Taste and Smell

6 Biochemical and Physiological Aspects of Animal

Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on May 26, 2018 | https://pubs.acs.org Publication Date: February 2, 1978 | doi: 10.1021/bk-1978-0067.ch006

Behavior: Taste and Smell G.V.ODELL,J.E.HALL, andW.E.McMURPHY Departments of Biochemistry and Agronomy, Oklahoma Agricultural Experiment Station, Oklahoma State University, Stillwater, OK 74074 J.E.McCROSKEY Department of Animal Sciences, University of Idaho, Moscow,ID83843 Considerable data has accumulated on the behavior o f animals to s p e c i f i c chemicals. The i n t r o d u c t i o n of certain chemicals i n t o the animals area will produce a p r e d i c t a b l e behavior response such as r e p r o d u c t i o n , f e e d i n g , alarm, attraction, r e p e l l e n c e or defense. Taste and s m e l l by animals will be the two p h y s i o l o g i c a l d e t e c t i o n routes considered in this paper. An e x c e l l e n t review on sensory r e c e p t i o n covers the literature up to the e a r l y seventies as Vol. 17 o f the s e r i e s M o l e c u l a r Biology Biochemistry B i o p h y s i c s ( 1 ) . The e d i t o r V i n n i k o v and c o - e d i t o r s Kleinzeller, Springer and Wittman has covered the reported research on c y t o l o g y , molecular mechanisms and e v o l u t i o n of vision, t a s t e , s m e l l , hearing and g r a v i t y r e c e p t i o n . Many classical molecular b i o l o g y , b i o c h e m i s t r y and b i o p h y s i c a l experiments a r e reviewed (1) (Table I). As s t a t e d earlier, t a s t e , chemicals that initiate a gustatory response, and s m e l l , chemicals that f u n c t i o n as odorant molecules have been e x t e n s i v e l y s t u d i e d , first w i t h arthropods and more r e c e n t l y w i t h v e r t e b r a t e s . Since the development o f very efficient s e p a r a t i o n techniques and h i g h s e n s i t i v e d e t e c t i o n systems, we a r e no longer l i m i t e d to t a s t e panels and t h r e s h o l d odor d e t e c t i o n by humans. Table I shows some examples of the behavior response as shown by certain species f o r a specific chemical. This very l i m i t e d l i s t does not i n c l u d e m i g r a t i o n s , rhythms and many primary s e c r e t o r y processes i n i t i a t e d by a p h y s i c a l or chemical s t i m u l u s . C e r t a i n m i g r a t i o n s are i n i t i a t e d by chemical stimuli. Rhythms of organisms may be i n i t i a t e d by p h y s i c a l changes but secondary chemical processes are d e f i n i t e l y i n v o l v e d . Glandular s e c r e t i o n s such as s a l i v a t i o n and many others r e s u l t from chemical odorant molecules o r gustatory s t i m u l i . Taste V i n n i k o v (1) c r e d i t s Lomonosov (2) w i t h d i s t i n g u i s h i n g seven d i f f e r e n t t a s t e sensations — "1. a c i d , as i n v i n e g a r ; 2. c a u s t i c , as i n g r a i n a l c o h o l ; 3. sweet, as i n honey; 4. b i t t e r , as i n t a r ; ©

0-8412-0404-7/78/47-067-092$05.00/0

Bullard; Flavor Chemistry of Animal Foods ACS Symposium Series; American Chemical Society: Washington, DC, 1978.


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Taste and Smell

Table I Species Response t o Gustatory and O l f a c t o r y Chemical S t i m u l i Response or Condition

Species

Chemicals or Substance

Feeding

Deer, Antelope, C a t t l e Herbivores

Essential o i l s Tannins

Reproduction

Deer Rodents

Muskone C e r t a i n grass odors (food supply)

Alarm

Deer, Antelope

Predator body odor (low molecular weight organic a c i d s )

T e r r i t o r i a l markers

Deer, Coyote, Wolf

Gland s e c r e t i o n s

Defense

Skunk, C i v e t c a t

Gland S e c r e t i o n s (skunk o i l )

Insects

Plant v o l a t i l e s (essential o i l s ) Nepetalactone (catnip)

Attractants

Cats Repellants

Insects Humans

Plant v o l a t i l e s Cadaverine, putrescine, H S (amines) 2

Death

Mammals

Amines as above


FLAVOR CHEMISTRY OF ANIMAL FOODS

94

5. s a l t y , as i n s a l t ; 6. pungent, as i n w i l d r a d i s h ; 7. sour, as i n unripe f r u i t — . With v e r t e b r a t e s a c i d , s a l t , sweet and b i t t e r can be perceived w i t h s p e c i f i c chemcials. Table I I shows the c l a s s i f i c a t i o n o f gustatory substances as made by most researchers. 1 1

Table I I Downloaded by UNIV OF CALIFORNIA SANTA BARBARA on May 26, 2018 | https://pubs.acs.org Publication Date: February 2, 1978 | doi: 10.1021/bk-1978-0067.ch006

Gustatory S e n s i t i v i t y o f Vertebrates and Some I n v e r t e b r a t e s Lomonosov Ref. 2

Other ^ Researchers*

Sweet

Sweet

C o o l i n g (menthol)

Sour

Sour (acid)

Salt

Salt

Commonly Accepted

(sugar)

Burning

(salt) Biting

Bitter

(aminoethanol) 1* (vanillin)

B i t t e r (quinine, a l k a l o i d s ) Caustic (ethyl alcohol) Pungent ( w i l d r a d i s h )

^Personal Communication ^Reference 7 The s t r u c t u r a l o r g a n i z a t i o n o f the g u s t a t o r y receptor c e l l s and t h e i r l o c a t i o n i n mammals i s w e l l described i n V i n n i k o v s review. Farbman's (3) diagram shows the stages o f development of the t a s t e bud w h i l e Murray (4) shows t a s t e buds a r e o v a l (or bulbous) i n shape and t h e i r lengths and widths a r e described. I n the I960's researchers i s o l a t e d a " s w e e t - s e n s i t i v e " p r o t e i n from t a s t e receptor c e l l s l o c a t e d i n the p o s t e r i o r p o r t i o n of p o r c i n e and bovine tongue, D a s t o l i and P r i c e ( 5 ) . The i n t e r a c t i o n of the sweet s e n s i t i v e p r o t e i n w i t h f r u c t o s e shows a s t r a i g h t l i n e assoc i a t i o n to form a complex ( 5 ) . V i n n i k o v (1) suggests more research by modern techniques i s needed on the s w e e t - s e n s i t i v e p r o t e i n as the reported molecular weight o f 152,000 (6) seems t o be w e l l e s t a b l i s h e d . I t i s t h i s author's views that t h i s may be a subunit p r o t e i n i f one considers the s t a t e o f research on the a c e t y l c h o l i n e r e c e p t o r . A f f i n i t y chromatography may be u s e f u l i n f u t u r e research on receptor p r o t e i n s even though homogeneity i s w e l l e s t a b l i s h e d f o r the s w e e t - s e n s i t i v e p r o t e i n . A b i t t e r s e n s i t i v e p r o t e i n has been i s o l a t e d and s t u d i e d by D a s t o l i e t a l . (6). This p r o t e i n was from the p o s t e r i o r t a s t e buds o f the p o r c i n e tongue and the i n t e r a c t i o n c h a r a c t e r i s t i c s w i t h four b i t t e r compounds was made. A l a r g e number of compounds i n the sweet, s a l t , sour and b i t t e r c l a s s a r e l i s t e d by V i n n i k o v (1). The e f f e c t s of the a d d i t i o n o r n a t u r a l presence of c e r t a i n components i n p l a n t s has been shown t o determine feeding s t i m u l u s . Hedin e t a l . (7) 1



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r e c e n t l y compiled the f e e d i n g a c t i v i t y o f f l a v o n o i d compounds (7) and many other organics f o r the b o l l w e e v i l . Formulation of a s t i m u l a n t f e e d i n g mixture was made and no s i n g l e component was e f f e c t i v e but 52 of 286 compounds bioassayed e l i c i t e d s u b s t a n t i a l f e e d i n g a c t i v i t y . Hedin et a l . have a l s o t a b u l a t e d compound, f l a v o r and odor i n t h e i r review ( 7 ) . Very r e c e n t l y work by Berger _e_t a l . (8) shows p h e n o l i c p l a n t substances, n a t u r a l l y o c c u r r i n g cinnamic a c i d and v i n y l phenols i n h i b i t r e p r o d u c t i o n i n Microtus montanus. This same group of workers (9) have t r i g g e r e d a r e p r o d u c t i v e response i n the same organism by p l a c i n g f r e s h green wheat grass i n a nonbreeding p o p u l a t i o n . This could be an o l f a c t o r y response as w e l l as g u s t a t o r y . McMurphy (10) observed "young forage i s more p a l a t a b l e , more d i g e s t i b l e , g r e a t e r i n percent crude p r o t e i n , g r e a t e r i n d i g e s t i b l e energy and consumed i n g r e a t e r q u a n t i t i e s than o l d e r forages." This author would suggest t h i s i s t r u e f o r most h e r b i v o r e s . I n Oklahoma there i s " N a t i v e " and "Introduced" grass s p e c i e s . The chemical composition of the n a t i v e grasses i n C e n t r a l Oklahoma has been compiled by W a l l e r et a l . (11) f o r a p e r i o d from 1947 to 1962 and provides a b a s i s f o r f u r t h e r study on gustatory response. An approach u s i n g modern s e p a r a t i o n techniques on grass preference by c a t t l e i s shown i n Tables V through V I I I . Table I I I d e s c r i b e s a gas l i q u i d column, d e t e c t o r , c o n d i t i o n s and instrument used t o separate and detect the compounds of Oklahoma n a t i v e and i n t r o d u c e d grasses. The preference was determined by hand c l i p p i n g p o r t i o n s and p l a c i n g the grasses i n c a t t l e dry feed l o t s . The grasses were a t a peak l u s h p e r i o d so t a s t e and odor were i n v o l v e d . Tables IV, V, and VI show the g r a s s , e s s e n t i a l o i l y i e l d (by d i s t i l l a t i o n and e x t r a c t i o n ) preference by c a t t l e and the number of compounds observed. Taste could not be separated from odor i n t h i s l i m i t e d study but we do see a "low p r e f e r e n c e " f o r grasses h i g h i n v o l a t i l e e s s e n t i a l o i l s . One can s p e c u l a t e the nightshade p l a n t was not consumed due to t o x i c compounds present. This a l s o suggests overgrazing o f pastures w i l l g i v e the l e s s d e s i r a b l e p l a n t s an advantage. V i n n i k o v (1) concludes the t a s t e o f s a l t s depends on the c a t i o n and anion, sour o r a c i d s t i m u l u s of the hydrogen i o n , sweet and b i t t e r on i n t r a m o l e c u l a r s h i f t s of p r o t e i n r e c e p t o r s and gustatory substance complexes. He approaches the problem from a molecular b a s i s of both substance and r e c e p t o r . Exact behavior to t a s t e has covered mostly f e e d i n g and r e p r o d u c t i o n i n t h i s paper and much more f i e l d and l a b o r a t o r y research i s needed on s p e c i f i c animal s p e c i e s .



PRIMARY

PRIMARY

ODOR

TABLE

III

ODORS

AND

CHEMICAL


CAMPHORACEOUS

MOTH

CAMPHOR

PHENYLETHYL

FLORAL

ETHYL

PUNGENT

MINT

DRY

FLUID

VINEGAR

ACID

TABLE

CANDY

CLEANING

BAD

BUTYLMERCAPTAN

ODOR

OIL

ROSES

METHYL

DICHLORIDE

FORMIC

PUTRID

ROOT

CARBINOL

ETHYLENE

ETHERAL

REPELLANT

ANGELICA

METHONE

PEPPERMINTY

EGG

IV

SENSATION

PRIMARY

ET

SUBSTANCE

EXAMPLE

PENTADECANOLACTONE

MUSKY

AMOORE

EXAMPLES

ODORS

AL.

VIA

HEDIN

ET

AL.

VINNIKOV

CAMPHORACEOUS

CAMPHORACEOUS

(1,8-CINEOLE)

PUNGENT

PUNGENT

(BENZYLAMINE)

ETHEREAL

AROMATIC

FLORAL

FLORAL

(STYRENEGLYCOL)

(FERULIC

ACID)

(METHONE)

MINTY

PEPPERMINTY

MUSKY

MUSKY

PUTRID

PUTRID

(H S

SWEATY

(ALPHA-KETOBUTYRIC

(CYCLOPENTADECANONE)

2

OR

NICOTINE)

ACID)


ODELL ET AL.

Taste and Smell

TABLE V

COLUMN


Column 4 % Injector

DESCRIPTION

OV-17 on

GC-Q;

2 4 ' X 1/4",

Detector

temp.

260° C. ( H

Flame )

temp.

120° C

Helium

flow,

4 3 ml / min ( gauge

Instrument, size

to

2

Column

Sample

Glass

temp. 180° C.

200° C.

Barber - Coleman, 3 pi

of

at

Series

concentrated

l°C./min.

setting 7 0 ) 5000

ether

soin.

Τ Λ Β Ι Ι VI

OIL

YIELD AND COMPOUNDS OBSERVED WITH SELECTED GRASSES

Common Name Marestail Prairie

Threeawn

Preference

Oil Isolated mg/kg

Compounds Observed

Low

2297

55

Low

67

64

Low

2730

51

Silver Leaf Nightshade

Low

99

54

Piper

High

30

63

Mod

39

59

Low

35

55

Louisiana

Sweet T. E.

Sagewort

Sudangrass Sudangrass Haygrazer

Broomweed

Very

Low

3851

44



TABLE V I I


ESSENTIAL OIL YIELD AND COMPOUNDS OBSERVED WITH S E L E C T E D G R A S S E S

Sample Description Big

Bluestem

Switch Little

grass Bluestem

Weeping

lovegrass

Johnson

grass

Prairie

Threeawn

Western Caucasian

Ragweed Bluestem

Preference

Oil Isolated mg/kg

Compounds Observed 64

High

17

25

58

High

33

48

59

69

58

62

High

65

Low Very

High

Low (Fair to) Low "Medium"

71 81

55

181

70

67

64

1524

56

37

60

TABLF V I I Ï

ESSENTIAL OIL YIELD AND COMPOUNDS O B S E R V E D WITH S E L E C T E D GRASSES

Sample Description

Preference

Oil Isolated mg/kg

Compounds Observed 63

S-Blend

Low

178

M-Blend

Low

277

69

LL-Blend

High

375

59

L-Blend I - Blend

High No Data

189

62

938

52


6.

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Smell Again V i n n i k o v (1) presents a review on t h i s s u b j e c t a t the molecular l e v e l . F u n c t i o n of the o l f a c t o r y organ i s suggested as a simple d i f f u s i o n of odorant molecules — "wafted around by a i r c u r r e n t s " — as they are v o l a t i l e . I n t e r a c t i o n w i t h r e c e p t o r s i n the o l f a c t o r y r e g i o n t r a n s m i t s an impulse to the c e n t r a l nervous system. One important p o i n t on s m e l l i s t h a t j u s t as w i t h t a s t e molecules of d i f f e r e n t s t r u c t u r e s , o f t e n t o t a l l y d i f f e r e n t molecules, have the same or d i f f e r e n t s m e l l . An example of rose odor i n r e f e r e n c e (1) s i t e s the work of Wright (12) where rosetone, phenylethanol, g e r a n i o l and p e l a r g o l are compounds w i t h v e r y d i f f e r e n t s t r u c t u r e s but the same s m e l l . He a l s o a t t r i b u t e s camphor s m e l l to camphor, chloroethane and e t h y l - t e r t - b u t y l ether (12). Other r e s e a r c h of t h i s type would be odorant molecules of s i m i l a r s t r u c t u r e w i t h a d i f f e r e n t o l f a c t o r y response. I n 1929 Braun (13) s t u d i e d a s e r i e s of ketones where the c a r b o n y l moved from carbon two through carbon s i x of an eleven carbon ketone. The odor ranged from rue to f r u i t y f o r d i p e n t y l ketone. These observations do not d i r e c t l y r e l a t e to behavior as t a b u l a t e d i n Table I of t h i s paper but are important on s t r u c t u r e and s m e l l . Table I I I covers a l i s t of primary odors w i t h examples (1,7). The l i s t i n g i s c u r r e n t but animal behavior i s s t i l l not covered. Amoore (14) a l s o l i s t s primary odors and chemical examples w i t h substance t a b u l a t e d i n Table IV. Amoore et a l . a r t i c l e presents the concept of o l f a c t o r y r e c e p t o r s i t e s i n t o which molecules must f i t to g i v e the odor response. A molecule could f i t one or more s i t e ( s ) to show a v a r i a b l e odor combination (14). E s s e n t i a l o i l s or v o l a t i l e o r g a n i c s of p l a n t s has a l r e a d y been shown to a f f e c t f e e d i n g , choice of food and r e p r o d u c t i o n . There i s no q u e s t i o n that organic v o l a t i l e s are r e p e l l e n t s , a t t r a c t a n t s , alarm, defense and other behavior s t i m u l i f o r animals. The word "pheremone" i n d i c a t e s a chemical t h a t e l i c i t s a s p e c i f i c animal response through o l f a c t o r y s t i m u l u s (14, 15). The f e l i n e a t t r a c t a n t , nepetalactone, has been thoroughly s t u d i e d as to s t r u c t u r e , occurrence and metabolism by W a l l e r and coworkers (16). The b i o l o g i c a l a c t i v e component i s a b i c y c l i c monoterpene l a c t o n e found i n Nepeta c a t a r i a w i t h the common name c a t n i p (17). An alarm substance has been found by the same group f o r ants (18). The i r i d o l a c t o n e s could be c l a s s e d as defense chemicals f o r t h i s s o c i e t y i n s e c t and i s s t r u c t u r a l l y r e l a t e d to c a t n i p . Another ant uses 6-methyl-5-hepten-2-one. F i e l d observers are w e l l aware of alarm substances from predators that are a i r b o r n e o r g a n i c s . Low molecular weight o r g a n i c a c i d s (sweaty), aldehydes, ketones, a l c o h o l s and amines could serve. Many a t t r a c t a n t s have been r e p o r t e d f o r i n s e c t s and would be d i f f i c u l t to d i s t i n g u i s h from t e r r i t o r i a l markers (muskone-musk


100



deer and c i v e t o n e f o r c i v e t c a t s ) . Reproduction, a t t r a c t a n t s and t e r r i t o r i a l markers become one i n these cases. I t i s a l s o o f i n t e r e s t that the p u t r i d amines of dead animals become feeding a t t r a c t a n t s f o r bear, raccoons, opossum and perhaps buzzards. C a r r i o n b e e t l e s a r e a t t r a c t e d to dead animals. Again V i n n i k o v (1) has thoroughly reviewed the p h y s i o l o g i c a l s t r u c t u r e of the o l f a c t o r y system i n mammals and arthropods. In c o n c l u s i o n we must say the o l f a c t o r y system ranks above gustatory s t i m u l i i n animal behavior. T h i s author w i l l c l o s e with a p o l o g i e s to the many r e s e a r c h e r s whose r e p o r t s were not i n c l u d e d i n t h i s b r i e f review. Other p a r t i c i p a n t s i n t h i s symposium w i l l cover much of t h i s work. Literature Cited (1)

(2) (3) (4) (5) (6) (7) (8) (9) (10)

(11)

(12) (13) (14)

(15) (16) (17)

V i n n i k o v , Ya. V., M o l e c u l a r B i o l o g y Biochemistry and B i o p h y s i c s , V o l . 17. Sensory Reception, S p r i n g e r - V e r l a g , New York, 1974 Chapters V and V I . Lomonosov, --via r e f e r e n c e (1) 1752-1757 L e c t u r e notes. Farbman, A. I . , Developm. Biol. 11, 110 (1965a). Murray, R. G. and Murray, Α., Jour. of U l t r a s t r u c t u r e Res. 19, 337 (1967). D a s t e l i , F. R. and P r i e c , S. Science 154, 905 (1966). D a s t o l i , F. R., Lopickes, D., P r i c e , S., Biochemistry 7, 1160 (1968). Hedin, P. Α., M i l e s , L. R., Thompson, A. C. and Minyard, J . P. Jour. Ag. and Food Chem. 16, 505-513 (1968). Berger, P. J . , Sanders, Ε. Η., Gardner, P. D., and Negus, N. C., Science 195, 575-577 (1977). Negus, N. C. and Berger, P. J . , Science 196, 1230-1231 (1977). McMurphey, W. E. "The Grasses and Grasslands of Oklahoma", Annals of the Oklahoma Academy of Science, E d i t o r s J . R. Estes and R. J . Tyrl, P u b l . Robert Noble Res. Fdn., Ardmore, Okla., 1976. W a l l e r , G. R., Morrison, R. D. and Nelson, A. B. "Chemical Composition o f Native Grasses in C e n t r a l Oklahoma from 1947 to 1962", B u l l e t i n B-697, Oklahoma A g r i c u l t u r e Expt. S t a . , S t i l l w a t e r , Okla., 1976. Wright, R. Η., "The Science of Smell", A l l e n & Unwin, London 1964. Braun, J . V., Kroper, Η., Wienhaus, Η., Ber. Dtsch. Chem. Ges. 62, 2880 (1929). Amoore, J . Ε., Johnston, J . W., and Rubin, Μ., "The S t e r o chemical Theory of Odor", Scientific American, Feb. 1964, W. H. Freeman and Co., San F r a n c i s c o . Wilson, E. 0., "Pheromones", Scientific American, May 1963, W. H. Freeman and Co., San F r a n c i s c o . W a l l e r , G. R., P r i c e , G. Η., and M i t c h e l l , E. D., Science 164, 1281-1282 (1969). Regnier, F. E., Eisenbraun, Ε. J . and W a l l e r , G. R., Phyto-


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chemistry 6, 1271 ( 1 9 6 7 ) . McGurk, D. J . , F r o s t , J . , Waller, G. R., Eisenbraun, E. J . , V i c k , Κ., Drew, W. A. and Young, J . , J . Insect P h y s i o l . 1 4 , 841-845

(1968).


RECEIVED October 25, 1977.


Taste and Smell

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