Phenolic, Sulfur, and Nitrogen Compounds in Food Flavors

10 Nonvolatile Nitrogen and Sulfur Compounds in Red Meats and Their Relation to Flavor and Taste A H M E D FAHMY MABROUK

Downloaded by PURDUE UNIV on May 23, 2016 | http://pubs.acs.org Publication Date: June 1, 1976 | doi: 10.1021/bk-1976-0026.ch010

Food Science Laboratory, U.S. Army Natick Development Center, Natick, Mass. 01760

Each meat has a c h a r a c t e r i s t i c f l a v o r , which can

be m o d i f i e d by c h a n g i n g c o o k i n g c o n d i t i o n s : roasting, p a n - f r y i n g , b o i l i n g , o r b r o i l i n g * The d i f f e r e n t f l a v o r s which a r i s e under t h e s e c o n d i t i o n s are more e a s i l y a c counted f o r . I f meat i s b o i l e d , the c h e m i c a l r e a c t i o n s whioh produce f l a v o r s take place a t 1 0 0 C , but when i t is r o a s t e d , the temperature may r i s e to 15 0° C , o r h i g h er* Thus, i n a d d i t i o n to the reactions t a k i n g p l a c e i n the hot Juices o f the meat, the p y r o l e t l c r e a c t i o n s o c c u r r i n g a t the s u r f a o e a r e r e s p o n s i b l e f o r t h e r o a s t e d f l a v o r notes* As i t i s n e c e s s a r y t o heat meat t o d e v e l o p the d e s i r e d f l a v o r s , meat must c o n t a i n substances which p r o duce t h e s e f l a v o r s upon c o o k i n g * These compounds a r e c a l l e d f l a v o r p r e c u r s o r s ; they may o c c u r n a t u r a l l y i n raw meat or may be produced d u r i n g p r o c e s s i n g . The n o n aqueous f l a v o r p r e c u r s o r s ( l i p i d s ) produce compounds which t a k e p a r t i n browning r e a c t i o n s f o r the d e v e l o p ment o f cooked meat aroma n o t e s * S p e c i e s aroma d i f f e r ences r e s u l t i n g from t h i s r e a c t i o n seem t o be more i n q u a n t i t y t h a n i n q u a l i t y . W h i l e odd-numbered n - f a t t y a c i d s , and abnormal p r o p o r t i o n s o f branched c h a i n f a t t y a c i d s a r e r e s p o n s i b l e f o r the c h a r a c t e r i s t i c s p e c i e s f l a v o r n o t e s o f cooked lamb and mutton ( 1 ) , 5 - a n d r o s t l 6 - e n e - 3 - o n e i s r e s p o n s i b l e f o r the t a i n t n o t e s i n b o a r meat ( 2 ) . Two approaches are used i n meat f l a v o r r e s e a r c h . The most common a p p r o a c h i s the i s o l a t i o n and i d e n t i f i c a t i o n o f v o l a t i l e f l a v o r components. The o t h e r one i s t o e s t a b l i s h the I d e n t i t y o f the i n d i v i d u a l components o f f l a v o r p r e c u r s o r s . B o t h approaches have p r o v i d e d i n d i s p e n s a b l e i n f o r m a t i o n s . S e v e r a l hundred compounds had b e e n i d e n t i f i e d i n cooked b e e f v o l a t i l e s whioh had odor o r t a s t e r e m i n i s c e n t o f cooked b e e f . These components a r e n o t , however, the compounds we would r e c o g n i z e as e

Charalambous and Katz; Phenolic, Sulfur, and Nitrogen Compounds in Food Flavors ACS Symposium Series; American Chemical Society: Washington, DC, 1976.

10.

Nonvolatile Nitrogen and Sulfur Compounds in Red Meats 147

MABROUK

b e e f f l a v o r s * I n t h i s p a p e r , 1 w i l l be c o r r e l a t i n g the work done on b e e f f l a v o r p r e c u r s o r s i n o u r l a b o r a t o r y and by o t h e r r e s e a r c h e r s w i t h p u b l i s h e d d a t a on v o l a t i l e s c o l l e c t e d from cooked meats and. from pure compo nents of f l a v o r p r e c u r s o r s * Aqueous meat f l a v o r p r e c u r s o r s encompass f i f t e e n c l a s s e s o f o r g a n i c compounds:l) g l y o o p e p t i d e s , 2) n u c l e i c a c i d s , 3) f r e e n u c l e o t i d e s , 4) p e p t i d e - b o u n d n u c l e o t i d e s , 5) n u c l e o t i d e s u g a r , 6) n u c l e o t i d e s u g a r a in i n e , ?) n u c l e o t i d e a o e t y l s u g a r a m l n e , 8) n u c l e o s i d e s , 9) p e p t i d e s , 10) amino a c i d s , 11) f r e e s u g a r s , 12) s u g a r p h o s p h a t e , 13) sugaramine, Ik) a m i n e s , and 15) o r ganic a c i d s Compounds b e l o n g i n g t o t h e s e f i f t e e n s e t s c o n t r i b u t e f l a v o r n o t e s t o the o v e r a l l i m p r e s s i o n o f cooked meat* A l l raw r e d meats have weak b l o o d - l i k e f l a v o r , on w h i c h was superimposed f l a v o r n o t e s d i s t i n c t i v e of s p e c i e s , f o o d , and environment o f the a n i m a l ( 3 ) . The f l a v o r s d e v e l o p e d on c o o k i n g were s i m i l a r f o r zhe v a r i o u s meats b u t a g a i n m o d i f i e d by s p e c i e s , f o o d , and e n v i r o n ment o f the a n i m a l . These c h a r a c t e r i s t i c s tended t o be l o s t w i t h p r o l o n g e d c o o k i n g . Such d i f f e r e n c e s seemed t o be more i n q u a n t i t y t h a n i n q u a l i t y * A l l r e d meats were found t o have some o f the f l a v o r c h a r a c t e r i s t i c s o f f i s h , and b i r d s ; and the meat o f b i r d s and f i s h had r e d meat c h a r a c t e r i s t i c s * The d i a l y z a b l e w a t e r - s o l u b l e f r a c t i o n of ox muscle was r e p o r t e d t o c o n t a i n p r i m a r i l y amino a c i d s and r e d u c i n g sugars ( 4 ) . When a m i x t u r e o f t h e s e I d e n t i f i e d amino a c i d s was h e a t e d w i t h g l u c o s e , a meaty aroma and f l a v o r was p r o d u c e d ( 5 ) · O m i s s i o n o f g l u c o s e r e s u l t e d n e i t h e r i n browning c o l o r n o r i n f l a v o r development, thus b r o w n i n g - t y p e r e a c t i o n may be r e s p o n s i b l e f o r l e a n meat f l a v o r p r o d u c t i o n . Some o f b e e f f l a v o r p r e c u r s o r s have b e e n r e p o r t e d t o be a r e l a t i v e l y s i m p l e m i x t u r e of g l u c o s e , l n o s i n l o a d d , and a g l y c o p r o t e i n ( 6 , j O · G l u tamic a d d , s e r i n e , g l y c i n e , a l a n i n e , ρ - a l a n i n e , i s o l e u o i n e , l e u c i n e , and p r o l i n e were the amino a c i d com ponents o f the g l y c o p r o t e i n . When t h e s e amino a c i d s were u s e d i n c o n j u n c t i o n w i t h g l u c o s e , i n o s i n e , and i n o r g a n i c p h o s p h a t e , meaty odors and f l a v o r s were p r o d uced upon h e a t i n g . The v o l a t i l e s from l e a n meats such as b e e f , p o r k , and lamb were f o u n d t o c o n t r i b u t e an i d e n t i c a l meaty f l a v o r , and t h a t s p e c i e s flavor dif f e r e n c e s can be t r a c e d t o the f a t c o n t e n t (8) * T h i r t y


#

1

b e e f , p o r k , and lamb (9_, 1 0 ) . M e t h i o n i n e was p r e s e n t i n the meaty aroma f r a c t i o n s o b t a i n e d by d i a l y s i s and g e l p e r m e a t i o n chrometography of aqueous b e e f e x t r a c t s ( 1 1 ) · A s t u d y t o e v a l u a t e the i n d i v i d u a l c o n t r i b u t i o n of tRe


148

P H E N O L I C ,

S U L F U R ,

A N D N I T R O G E N

C O M P O U N D S

I N

F O O D

F L A V O R S


nitrogenous components of beef f l a v o r p r e c u r s o r s i n d i c a t e d t h a t t y r o s i n e , p h e n y l a l a n i n e , t a u r i n e , a n d glutamic a c i d may be removed from the f l a v o r f r a c t i o n s w i t h o u t s e r i o u s l y a f f e c t i n g t h e aroma ( 1 2 ) · F u r t h e r m o r e , c r e a -

t i n e , c r e a t i n i n e , p u r i n e , and p u r i n e d e r i v a t i v e s a r e n o t i n v o l v e d i n the development of meaty aroma. B e e f f l a v o r p r e c u r s o r s were found t o be d i s t r i b u t e d among seven major f r a c t i o n s obtained by d i a l y s i s ( o r u l t r a f i l t r a t i o n ) and g e l p e r m e a t i o n chromatography o f aqueous e x t r a c t s ( 1 2 , 1 4 ) . The methods employed were s u f f i c i e n t l y p r e c i s e t o p e r m i t d i s t i n c t i o n between d i f f e r e n t m u s c l e s . M e t h i o n i n e and c y s t e i c a c i d were found t o b e the most i m p o r t a n t amino a c i d s c o n t r i b u t i n g t o f l a v o r . E v i d e n c e suggests t h a t p r e c u r s o r s c h a r a c t e r i s t i c s r e s i d e i n more t h a n one molecular s t r u c t u r e and a r e c o r r e l a t e d w i t h s u l f u r c o n t a i n i n g amino a c i d s p r e s e n t * The c o m p l e x i t y o f meat f l a v o r p r e c u r s o r s w i l l be c l e a r from the f o l l o w i n g d i s c u s s i o n on the u n p u b l i s h e d d a t a from our l a b o r a t o r y on t h e g l y c o p e p t i d e s f r a c t i o n (15)·

An aqueous s o l u t i o n of ( o a . 20g.) f r e e z e d r i e d raw b e e f d l f f u s a t e p r e p a r e d a c c o r d i n g t o Mabrouk e t a l . ( 1 3 ) was f r a c t i o n a t e d by p r e p a r a t i v e g e l p e r m e a t i o n chromat o g r a p h y (PGPC) on t h r e e columns (4.5X110 om) o f S e p h a d e x . The v o i d volume from Sephadex 0-10 column was p a s s e d t h r o u g h Sephadex 0-15 column. The e x c l u d e d f r a c t i o n from the second oolumn was f r a c t i o n a t e d on 0-25F column. A l l r e s u l t i n g f r a c t i o n s were f r e e z e d r i e d and t h e i r odor upon h e a t i n g were e v a l u a t e d . The second f r a c t i o n from 0-10 column gave a n i n t e n s e meaty odor when h e a t e d . The t o t a l n i t r o g e n and c a r b o h y d r a t e c o n t e n t s o f t h i s f r a c t i o n a r e 7 . 9 6 - 0 . 2 3 and (calcul a t e d as g l u c o s e ) , r e s p e c t i v e l y . Q u a n t i t a t i v e data on i t s amino oompounds c o n t e n t (mg./100 g . ) a r e : glucosamine ( 1 . 1 1 ) , h y d r o x y l y s i n e ( 0 . 1 9 ) , l y s i n e ( 0 . 4 5 ) , s e r i n e (3*96), glutamic a c i d ( 2 1 . 3 0 ) . p r o l i n e (1.02), g l y c i n e ( 5 . 0 0 ) , a r g i n i n e ( 1 . 0 0 ) , phosphoserine ( t r a c e ) , t a u r i n e ( 9 . 1 7 ) , methionine s u l f o x i d e (2.16), a s p a r t l c a c i d ( 3 . 9 4 ) . ( X - a l a n l n e ( 1 6 . 0 0 ) , v a l i n e ( 5 . 6 4 ) . m e t h i o n i n e (3*55), i s o l e u c i n e (4.81), leucine ( 9 · ? 4 ) p h e n y l a l a n i n e (2.01), ^ - a l a n i n e ( 0 . 7 6 ) , and two unknowns. Upon f u r t h e r f r a c t i o n a t i o n o f t h i s f r a c t i o n on a n a n a l y t i c a l column ( 1 . 1 X 110 cm) o f Sephadex G-25F , i t was r e s o l v e d t o f o u r peaks ( F i g u r e 1 ) · W h i l e t h e second and t h i r d f r a c t i o n s had I n t e n s e meaty o d o r , t h e f i r s t and f o u r t h d i d n o t . Attempts t o improve t h e f r a c t i o n a t i o n b y u s i n g Sephadex G-10 ( 1 . 1 X 110 cm) were u n s u c c e s s f u l as none f



10.

MABROUK


o f t h e r e s u l t i n g f i v e f r a c t i o n s d e v e l o p e d the p l e a s a n t meaty odor upon h e a t i n g . W h i l e t h i n l a y e r chromatography i n d i c a t e d t h e p r e s e n c e o f a t l e a s t seven compounds i n POPC b e e f f l a v o r p r e c u r s o r , t h i n l a y e r e l e c t r o p h o r e s i s showed o n l y t h r e e r e s o l v e d s p o t s upon r e a c t i n g w i t h ninhydrin. To p r o v i d e s u f f i c i e n t m a t e r i a l f o r f r a c t i o n a t i o n and s e n s o r y e v a l u a t i o n , a p r e p a r a t i o n o f b e e f u l t r a f i l t r a t e (14) f o l l o w e d by p r e p a r a t i v e g e l p e r m e a t i o n chromatography was a c h i e v e d ( F i g u r e 2 ) . The meaty f r a c t i o n o b t a i n e d b y POPC was f r a c t i o n a t e d b y p r e p a r a t i v e t h i n l a y e r chromatography(PTLC),usi n g MN 300 c e l l u l o s e p l a t e s , 20X20 c m . , p r e c o a t e d ( o a . 5 0 0 - m i o r o n t h i c k n e s s ) . About 200-jul o f 0*075 g . / m l . s o l u t i o n o f t h i s f r a c t i o n was a p p l i e d t o each p l a t e . The p l a t e s were d e v e l o p e d i n n - p r o p a n o l - w a t e r , 7 : 3 ( v . / v . ) , d r i e d , v i s u a l i z e d and s c r a p e d ( F i g u r e 3)· The r e s u l t i n g PTLC c e l l u l o s e f r a c t i o n s were e x t r a c t e d t w i c e w i t h 50% e t h a n o l , the a l o o h o l e x t r a c t s were c o n c e n t r a t e d under vacuum a t room t e m p e r a t u r e , f r e e z e d r i e d and s t o r e d i n a d e s s i o a t o r under vacuum above phosphorus pent o x i d e a t -20° C . The n i t r o g e n c o n t e n t and odor e v a l u a t i o n o f each PTLC f r a c t i o n a r e l i s t e d i n T a b l e I . The r e s u l t i n g s e v e n PTLC f r a c t i o n s were h y d r o l y z e d by i o n exchange r e s i n c a t a l y s i s f o l l o w i n g the p r o c e d u r e o f P a u l s o n e t a l ( 1 6 ) . The amino a c i d s p r e s e n t i n t h e s e f r a c t i o n s a r e r e c o r d e d i n T a b l e I I . The major amino a c i d s i n each f r a o t i o n a r e l i s t e d i n T a b l e I I I . T a b l e I I n d i c a t e s t h a t PTLC f r a c t i o n # 2 e x h i b i t e d s t r o n g meaty aroma I n t e n s i t y . When t h i s f r a o t i o n was subjected to preparative T L C , eight subfractions r e s u l t e d ( F i g u r e 4 ) . About 2 0 0 - j i l o f 0.075 g . / m l . s o l u t i o n o f t h i s f r a c t i o n was a p p l i e d t o 108 p r e p a r a t i v e TLC p l a t e s M l 300 c e l l u l o s e ( c a . 5 0 0 - m i o r o n t h i c k n e s s ) . T h u s , a t o t a l o f 1 . 6 2 g . o f TLC f r a c t i o n # 2 was s u b m i t t e d t o a second s t e p o f f r a c t i o n a t i o n b y P T L C . E i g h t PTLC s u f r a c t i o n s were c o l l e c t e d . T a b l e IV l i s t s the weight o f each s u b f r a c t i o n r e c o v e r e d . The e x c e s s r e c o v e r y o f 0.82687 g « , appears t o be due t o the p r e s ence o f m a t e r i a l s i n the p l a t e s which were s o l u b l e i n t h e 50% e t h a n o l used t o e x t r a c t each s u b f r a c t i o n * PTLC p l a t e s used i n f r a c t i o n a t i o n p r o v e d t o c o n t a i n m a t e r i a l s t h a t were e x t r a c t e d w i t h e t h a n o l d u r i n g r e c o v e r y o f the s u b f r a c t i o n s . The c o a t i n g s o f t e n p l a t e s were s c r a p e d and e x t r a c t e d w i t h 50% e t h a n o l . About 60 mg. " c o n t a m i n a n t s " were r e c o v e r e d , i . e . , about 6 m g . / p l a t e . The chromatograms o b t a i n e d w i t h a n a l y t i c a l g e l permeat i o n chromatography u s i n g Sephadex O-10 ( 0 . 7 * 2 8 cm.) o f the contaminants ( F i g u r e 5 ) and PTLC s u b f r e c t l o n # 3 ( F i g u r e 6 ) , i n d i c a t e the f e a s a b i l l t y o f s e p a r a t i n g the


PHENOLIC,

150

SULFUR,

A N D NITROGEN

COMPOUNDS

I N FOOD

FLAVORS

MW = 500

1.4

3 Ε 12

c ο

Ί ίο U

z 2 0.8 Downloaded by PURDUE UNIV on May 23, 2016 | http://pubs.acs.org Publication Date: June 1, 1976 | doi: 10.1021/bk-1976-0026.ch010

Ο

co 0.6 < 0.4 0.2

MW = 600 2

MW = 1645 1

0 Figure 1.

20

40

ι

60 80 100 120 TUBE NUMBER

Gel permeation chromatography of GPC-BFP, 110 X 1.1 cm column, Sephadex G25F

% OF FRESH BEEF 1- TRIM, GRIND, BLEND WITH WATER 2-

(1 LITER /KG.)

FREEZE DRY, LYOPHILIZED BEEF

3 - EXTRACT WITH PETROLEUM ETHER, LIPIDS

28.20 3

5

0

7

0

4 - BLEND FREE-LIPIDS FREEZE DRIED BEEF WITH WATER,(10 ML. / G.), STIR SLURRY FOR THREE HOURS AT 5°C, CENTRIFUGE ,FILTER 5 - REPEAT STEP 4, FREEZE DRY FILTRATES 6-

7-

6

DIALYSIS a—ULTRAFILTRATION

3.68

b—CONVENTIONAL

2.98

PREPARATIVE GEL PERMEATION CHROMTOGRAPHY

1

6

6

(BROILED BEEF AROMA WHEN HEATED) Figure 2.

A schematic outline of the method used to prepare aqueous beef flavor precursors



10. MABROUK


7

C

6

C

4

/

3

/

2

/

'J

—~~~>

.

J-

1

Figure 3. Preparative thin layer chromatogram of PGPC-BFP, MN 300 cellulose plate, 500 μ thickness, developing solvent: propanolr-water, 7:3 (v/v), silver nitrate visualiza tion

Table I. Comparison of PTLC Fractions of PGPC of Beef Flavor Precursors

Fraction No.

Nitrogen Content I

1

4.42

2 3

9.87 13.13

4 5

7.03 4.28

6 7

3.52 2.88

PGPC-BFP Ultrafiltrate

Yield % of PGPC Odor Description ) )29 ) ) )45 ) 10

BFP, Very Sweet. Strong BFP, Very Sweet. Weak BFP,Oily,Not Sweet. Weak BFP, Sweet. Heated Protein,Fishy,Musty, Not Sweet. Wet Cardboard. Musty, Hay.

7.92 9.20


PHENOLIC,

SULFUR, AND NITROGEN

COMPOUNDS

I N FOOD FLAVORS

Table II. Amino Acids Present in PTLC Fractions of PGPC-Beef Flavor Precursors.

Amino Acids


1 Histidine Glutamic B-alanine Aspartic Glycine Alanine Arginine Serine Tyrosine Leucine 1-methylhistidine Tryptophan Threonine Lysine Valine Isoleucine Ammonia Ornithine Phenylalanine a-amino-n-butyric acid Proline Methionine ) Methionine ) Sulfoxide) Cysteic Acid

μΜ/mg. of Fraction No. 2 3 4 5

0.]26 0.098 0.110 0.052 0.059 0.040 0.017 0.022 0.009 0.010

0.023 0.299 0.026 0.023 0.281 0.078 0.014 0.171 0.001 0.003

0.008 0.005 0.008 0.006 0.006 0.004 0.024 0.001 0.001

0.004 0.023 0.020 0.003 0.006 0.002 0.212 0.002 0.001

0.003 0.025 0.008 0.004 0.020 0.503

0.001 0.002 0.003 0.003 0.001 0.003 0.003 0.003 0.207 0.008

6 .....

7 .....

0.003 0.0002 0.001 0.0004 0.012 0.0001 0.006 0.0001

0.023 0.003 0.008 0.006 0.0004 0.003 0.004 0.051 0.427 0.041 0.017 0.001 0.066 0.011 0.004 0.001 0.006 0.014 0.413 0.002 0.002 0.047 0.091 0.019 0.020 0.001 0.001 0.006

0.002 0.0001 0.009 0.223 0.021 0.005 0.0001 0.003

0.001 0.003 0.010 0.048 0.005 0.002 0.002 0. 001 0.041 0.001


10.

MABROUK


Table III. The Major Amino Acids i n PTLC Fractions

Amino Acids


1

Histidine Glutamic B-alanine Aspartic Glycine a-alanine Arginine Serine Ammonia Tryptophan Proline Valine Leucine Isoleucine Methionine + Methionine Sulfoxide Threonine

yiM/mg. of Fraction No. 3 2 4

0.126 0.098 0.110 0.052 0.059 0.040 0.017

5

6

0.413 0.051 0.047 0.041

0.427 0.223

0.299

0.281 0.078

0.503

0.207

0.171 0.091 0.041 0.048

0.066

Figure 4. Preparative thin layer chromatogram of PTLC, fraction #2, MN 300 cellulose plate, 500 μ thickness, developing solvent: propanolr-water, 7:3 (v/v), ninhydrin visualization


PHENOLIC,

154

SULFUR,

A N DN I T R O G E N

COMPOUNDS

I N FOOD

FLAVORS

Table IV. Weight of PTLC Subfractions of PTLC Fraction 2


Subfraction No. 1 2 3 4 5 6 7 8

% of Recovered Material

Weight g.

12.7 19.6 13.9 7.4 10.2 16.8 10.5 9.0

0.31091 0.47833 0.33921 0.18154 0.24900 0.41012 0.25748 0.22028 2.44687

Weight of PTLC Fraction #2 used = 1.62 g.

Figure 5. Gel permeation chromatography of "contaminants," 28 X 0.7 cm column, Sephadex G-JO

Figure 6. Gel permeation chromatography of PTLC subfraction #3, 28 X 0.7 cm column, Sephadex G-10

15

25

35

45

55

TUBE NUMBER


65

75

10.

MABROUK


s u b f r a o t l o n s from the c o n t a m i n a n t s . The homogeneity of each s u b f r a c t i o n needs t o be evaluated before subject ing t o sensory e v a l u a t i o n and a n a l y s i s *

Amino A o l d s


Of 27 amino compounds i n aqueous beef e x t r a c t , 23 were i d e n t i f i e d and q u a n t i f i e d (mg./lOQ g . f r e s h weight meat): p h o s p h o s e r i n e , 1 . 8 4 ; t a u r i n e , 0 . 0 9 ; a s p a r t i c ,

0.95 ; t h r e o n i n e , 3 . 1 ? » s e r i n e , 3 . 6 0 ; g l u t a m i c , 1 1 · 6 0 ; p r o line,0.9^5 g l y c i n e , 3 * 1 0 ; c9,10) on the p r e s e n c e o f c a r n o s i n e , a n s e r i n e , and g l u t a t h i o n e , no p u b l i s h e d work e x i s t s i n l i t e r a t u r e on t h e p r e s e n c e o f o t h e r p e p t i d e s I n r e d meats. As the t o t a l c o n t e n t o f the amino a c i d s i d e n t i f i e d I n aqueous meat e x t r a c t s account f o r a s m a l l p o r t i o n o f t h e t o t a l n i t r o g e n c o n t e n t , the b a l a n c e o f the n i t r o g e n o u s compounds s h o u l d account f o r p e p t i d e s , g l y o o p e p t i d e s , n u c l e o t i d e s , n u c l e o t i d e d e r i v a t i v e s , and a m i n e s . The i n c r e a s e i n the number o f the components o b t a i n e d b y f r a c t i o n a t i o n o f meat f l a v o r p r e c u r s o r s b y PGPC, P T L C , and a n a l y t i c a l GPC , i n d l o a t e s t h e p r e s e n c e o f p e p t i d e s a n d / o r g l y o o p e p t i d e s depending upon the p r e s e n c e o f c a r b o h y d r a t e m o i e t i e s ( F i g u r e s 3 and k) and

(Tables I I ,

1 1 1 and I V ) ·


158

P H E N O L I C ,

S U L F U R ,

A N D

N u c l e o t i d e s and Nucleotide

N I T R O G E N

C O M P O U N D S

I N

F O O D

F L A V O R S

Derivatives

Nucleotides present i n red meats vary according not only t o species, breed, age of the animal, and feed but a l s o t o the freshness of the meat* 5 - I n o s l n e mono1


phosphate

(IMP) and 5 ' - g u a n o s l n e

monophosphate(GMP)

have f l a v o r enhancing e f f e c t s , and these e f f e c t s are considered t o be e s s e n t i a l l y the same. The f l a v o r e f f e c t of GMP i s s a i d t o be b r o a d e r than that of IMP and g e n e r a l l y produces a more harmonizing e f f e c t * GMP i s about 4 times s t o n g e r t h a n IMP i n aqueous solutions» Meats c o n t a i n a very small q u a n t i t y o f GMP i n a d d i t i o n to IMP, b u t the l e v e l i s so small that i t cannot be considered t o have any e f f e c t on t a s t e ( 2 2 ) . Eight f r a c t i o n s of p e p t i d e - b o u n d nucleotides were reported i n beef, one f r a c t i o n e x h i b i t e d meaty aroma when heated (23)» l e d meats c o n t a i n n u c l e o t i d e sugars which are c l o s e l y r e l a t e d t o the metabolism and b i o s y n t h e s i s o f sugars. Nucleotide c h o l i n e i s i n v o l v e d i n l i p i d m e t a b o l i s m . 5 - c y t l d l n e monophosphate, 5 ' - a d e n o s i n e monophosphate, and 5 u r i d i n e monophosphate a r e a l s o p r e s e n t i n meat i n s m a l l c o n o e n t r a t i o n s . N u c l e o t i d e content i n r e d meats i s t a b u l a t e d i n T a b l e V I I . f

1

Effect

Of H e a t i n g On Meat F l a v o r P r e c u r s o r s

D u r i n g heat p r o c e s s i n g , the types o f r e a c t i o n s which can o c c u r t o the non-aqueous f l a v o r p r e c u r s o r s a r e : a u t o x l d a t i o n , h y d r o l y s i s , d e h y d r a t i o n and d e c a r b o x y l a t i o n of f a t s g i v i n g r i s e to aldehydes, f a t t y acids, lactones, ketones, hydrocarbons, a l c o h o l s , . . e t c . The aqueous f l a v o r p r e c u r s o r s may be s u b j e c t e d t o g l y c o s i d e s p l i t t i n g , o x i d a t i o n , p y r o l y s i s ( t h e r m a l decomp o s i t i o n ) t o y i e l d v o l a t i l e and n o n - v o l a t i l e compounds t h a t i n f l u e n c e f l a v o r . P r o d u c t s o f amino a c i d s p y r o l y s i s a r e v e r y complex. The most Important f l a v o r p r o d u c i n g c h e m i c a l r e a c t i o n i s t h e non-enzymic browning r e a c t i o n o f the amino a c i d s . T h i s r e a c t i o n i n v o l v e s o x i d a t i v e d e a m i n a t i o n o f a n amino a c i d m o l e c u l e w i t h the f o r m a t i o n o f an aldehyde w i t h one c a r b o n atom l e s s t h a n the o r i g i n a l a c i d . a- Nucleotides. I n a s t u d y on the browning r e a c t i o n o f 5 ' - r i b o n u c l e o t i d e s w i t h D - g l u o o s e , F u j i m a k i et al. (26) c o n c l u d e d t h a t phosphate p l a y s an important r o l e I n the browning r e a c t i o n of a l d o s e s w i t h n u c l e o t i d e s , and t h a t the phosphate e s t e r at the p r i m a r y a l c o h o l of r l b o s e r e s i d u e , as w e l l a s , the i n o r g a n i c orthophosphate w h i c h i s l i b e r a t e d due t o the h y d r o l y s i s o f t h e e s t e r causes the development of the r e a c t i o n . At


10.

MABROUK

Nonvolatile

Table VI.

Nitrogen and Sulfur Compounds

in Red Meats

159

Classification of Free Amino Compounds in Red Meats.

Percent


Amino Compound

Neutral Amino Acids Hydroxy Amino Acids Acidic Amino Acids Sulfur - Containing Amino Acids Basic Amino Acids Aromatic Amino Acids Dipeptides "Anserine + Carnosine"

Beef

Lamb

Pork

14.4 5.5 3.4 9.6

18.1 6.2 5.9 27.0

9.4 3.4 2.9 13.9

9.8 2.0 55.8

20.2 2.9 19.7

7.1 1.0 61.1

Table VII. Nucleotide Content in Red Meats

Meat CMP Beef Beef Pork Mutton

12.0 1.0 1.9 1.9

Nucleotide Content, mg/100g. IMP IMP GMP AMP 13.0 1.6 1.6 0.6

150.0 107.0 123.0 83.5

8.0 2.1 2.5 5.1

17.0 6.6 7.6 6.8

Reference

24 22 22 25


160

P H E N O L I C ,

S U L F U R ,

A N D

N I T R O G E N

C O M P O U N D S

I N

F O O D

F L A V O R S


higher temperature ( 1 2 0 ° C ) , glucose a c c e l e r a t e the deg r a d a t i o n of IMP, which may be a t t r i b u t e d t o i n t e r a c t i o n o f the n u c l e o t i d e w i t h some r e a c t i v e compounds such as osones and others which are p o s s i b l y formed through 1 , 2 - and/or 2 , 3 - e n o l i z a t i o n of aldoses and f u r t h e r degradation, condensation, and p o l y m e r i z a t i o n * a l though IMP i s more s t a b l e than GMP, I M P - g l u c o s e s o l u t i o n produced more 3-deoxy-D-gluoosone and developed more intense brown c o l o r than OMP-glucose s o l u t i o n d i d , these d i f f e r e n c e s may be a t t i b u t e d t o the amino group on the purine r i n g i n GMP. I n a study on the e f f e c t of heating on n u c l e o t i d e s i n beef, pork, and lamb, Maey

et a l (2?) r e p o r t e d the f o l l o w i n g c o n c l u s i o n s . I n the case o f b e e f , CMP was not g r e a t l y I n f l u e n c e d by h e a t i n g to 49°C and ?? G i n t e r n a l t e m p e r a t u r e . AMP content a p p r e c i a b l y i n c r e a s e d upon h e a t i n g t o b o t h temperat u r e s , t h i s I n c r e a s e might be due to the h y d r o l y s i s o f adenosine diphosphate(ADP) and adenosine t r i p h o s p h a t e ( A T P ) . UNP and IMP c o n t e n t s d e c r e a s e d by h e a t i n g to 6

%^C and ?7°C.

The i n f l u e n c e o f r o a s t i n g t o ^9°C and

71 C i n t e r n a l t e m p e r a t u r e s , on p o r k n u c l e o t i d e s was s i m i l a r t o t h a t on b e e f . A l l n u c l e o t i d e s d e c r e a s e d d u r i n g r o a s t i n g except AMP which i n c r e a s e d i n q u a n t i t y 0 when h e a t e d t o 7 1 ° C . When lamb was heated t o 6O C i n t e r n a l t e m p e r a t u r e , GMP and UMP were d e s t r o y e d a f t e r 5 and 15 minutes r e s p e c t i v e l y . CMP d o u b l e d i t s o r i g i n a l c o n c e n t r a t i o n and t h e n degraded g r a d u a l l y . About 85% o f IMP content was l o s t a f t e r h e a t i n g f o r 30 m i n . ( F i g ure 7 ) . b - Amino Compounds and G u a n i d l n e s . Cooking caused s i g n i f i c a n t i n c r e a s e s i n c r e a t i n e and d e c r e a s e i n amino a c i d s , c r e a t i n e , non-amino n i t r o g e n and t o t a l c a r b o h y d r a t e s (28, 29) · I n the case o f b e e f , c r e a t i n e c o n t e n t l o s s was dependent on the h e a t i n g t e m p e r a t u r e . The l o s s amounted t o 10 and 20$ of the o r i g i n a l c o n c e n t r a t i o n , when h e a t e d up t o k^°t and 7 7 ° C , r e s p e c t i v e l y . D u r i n g c o o k i n g t o 77*C, a l l f r e e amino a c i d s o f b e e f r o a s t s i n c r e a s e d , exoept t h r e o n i n e , s e r i n e , g l u t a m i c , h i s t i d l n e , and a r g i n l n e , which d e c r e a s e d . The o v e r a l l e f f e c t o f c o o k i n g was an I n c r e a s e o f 38.3# I n the t o t a l amino a c i d s . T o t a l e x t r a c t a b l e amino n i t r o g e n i n c r e a s e d a p p r o x i m a t e l y 18# I n the same sample d u r i n g c o o k i n g . These i n c r e a s e s were p r o b a b l y due t o p r o t e i n h y d r o l y s i s and p o s s i b l y i n v o l v e d c a t h e p s i n s o r o t h e r p r o t e o l y t i c enzymes i n the t i s s u e , s i n c e i t has been shown t h a t most f r e e amino a c i d s d e c r e a s e d d u r i n g h e a t i n g when i s o l a t e d from the p r o t e i n s by d i a l y s i s ( T a b l e V I I I ) . T a u r i n e , a n s e r i n e , and c a r n o s i n e i n c r e a s e d to the g r e a t e s t e x t e n t d u r i n g c o o k i n g . These were the major



10. MABROUK


o

' 10

20

30

40

50

60

TIME , MIN

Figure 7. Effect of heating lamb to 60° C internal temperature on inosine 5''-monophosphate


162

PHENOLIC, SULFUR, AND NITROGEN COMPOUNDS I N FOOD FLAVORS

Table VIII.

Percent Change in Free Amino Compounds of Lyophilized Red Meats Diffusâtes

Amino Compounds


Beef Phosphoserine Glycerophosphoethanolamine Phosphoethanolamine Taurine Urea Aspartic Threonine Serine+Asparagine Glutamic Acid Proline Glycine Alanine Cystine Valine Methionine Isoleucine Leucine Tyrosine Phenylalanine Ornithine NH3 + Lysine Histidine Carnosine + Anserine 1-Methylhistidine aAmino-n-butyric acid Total

-19.4 -50.0 + 24.2 -55.5 -100.0 - 61.0 - 33.3 - 82.1 - 52.1 - 45.0 - 44.9 -100.0 - 50.8 - 62.7 - 57.4 - 38.6 - 56.8 - 28.7 + -

33.6 1.7 57.7 89.8

-55.77

Percent Change Lamb

Pork

65.2

- 34.3 - 50.0 +320.0

- 37.3

- 36.9

- 10.5

- 67.2 - 6.3

- 26.7

- 100.0 +

- 56.7 - 52.3 - 53.1

- 72.8 - 47.6 _

-

28.9 18.9 59.1 35.4 33.0 45.6 15.7 39.5 31.6 46.8 26.2 36.3 47.8

- 37.3

-

82.0 39.0 62.5 42.5 33.2 57.8 - 33.3 + 44.9 - 19.4 - 40.5 - 33.9 - 23.5 -

4.9 22.0 - 14.1 -100.0

+

- 19.8

(-) decrease in value (+) increase in value From reference (9)



10.

MABROUK


amino compounds present I n both, raw and cooked beef. The increase i n f r e e amino compounds content during cooking i s important f o r meat f l a v o r development due t o t h e i r p a r t i c i p a t i o n i n the browning r e a c t i o n . The r e c ommended usage o f c a r n o s i n e i n soup p r e p a r a t i o n and c r e a t i n e i n meat e x t r a c t s a r e due t o t h e i r c o n t r i b u t i o n the m o u t h f e e l . anserine i s d e s i r e d as i t s f l a v o r l i n gers i n the mouth and was therefore savored more s t r o n g l y than would be expected simply from a consider a t i o n of t a s t e i n t e n s i t y as measured by t h r e s h o l d d i l u t i o n technique (JO). A r g i n i n e , l y s i n e and h i s t I d i n e exert the same e f f e c t as the f l a v o r sensation clung t e n a c i o u s l y t o the mouth. The odor and t a s t e of cooked beef were improved by c o n t r a c t i n g raw beef w i t h b a s i c amino a c i d s . Smearing beef w i t h a r g i n i n e before b r o i l ing or r o a s t i n g , r e s u l t e d i n a superior o r g a n o l e p t i c e v a l u a t i o n (31)· Seventeen amino a c i d s and ten peptides were sub jected t o p y r o l y s i s (Barber Coleman u n i t Model 4180) and the products were i d e n t i f i e d by mass spectrometry, Table I X (32). B e n z e n e , t o l u e n e , e t h y l benzene, and s t y r e n e were i d e n t i f i e d i n the p r o d u c t s o f the t h e r m a l d e g r a d a d a t l o n o f p h e n y l a l a n i n e ( 3 3 , 3 ^ ) . These r e p o r t s were r e s u l t s o f work done a t v e r y higK temperatures above 700° C . , which i s f a r h i g h e r than the temperature of the oven used i n c o o k i n g . U s u a l l y , the oven used f o r r o a s t i n g i s set between 1 7 6 ° and 1 9 0 ° C . D u r i n g b r o i l ing, the temperature at the s u r f a c e o f the meat might r e a c h a degree as h i g h as 280~300°C. depending upon i t s d i s t a n c e from the s o u r c e o f h e a t . T h u s , my d i s c u s s i o n w i l l be l i m i t e d t o r e p o r t s i n the l i t e r a t u r e where the temperature d i d not exceed 300* C .

c - P y r o l y s i s of S u l f u r C o n t a i n i n g Amino A c i d s . P y r o l y s i s o f c y s t e i n e and c y s t i n e r e s u l t e d i n 7-8 v o l a t i l e compounds i n c l u d i n g 2 - m e t h y l t h l a z o l o d l n e which i s c o n s i d e r e d to be a a p r o d u c t o f the r e a c t i o n of a c e t a l dehyde and m e r o a p t e t h y l a m i n e ( 3 5 ) · E l e v e n compounds were i d e n t i f i e d i n the p r o d u c t s o f m e t h i o n i n e p y r o l y s i s . B e s i d e these v o l a t i l e compounds, a l a n i n e , c y s t i n e and 1 s o l e u c ine ( n o n - v o l a t i l e s);and a l a n l n e , i s ο l e u c i n e , and m e t h i o n i n e were d e t e c t e d i n the p y r o l y z e d p r o d u c t s o f c y s t e i n e and c y s t i n e , r e s p e c t i v e l y , but no amino a c i d s were found among m e t h i o n i n e p r o d u c t s . The m i x t u r e o f the seven i d e n t i f i e d v o l a t i l e compounds produced from c y s t i n e d e v e l o p e d a p o p - c o r n l i k e aroma w i t h a r o a s t e d s e s a m e - l i k e o n e . M e t h y l mercaptan seemed to be the main c o n t r i b u t o r t o a p i c k l e d r a d i s h odor produced from the p y r o l y s i s of m e t h i o n i n e . In 1973, Kato et a l . ( 3 6 ) i d e n t i f i e d f i f t e e n new v o l a t i l e compounds i n the p y r o l y s i s


PHENOLIC, SULFUR, AND NITROGEN COMPOUNDS IN FOOD FLAVORS

164

Table IX.

Pyrolysis Products of Amino Acids and Dipeptides

Product


Compound Glycine Alanine B-alanine Valine Norvaline Leucine Isoleucine Serine Threonine Taurine Methionine Cystine Phenylalanine Tyrosine Tryptophan Proline Hydroxyproline Glycyl-glycine Glycyl-valine Glycyl-proline Glycyl-methionine Glycyl-serine Glycyl-tryptophan Glycyl-alanine Alanyl-glycine Glycyl-leucine Leucyl-glycine

Fran reference

Acetone Acetaldehyde Acetic Acid 2-Methyl propanal n-But anal 3-Methyl butanal 2-Methyl butanal Pyrazine 2-Ethylethyleneimine Thiophene Methyl propyl sulfide Methyl thiophene Benzene Toluene Ammonia, Carbon dioxide Pyrrole N-Methyl pyrrole Acetone Acetone, 2-Methyl propanal Acetone, Pyrrole Acetone, Methyl propyl sulfide Acetone, Pyrazine Acetone, Anmonia Acetone, 2-Methyl pyrrole Acetone, Acetaldehyde, anmonia Acetone, Cyclopentane Acetone, Acetic Acid

(32)



10.

MABROUK


p r o d u c t s o f c y s t e i n e and f i v e more from c y s t i n e * The p o p c o r n - l i k e aroma most p r o b a b l y i s made up from t h e aroma o f many compounds such as hydrogen s u l f i d e , t h i a z o l e s , p y r i d i n e s and 2 - m e t h y l t h i a z o l i d i n e . T h i a z o l e s and r e l a t e d compounds g i v e a p y r i d i n e - o r p i c o l i n e - l i k e o d o r . û c - P i o o l i n e g i v e s a m i l d p y r i d i n e - l i k e aroma and resembles p o p c o r n - l i k e one produced from p y r o l y z e d s u l f u r c o n t a i n i n g amino a c i d s (35)· Thiophenes were d e t e c t e d i n the v o l a t i l e s o f p y r o l y z e d c y s t e i n e , b u t were not detected i n those of p y r o l y z e d c y s t i n e , t h e y g e n e r a l l y g i v e s l i g h t l y u n p l e a s a n t and c h a r a c t e r i s t i c odors* The d i f f e r e n c e s i n odor between c y s t e i n e and c y s t i n e may be p a r t l y a t t r i b u t e d t o t h e p r e s e n c e o f t h i o p h e n e s I n the v o l a t i l e s * T a b l e X l i s t s t h e compounds i d e n t i f i e d i n p y r o l y s i s p r o d u c t s o f s u l f u r - c o n t a i n i n g amino a c i d s . T h i a z o l e s and t h l a z o l l n e s may be p r o d u c e d by the o x i d a t i o n o f 2 - m e t h y l t h l a z o l l d l n e ; and c ^ - p l c o l i n e and 2e t h y l - 5 - m e t h y l p y r i d i n e may produced by t h e r e a c t i o n o f a c e t a l d e h y d e and ammonia. 2 - M e t h y l t h l a z o l l d l n e I s thought t o be produced from cystearnine and a c e t a l d e h y d e (37)· I t i s q u i t e obvious t h a t s i m p l e compounds such as ammonia, a c e t a l d e h y d e , cysteamine appear t o be import a n t p r e c u r s o r s o f many v o l a t i l e compounds. d - P y r o l y s i s o f A r o m a t i c Amino A c i d s . Amine-like, p h e n o l - l i k e and i n d o l e - l i k e odors developed from p y r o l y z e d p h e n y l a l a n i n e , t y r o s i n e and t r y p t o p h a n , r e s p e c t i v e l y ( 3 8 ) . Twelve compounds, many o f which have a r o m a t i c r i n g s , were i d e n t i f i e d i n the v o l a t i l e s from t h e r m a l d e g r a d a t i o n o f p h e n y l a l a n l n e ( T a b l e X I ) . T y r o s i n e and t r y p t o p h a n produced some p h e n o l s and I n d o l e s , r e s p e c t i v e l y , a l o n g w i t h s e v e r a l o t h e r compounds. e- P y r o l y s i s o f Hydroxy Amino Compounds. Ten v o l a t i l e compounds i n c l u d i n g s e v e r a l p y r a z i n e s were i d e n t i f i e d i n the p y r o l y s i s products of L - s e r i n e ( 3 9 ) . P y r a z i n e s were a l s o i d e n t i f i e d i n t h e p y r o l y s i s p r o d u c t s o f L - t h r e o n i n e , b u t n o t from a l a n i n e and a r e c o n s i d e r e d t o be c h a r a c t e r i s t i c p y r o l y s i s p r o d u c t s o f ^ - h y d r o x y amino compounds. A l s o , d i k e t o p l p e r a z i n e s . amines and c a r b o n y l compounds were i d e n t 1 f i e d , T a b l e X I I . P y r a z i n e s a r e h e t e r o c y c l i c n i t r o g e n compounds which c o n t r i b u t e s i g n i f i c a n t l y t o t h e d e s i r a b l e unique f l a v o r and odor a s s o c i a t e d w i t h r o a s t i n g o r t o a s t i n g o f f o o d s . The odor o f p y r a z i n e s has been d e s c r i b e d as c h a r a c t e r i s t i c a l l y e a r t h y , n u t t y and r o a s t e d . Maga and Sizer(40) r e v i e w e d p y r a z i n e s i n f o o d s . P y r a z i n e s c o u l d n o t be f o u n d when g l y c i n e , a l a n i n e , p h e n y l a l a n i n e , β - a l a n i n e , l e u c i n e , i s o l e u c i n e , v a l i n e , methionine, c y s t i n e , hydro xy l y s i n e , t y r o s i n e , h i s t i d i n e , p r o l i n e , h y d r o x y p r o l i n e ,


166

PHENOLIC, SULFUR, A N D NITROGEN COMPOUNDS I N FOOD FLAVORS


Table Χ.

Pyrolysis Products of Sulfur-Containing Amino Acids

Compounds

Cystine

Cysteine

Ethylamine Propylamine Allylamine Crο ty lamine α-Alanine Isoleucine 2-Amino-4-methylthiobutyric Acid 2- Methylthiazolidine Mercaptehylamine Hydrogen Sulfide Sulfur 3- Methylthiopropylamine Methional Acetaldehyde Propionaldehyde Isobutyladehyde Acetone Ammonia Ammonium carbonate 2-Methyl thiazoline a-Picoline 2 - Ethyl - 5-methylpyridine 2-Ethylthiazole Thiophene 2- Methyl thiophene 3- Methyltetrahydrothiophene 2,5-Dimethyl thiophene 2,3-Dimethyl thiophene 2 (or 3)-Ethylthiophene 2.3- Dihydro-4(or 5) ethylthiophene 2-Methyl-3(or 4)-ethylthiophene 2,3,5-Trimethylthiophene 3 - Methyl - η - propy 1 thiophene 2.4- Dimethyl-5-ethylthiophene 2-Methylthiazole 2-Methyl-5-ethyl thiazole

35 35 35 35 35,36 35 35 35 -

35 35 -

35 35 36 36 36 36 36

35 35 36 36 36 36 36 36 36 36 36 36 36 36 36 36 36

Methionine 35 35 35 35 35

35,36 35 35 -

35 35 35 35 35

From reference (35) and (36)


10. MABROUK


Table XI. Volatile Compounds Produced From The Pyrolysis of Aromatic Amino Acids


Volatile Compounds Benzylamine Bibenzyl p-Cresol m-Cresol Ethyl Benzene 3-Ethylindole Indole Phenol 3-Phenyl ethylamine 3-Phenylpropionitrile Skatole Stilbene Toluene Vinylbenzene Phenylacetaldehyde Acetaldehyde Benzaldehyde Ammonia Methylamine Aniline Tyramine Ethylamine

Phenylalanine

Tyrosine

Tryptophan

+ + + +

+ + +

+ +

+ +

+

+

+ +

+ + + + + +

+ +

+

+ +

From reference (38)



39,41 39,41 41

Pyrazine 2-Methylpyrazine 2,3-Dimethylpyrazine 2,5-Dimethylpyrazine Trimethylpyrazine 2-Ethylpyrazine 2-Ethyl-5-methylpyrazine 2 - Ethyl - 6 -methy lpyraz ine 2,6 - Die thy lpyraz ine 2.5- Dimethyl- 3-ethylpyrazine 2.6- Diethyl- 3-methylpyrazine Pyrazine, mol wt 136 Pyrazine, mol wt 136 pyrazine, mol wt 150 Pyrazine, mol wt 150 Pyrazine, mol wt 164 Pyrazine, mol wt 178 4-methyl-n-propylpyrazine 2,5-diketo-3,6-dimethylpiperazine Pyrrole 39 39

41 41 41

39,41 39,41 41 39

39,41

Serine

39

39

41

41 41 41 41 41 41 41 41

41

41

41 41 41

41 41 41

Glucosamine

41 41

Ethanolamine

39,41

39 39,41

41

Threonine

41

41

4-Amino-3hydroxybutyric

V o l a t i l e Compounds Produced From Hydroxy Amino Compounds

Compound

Table XII.


41 41 41

41 41

41

41 41

Alanylserine


(41).

39 39 39 39 39 39 39 39 39

2-Methylpyrrole Dime thylpyrrole 3-Methyl- 4- ethylpyrrole Ethylamine Ethanolamine Ammonia Acetaldehyde Propionaldehyde Paraldehyde

From references (39} and

Serine

39 39

39

39

Threonine

Ethanolamine

Glucosamine

4-Amino-3hydroxybutyric Alanylserine

V o l a t i l e Compounds Produced from Hydroxy Amino Compounds (cont'd)

Compound

Table XII.


170

P H E N O L I C ,

S U L F U R ,

A N D

N I T R O G E N

C O M P O U N D S

I N

F O O D

F L A V O R S

tryptophan, l y s i n e , a s p a r t i c , a s p a r a g i n e , glutamic, adenine, and adenosine were i n d i v i d u a l l y to p y r o l y s i s * On the other hand, pyrazines were obtained by heating i n d i v i d u a l amino-hydroxy compounds, notably those having amino and hydroxy groups i n adjacent c a r b o n p o s i t i o n s without the p a r t i c i p a t i o n of s u g a r s . I t i s obvious that the amino-hydroxy compounds themselves serve as a s o u r c e of b o t h carbon and n i t r o g e n i n the pyrazine molecule. Thus,these compounds glutamlne, subjected


are

important p r e c u r s o r s i n f o o d s , e . g . ,

ethanolamlne,

glucosamine, s e r i n e , threonine, 4 - a m i n o - 3 - h y d r o x y b u t y r i e a c i d , and a l a n y l s e r l n e . The composition of pyraz i n e mixtures and the r e l a t i v e amounts of each pyrazine p r o d u c e d v a r i e d from one amino-hydroxy compound t o a n o t h e r * F o r example, p y r a z i n e , 2 - m e t h y l p y r a z i n e , 2 , 5 - d i -

m e t h y l p y r a z i n e , 2 , 3 - d l m e t h y l p y r a z i n e , and t r l m e t h y l p y r a z l n e w i t h ( 2 - m e t h y l p y r a z i n e f o r the l a r g e s t peak) r e s u l t e d from g l u c o s a m i n e ; w h i l e t r i m e t h y l - , 2 , 5 - d i m e t h y l - , and 2 , 5 - d i m e t h y l - 3 - e t h y l p y r a z i n e ( w l t h 2 , 5 - d i m e t h y l p y r a z i n e f o r the l a r g e s t peak were o b t a i n e d from 4 - a m i n o - 3 - h y d r o x y - b u t y r l c a c i d (hi). Dawes and Edwards (42) s p e c u l a t e d on the mechanism o f f o r m a t i o n o f s u b s t i t u t e d p y r a z i n e s i n s u g a r - a m i n e systems.

f - Nonenzymlo Browning R e a c t i o n . Reactions i n duced by h e a t i n g amino a c i d s and sugars a r e known as nonenzymic browning o r M a i l l a r d r e a c t i o n s . Meat f l a v o r s a r e a l s o g e n e r a t e d i n r e a c t i o n s o f t h i s t y p e . T h i s had been the s u b j e c t o f s e v e r a l r e v i e w s (43, 44, 4 5 , 46). The M a i l l a r d r e a c t i o n i s the r e a c t ! o n ^ b e t w e e n an amino compound (amine, amino a c i d , p e p t i d e , or a p r o t e i n ) and a g l u c o s i d i c hydroxy group i n a sugar · Hodge (44) p r o posed a s e v e n - s t e p mechanism: 1 - Sugar-amino a c i d c o n d e n s a t i o n ( f o r m a t i o n o f N - s u b s t i tuted glycosylamine ). 2- Amadori rearrangement ( rearrangement t o produce a substituted l-amino-l-deoxy-2-ketose)· 3 - Sugar d e h y d r a t i o n . 4- Sugar f r a g m e n t a t i o n . 5 - Amino a c i d d e g r a d a t i o n . 6- A l d o l c o n d e n s a t i o n . ?- A l d e h y d e - a m i n e p o l y m e r i z a t i o n . P r o d u c t s of the M a i l l a r d r e a c t i o n i n c l u d e a l i p h a t i c a l d e h y d e s , f u r f u r a l , f u r f u r a l d e r i v a t i v e s , k e t o n e , and 1 , 2 - d l c a r b o n y l compounds. The a l i p h a t i c a l d e h y d e s a r e p r o d u c e d by the o x i d a t i v e d e g r a d a t i o n o f the amino acide (known as S t r e c k e r d e g r a d a t i o n ) . The r e s u l t i n g a l d e h d e s c o n t a i n one c a r b o n atom l e s s t h a n t h e i n i t i a l amino a c i d . The S t r e o k e r d e g r a d a t i o n can o c c u r by r e a c t i o n o f amino a c i d s e i t h e r w i t h Amadori rearrangement p r o d u c t s


10,

MABROUK


o r w i t h d l c a r b o n y l compounds p r e s e n t i n the r e a c t i o n m i x t u r e * F u r f u r a l and i t s d e r i v a t i v e s a r e produced by

dehydration of the amadori rearrangement products, and they can p a r t i c i p a t e i n the S t r e o k e r degradation. There i s no d e f i n i t e r e l a t i o s h i p between the odor produced and the temperature t o which v a r i o u s i n d i v i d u a l amino a c i d s were h e a t e d w i t h g l u c o s e ( 4 7 ) · For example , w i t h l e u c i n e and threonine the odor was"pleasant at 100? but u n p l e a s a n t a t 1 8 0 ° C . With h l s t i d l n e an odor a p p e a r ed a t 1 8 0 ° C . I r r e s p e c t i v e of the temperature, g l y c i n e , c i - a l a n l n e , / ^ - a l a n i n e and glutamic a c i d produced only the odor of b u r n t sugar when h e a t e d w i t h g l u c o s e ; w h i l e


o

tryptophan, tyrosine, a r g l n i n i n e , and«-amlnobutyric a c i d produced t h e b u r n t sugar odor o n l y a t 1 8 0 ° C T a b l e X I I I l i s t s the v o l a t i l e compounds produced by the r e a c t i o n o f c y s t e i n e and c y s t i n e w i t h g l u c o s e and p y r u v a l d e h y d e (48).At l60°C, t h e r e a r e not too many d i f f e r e n c e s between the aroma produced by t h e r e a c t i o n o f p y r u v a l d e h y d e and g l u c o s e • P y r a z i n e s had been i d e n t i f i e d as the v o l a t i l e s c o n t r i b u t i n g to the f l a v o r s p r o d uced b y the sugar-amino a c i d r e a c t i o n . 2 , 5 - D l m e t h y l - , and 2 , 5 - d i m e t h y l - 3 - e t h y l p y r a z l n e were d e t e c t e d i n the v o l a t i l e s r e s u l t i n g from h e a t i n g c y s t e i n e and c y s t i n e w i t h p y r u v a l d e h y d e . Trime t h y I p y r a ζ i n e was found o n l y i n the p r e s e n c e o f c y s t e i n e . W h i l e m e t h y l - , 2 , 5 - d i m e t h y l - , 2- m e t h y l - 3 - e t h y l - , 2 - m e t h y l - 6 - e t h y l - , and 2 , 5 - d l m e t h y l 3- e t h y l p y r a ζ ine were p r o d u c t s o f h e a t i n g g l u c o s e w i t h c y s t e i n e ; m e t h y l p y r a z i n e was the o n l y p y r a z i n e p r e s e n t in the v o l a t i l e s r e s u l t i n g from a m i x t u r e o f g l u c o s e and c y s t i n e . S e v e r a l t h l o p h e n e s were d e t e c t e d i n t h e v o l a t i l e s p r o d u c e d b y the r e a o t i o n o f c y s t e i n e w i t h p y r u v a l d e h y d e except 2 - t h l o p h e n o l c a d d w h i c h e x i s t e d o n l y i n the p r e s e n c e o f c y s t i n e . Thiophene and h y d r o x y t h i o p h e n e were found i n the v o l a t i l e s p r o d u c e d from heat ed g l u c o s e - o y s t e i n e . T h l o p h e n e s g e n e r a l l y g i v e a l i t t l e u n p l e a s a n t and c h a r a c t e r i s t i c o d o r . T h i a z o l e s were p r o d uced from s u l f u r - c o n t a l n i n g amino a c i d s i n the p r e s e n c e of e i t h e r g l u c o s e o r p y r u v a l d e h y d e , b u t t h e i r s p e c i e s were d i f f e r e n t . #

g- Peptides. I n f l a v o r c h e m i s t r y , p e p t i d e s have been s t u d i e d as components w h i c h c o n t r i b u t e a b i t t e r , s o u r and sweet t a s t e . R e p o r t s on p e p t i d e s as o o n t r t r i b u t o r s t o d i s c o l o r a t i o n and aroma o f f o o d s was seldom r e p o r t e d . R e l a t i n g t o the p r o d u c t i o n o f f o o d f l a v o r and nonenzymic b r o w n i n g , s t u d i e s were c o n c e n t r a t e d on amino a c i d s , amines and p r o t e i n s . The o r d e r o f the browning r a t e o f amino compounds i s : t e t r a g l y c i n e > t r i g l y c i n e > diglycine^> DL-alany 1-DL-alanine]> g l y c i n e > D L - a l a n i n e , and the r e a c t i v i t y o f p e p t i d e i s much h i g h e r t h a n t h a t


172

PHENOLIC, SULFUR, AND NITROGEN COMPOUNDS I N FOOD FLAVORS

Table XIII.

Volatile Compounds Produced by the Reaction of Sulfur-Containing Amino Acids with Glucose or Pyruvaldehyde.


Volatile Compounds

Glucose and Cysteine Cystine

Thiophene Hydroxy thiophene 2- Methylthiophene 3- Methyl Thiophene 2,5-Dimethyl thiophene 2.3- Dihydro-4(or 5)-ethylthiophene 2 (or 3-)Ehtylthiophene 2- Methyl-3(or 4-)ethylThiophene 2,3,5-Trimethy1thiophene 3- Methyl-n-propylthiophene 2.4- Dimethyl-5-ethylthiophene 2-Thiophenoic acid 2-Methyltetrahydrothiopehen-3-one Thiazole 2-Ethylthiazole 2-Methylthiazole 5 (or 4)-Methyl thiazole 5 (or 4)-Ethylthiazole Trimethyl thiazole 2-Methylthiazoline 2-Acetyl-4-methylthiazole Pyridine α-Picoline β-Picoline 2-Methyl-5-ethylpyridine Methylpyrazine 2.5- Dimethylpyrazine 2-Methyl-6-ethylpyrazine 2-Methyl-3-ethylpyrazine 2,5-Dimethyl- 3-ethylpyrazine Trimethylpyrazine Furfural 2-Methyl-5-ethylfuran 2-Acetylfuran 2-Acetyl- 5-methylfuran Furfural alcohol 5-Methylfurfural 2,5-Dimethyl-3-ethylfuran 2-Furoic acid Phenol p-Nfethylbenzoic Acid

X X -

Pyruvaldehyde § Cysteine Cystine

-

X

-

-

X X

-

-

-

X

-

_ X -

-

-

-

X X

X X X X X -

X X -

-

X Χ X X X χ X X -

X

X

X X X X X X -

X

X

-

Χ

"

-

X "

X

Χ X

X -

Χ X -

X X X X


10. MABROUK Table XIII.

Nonvolatile Nitrogen and Sulfur Compounds in Red Meats 173 V o l a t i l e Compounds Produced by the Reaction of Sulfur-Containing Amino Acids with Glucose or Pyruvaldehyde. (cont'd)


V o l a t i l e Compounds Ethyl Alcohol 2,4 (or 5) Dimethyl thiazole 2-Methyl-4(or 5) ethylthiazole 2-Ethylthiazoline Benzoic Acid p-Methylbenzoic Acid Acetic Acid 2-Methylthiazoline Furfuryl alcohol Benzene

Glucose and Cysteine Cystine X Χ -

X X X X X -

Pyruvaldehyde ξ Cysteine Cystine

X

-

-

X Χ Χ -

X X X -

X

-

From reference (48)


x

174

P H E N O L I C ,

S U L F U R ,

A N D N I T R O G E N

C O M P O U N D S

I N

F O O D

F L A V O R S

o f the amino a c i d ( ^ 9 ) · The t a s t e o f g l j o y 1 - L - l e u c i n e i s v e r y b i t t e r , b u t t h e p r o d u c t of i t s r e a c t i o n w i t h g l y o x a l a t ! O O C , p H 5·00; has an a s t r i n g e n t , β l i t t l e sour and l a t e r a m i l d t a s t e . A s e r i e s o f new p y r a z l n o n e s 2-( 3 - a I k y 1 - 2 - o x o - p y r a z i n - 1 - y l ) a l k y l a o i d s were p r e p a r e d from v a r i o u s d i p e p t i d e s , T a b l e X I V . P y r a z i n e p r o 0

1

1

1


ducts r e s u l t i n g from the r e a c t i o n o f amino a c i d s w i t h o a r b o n y l compounds and by the p y r o l y s i s o f some amino a o i d s were considered t o be s t a b l e , e s p e c i a l l y when i t s s u b s t i t u e n t s are a l k y l groups* Pyrazines w i t h s u b s t i t u e n t s o t h e r t h a n a l k y l group such as i n the c a s e of d i h y d r o p y r a ζ i n e was shown t o be r e a c t i v e * The a d d i t i o n

of pyrazinone to d i p e p t i d e - g l y o x o l s o l u t i o n Increased the browning w h i l e amino a c i d - p y r a z i n o n e o r g l y o x a l p y r a z i n o n e s o l u t i o n caused no browning ( 4 9 ) » One c a n assume t h a t p y r a z i n o n e p l a y s a r o l e i n the browning r e a c t i o n , and i t probably r e a c t s w i t h n e i t h e r the amino a c i d n o r w i t h g l y o x a l , b u t w i t h the p r o d u c t produced i n the r e a c t i o n . The e x p e r i m e n t a l r e s u l t s i n d i c a t e d t h a t 2 - ( 3 - m e t h y l - 2 - o x o - p y r a z l n - l - y l ) p r o p l o n i c a c i d was more a c t i v e i n browning t h a n 2-(2 -oxopyrazln-1 -yl) i s o c a p r o l c a c i d , t h e s u b s t i t u e n t may be c o n s i d e r e d as a causative factor. I n a study on l i p i d browning,Dugan and Rao (50) r e p o r t e d t h a t the r e a c t i o n s p r o c e e d r e a d i l y at low mois t u r e l e v e l s ( 2 . 5 $ ) and ambient o r e l e v a t e d t e m p e r a t u r e s . The r e a c t i o n between p h o s p h a t i d y l e tha n o l a m i n e ( P E ) and n o n a n a l ( T a b l e XV) on p r o t e i n m a t r i x ( l l p l d - f r e e b e e f muscle f i b e r s ) i n d i c a t e d t h a t the c a r b o n y l r e a c t i o n s prooeeded w i t h b o t h amino groups from PE and from the p r o t e i n m a t r i x . C e r t a i n amino a c i d s , such a s , l y s i n e , a l a n i n e , p h e n y l a l a n i n e , and t y r o s i n e r e a c t e d w i t h a l dehydes (nonanals o r o x i d a t i o n p r o d u c t s o f u n s a t u r a t e d Ρ Ε ) , s u f f i c i e n t l y t o reduce t h e i r q u a n t i t y i n the t o t a l amino a c i d c o n t e n t i n the s y s t e m . The r e a c t i o n s were c o m p e t i t i v e t h a t the p r e s e n c e o f PE had a s p a r i n g e f f e c t on amino a c i d s i n the p r o t e i n m a t r i x . T h i s o b s e r v a t i o n may p r o v i d e a r a t i o n a l e f o r the changes I n t e x t u r e , c o l o r , f l a v o r , and n u t r i t i v e v a l u e o f d r i e d f o o d s c o n t a i n i n g p r o t e i n s and p h o s p h o l i p i d s . ,

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ana 3-meroaptothiophenes i n v a r i o u s degrees of s a t u r â t i o n ( 5 2 ) . T h e t h i o p h e n e analogs of the h y d r o x y f u r e n o n e s s t a r t i n g m a t e r i a l s were a l s o formed i n t h e s e r e a c t i o n s . These a n a l o g s i n t u r n a f f o r d e d s t i l l more m e r o a p t o t h i o phenes and m e r c a p t o t h i o p h e n o n e s . T h e r e a c t i o n systems and many o f p u r i f i e d i s o l a t e d compounds had m e a t - l i k e o d o r s . As hydroxyfuranones and hydrogen s u l f i d e had been r e p o r t e d i n b o i l e d b e e f ( 5 1 ) , i t i s expected t h a t t h e i r r e a c t i o n p r o d u c t s a r e a l s o p r e s e n t , though i n conc e n t r a t i o n s u n d e t e c t e d by the a v a i l a b l e i n s t r u m e n t a l techniques.


Taste

of F l a v o r

Precursors

The o v e r a l l flavor" s e n s a t i o n may c o n v e n i e n t l y be d i v i d e d i n t o s e n s a t i o n due to " t a s t e " and " a r o m a " . I n the case o f cooked meats, the c o n t r i b u t i o n o f a r o m a t i c compounds would be l a r g e i n comparison w i t h t h a t due t o the n o n - v o l a t i l e t a s t e - b e a r i n g components. A l l D-amino a c i d s have sweet t a s t e . W i t h the e x c e p t i o n o f L - p h e n y l a l a n l n e which i s b i t t e r , a n d 1 - a l a n i n e w h i c h i s s l i g h t l y sweet, a l l L-amino a c i d s a r e t a s t e l e s s * F r e e L - g l u t a m l c a c i d has a w e l l known b r o t h y t a s t e . Some o f the L - g l u t amyl d i p e p t i d e s formed from c o u p l i n g a n amino a c i d t o the ( X - o a r b o x y l group o f L - g l u t a m i c a c i d were found t o t a s t e b r o t h y : glutamyla spart1ο , glutamylthreonine , g l u t a m y l s e r i n e , and g l u t a m y l g l u t a m i c (53)· G l u t a m y 1 g l y c y l s e r i n e i s r e s p o n s i b l e f o r the b r o ï B y t a s t e o f a n e n z y m a t l o a l l y m o d i f i e d soybean p r o t e i n . About t h i r t y a c i d i c o l i g o p e p t i d e s were i s o l a t e d and I d e n t i f i e d i n a f l a v o r p o t e n t i a t i n g f r a c t i o n from f i s h p r o t e i n h y d r o l y s a t e (5*0 · F o u r d i p e p t i d e s ( g l u t a m y l a spar11c, g l u t a my I g l u t a m l o , g l u t a m y l s e r i n e , and t h r e o n y l g l u t a m i c ) , and five tripeptldes (aspartylglutamylserine,glutamylaspart y l g l u t a m i c , glutamylglutanrineglutamic, g l u t a m y l g l y c y l s e r i n e , and s e r y l g l u t a m y l g l u t a m i c ) had a f l a v o r q u a n t i t a t i v e l y r e s e m b l i n g t h a t o f monosodium glutamate(MSG). The t h r e s h o l d l e v e l o f g l u t a m y I g l y c y l s e r i n e , f o r examp l e , was e s t i m a t e d t o be a p p r o x i m a t e l y 0.2$ i n water a t pH 5.0 , whereas t h a t o f MSG was almost one t e n t h o f t h i s l e v e l under the same c o n d i t i o n s . Some i s o l a t e d p e p t i d e s were r e p o r t e d t o e x h i b i t b i t t e r taste(glutamylaspartylvaline, aspartylleucine. isoleucylglutamylg l u t a m i c , and i s o l e u o y l g l u t a m i c ) w h i l e o t h e r s had a f l a t t a s t e . A strong s y n e r g i s t i c r e l a t i o n s h i p exists between n u c l e o t i d e s and MSG w i t h the r e s u l t t h a t b l e n d s of MSG and n u c l e o t i d e s exceed the p o t e n c y and v e r s a t i l i t y o f e i t h e r m a t e r i a l a l o n e . T h e optimum b l e n d w h i c h o f f e r s the g r e a t e s t e f f e c t i v e n e s s f o r t h e l e a s t c o s t i s a b l e n d o f 95% MSG and 5% n u c l e o t i d e s . D e s i r a b l e f l a tt



178


vors were enhanced by a d d i t i o n of sodium lnosinate r e gardless of the type of the meat or cooking method (5§)« Disodium lnosinate oonsistently produced an Impression of greater v i s c o s i t y and Increased f l a v o r . Amino acids play an Important part In the p a l a t a b l e taste of foods* When glycine was added to a 1# NaCl s o l u t i o n containing L-glutamlo or L-aspartlo and IMP plus GMP at 0.1# , the palatable taste of the medium was s i g n i f i c a n t l y Improved. The ternary synergism among L-glutamic or L-aspartic,5'-nucleotides and glycine Is d i f f e r e n t from the binary synergism already known between L-glutamlo a d d and 5 ' - n u c l e o t i d e s (56). The t e r nary synergism i s s i g n i f i c a n t at the concentration of the stimulus threshold of these components. The ternary synergism was not due to the sweet taste of glyolne. No binary synergism of palatable taste was observed between glyolne and L-glutamic or L-aspartlo, or g l y c i n e and 5'-nucleotides.Extending the study to i n clude other o(-amlno a d d s , Indicated the absemoe of any binary synergism of palatable taste between IMP plus GMP or MSG and glyolne, L-alanine, L-serine, L - h l s t l dine-HCl, L-methlonine, or DL-tryptophan In 1$ NaCl sol u t i o n i s ? ) •However, L - a l a n l n e ( 0 . 0 5 ) , L - e y s t i n e ( 0 . 0 5 ) , Çlyclne(O.lO), L-histldlne-HCl(0.004), ^methionine 1 0 . 0 3 ) . L - p r o l l n e ( 0 . 2 0 ) , L-serIne(0.10), DL-tryptophan (0*015), or L-valine(0.15g./dl.) gave a ternary synergism with IMP plus GMP and MSG(0.01#, respectively) In 1# NaCl s o l u t i o n . When two or three of t h i s group of amino aoids were added to 1# NaCl s o l u t i o n containing MSG and IMP plus GMP at 0.01JÉ, the ternary synergism caused by these amino acids was estimated as the algeb r a i c sum of the a c t i v i t y of the Individual amino acids ( 5 8 ) ·

PfcaymaoolgKlogl E f f e c t ? Bed meat f l a v o r precursors have w e l l known functions In human n u t r i t i o n . The evidence of t h e i r pharmacological properties has been known f o r many decades before t h e i r contributions to f l a v o r were established. Suoh propert i e s of amino a c i d s , peptides, sugars,nucleotides..etc have been reviewed In human physiology ,human biochemi s t r y and human n u t r i t i o n books and reviews (££,60). Meat extract, which Is a concentrate of aqueous beef extract, Is olalmed to be a stimulant. Products containing meat e x t r a c t , have been regarded as general t o n i c s and stimulants, a s s i s t i n g recovery from exhaust i o n and f a t i g u e . Preoise information about these e f f e c t s are lacking. I t Is, of course possible that the well-known promotion of g a s t r i c and I n t e s t i n a l seore-



10. MABROUK


tion and motility might cause secondary,more generalized effects and result In a real or apparent stimulation. Injecting creatine i n frogs before setting them to work on a treadmill, proved to be responsible for Improving muscular performance and hastened recovery after work(61). In his classical fistulas experiments with dogs,. Pavlov (62) had Indicated that meat extract was a powerful stimulant of gastric secretion. He evaluated some of meat extract components and concluded that creatIne,hypoxanthlne, xanthine,leucine and a mixture of inoslne and hypoxanthlne were Ineffective* Later, Krimberg and Komarov (63,64,6j>) and Korohow (66) demonstrated that carnosine at a concentration of 0*02 g./kg was the compound responsible for the gastric stimulating properties* Using a dose of 0*005 g./kg. , Schwarz and Goldschmldt reported no stimulation of secretion following the administration of carnosine into dogs with gastric f l s t u l a s ( 6 £ ) · Evaluating pure samples of carnosine, carnitine and methyl guanidlne for their effect as stimulant of gastric secretion, proved that carnosine was the most powerful one. Intravenous injection of carnosine was most effective than subcutaneous and oral administration. The principal funotlon of anserine and carnosine Involves the coupling of phosphorylation with glycolysis and the synthesis of adenosine triphosphate. Carnitine which had been reported in meat extracts is Identical with vitamin % ( 6 8 ) . Methionine has been reported to be beneficial In the prevention and treatment of l i v e r Injury due to poisoning by arsenic, chloroform, carbon tetraohoride, or t r i n i t r o toluene.lt has been recommended in the treatment of eclampsia, shook, infectious hepatitis and cirhosls of the l i v e r . It has been prescribed In the management of obese, and patients with severe burns(69)· "The whole f i e l d of flavor precursor chemistry is In i t s Infancy, and It is reasonable to say that no study — be i t academic or commercial — of a natural flavor can be considered oomplete unless i t includes the precursors of that flavor. An approach to any f l a vor problem which recognizes the importance of the two complementary approaches is more likely to give a complete picture of the flavor and the mechanism of Its formation than attempts to Interpret i t s chemical constitution , Rohan s statement(70) expresses my views. 11

1

ABSTRACT

Red meats e x h i b i t d i s t i n c t t a s t e and f l a v o r which are c h a r a c t e r i s t i c of t h e i r animal speies. Age of the animal, type of feed, animal c o n d i t i o n , type of meat


180


cuts, meat processing, etc., strongly affect the taste and flavor of individual meats. Non-volatile nitrogen and sulfur compounds play an important role in the development of the characteristic flavors of red meats. Their pharmacological effect, relative importance, and their role i n the formation of flavor components were discussed. Speculations on the reasons for differences in red meat flavors that intrigue flavor chemists were reported.


Literature Cited 1. Wong, Ε., Nixon, L . N . , Johnson, C . B . , J. Agr. Food Chem. (1975), 23, 495. 2. Patterson, R.L.S., J. Sci. Food Agr. (1968), 19, 31. 3. Crocker, E.C., Food Res. (1948), 13, 179. 4. Bender, A.E., Wood, T., Palgrave,J.A., J. S c i . Food Agr. (1958), 9, 812. 5. Wood, T., J. Sci. Food Agr. (1961), 12, 61. 6. Batzer,O.F., Santoro, A . T . , Landmann, W.A., J. Agr. Food Chem. (1962), 10, 94. 7. Batzer, O . F . , Santoro, A.T., Tan, M.C., Landmann, W.A., Schweigert, B . S . , J. Agr. Food Chem. (1960), 8, 498. 8. Hornstein, J., "Chemistry and Physiology of F l a vors" ,Schults, H.W., Day, E . A . , Libbey, L . M . , Eds. pp. 228-250, Avi Publishing Co., Westport, Conn. 1967. 9. Macy, R . L . , Jr., Naumann, H.D., Bailey, M.E., J. Food Sci. (1964), 29, 136. 10. Macy, R . L . , Jr., Naumann, H.D., Bailey, M.E., J. Food Sci. (1964), 22, l42. 11. Wasserman, A.E., Gray, N . , J. Food Sci. (1965), 30, 801. 12. Zaika, L.L., Wasserman, A.E., Monk, C . B . , Jr., Salay, J., J. Food Sci. (1968), 33, 5 3 · 13. Mabrouk, A.F., Jarboe, J.K., O'Connor, E.M., J. Agr. Food Chem. (1969), 17, 5. 14. Mabrouk, A.F., J. Agr. Food Chem. (1973), 21, 942. 15. Mabrouk, A.F., Kramer, R . , Jarboe, J.K., Alabran, D.H., Unpublished data. 16. Paulson, J.C., Deatherage, F.E., Almy, E . P . , J. Am. Chem. Soc. (1953), 75, 2039. 17. Jarboe, J.K., Mabrouk, A.F., J. Agr. Food Chem. (1974), 22, 787. 18. Dvorak, Z., Vognarova, I., J. Sci. Food Agr. (1969), 20, l46. 19. Johnson, A.R., Viokery, J . R . , J. Sci. Food Agr. (1964), 15, 695.



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Mabrouk


20. Dahl, O., J. Agr. Food Chem. (1963), 11, 350. 21. Bendall, J.R., J. Soc. Chem. Ind. (1946), T226. 22. Nakajima, N., Ichikawa, K., Kamada, M., Fujita, Ε., J. Agr. Chem. Soc. Japan (1961), 35, 797· 23. Mabrouk, A.F., Abstracts of Papers. 86, Division of Agricultural And Food Chemistry, 160th ACS National Meeting, Chicago, I l l i n o i s , September 1970. 24. Mabrouk, A.P., Abstracts of Papers. 39, Division of Agricultural And Food Chemistry, 162nd ACS National. Meeting, Washington, D . C . , September 1971. 25 Terasaka, Μ., Takeda Scientific Information Bulle t i n No. 26. 26. Fujlmakl, M . , Chuyen, Ν. V . , Matsumoto. T., Kurata, T., J. Agr. Chem. Soo. Japan (1970), 44, 275. 27. Maoy, R . L . , Jr., Neumann, H . D . , Bailey, M . E . , J. Food S c i . (1970), 35, 78. 28. Maoy, E.L., Jr., Neumann, H.D., Bailey, M . E . , J. Food Sci.(1970), 35, 81. 29. Maoy, R . L . , Jr., Neumann, H.D., Bailey, M . E . , J. Food S c i . (1970), 35, 83. 30. Craske, J.D., Beuter, P . H . , J. Sci Food Agr. (1965), 16, 243. 31. Miyake, Μ., Tanaka, Α . , J.Food S c i . (1971), 36, 674. 32. Merrltt, C . , Jr., Bobertson, D . H . , J.Gas Chromatog. (1967), 4, 96. 33. Giacabbo, Η . , Simon, W., Pharm. Acta Helv. (1964), 32, 162. 34. Vollmin, J., Kriemler, P . , Omura, J., Selble, J., Simon, W., Microchem. J. (1966), 11, 73. 35. Fujimaki, M . , Kato, S., Kurata, T., Agr. Biol. Chem. (1969), 22, 1144. 36. Kato, S., Kurata, Τ . , Fujimaki, Μ., Agr. B i o l . Chem. (1973), 37, 1759. 37. Tondeur, Β . , Slon, Β . , Deray, Ε . , Bull. Soc. Chim. France (1964), 2493. 38. Kato, S., Kurata, T., Fujimaki, M . , Agr. B i o l . Chem. (1971), 21, 2106. 39. Kato, S., Kurata, T., Ishitsuka, B . , Fujimaki. Μ., Agr. B i o l . Chem. (1970), 34, 1826. 40. Maga, J.A., Sizer. C . E . , CBC C r i t i c a l Rev. Food Technol., (1973), 4, 39. 41. Wang, P . , Odell, G . V . , J. Agr. Food Chem.(1973), 21, 868. 42. Dawes, I.W., Edwards, R . A . , Chem. Ind. (London), (1966), 2203. 43. Hodge, J.E., J. Agr. Food Chem. (1953), 1, 928. 44. Hodge, J.E., "The Chemistry and Physiology of F l a vors" , Sohultz, H.W., Day, Ε . Α . , Libbey, L.N., Eds., pp 465-491, Avl Publishing C o . , Westport, Conn. , 1967. Charalambous and Katz; Phenolic, Sulfur, and Nitrogen Compounds in Food Flavors ACS Symposium Series; American Chemical Society: Washington, DC, 1976.

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