono-Sodium GlutimateA non-essential amino acid Taste enhancerE621LD50 15-18g / KgNo scientific evidence for Chinese Food Syndrome

Goodie Bag 6 MSG 23Taste ThresholdYour taste threshold is the lowest concentration of a solution that a you can still taste.Latter we will determine our own taste & recognition threshold forSweetSourSaltyBitter

24ActivitiesDry tongue, no tasteNo smell, little tasteNumber of taste budsTaste threshold of SweetTaste threshold of SourTaste threshold of SaltyTaste threshold of BitterToothpaste & OJ

30 mins Back at 12.30pm25Flavour = Taste + Smellflavour is the sensory impression of a food or other substance, and is determined mainly by the chemical senses of taste and smellIf you can smell you cant taste much eg when you have a cold

Activity B showed this26primary taste: umami.

How Humans Experience Their Food

Back to What is Umami?

How Humans Experience Their Foodhttp://www.umamiinfo.com/2011/02/What-exactly-is-umami.phpGoodie Bag 7 - chocolate

Use all the 5 sensesLook at itSmell itListen to the sound it make when you break it the snap of quality choc!Put it into your mouth but dont chewAllow it to meltFeel the textureBreath in through your mouth-> taste & smellNow chew and swallow

27SmellOlfaction or olfactory perception is the sense of smell.

The sense of smell is considered to be one of the least developed senses humans possess.

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28

http://www.exploratorium.edu/cooking/seasoning/taste/smell.htmlThis sense is mediated by specialized sensory cells of the nasal cavity of vertebrates. In humans, olfaction occurs when odorant molecules bind to specific sites on the olfactory receptors. They come together at what is called the glomerulus. The glomerulus is a structure that transmits signals to the olfactory bulb (a brain structure located directly above the nasal cavity and below the frontal lobe).

29Odour ThresholdsDetectionThe lowest concentration of an odour that is perceivable by the human sense of smell.

RecognitionThe concentration at which you can identify an odor.

30Odour Thresholds & MSDS/SDSFormaldehyde - ES 1 ppm ( 1.2 mg/m3)Toxic, causes burns, may cause cancer, sensitiser0.8 ppm typical threshold of perception0.98ppm typical threshold of recognition1-2 ppm typical threshold of irritationAt 0.3ppm up to 20% of people will not be protectedChemWatch Blue

Formalin if you can smell it, it is above the ES but 30 % will still be affected at that level

Butyric Acid 0.0028 0.00056 ppm

Other chemicals the perception or recognition level may be above the ES

31Odour Fatigue Is the temporary, normal inability to distinguish a particular odor after a prolonged exposure to that airborne compound.

Goodie Bag 8 & 9 perfume & coffee

Odour fatigue is an example of sensory adaptation, the body becomes desensitized to stimuli to prevent the overloading of our nervous system, thus allowing it to respond to new stimuli that are out of the ordinary.

Thus using smell as a detection tool for exceeding ESs is not satisfactory.

Coffee beans at perfume counter

32ActivitiesWine Odour QuizTabulation of ResultsSample 1-5 white wineSample 6-10 red wine but some overlap

15 mins Back at 1 pm33Australian Curriculum - SensesFoundation Year - Science as a Human EndeavourNature and development of scienceScience involves exploring and observing the world using the senses (ACSHE013)

Foundation Year - Science Inquiry SkillsQuestioning and predictingRespond to questions about familiar objects and events (ACSIS014) Planning and conductingExplore and make observations by using the senses (ACSIS011) Taste & smell not mentioned specifically34Australian Curriculum Year 9 - Science UnderstandingBiological sciencesMulti-cellular organisms rely on coordinated and interdependent internal systems to respond to changes to their environment (ACSSU175)

Year 9 - Science Inquiry Skills

Year 8 - Science UnderstandingBiological sciencesMulti-cellular organisms contain systems of organs that carry out specialised functions that enable them to survive and reproduce (ACSSU150)

Year 8 - Science Inquiry Skills

35Science Inquiry SkillsTaste & smell experiments are simple cheap and interesting enough to explore and for students to design their own experiments.Science Inquiry SkillsQuestioning and predicting

Formulate questions or hypotheses that can be investigated scientifically (ACSIS164)

Plan, select and use appropriate investigation methods, including field work and laboratory experimentation, to collect reliable data; assess risk and address ethical issues associated with these methods (ACSIS165)

Select and use appropriate equipment, including digital technologies, to systematically and accurately collect and record data (ACSIS166)

Processing and analysing data and information

Analyse patterns and trends in data, including describing relationships between variables and identifying inconsistencies (ACSIS169)

Use knowledge of scientific concepts to draw conclusions that are consistent with evidence (ACSIS170)

Evaluate conclusions, including identifying sources of uncertainty and possible alternative explanations, and describe specific ways to improve the quality of the data (ACSIS171)

Critically analyse the validity of information in secondary sources and evaluate the approaches used to solve problems (ACSIS172)

CommunicatingCommunicate scientific ideas and information for a particular purpose, including constructing evidence-based arguments and using appropriate scientific language, conventions and representations (ACSIS174)

36ResultsDry tongue, no tasteNo smell, little tasteNumber of taste budsTaste threshold of SweetTaste threshold of SourTaste threshold of SaltyTaste threshold of Bitter

Summary of results will be put on my Webpage in 2 weeks time37Toothpaste & OJSodium Lauryl Sulfatelowers the surface tension of the saliva in your mouthsuppresses your sweet receptorsdestroys phospholipids thus removing an inhibitors on your bitter receptors

SLS dulls the sweetness and promotes the bitter taste in orange juice.

The foaming agent found in almost all toothpastes. Sodium lauryl sulfate (SLS) is a surfactant , it lowers the surface tension of the saliva in your mouth and allowing bubbles to form, it suppresses your sweet receptors, & destroys phospholipids. These fatty compounds act as inhibitors on your bitter receptors. So by inhibiting sweet receptors and destroying phospholipids, SLS dulls the sweetness and promotes the bitter taste in orange juice.

38Answer to Wine QuizWhite Wine Mint Lime Honey Vanilla Lemon

Red WineBlackcurrant Tobacco Pepper Chocolate Raspberry

39RefereneceThe majority of information came from Wikipedia.Other references are indicated on individual slides or curated at: http://www.scoop.it/t/taste-and-smell

Plus:Page 18 - Dehlia Smith, How to Cook, Book 2, 1999, BBC Worldwide Ltd London. - TV Series & book

40WeeblyCopy of powerpoint & handout: http://sherylhoffmann.weebly.com/

Goodie bag 10 Menz Crown mint to clear the palate

41130513.1750: A sense of sweetnessHealth ReportHealth Report2013Podcast574488.0eng - We're going to test your sense of sweetness, so get yourself a lolly before the show. presenter: Dr Norman Swan; producer: Brigitte Seega;