Loss of Flavor Compounds from Aseptically Processed Food Products

Processed Food Products Packaged in Aseptic. Containers. A. P. Hansen ... The sale of fruit juice and juice ... Aaron Brody of Schotland Business Rese...
0 downloads 0 Views 832KB Size
Chapter 17

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

Loss of Flavor Compounds from Aseptically Processed Food Products Packaged in Aseptic Containers A. P. Hansen and D. K. Arora Department of Food Science, North Carolina State University, Box 7624, Raleigh, NC 27695-7624

The l o s s of n a t u r a l f l a v o r compounds in a s e p t i c a l l y processed and packaged milk and cream and the aroma changes in the headspace of UHT milk were monitored during storage. The concentration of methanal, propanal, butanal and nonanal decreased over s i x months for two processes (138°C for 20.4 s and 149°C for 3.4 s ) . Total aldehyde concentration decreased over a s i x month storage p e r i o d . Headspace a n a l y s i s of UHT processed milk revealed a l o s s of higher molecular weight f l a v o r compounds at 12 week storage. The loss of flavor compounds may be due to the interaction with the packaging m a t e r i a l (low density polyethylene) and with the p r o t e i n s . The l o s s of f l a v o r compounds in UHT processed and packaged milk and cream v a r i e d from 50-97% over a 12 month storage p e r i o d . Food p a c k a g i n g i s u n d e r g o i n g enormous c h a n g e s due t o t h e shift i n consumer i n t e r e s t towards convenience foods. Among f o o d p a c k a g i n g m a t e r i a l s , t h e u s e o f p l a s t i c s i s e x p e c t e d t o i n c r e a s e by 55% by 1990 ( 1 ) . The m a r k e t s h a r e of f l e x i b l e and r i g i d p l a s t i c p a c k a g i n g i s e x p e c t e d t o i n c r e a s e from $19 b i l l i o n t o $44 b i l l i o n by t h e y e a r 2000 (2) . Since the approval of hydrogen peroxide f o r sterilizaion of polyethylene food-contact surfaces i n 1981, t h e r e has been an enormous p r o l i f e r a t i o n i n a s e p t i c processing and p a c k a g i n g of food products. Besides convenience, a s e p t i c p a c k a g i n g has r e s u l t e d i n i m p r o v e d 0097-6156/90/0423-0318S06.00/O © 1990 American Chemical Society Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

17.

HANSEN & ARORA

Loss of Flavor Compounds from Packaged Foods

product q u a l i t y and i n lower p a c k a g i n g / o p e r a t i n g cost. Milk-based products, fruit j u i c e s and juice drinks are t h e major a s e p t i c p r o d u c t s i n t h e m a r k e t ( 3 - 5 ) . More t h a n 50 U.S. companies a r e c u r r e n t l y m a r k e t i n g f r u i t j u i c e s and drinks in aseptic packages (6). Tomato-based p r o d u c t s , s o u p s , wine and m i n e r a l w a t e r a r e e x p e c t e d t o be i n t r o d u c e d soon ( 6 ) . The s a l e o f f r u i t j u i c e and j u i c e drinks i s estimated t o be $60 m i l l i o n by t h e y e a r 2000 ( 6 ) . The U.S. m a r k e t may have a volume o f o v e r 15 b i l l i o n a s e p t i c p a c k a g e s by t h e y e a r 2000 ( 6 ) . Most a s e p t i c f o o d s a r e packaged i n a v a r i e t y of p o l y m e r i c m a t e r i a l s . The p l a s t i c p o l y m e r s u s e d i n a s e p t i c packages are e i t h e r i n a pure or a coextruded form to optimize b a r r i e r properties. T h e s e p l a s t i c s a r e n o t as inert as metal and glass containers resulting in a s h o r t e r s h e l f l i f e f o r l a m i n a t e d p a c k a g e s when compared t o m e t a l and g l a s s c o n t a i n e r s . A v a r i e t y of i n t e r a c t i o n s such as permeability, migration, light penetration and sorption between p l a s t i c s and f o o d p r o d u c t s have been d e s c r i b e d ( 7 ) . The s o r p t i o n o f f l a v o r compounds by p o l y m e r i c m a t e r i a l s has n o t been e x t e n s i v e l y d i s c u s s e d . S o r p t i o n r e f e r s t o the s c a l p i n g o f f l a v o r s and aroma components o f f o o d p r o d u c t s by p l a s t i c s . F l a v o r s c a l p i n g may i n f l u e n c e the sensory q u a l i t y and the a c c e p t a b i l i t y of food products by the consumer. Most o f t h e a s e p t i c p a c k a g i n g i s done i n c o n t a i n e r s where a low d e n s i t y p o l y e t h y l e n e (LDPE) l a y e r comes i n contact with the food p r o d u c t . I t has been shown t h a t LDPE f i l m does n o t p r o v i d e a good b a r r i e r t o t h e l o s s o f f l a v o r compounds. M o r r i s Salame (8) r e p o r t e d 71% and 66% absorption of non-polar and polar flavor compounds, respectively, by polyethylene (PE). The sorption of f l a v o r compounds i n t o PE f i l m i n c r e a s e d w i t h c a r b o n c h a i n length (9). Greater s o r p t i o n o f f l a v o r compounds was observed i n l e s s c r y s t a l l i n e PE f i l m , which suggested t h a t h i g h c r y s t a l l i n e f i l m s may r e d u c e f l a v o r compound s o r p t i o n i n t o t h e PE. Kwapong and H o t c h k i s s (10) r e p o r t e d t h a t d - l i m o n e n e was absorbed to a higher degree than benzaldehyde, citral and ethylbutyrate i n t o LDPE and ionomer r e s i n ( S u r l y n ) . Meyers and H a l e k (11) reported 30-40% l o s s i n hydrocarbon terpenes and 10% loss in o x y g e n a t e d t e r p e n e s when e x p o s e d t o LDPE. Mannheim e t a l . (12) r e p o r t e d a 25% r e d u c t i o n i n d-limonene content over 14 d a y s i n o r a n g e j u i c e s a m p l e s c o n t a i n i n g LDPE s t r i p s . Marcy et al. (13) reported lower flavor scores in concentrated o r a n g e j u i c e and c o n c e n t r a t e d orange d r i n k s t o r e d i n a s e p t i c f l e x i b l e bags. R e c e n t l y , C h a r a r a (14) r e v i e w e d s o r p t i o n o f flavor compounds i n t o p a c k a g i n g m a t e r i a l s . T h i s comprehensive r e v i e w showed t h a t p o l y m e r i c materials in contact with f o o d p r o d u c t s c a u s e d a l o s s o f f l a v o r compounds i n f o o d p r o d u c t s and model f o o d s y s t e m s . Low l e v e l s o f f r u i t p u l p content i n j u i c e r e s u l t e d i n higher a b s o r p t i o n of f l a v o r

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

319

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

320

BARRIER POLYMERS AND STRUCTURES

compounds ( t e r p e n e h y d r o c a r b o n s ) and t h a t t h e d e g r e e o f absorptivity depended upon the nature of the flavor compounds. In dairy products the lipid component is an i m p o r t a n t c o n t r i b u t o r o f d a i r y f l a v o r . Compounds s u c h as mono- and d i - c a r b o n y l s and v o l a t i l e f a t t y a c i d s impart f l a v o r t o m i l k t h o u g h p r e s e n t o n l y i n low c o n c e n t r a t i o n s . S a t u r a t e d and u n s a t u r a t e d a l d e h y d e s and v a r i o u s k e t o n e s a f f e c t f l a v o r t h o u g h p r e s e n t i n c o n c e n t r a t i o n s o f ppm or ppb (15). Most o f t h e f l a v o r e d a s e p t i c f o o d s i n t h e m a r k e t a r e f o r t i f i e d w i t h e s s e n t i a l f l a v o r s t o compensate f o r any f l a v o r compounds l o s t d u r i n g p r o c e s s i n g and s t o r a g e . T h i s e m p i r i c a l technique o f f o r t i f i c a t i o n may work f o r some f o o d p r o d u c t s ; i n o t h e r s t h i s p r o c e s s may l e a d t o f u r t h e r d e t e r i o r a t i o n as the sorption process i s d r i v e n by a concentration gradient. Loss of one component in a complex f l a v o r m i x t u r e may r e s u l t i n a l o s s of flavor i n t e n s i t y o r a change i n f l a v o r n o t e s . D i f f e r e n t polymeric m a t e r i a l s w i t h h i g h aroma and flavor barrier p r o p e r t i e s are c u r r e n t l y being tested. Recently, i t was reported that ethylene vinyl alcohol (EVOH) c o e x t r u d e d containers resulted in no loss of e s s e n t i a l o i l and 24% l o s s o f v i t a m i n C i n o r a n g e j u i c e (16). Aaron Brody of S c h o t l a n d B u s i n e s s R e s e a r c h , I n c . ( 17) r e p o r t e d t h a t EVOH i m p r o v e d gas and aroma b a r r i e r p r o p e r t i e s and w i l l be u s e d e x t e n s i v e l y i n b a r r i e r f i l m s . To minimize flavor compounds sorption into packaging materials, impregnation of the polymeric layer with s u i t a b l e f l a v o r compounds has been s u g g e s t e d (7,17). The reports on sorption of flavor compounds by packaging materials suggest that more elaborate and detailed research on the i n t e r a c t i o n s between flavor compounds and p a c k a g i n g m a t e r i a l s i s needed t o p r o d u c e a s e p t i c p r o d u c t s h a v i n g a more s t a b l e f l a v o r p r o f i l e , a l o n g e r s h e l f l i f e and i n c r e a s e d consumer a c c e p t a n c e . In t h i s p a p e r we w i l l d i s c u s s the e f f e c t of UHT p r o c e s s i n g and s t o r a g e on t h e l o s s o f n a t u r a l f l a v o r s i n m i l k and cream and on t h e aroma c h a n g e s i n t h e h e a d s p a c e of aseptically processed and packaged milk during storage. M a t e r i a l s and

Methods

F r e s h m i l k and cream were o b t a i n e d from t h e N.C. State U n i v e r s i t y d a i r y f a r m and s t a n d a r d i z e d t o 3.25% f a t and 10% f a t , r e s p e c t i v e l y . M i l k was processed a t 149 °C f o r 3.4 s f o r s h o r t r e s i d e n c e t i m e (SRT) and 138°C f o r 20.4 s for l o n g r e s i d e n c e t i m e ( L R T ) . Cream was processed at 138°C f o r 20.4 s, a t 143°C f o r 7.8 s, a t 149°C f o r 3.4 s and a t 149°C f o r 20.4 s. A l l samples were p r e h e a t e d t o 78 °C. The milk was cooled in a No-Bac Aro-Vac ( C h e r r y - B u r e l l ) t o a f i l l i n g t e m p e r a t u r e o f 7°C. A s e p t i c p a c k a g i n g was a c c o m p l i s h e d by a T e t r a B r i k Model AB3-250

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

17.

HANSEN & ARORA

Loss of Flavor Compounds from Packaged Foods

f i l l e r . M i l k and cream samples were s t o r e d a t 24°C and 40°C and a n a l y z e d m o n t h l y f o r up t o one y e a r . The m i l k and cream were c e n t r i f u g e d , and t h e f a t f r a c t i o n was removed. The f a t was e x t r a c t e d w i t h c a r b o n y l f r e e h e x a n e , and t h e f a t e x t r a c t was i m m e d i a t e l y r e a c t e d w i t h 2 , 4 - d i n i t r o p h e n y l h y d r a z i n e . The c a r b o n y l compounds formed r e s p e c t i v e 2 , 4 - d i n i t r o p h e n y l h y d r a z o n e s (2,4-DNPH). The h y d r a z o n e s were s e p a r a t e d i n t o m o n o c a r b o n y l s and t h e n further p u r i f i e d using thin l a y e r chromatography (18). Alkanal 2,4-DNPH were a n a l y z e d by gas chromatography u s i n g a 1.83 m g l a s s column ( i . d . 4 mm) p a c k e d w i t h 2% OV-1 on a c i d washed Chromosorb W (180-200 mesh) ( 1 8 , 1 9 ) . Headspace a n a l y s i s was conducted by gas c h r o m a t o g r a p h y a c c o r d i n g t o t h e method o f K e l l e r and K l e y n (20) w i t h t h e m o d i f i c a t i o n d e s c r i b e d by Nash ( 2 1 ) . Headspace analysis of milk samples was conducted biweekly. R e s u l t s and

Discussion

Loss o f F l a v o r Compounds i n UHT Processed Milk. The f l a v o r compound p r o f i l e s o f UHT p r o c e s s e d m i l k (138°C f o r 20.4 s, LRT) a r e shown i n F i g u r e 1 and F i g u r e 2 f o r 0 and 6 mo s t o r a g e a t 24°C, r e s p e c t i v e l y . Peaks 2, 3 and 5 corresponding to propanal, butanal and nonanal, respectively, disappeared over 6 mo. Similarly, UHT p r o c e s s e d m i l k (149°C f o r 3.4 s, SRT) s t o r e d f o r 6 mo a t 24° C showed significant decreases i n t h e peak areas u n d e r m e t h a n a l , p r o p a n a l and b u t a n a l w h i l e t h e nonanal peak d i s a p p e a r e d ( F i g u r e 3 and F i g u r e 4 ) . A t z e r o time SRT samples r e t a i n e d a h i g h e r c o n c e n t r a t i o n o f flavor compounds t h a n LRT s a m p l e s . The i n d i v i d u a l c o n c e n t r a t i o n s o f f l a v o r compounds i n UHT p r o c e s s e d m i l k a t LRT and SRT s t o r e d a t 24°C and 40°C i s shown i n F i g u r e 5 - F i g u r e 8. In LRT p r o c e s s e d m i l k , higher molecular weight aldehydes and total aldehydes d e c r e a s e d i n c o n c e n t r a t i o n . In a l l o t h e r i n s t a n c e s t h e r e was a n e t l o s s i n a l d e h y d e s . I n SRT p r o c e s s e d m i l k , a l l of the i n d i v i d u a l aldehydes decreased as w e l l as the t o t a l a l d e h y d e s a t b o t h 24°C and 40°C s t o r a g e . The l o s s o f a l d e h y d e s may be a t t r i b u t e d t o b i n d i n g by t h e p a c k a g i n g materials and by the proteins in milk which have u n d e r g o n e g r e a t e r c h e m i c a l and p h y s i c a l a l t e r a t i o n c a u s e d by t h e e x t e n d e d p r o c e s s i n g h o l d t i m e . The h e a d s p a c e a n a l y s i s o f a r o m a t i c compounds o f UHT p r o c e s s e d m i l k f o r t i m e z e r o i s shown i n F i g u r e 9. The f l a v o r compound p r o f i l e a f t e r s t o r a g e f o r 12 wk i s shown in Figure 10. The higher molecular weight flavor compounds have a l m o s t d i s a p p e a r e d . T h e s e r e s u l t s agree w i t h Shimoda e t a l . (9) who r e p o r t e d g r e a t e r s o r p t i o n o f flavor compounds into PE as carbon chain length i n c r e a s e d . F i g u r e 11 shows t h e f l a v o r compound p r o f i l e o f UHT p r o c e s s e d m i l k a t 24 wk. A t t h i s s t o r a g e p e r i o d t h e low m o l e c u l a r w e i g h t f l a v o r compounds were a l s o r e d u c e d .

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

321

322

BARRIER POLYMERS AND STRUCTURES

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

M E T H A N A L 2,4-DNPH P R O P A N A L 2,4-DNPH B U T A N A L 2,4-DNPH UNIDENTIFIED P E A K A N O N A N A L 2,4-DNPH INTERNAL S T A N D A R D UNIDENTIFIED P E A K Β UNIDENTIFIED P E A K C UNIDENTIFIED P E A K D UNIDENTIFIED P E A K Ε

10

V

R E T E N T I O N TIME

Figure 1. Time z e r o gas c h r o m a t o g r a m o f alkanal 2,4-DNPH f r o m UHT m i l k p r o c e s s e d a t 138 °C f o r 20.4 s (LRT). (Reproduced with p e r m i s s i o n from R e f . 18. C o p y r i g h t 1982 A m e r i c a n D a i r y S c i e n c e A s s o c i a t i o n . )

1. 2. 3. 4. 5. 6. 7.

M E T H A N A L 2,4-DNPH UNIDENTIFIED P E A K A INTERNAL S T A N D A R D UNIDENTIFIED P E A K Β UNIDENTIFIED P E A K C UNIDENTIFIED P E A K D UNIDENTIFIED P E A K Ε

R E T E N T I O N TIME

F i g u r e 2. Gas c h r o m a t o g r a p h o f a l k a n a l 2,4-DNPH f r o m UHT m i l k p r o c e s s e d a t 1 3 8 ° C f o r 20.4 s and s t o r e d s i x mo a t 24°C (LRT). (Reproduced w i t h p e r m i s s i o n from Ref. 18. Copyright 1982 American Dairy Science Association. )

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

17. HANSEN & ARORA

Loss of Flavor Compounds from Packaged Foods

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

M E T H A N A L 2,4-DNPH P R O P A N A L 2,4-DNPH B U T A N A L 2,4-DNPH UNIDENTIFIED P E A K A NONANAL 2,4-DNPH INTERNAL S T A N D A R D UNIDENTIFIED P E A K Β UNIDENTIFIED P E A K C 6 UNIDENTIFIED P E A K D UNIDENTIFIED P E A K Ε

R E T E N T I O N TIME

Figure 3. Time z e r o gas c h r o m a t o g r a m of a l k a n a l 2 4-DNPH f r o m UHT m i l k p r o c e s s e d a t 149 °C f o r 3.4 s (SRT). (Reproduced with p e r m i s s i o n from R e f . 18. C o p y r i g h t 1982 A m e r i c a n D a i r y S c i e n c e A s s o c i a t i o n . ) f

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

M E T H A N A L 2,4-DNPH P R O P A N A L 2,4-DNPH B U T A N A L 2,4-DNPH H E X A N A L 2,4-DNPH UNIDENTIFIED P E A K A INTERNAL S T A N D A R D UNIDENTIFIED P E A K Β UNIDENTIFIED P E A K C UNIDENTIFIED P E A K D UNIDENTIFIED P E A K Ε

R E T E N T I O N TIME

F i g u r e 4. Gas c h r o m a t o g r a m o f a l k a n a l 2,4-DNPH f r o m UHT m i l k p r o c e s s e d a t 1 4 9 ° C f o r 3.4 s and s t o r e d s i x mo a t 24°C (SRT). (Reproduced w i t h p e r m i s s i o n from Ref. 18. Copyright 1982 American Dairy Science Association.)

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

323

324

BARRIER POLYMERS A N D STRUCTURES

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

"o 5 METHANAL f ω

3

I

2 1

*

io-8

L

NONANAL

§0.6

ι

Φ

g 0.4 5,0.2

^7.5

PROPANAL

§6.0 σ> 7» 4.5 Φ

13.0

%, 1.0

100

£ g

60

I 40

*

TOTAL ALDEHYDES

8 0

h

n 20

^1.5

0 6 12 18 24 STORAGE TIME (WEEKS)

BUTANAL

S

3

6 12 18 24 STORAGE TIME (WEEKS)

F i g u r e 5. Changes i n a l k a n a l c o n c e n t r a t i o n s i n UHT m i l k p r o c e s s e d a t 138° C f o r 20.4 s and s t o r e d a t 24° C (LRT).

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

17. HANSEN & ARORA

"o

¥

Loss of Flavor Compounds from Packaged Foods

METHANAL

5 4

£ω 3 Ε

°b 1.0

2

NONANAL

f 0.8

* 1

f0.6 o |0.4 3>Û.2 ^2.0

PROPANAL

f 1.6 §1.2

TOTAL ALDEHYDES

*fe 100

|0.8 ^0.4

0,60 |40 * 20 "b 1.0 f

0.8 L

S ω

0.6

BUTANAL

h 0 6 12 18 24 STORAGE TIME (WEEKS)

8 0.4 L

0 6 12 18 24 STORAGE TIME (WEEKS)

F i g u r e 6. Changes i n a l k a n a l c o n c e n t r a t i o n s i n UHT m i l k p r o c e s s e d a t 138° C f o r 20.4 s and s t o r e d a t 40° C (LRT).

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

325

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

326

BARRIER POLYMERS A N D STRUCTURES

METHANAL

«

3

jg 2

I

ΊΞ

1.0

f

0.8

I

0.6

1

"b 30

PROPANAL

g 24

-

§ 0.4 â

0.2

S18 α § 12 " *

6 -

1.5 I· I 0 6 12 18 24 STORAGE TIME (WEEKS)

F i g u r e 8. Changes i n alkanal concentrations i n UHT m i l k p r o c e s s e d a t 1 4 9 ° C f o r 3.4 s and s t o r e d a t 40°C (SRT) .

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

327

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

328

BARRIER POLYMERS AND STRUCTURES

0

2

4

6

8

10 12 14 16 18 20 22 24 26 28 30 RETENTION TIME (MIN)

F i g u r e 9. Time z e r o g a s c h r o m a t o g r a m o f headspace v o l a t i l e s f r o m d i r e c t - p r o c e s s e d UHT m i l k .

J

I

L θ

J-

JL

Κ) 12 14

16 18 20 22 24 26 28 30

J.

RETENTION TIME (MIN) F i g u r e 1 0 . Gas c h r o m a t o g r a m o f h e a d s p a c e volatiles f r o m d i r e c t - p r o c e s s e d UHT m i l k s t o r e d 12 wk.

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

17.

HANSEN & ARORA

Loss of Flavor Compounds from Packaged Foods

F i g u r e 11. Gas c h r o m a t o g r a m o f h e a d s p a c e v o l a t i l e s f r o m d i r e c t - p r o c e s s e d UHT m i l k s t o r e d 24 wk.

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

329

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

330

BARRIER POLYMERS AND STRUCTURES

Table

1.

Concentration of Flavor Compounds i n UHT Cream Over Twelve Months Storage

Flavor Compounds (umoles/g f a t )

Butanal

Months 0

3

6

9

12

0.65

0.66

0.65

0.52

0.33

0.21

0.21

0.21

0.23

0.26

0.36

0.25

0.18

0.14

0.09

1.14

1.13

0.98

0.68

0.27

2.00

1.56

1.10

0.71

0.26

2.18

1.55

1.07

0.80

0.46

8.06

5.28

3.21

1.90

0.24

4

(χ 10 ) Hexanal 4

(χ 10 ) Heptanal 4

(χ 10 ) Octanal 4

(χ 10 ) Nonanal 4

(χ 10 ) Decanal 4

(χ 10 ) Total Carbonyls 2

(χ 10 )

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

17.

HANSEN & ARORA

Loss of Flavor CompoundsfromPackaged Foods

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

The l o s s o f f l a v o r compounds may have been due t o b i n d i n g by t h e p a c k a g i n g m a t e r i a l s o r due t o i n t e r a c t i n g w i t h t h e chemical c o n s t i t u e n t s of foods. L o s s o f F l a v o r Compounds i n UHT P r o c e s s e d Cream. Table 1 shows the concentrations of flavor compounds in UHT p r o c e s s e d cream p a c k a g e d i n T e t r a B r i k p a c k a g e s o v e r 12 mo storage. The concentration of flavor compounds represents an average of four processes. Butanal c o n c e n t r a t i o n d e c r e a s e d 50%, a l d e h y d e s decreased 75-85% and t o t a l carbonyls (aldehydes, Ketones, enals, dienals, ketoacids, ketoglycerides, and dicarbonyls) decreased 97%. L o s s o f F l a v o r Compounds i n M o d e l S y s t e m s . Preliminary work conducted i n our laboratory showed sorption of a l d e h y d e s by LDPE u s e d i n a s e p t i c p a c k a g e s (Hansen, A. P.; Arora, D. K., North Carolina State University, R a l e i g h , u n p u b l i s h e d d a t a ) . The s o r p t i o n r a t e was related to concentration of aldehydes and to time, as both parameters increased so did the amount of flavor compounds s o r b e d i n t o t h e f i l m . A second mechanism, t h e possible interaction of aldehydes with amino a c i d s o r p e p t i d e s forming Schiff b a s e r e a c t i o n p r o d u c t s , was a l s o s t u d i e d . I n i t i a l r e s u l t s (Hansen, A. P.; Heinis J. J . , North Carolina State U n i v e r s i t y , R a l e i g h , u n p u b l i s h e d d a t a ) showed a d e c r e a s e in the aldehyde concentration when model systems c o n t a i n i n g v a r i o u s a l d e h y d e s and amino a c i d s were h e a t processed. Losses ranging from 8 to 50% of various a l d e h y d e s have been o b s e r v e d i n the p a s t e u r i z a t i o n of aldehydes and amino a c i d s m i x t u r e s in simulated milk ultrafiltrate. Summary F l a v o r i s one o f t h e most i m p o r t a n t a t t r i b u t e s o f a f o o d p r o d u c t because i t o f t e n d e t e r m i n e s whether the food i s accepted or rejected. Reduction of flavor compounds sorbed i n t o packaging m a t e r i a l may p r o d u c e more f l a v o r stable a s e p t i c food products. UHT processed milk and cream s t o r e d a t 24 °C and 40 °C showed d e c r e a s e in both aldehyde and total carbonyl concentrations. Further r e s e a r c h i s needed t o d e t e r m i n e t h e d e g r e e o f b i n d i n g o f flavor compounds to chemical constituents of food p r o d u c t s and t o p o l y m e r s u s e d i n a s e p t i c p a c k a g i n g . Acknowledgments The a u t h o r s would l i k e t o t h a n k M. S. Armagost a s s i s t a n c e i n p r e p a r a t i o n of t h i s manuscript.

for

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.

his

331

332

BARRIER POLYMERS AND STRUCTURES

Literature Cited

Downloaded by UNIV OF MASSACHUSETTS AMHERST on June 1, 2018 | https://pubs.acs.org Publication Date: May 9, 1990 | doi: 10.1021/bk-1990-0423.ch017

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

Hotchkiss, J.H. In Food and Packaging Interactions; Hotchkiss, J . H . , Ed.; American Chem. Soc.: Washington DC, 1988; pp. 1-10. Anonymous. 1987. Food Eng. 1987, 59, 54. Anonymous. Food Processing 1983, 44, 30-32. LaBell, F. Food Processing 1986, 47, 104-105. Swientek, R.J. Food Processing 1984, 45, 28-30. Sacharow, S. Prepared Foods 1986, 155, 31-32. Landois-Garza, J.; Hotchkiss, J.H. Food Eng 1987, 59, 39,42. Salame, M. 1988. Paper presented at Bev-Pak '88. Shimoda, M.; Ikegami, T.; Osajima, Y. J . Sci. Food Agric. 1988, 42, 157-163. Kwapong, O.Y.; Hotchkiss, J.H. J . Food Sci. 1987, 52, 761-763, 785. Meyers, M.A.; Halek, G.W. Proc. Inst. Food Tech. 46th Annual Meeting, June 15-18, 1986, p 131 (Abst. 161). Mannheim, C.H.; Miltz, J.; Letzter, A. J . Food Sci. 1987, 52, 737-740. Marcy, J . E . ; Hansen, A.P.; Graumilch, T.R. J . Food Sci. 1989, 54, 227-230. Charara, Z.N. M.S. Thesis, University of Florida, 1987. Kinsella, J . E . Chemistry and Industry 1969. No. 2, p. 36. Anonymous. Packaging Digest Magazine 1988, 25, 86,89,91-92,94. Brody, A.L. Food Engineering 1987, 59, 49-50,52. Earley, R.R.; Hansen, A.P. J . Dairy Sci. 1982, 65, 11-16. Hutchens, R.K. M.S. Thesis, N.C. State University, Raleigh, 1979. Keller, W.J.; Kleyn, D.H. J . Dairy Sci. 1972, 55, 564. Nash, J.B. M.S. Thesis, N.C. State University., Raleigh, 1984.

RECEIVED

November 14, 1989

Koros; Barrier Polymers and Structures ACS Symposium Series; American Chemical Society: Washington, DC, 1990.