Sensory Integration: Understanding and Meeting Your Child’s
Understanding Sensory Analysis of Drinking Water
Transcript of Understanding Sensory Analysis of Drinking Water
Understanding Sensory Analysis of Drinking Water:
Challenges for Describing Taste and Odor
Andrea M. DietrichProfessor, Civil and Environmental Engineering
OUTLINE
•T+O in Drinking Water
•Human Senses of Taste and Smell
•Communicating T&O
•Moving forward
• Sensory Monitoring and Analysis of Taste, Odor, Color, and Turbidity for aesthetic and algal/cyanobacteria problems.
HUMAN sense of odor, taste, and sight are essential!
• Chemical Analysis to determine the identity of and measure the concentration of the problem compound
• Treat and Remove Once the cause of the taste/odor/color is known
Burlingame, GA. Solving Customers’ Taste and Odor Complaints –Opflow, 1999. Dietrich, Aesthetic Issues in Drinking Water, JW&H, 2006.Burlingame. Diagnosing Taste and Odor Problems Field Guide, AWWA, 2011.Lauer. Water Quality Complaint Investigator’s Field Guide, AWWA, 2011.Dietrich, Phetxumphou, and Gallagher. Water Research, 2014.
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Keys to Solving Aesthetic Issuesin Drinking Water
Data customers provide
1. Description of problem2. Location of problem3. Number people/type of
residence affected
1. Is this routine or serious?2.GIS‐ spatial cluster3. Prevalence of problem
How Water Industry can use
TEAMWORK to identify and resolve Water Quality Issues/Concerns
REMINDER‐Water Industry depends on consumers to report for water main breaks and low pressure.
Environmental and Water ResourcesCivil and Environmental Engineering
Humans are GREAT at detecting odors and tastes Can be better than instrumentation Temperature impacts Varying sensitivities Expect 100‐, even 1000‐, fold difference between
individuals ppt detection common for air and water Genetics, exposure, culture, age Time of day, recent meal, health
Humans as Sensory Instruments
Environmental and Water ResourcesCivil and Environmental Engineering
CONSISTENCY!
What do humans want in water, foods, beverages?
Human Chemical Senses
Tasteof select tastants in water
Taste, a “Chemical” Sense5 tastes are straight forward to recognize and describe
Different receptors in mouth for each taste
About 100‐fold difference in sensitivity between least and most sensitive humans for sweet (sucrose), salty (sodium chloride) and sour (citric acid)
•Sweet•Salty•Sour•Bitter•UmamiHöchenberger, Ohla, Nutrients (2020) 1‐19.
Descriptors for the Taste of Sodium as NaCl
Literature demonstrates consensus in descriptors
Sodium has a salty taste, especially in presence of chloride. Less so with sulfate and carbonate.
Dietrich & Burlingame. 2020 Science of the Total EnvironmentPlatikanov et al. 2013. Water Research
Descriptors for of AntifreezeEthylene Glycol (OH groups)
Literature demonstrates consensus in descriptorsHydroxyl groups cause sweet taste.
Dietrich & Burlingame. 2020 Science of the Total Environment
The intriguing and variable human chemical sense of
Odorof select odorants in water
• Million+ odors – a lot to smell and name!
• Challenging for humans to recognize and describe because highly depends on memory and vocabulary
• Literature demonstrates diversity for descriptors, sometimes without consensus
Odor
Complex Human Olfactory SystemBC open textbookHumans have ~350
different types and >1,000,000 odorreceptors.
An odor receptor recognizes multiple odorants.A single odorant interacts strongly/weakly with multiple receptors.Combinations of receptors produce million recognizable smells.
Nobel Prize, 2004, https://www.nobelprize.org/prizes/medicine/2004/buck/symposia/
• Odor Threshold Concentration (OTC) is the concentration at which 50% of the population can detect an odor; which means 50 % cannot.
• An OTC range, but not often reported
• 100‐1000 fold difference in sensitivity common
• Specific anosmia common – inability to smell specific odors
Odor
Those trained in odor identification do not experience the “Natural Emotional Impact”
• Naïve subjects descriptions were individual dependent and difficult to materialize; subjective
• Trained perfumers used more objective descriptions and formal terminology; objective
Degel & Köster, 1999 Rouby et al., 2002 Chastrette, 2002
Trained vs. Naïve subjects
1.People readily Detect an odor1. “it’s different”2. “it smells”
2.More difficult to Recognize the odor
3.Even more difficult to Describe the odor
Jonsson & Olsson, 2003 Köster, 2005Dietrich, Phetxumphou, Gallagher, 2014
Linguistics of Odors
Taste and Odor Wheel
Standard Method 2170
Global Water Odors
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Global Taste and Odor Survey of Water Utilities, P. Ömür-Özbek, 2012
2012
Khiari et al., WRF 2002
More than Geosmin and 2‐MIB….
Algae and Cyanobacteria BloomsGeosmin (earthy)
2‐Methylisoborneol (musty)
Geosmin and 2‐MIB
• Both have odor threshold concentrations of 1‐10 ng/L(Rashash et al. JAWWA, 1997; Piriou et al. 2009)
• 12 ng/L is median concentration for consumer complaints (Graham et al., WRF 2000)
• Estimates are that about 15 % of the population have specific anosmias to either geosmin or 2‐MIB
2-MIBLiterature descriptors
Descriptors given by50 naïve consumers
Dietrich, Burlingame. Science of the Total Environment, 2020
Phetxumpou et al., JAWWA 2017
Environmental and Water ResourcesCivil and Environmental Engineering
Lab staff
Operators
Consumers
2‐MIB ‐MUSTY, earthy, moldy
earthy
musty
dirty
medicinal
mothballsammonia
camphorcloves
grassy
leather
moldy-bread
old-lady-perfume
restroom
smokey
weak-pinesol
earth
y
musty
dirty
grassy
flow
ers
mild
ew
pinesol ammonia
cave fu
ngal
gras
s
hunt
ing-
cove
r
medicinal
mol
d
moldy
mus
hroo
ms
old-dudes
piney
shoe-polish
soil
wax
wet
dirt
medicine
mustysoil
camphor
chlorine
cleaner
drug
earthy
male-musk
medicinalmib
mold
moldy-breadmoth
mothballs
no-idea
not-good
pillsstagnant-pond
wet-wood
Dietrich, Phetxumphou, Gallagher; Water Research, 66:63‐74, 2014.
LAB = Operators > Consumers
Odor threshold 1‐10 ng/L around world Customer complain at ~12 ng/LUtilities 10 ng/L guideline
Geosmin
Phetxumpou et al. JAWWA 2017
Descriptors given by50 naïve consumers
Summary: Geosmin and 2‐MIB
•Experience with these odors matters
•Water utility personnel are better at describing as “earthy, musty” than typical customer smelling their tap water
HALOANISOLESEarthy, Musty, Moldy
INCREASING Odor Episodes by these Compounds
• 0.01‐100 ng/L haloanisoles in tap water from 22 cities
• 2,4,6‐trichloroanisole most odor, some 2,4,6‐tribromoanisole
• 2,3,4 and 2,3,5 –trichloroanisole frequently present below OTC
• Positively correlated with drinking water chlorination
• Greater concentrations in summer than winter
N. Zhang et al., Water Research, 2016
Haloanisoles
Malleret and Bruchet, JAWWA 2002; Díaz et al. JAFC 2005
K. Zhang et al. Envir Poll. 2016; N. Zhang et al. Water Res. 2016
45° GC-O
Earthy, Musty, Moldy Haloanisoles
•Focus 2,4,6‐trichloroanisole from 2,4,6‐TCP•Biomethylation: O‐methyltransferases in bacteria, actinomycetes, fungi, CYANOBACTERIA and ALGAE
•Rates of biomethylation affected by water quality and temperature
K. Zhang et al. Envir Poll. 2016
Haloanisolesvariable descriptors
2,4,6-Tribromoanisole 2,4,6-Chloroanisole
Descriptors given by50 naïve consumers
Pyrazines•Produced from cooking – pyrazines are the reaction product of a simple sugar and an amino acid
• “Roasted” flavor is desirable in many foods, but not water•Meat•Coffee•Nuts
Baneras et al. Food Chem, 2013Wang et al. Water Research 2020
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mustysweet
pungent
grassy
earthyirritatingfloral
personal-care-products
metallic
chemical
unpleasantgreen
burnt
nutty
plastic
woody
solventmustysweet
chocolate
earthynutty
grassy solventcoffeeburnt
candyirritating
rubber-smellpungent
medicinal
greenmetallic
plant-smell
almond-like
fragrantroasted
unpleasant
woody
cheese
copper
licorice
cleaningagent
food-smell
chemicalsmoky
green
plastic
chlorox
benzenes
medicine
orange
vinegar
sharpodor
lemon
muddy
mustychocolate
sweet
earthy
grassyirritatingnutty
pungentsolvent
coffee
rubber-smell
medicinal
green
chemicalcandy
foul
almond-like
copper
licoricesweat-smell
organic
spicy
sharp
cheeseroasted-hazelnut-like
dirt
chlorox
plant-smell
burnt-plasticsoap-laundry-products
baking
floral
sea-weed-smell
rancid
bitter
dusty-smell
metallic
sweetirritating
mustyfloralpungent
grassyunpleasant
fired-corn
rice-boiling-smell
personal-care-products
smoke
roastedsweat-smell
cheese
rubber-smell
sweetsolvent
pungent
musty
sulphurous
pine-tree-smellmedicinal
burnt
organic
plastic
fruity
candybenzene-smell
soap-laundry-products
floral
irritating
eggshell-like
acid
rubber-smell
salty-mixed-smell
woodydeodorant
personnel-care-products
rancidchocolate
chemicalalcohol
spicy
earthy
vinegar
personal-care-products
glue-like
sour
bad-odor
metallic
pyrazine 2,6-dimethyl-pyrazine 2,3,5-trimethyl-pyrazine
3,5-dimethyl-2-methoxypyrazine 2,3,5,6-tertramethyl-pyrazine
Wang et al., Water Research, 2020
Naming the Odor, so that everyone understands the problem, is key to solving an odor problem. So
many earthy, musty, moldy odorants and descriptors increases challenge to implement.
Sensory Monitoring
Chemical Analysis
Treat and Remove
Other Common Odorants and Their Descriptors
Odor of Hydrogen sulfide, H2S
Dietrich and Burlingame, Sci. Total. Envir. 2019Carneiro et al. Sci. Total. Envir. 2020
Literature demonstrates consensus in descriptors
• Sometimes, lack of consensus for descriptors
•N‐Heptanal(lipid oxidation product of cell walls, especially algae)
Odor, a “challenging” Sense
Dietrich and Burlingame, Sci. Total. Envir. 2020Carneiro et al. Sci. Total. Envir. 2021
Do Chlorinated Water Drinkers Like Chlorine?
• A study of French consumers…
•No significant difference in chlorine flavor threshold between chlorinated tap water and non‐chlorinated water consumers
• Chlorinated tap water consumers gave a higher liking score for chlorinated solutions and were more inclined to accept these solutions as drinking water.
•Hedonics/Preference vs. Detection/ThresholdPuget et al, Water Research 2010
Environmental and Water ResourcesCivil and Environmental Engineering
CONSISTENCY!Provide “language” tools
HOW TO ASSIST CONSUMERS with DESCRIPTORS
_____ Astringent/Aftertaste_____ Bitter_____ Cardboard_____ Chemical/Solvent_____ Chlorine/Swimming _____ Citrus/Orange/Lemon_____ Earthy/Dirt_____ Flat/Stale_____ Fishy_____ Gasoline_____ Grassy_____ Metallic_____ Mineral‐like_____ Muddy_____ Musty/Moldy/Damp _____ Plastic_____ Salty_____ Shoe‐Polish_____ Sulfurous/Rotten Egg/Sewage _____ Sweet_____ Other
Assessing Consumers’ Ability to Describe Odors
1. Naïve, Untrained Consumers asked to describe single odorant in vials.
2. 2 months later, same subjects given 5‐10 min of instruction about wheel.
3. After instruction, asked to again describe the odorants.
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General categoriesInner wheel
Specific categoriesOuter wheel
Phetxumphou, et al. 2017. Implementing the drinking water taste-and-odor wheel to improve consumer lexicon. JAWWA, 109(11)
McNemar’s Test: p‐value
3.8x10‐4
InterpretationT&O Wheel significantlyimproved consumer
descriptionPhetxumphou et al. JAWWA 2017
Pre‐wheel2‐mos later with wheel
Naïve Consumers Describing 2‐MIB
Untrained Consumers Describing Odors with
T&O WheelQuestions to Consumers Response
Would you prefer to have a copy of the T&O Wheel to identify aesthetic problems? 92 % yes
How helpful would theT&O wheel be for describing the general category of the odor? 94 % helpful
How helpful was having a copy of the T&O Wheel in improving your ability to identify specific odors? 78% helpful
Phetxumphou, Raghuraman, Dietrich. 2017. Implementing the drinking water taste-and-odor wheel to improve consumer lexicon. JAWWA, 109(11)
T&O Check-If-Apply List
Another approach is to use check lists, which are common in the food and beverage industry.
Both consumers and water industry personnel can use.
_____ Astringent/Aftertaste_____ Bitter_____ Cardboard_____ Chemical/Solvent_____ Chlorine/Swimming Pool/Bleachy_____ Citrus/Orange/Lemon_____ Earthy/Dirt_____ Flat/Stale_____ Fishy_____ Gasoline_____ Grassy_____ Metallic_____ Mineral‐like_____ Muddy_____ Musty/Moldy/Damp Basement_____ Plastic_____ Salty_____ Shoe‐Polish_____ Sulfurous/Rotten Egg/Sewage _____ Sweet_____ Other
Carneiro et al. Science of the Total Environment, 2021Dietrich, A.M., Burlingame, JAWWA, 113(3) 33-42, 2021
Consumer Testing of Check‐If‐Apply:It works!
Check‐If ApplyDESCRIPTORS
Water Samples
Intense
Not selected
Salty
MetallicAstring.
EarthyMusty
Carneiro et al.; Sci. Total. Envir, 2020
Summary
• Customers and utility staff work collaboratively on aesthetic issues
• The common language provided by the Wheel or Check‐If‐Apply T&O List improves:
• dialogue
• consistency of descriptors
• easy of electronic data tracking
AcknowledgementsAesthetic Quality and Perception Committee
Djanette Khiari
Gary Burlingame
Anastasia Nicoloudakis
Rita Kopansky
Dennis O’Connor
… and all the human subjects who provided taste and odor data.
Colleagues, students
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