1209feat_swetteners

8/3/2019 1209feat_swetteners

1/6

BY GREG HORN

Humans sense ve dierenttypes o taste sensations,namely sweet, sour, bitter,

salty, and umami (savory). Theseve taste sensations were key in ourevolutionary development sincesweet oods have high energy con-centration and poisonous chemicalsin oods are typically bitter.

To improve the taste o oods,favor modication has been prac-ticed or centuries with some

historical signicance. For example,the spice trade during the Mid-dle Ages and the civilizations thatsprang up to support this commercewere partially driven by the need tomake stale or spoiled oods more pal-atable (Burdock, 2003). Licoriceroot is described in writings, inthe latter part o the Hans Dynastyin China, as a favoring substanceto improve the taste o herbaldrugs (Kitagawa, 2002).

For the past ew centuries, the

Japanese have been using driedseaweed, dried mushrooms, and

other natural sources o umamisubstances in their daily cookingto improve the taste o their meals.Over a century ago, a Japanesescientist identied glutamic acidas a favor-enhancing ingredientin seaweed. Vanillin, commonlyused to mask o-taste and pro-vide sweetness in some oods andbeverages, was known to be a fa-voring chemical as ar back as 1816and was rst extracted in its pure

orm rom vanilla beans in 1858(Matheis, 2007).

Taste Mechanism

Previously, it was believed thatthe tongue had specic areas thatsensed only one type o favor sen-sation. For example, sweetnesswas thought to be only tasted onthe tip o the tongue. Later, it washypothesized that taste buds acrossthe tongue and in some parts othe mouth could detect every

type o favor. Research in the late1990s and 2000s has shown that

Understanding taste modifers and avor enhancersfacilitates the formulation of better-tasting foods

and beverages with high-intensity sweeteners.Taste

HarmonizingSweetness&

pg 2020 12.09 www.ift.org


2/6

Flavor enhancers and taste modiers allow high-intensity

sweeteners to taste more like sucrose in beverage applications.

Photo copyright iStockphoto.com/vr joyner.

12.09 www.ift.org pg21


3/6

the receptor sites on the taste buds

can detect only one type o tastesensation but there can be hun-dreds o receptor sites on eachtaste bud. The receptor sites orsweet, umami, and bitter containdierent proteins that couple toorm receptors that are unique oreach type o taste sensation (Liet al., 2002; Wenner, 2008).

Not all sweeteners use thesame sensing mechanism and there

are a small number o sweetener-activated mechanisms (Halpern,

2002). The primary sweetness tastereceptor is the G-protein com-plex ormed rom T1R2 and T1R3proteins. Salt and sour tastes aredetected via ion channels, whichare an assembly o proteins. Thehydrogen ion channels detect theconcentration o hydrogen ionsrom acids and lead to the per-ceived sourness o oods. Saltinessis a taste that is primarily rom thepresence o sodium ions. Ions oother alkali metals provide salti-

ness but to a ar lesser degree. Onthe tongue, there are very slight

regional dierences in sensitivity

to the various taste sensations butthese dierences are minimal.

Sweeteners

Sweetness can derive rom simplecarbohydrates like sucrose, glucose,and ructose, rom some aminoacids like alanine, glycine, and ser-ine that are mildly sweet, and romhigh-intensity sweeteners that are10025,000 times sweeter than

sucrose. High-intensity sweetenerscan be classied into two groups:

1. Articial, chemically synthe-sized sweeteners include sucralose,alitame, cyclamate, aspartame, neo-tame, potassium acesulame, andsaccharin (which was discoveredaccidentally in 1878).

2. Natural high-intensity sweet-eners are extracted rom variousplant sources. Examples o thesesweeteners are extracts rom Steviarebaudiana (Figure 1), luo han guoruit, and glycyrrhizin rom licoriceroot. Sweet-tasting proteins rom

the ruits o Arican plants are alsobeing commercialized and include

thaumatin rom Thaumatococcus

daniellii, monellin rom Dioscoreoph-yllum cumminsii, and brazzein romPentadiplandra brazzeana (Kinghornand Compadre, 2001). Lysozymerom egg whites is also a sweet-tasting protein. The dierence inthe density o charged amino acidson the protein surace may resultin varying threshold values orthe sweet-tasting proteins, therebyresulting in diering levels operceived sweetness (Masudaet al., 2005).

The increased demand orhigh-intensity sweeteners isdriven by consumers concern orweight management. The WorldHealth Organization estimates thatthere are over one billion peo-ple globally who are overweight,400 million o which are obese.Unortunately, these numbers areexpected to nearly double by 2015(WHO, 2006). Launches o newproducts containing stevia extractshave risen while those o arti-

cial sweeteners have decreased asconsumers want no calorie, yetnatural, sweetening alternatives(Figure 2).

Formulation Challenges & Solutions

To a varying degree, high-inten-sity sweeteners have inherent favorissues associated with them. Themost common issues are a delay inthe onset o the perceived sweet-ness, a lingering sweetness, bitteratertaste, metallic atertaste, a non-

linear sweetener concentration tosweetness equivalency ratio, adap-tation or desensitizing, and a lacko moutheel or body. Additionally,many o the high-intensity sweeten-ers extracted rom plants have anherbal or licorice-type favor.

The delay in the onset o theperception o sweetness and theirlingering sweetness is hypothesizedto be caused by two accompany-ing reactions. One reaction is thedirect interaction o the high-inten-

sity sweetener with the G-proteincoupled receptor site or sweet

Figure 1. Natural high-intensity sweeteners are extracted from various plant sources, such as Stevia rebaudiana.



4/6

taste. The other co-occurring

reaction happens once the high-intensity sweetener permeatesinto the taste bud and is past theG-protein coupled receptor site.The sweetener directly activatessites that transport stimuli intothe nervous system, alerting ourbrain that we have eaten somethingsweet (Naim et al., 2002).

Flavor enhancers and taste mod-iers have been used to improve thetaste o oods or centuries. Flavorenhancers contribute a favor to the

product and are used to round outthe sweetness prole or to mask o-favors. The mechanism deployedby taste modiers can be adaption,cross-adaption, taste blocking, andtaste modiying.

Adaptation and cross-adaptationare orms o atigue. Adaptation isachieved by continuously exposingthe taste receptors to a particu-lar taste stimulus, resulting in thelavor perception ading rapidly.Cross-adaptation is when adaptation

o one taste may increase or lowerthe taste threshold o perception oranother taste. An example o this isthe use o sweeteners in medicinesto suppress their bitter favor.

Taste modication occurs whenconsumption o a compound creates anew perception o the taste o a ood.Tart oods will taste sweet i miracu-lin, the protein rom the miracleruit, is rst consumed. Taste blockersare compounds that prevent the per-ception o some or all o the favors.

The classic example o this mecha-nism is the utilization o cloves or anoral analgesic (Foster, 2007). Anotherexample o a taste blocker is gymne-mic acid, rom the leaves o an Indianvine, that suppresses the sweet taste.

Bitterness reduction is animportant requirement or manyhigh-intensity sweeteners to improvetheir consumer appeal. Organicacids such as aspartic and glutamicacids are known to reduce bitterness(Noguchi et al., 1975). Some o

the amino acids, such as glutamicacid and taurine, have been shown

to reduce bitterness o some, but

not all, o the common bitter com-pounds. The bitter taste o potassiumacesulame can be reduced by theaddition o DL-alanine and gly-cine. These amino acids contributea slightly sweet taste. Sclareolide,a natural favor chemical, has beenshown to reduce the bitterness inpotassium chloride-based salt substi-tutes, coee, and citrus ruits.

Mouthwashes typically employfavors with a cooling eect to maskbitterness and this approach may

also be a benet in some oods andbeverages. Menthol, mint oils, or

the aroma chemicals enchone, bor-neol, or isoborneol have all beenused commercially to reduce bitter-ness in oral pharmaceuticals.

In addition, increasing theviscosity o a ood product contain-ing high-intensity sweeteners candecrease the rate o diusion o thebitter compounds rom the ood tothe taste buds, thereby decreasingthe bitterness (Roy, 1997). WILDFlavors, Inc. oers a natural, botan-ical extract to reduce bitterness ohigh-intensity sweeteners as wellas other bitter compounds. Thisextract is hypothesized to block thebitter compounds rom the recep-

tor site (Gray, 2002). Most bitterblockers used in the ood indus-

try have little favor or odor at their

typical use level but help suppresso-favors in ood.

Flavor enhancers allow high-intensity sweeteners to taste morelike sucrose. Common favor ingre-dients that increase the uprontsweetness and provide more sugar-like notes are strawberry uranone,maltol, ethyl maltol, and vanillylssuch as vanillin and ethyl vanillin.Use caution when selecting the uselevel o such ingredients; overusemay create favors akin to pancake

syrup, cotton candy, or burnt sugarnotes. Also, not all o the chemicals

listed are considered natural. Theaddition o aconitic acid or gluconicacid is reported to improve the fa-vor and provide a slight umami

eect, resulting in a uller mouth-eel (Roy, 1997).

Glycyrrhizin and other gluc-uronide-saponins o licorice roothave a sweet taste and can be usedto augment the favor proles oother high-intensity sweeteners(Kitagawa, 2002). Ammoniatedsalts o glycyrrhizic acid are com-mercially produced lavoringagents that are approximately 50times sweeter than sucrose. Theaddition o other plant constitu-

ents, such as cynarin, chloragenicacid, and caeic acid, can provide

Figure 2. Launches of new beverages containing high-intensity sweeteners.

Sucralose

Potassium Acesulfame

Aspartame

Stevia

180

160

140

120

100

80

60

40

20

0

2005 2006 2007 2008 2009

Source: Mintel GNPD 2005October 2009

Numb

erofProducts

Beverage Launches USA 2005October 2009



5/6

a more sugar-like lavor proile(Kinghorn and Compadre, 2001).Considered an artiicial lavoringagent at restricted levels, neohes-peridan dihydrochalcone can be

added to high-intensity sweetenersto modiy the sweetness prole andreduce bitterness.

Sugar alcohols and other polyolsprovide sweetness and moutheel toproducts containing high-intensitysweeteners. Glycerol can increasethe sweetness, and at higher levels,can heighten the perceived vis-cosity (Noble and Bursick, 1984).Sugar alcoholssuch as erythritol,mannitol, xylitol, and sorbitoleectively add back moutheel and

body to oods ormulated withhigh-intensity sweeteners. Also,

these sugar alcohols have varyingdegrees o sweetness and coolingeect. Except or erythritol, sugaralcohols may cause gastrointesti-nal distress when consumed at high

levels, making them inappropriateor use in beverages because o theirlarge serving sizes.

A unique approach to modiyingthe sweetness perception involvesthe role o water in sweet taste per-ception. The addition o solutes willinteract with the water structure.Salts, such as sodium gluconate,decrease the apparent speciic vol-ume o high-intensity sweetenersand subsequently alter the tasteperception and decrease the pos-

sibility o tasting bitter. This roleo the water structure may also

explain the observed synergistic

eect o salt-structured, high-inten-sity sweeteners, such as sodiumsaccharin, potassium acesulame,and sodium cyclamates, with bulksweeteners. A 50:50 mixture osodium cyclamate with maltitol hada 27% synergy level (Birch, 2002).

Stevia and Beyond

Enhancing the taste o high-intensitysweeteners is a growing oppor-tunity as consumer demand orreduced-calorie products rises.

Reduction o bitter and metallictaste has been achieved and manyfavor houses oer commerciallyproduced bitter blockers and/orfavor masking agents.

WILD Flavors recently devel-oped a sweet taste modiier orrebaudioside (Reb) A 60%, a steviaextract with 95% steviol glycosidesand deemed a GRAS sweetener oroods and beverages in the UnitedStates. By using a trained sensorypanel, many o the attributes o Reb

A 95% were matched with Reb A60% and taste modiers (Figure 3).In act, two attributesimprovedonset o sweetness perception andless sour tastewere judged to bebetter or Reb A 60% with tastemodiers than or Reb A 95%.

A large consumer panel o morethan 300 people sampled sportsdrinks made with Reb A 95% orReb A 60% with taste modiers. Theresults demonstrated no signicancein taste preerence between the two

drinksa breakthrough since Reb A95% is approximately twice as expen-sive as the Reb A 60% with tastemodiers (WILD Flavors, 2009).

The uture looks bright as favorhouses, suppliers o high-inten-sity sweeteners, packaged goodscompanies, and contract researchacilities work together to explorenew techniques to rapidly and cost-eectively test new compoundsor improving the taste o high-intensity sweeteners and to improve

our understanding o the mechanismo perceiving sweet tastes. Govern-

Figure 3. Improving the taste of stevia with taste modiers.

Reb A 95% Reb A 60% + Taste Modifers

Upfront Sweetness

6

5

4

3

2

1

0

Lingering Sweetness

Acid/Sour

Body/Mouthfeel

Astringency

Bitterness

Metallic

Balance

Cooling

Overall Acceptance



6/6

mental pressure or healthier oods products and consumer demand or lower-calorieproducts will continue to uel this research.FT

Greg Horn is Senior Director, WILD Flavors, Inc., 1261 Pacic Ave., Erlanger, KY 41018 ([email protected]).

The author would like to thank J. Jones-Dille, S. Seiler, and K. Sparks for their assistance in writing this article;

and for his wife, Astrid, for all her support throughout the years.

R E F E R E N C E S

Birch, G. 2002. Role o water in sweet taste chemo-reception. Pure Appl. Chem. 74(7): 1103-1108.

Burdock, G. 2003. Sensory deception: the scienceo making oods more palatable. Func. Ingred.www.unctionalingredientsmag.com. AccessedOct. 30, 2009.

Foster, R. 2007. Flavor mask-erade. Food Prod.Design. www.oodproductdesign.com. AccessedOct. 23, 2009

Gray, K. 2002. Functional favours - usingResolver technology to blocks o-tastes. Drink.Tech. and Mktg. 6(1): 5-8.

Halpern, B. 2002. Taste. Chpt. 16 in StevensHandbook o Experimental Psychology, Sensation,and Perception. eds. S. Yantis and H. Pashler, pp.

653-690. John Wiley & Sons, Inc. New York.Kinghorn, A., and Compadre, C. 2001. Less com-mon high-potency sweeteners. Chpt. 12 inAltenative Sweeteners. ed. L. OBrien Nabors, pp.209-234. Marcel Dekker, Inc. New York.

Kitagawa, I. 2002. Licorice root. A natural sweet-ener and an important ingredient in Chinesemedicine. Pure Appl. Chem. 74(7): 1189-1198.

Li, X., Staszewski, L ., Xu, H., Durick, K., Zoller,M., and Adler, E. 2002. Human receptors or sweetand umami taste. Proc. Nat. Acad. Sci. USA. 99(7):4692-4696.

Masuda, T., Nobuyuki, I., and Kitabatake, N. 2005.Structure-sweetness relationship in egg white lyso-zyme: role o lysine and arginine residues on theelicitation o lysozyme sweetness. Chem. Senses30(8): 667-681.

Matheis, G. 2007. Flavour modiers. Chpt. 3.3.4 inFlavourings: Production, Composition,Applications, Regulations. ed. H. Ziegler, pp.351-370. Wiley VCH Verlag GmbH & Co.Weinheim, Germany.

Naim, M., Nir, S., Spielman, A., Noble, A., Peri,I., Rodin, S., and Samuelov-Zubare, M. 2002.Hypothesis o receptor-dependent and receptor-independent mechanisms or bitter and sweet tastetransduction: Implications or slow taste onset andlingering atertaste. Chpt. 1 in Chemistry o Taste:Mechanisms, Behaviors, and Mimics. eds. P. Givenand D. Paredes. pp. 2-17. American ChemicalSociety, Washington, DC.

Noble, A., and Bursick, G. 1984. The contributiono glycerol to perceived viscosity and sweetness inwhite wine. Am. J. Vitic. 35(2): 110-112.

Noguchi, M., Yamashita, M., Arai, S., andFujimaki, M. 1975. On the bitter-masking activityo a glutamic acid-rich oligopeptide raction. J. FoodSci. 4 0: 367-369.

Roy, G. 1997. General ingredient or processapproaches to bitterness inhibition and reduction inoods and beverages. Chpt. 5 in ModiyingBitterness: Mechanism, Ingredients, andApplications. ed. G. Roy. pp.71-124. TechnomicPublishing Co. Inc., Lancaster, PA.

Wenner, M. 2008. Magniying taste: new chemicalstrick the brain into eating less. Sci. Amer. www.scienticamerican.com. Accessed Oct. 20, 2009.

WILD Flavors, Inc. 2009. Unpublished data.

World Health Organization. 2006. Obesity andoverweight. Fact Sheet No. 311. www.who.int.Accessed Nov. 2, 2009.

- - -


Documents

1209feat_swetteners