The Elements of Taste Flavor in Fruits and Vegetables

1. The Elements of TasteFlavor in Fruits and Vegetables Chuck Marr K-State Research and Extension Horticulture

2. A New Area of Study • Anatomical and sense in 1920s and 1930s • Organoleptic differences • Modern ‘sensory analysis’ began in 1950s • First book on ‘sensory analysis’ in 1959 Taste or flavor characteristics of fruits and vegetables not very important in the ‘selection factors’ used by plant breeders until recently. Now being factored in along with other characteristics.

3. Topics • Difference between taste and flavor • How we perceive taste and flavor • Differences among us • Measuring or predicting flavor • Some ways we can determine flavor differences

4. Taste • We are able to taste only 4 things • Sweet • Sour • Salty • Bitter • These are sensed in specific locations on the tongue

5. Taste sensation areas on the tongue Bitter Sour Salty Sweet

8. Moves into taste bud in liquid (saliva or juice) Initial taste fades quickly- must be rejuvenated with a new movement of liquid

9. Trigeminic Receptors or “Pain Receptors” in the mouth • Hot- (Capsaicin in hot peppers, mustard oil in radish, mustards) • Cold- (Menthol, cucurbitacin in cucumber) • Astringent (Pucker in persimmon) Induce a pain response. Tolerance varies among individuals. May build up a resistance

10. Taste- A little controversy • We are able to taste only 4 things • Sweet • Sour • Salty • Bitter • Orientals claim to taste another • Umami (you mommy)- Glutamate Evidence is that it appears to be a legitimate taste factor; however, it is unknown where the taste is sensed on the tongue.

11. Taste Combinations • Sweet-Sour • Sugar Acid Ratio • Sweet- Salty We can mask or alter some tastes by combinations with others. For example, we can make taste less sour by adding sweet…. Actual acidity or sweetness levels may not be exact reflections of what we taste. Taste + Trigeminic Responses Sweet - Hot

12. Taste vs Flavor • Taste- those 4 tastes determined by the tongue • Flavor= Taste + Aroma or Smell While we can only determine 4 taste factors, it is estimated that we can differentiate over 10,000 aromas or flavors in foods.

13. Aroma is sensed in the nasal passages and usually is a volatile or aromatic compound that moves into the nasal chamber. Aroma is slower to respond that taste because it’s beyond the tongue.

14. Flavor Aroma • May be able to sense prior to entering the mouth. • May activate or excite the tasting process= “mouth watering” saliva formation anticipating a pleasant taste sensation • Lots of pleasant and unpleasant sensations- some very closely related

15. Important volatile compounds influencing flavor Aromatic compound group- example compound= edible crop example • Hydroxy compounds- geosmin=“earthy” • Aldehydes- hexenal=apples • Ketones- 2,3 butanedione=celery • Acids- acetic acid=vinegar • Esters- methyl anthranilate= Concord grape • Sulfur compounds- dimethyl sulfide=asparagus • Oxygen hetrocycles- furaneol= pineapple • Nitrogen hetrocycles- pyroles= peppers • Sulfur heterocycles- thiophenes= fried onion • Other compounds- iodine=edible seaweed

16. Aroma as part of food flavor • Compounds that form the primary flavor of a fruit or vegetable are called “character-impact compounds” There are several classes of foods where these compounds can be identified and duplicated. • Largely 1 compound • Mixture of a small number of compounds • Large number of compounds- no single one • Foods that number of compounds is so large or complex that we can’t duplicate

17. Some foods with character-impact compounds

18. Flavor complex in tomato Sugars Volatile flavor compounds hexanal trans-2-hexanal cis-3-hexanal cis-3-hexen-1-ol 2-isobutylthiozole Acids (primarily citric)

19. Saturation when additions don’t create a sense of increases May become disagreeable or cause you to lose sensation if concentration is too great Taste Sensation Increases Threshold when you can first sense No 2 people may be the same in when the threshold occurs or when saturation occurs or how long saturation lasts until a decline starts. Concentration of Taste or Flavor Element

20. Differences Among Us • Age • Youth- sweet • Older- bitter • Age dulls the senses • Illness or physical limitations (colds, etc) • Male vs female • Musk aromas sensed differently • Ethnicity or background • What we like established by what we’re exposed to • “Life Altering Experiences”

21. Sensory Analysis Methods Trained ‘taste panel’- 3-5 Expert panel- 5-10 Consumer preference 40-50

22. Quantifying Sensory Analysis • Triangle test (3 samples- 2 the same) • Hedonic ratings (1-10 scale) • Offer several sub questions • Taste, color, texture, eye appeal, etc • Be very specific in establishing the questions • How used, family likes, economy, etc

23. Several other components of flavor • Texture or ‘mouth feel’ • Grainy, mushy, crunchy, slimy, chalky • Color • Appealing color for the product Both these factors are independent of taste or flavor but contribute to our determinations of sensory quality.

24. Predicting Sensory Quality • pH- acidity • Optimum size or maturity index • Refractometer (sugar content) • Instron ‘shear press’ (tenderness) • Chromatography (gas or liquid)