Interaction Between Aseptically Filled Citrus Products and Laminated

Chapter 6

Interaction Between Aseptically Filled Citrus Products and Laminated Structures 1

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C. H. Mannheim , J. Miltz , and N. Passy Downloaded by GEORGETOWN UNIV on June 2, 2018 | https://pubs.acs.org Publication Date: March 9, 1988 | doi: 10.1021/bk-1988-0365.ch006

1Department of Food Engineering and Biotechnology, Technion-Israel Institute of Technology, Haifa, 32000, Israel The interaction between polyethylene(PE) contact surfaces of carton packs and "Bag in the box" packages with citrus products and model solutions was evaluated. The presence of corona treated polyethylene films in model solution and juices accelerated ascorbic acid de gradation and browning. Untreated PE films did not accelerate these reactions. In all cases d-limonene concentration in juices in contact with PE surfaces was reduced. In both orange and grape fruit juices, aseptically filled into cartons the extent of browning and loss of ascorbic acid was greater than in same juices stored in glass jars. Sensory evaluations showed a significant difference between juices stored in carton packs and in glass jars, at ambient temp. after 10-12 weeks. The cartons were found not to be completely gas tight. Storage life data of orange juice in bag in the box packages are presented. Dynamic vibration tests of bag in the box packaging systems, to simulate transport distribution environment, were carried out. In these tests behaviour of different metallized structures, to flex-cracking and pinholing when in contact with citrus products and simulants was evaluated. A s e p t i c p a c k a g i n g has been c o m m e r c i a l l y v i a b l e i n Europe f o r s e v e r a l decades. I n t h e U.S.A. a s e p t i c p a c k a g i n g has become one of t h e f a s t e s t growing a r e a s o f f o o d p a c k a g i n g s i n c e t h e Food and Drug A d m i n i s t r a t i o n (FDA) a p p r o v a l , i n 1981, o f t h e u s e o f hydrogen p e r o x i d e f o r s t e r i l i z i n g p o l y e t h y l e n e (PE) c o n t a c t s u r f a c e s (1_) . A p p r o v a l was l a t e r extended t o i n c l u d e o l e f i n polymers, EVA copolymers and p o l y e t h y l e n e p h t h a l a t e polymers (2^) . F r u i t j u i c e s i n g e n e r a l and c i t r u s j u i c e s i n p a r t i c u l a r a r e a t p r e s e n t e x t e n s i v e l y packed a s e p t i c a l l y Π ) . Most o f t h e s e p r o d u c t s a r e packed today i n s e m i - r i g i d b r i c k shaped l a m i n a t e d 2

Current address: Pillsbury Company, Research and Development Laboratories, Minneapolis, MN 55402 0097-6156/88/0365-0068$06.00/0 © 1988 American Chemical Society

Hotchkiss; Food and Packaging Interactions ACS Symposium Series; American Chemical Society: Washington, DC, 1988.

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MANNHEIM ET AL.

Aseptically Filled Products & Laminated Structures

P E / c a r b o a r d / aluminum f o i l / P E packages. A n o t h e r p o p u l a r p a c k a g i n g system f o r j u i c e s and c o n c e n t r a t e s i s the "bag-in-the-box" r a n g i n g i n s i z e from 2 t o 1200 l i t e r s . The s t r u c t u r e o f the bag i s g e n e r a l l y a l a m i n a t e made o f P E / m e t a l i z e d p o l y e s t e r / P E w i t h an i n n e r PE l i n e r . The m e t a l l i z e d p o l y e s t e r may be r e p l a c e d by a non metallized high b a r r i e r f i l m . A r i g i d coextruded m u l t i l a y e r high b a r r i e r c o n t a i n e r made on f o r m - f i l l - s e a l l i n e s o f f e r s a n o t h e r c h o i c e o f p a c k a g i n g f o r above p r o d u c t s (£).

Downloaded by GEORGETOWN UNIV on June 2, 2018 | https://pubs.acs.org Publication Date: March 9, 1988 | doi: 10.1021/bk-1988-0365.ch006

F a c t o r s A f f e c t i n g S h e l f - L i f e o f A s e p t i c a l l y Packed C i t r u s

Products

The s h e l f - l i f e o f p a s t e u r i z e d , h o t o r a s e p t i c a l l y f i l l e d , j u i c e s o r c o n c e n t r a t e s i s l i m i t e d by c h e m i c a l r e a c t i o n s which a r e p r i m a r i l y i n f l u e n c e d by s t o r a g e t e m p e r a t u r e , as w e l l as oxygen and light. In p l a s t i c l a m i n a t e s , compared w i t h g l a s s , gas p e r m e a t i o n o f the p a c k a g i n g m a t e r i a l as w e l l as a b s o r p t i o n by the c o n t a c t s u r f a c e o r m i g r a t i o n o f low m o l e c u l a r w e i g h t compounds may i n f l u e n c e s h e l f - l i f e (5,6). In s t o r a g e s t u d i e s o f orange j u i c e i n T e t r a B r i c k and g l a s s b o t t l e s , D u r r e t . a l Ο ) r e c o n f i r m e d t h a t s t o r a g e temperature was the main parameter a f f e c t i n g s h e l f - l i f e of orange j u i c e . In a d d i t i o n they found t h a t orange o i l , e x p r e s s e d as d-limonene, was absorbed by the p o l y e t h y l e n e c o n t a c t l a y e r o f the T e t r a Pack. These a u t h o r s c l a i m e d t h a t t h i s c o u l d be c o n s i d e r e d an advantage s i n c e limonene i s a p r e c u r s o r t o o f f - f l a v o r components. Marshall e t . a l (£) a l s o r e p o r t e d a b s o r p t i o n o f d-limonene from orange j u i c e i n t o p o l y o l e f i n s . They found t h a t the l o s s o f d-limonene i n t o the c o n t a c t l a y e r was d i r e c t l y r e l a t e d t o the t h i c k n e s s of the p o l y o l e f i n l a y e r and n o t i t s oxygen p e r m e a b i l i t y . M a r s h a l et.al(£) a l s o q u a n t i f i e d the a b s o r p t i o n o f s e v e r a l t e r p e n e s and o t h e r f l a v o r i n g s from orange j u i c e i n t o low d e n s i t y p o l y e t h y l e n e (LDPE). They found t h a t the predominant compounds absorbed were the t e r p e n e s and s e s q u i t e r p e n e s . More than 60% of the d-limonene i n the j u i c e was absorbed by LDPE b u t o n l y 45% by S u r l y n . O t h e r t e r p e n e s such as p i n e n e and myrcene were absorbed t o g r e a t e r extents. I n f r a r e d s p e c t r a of LDPE showed t h a t the t e r p e n e s were absorbed r a t h e r than a d s o r b e d . Thus s i n c e many d e s i r a b l e f l a v o r components i n c i t r u s j u i c e s a r e o i l s o l u b l e , t h e i r l o s s by a b s o r b t i o n as mentioned above can a d v e r s l y a f f e c t f l a v o r o f j u i c e s . F u r t h e r m o r e , S c a n n i n g E l e c t r o n M i c r o s c o p e (SEM) p i c t u r e s o f LDPE a f t e r exposure t o orange j u i c e , showed s i g n i f i c a n t s w e l l i n g o f the polymer, i n f e r r i n g s e v e r e l o c a l i z e d i n t e r n a l s t r e s s e s i n the polymer. These s t r e s s e s i n d i c a t e d a p o s s i b l e cause f o r d e l a m i n a t i o n problems o c c a s i o n a l l y e n c o u n t e r e d i n LDPE l a m i n a t e d b o a r d s t r u c t u r e s . The a d h e s i o n between LDPE and f o i l was much l e s s than between S u r l y n and f o i l . The p r e s e n c e o f d-limonene i n the polymer a i d e d i n the a b s o r p t i o n o f o t h e r compounds, such as c a r o t e n o i d pigments, thus r e d u c i n g c o l o r o f juice (8_). Buchner (9) a l s o mentions r e d u c t i o n i n aroma b e a r i n g orange o i l i n t o the p o l y e t h y l e n e c o n t a c t l a y e r o f the t h r e e p i e c e ΗΥΡΑ S a s e p t i c package. G h e r a r d i (H)) and G r a n z e r (JJ_) a l s o i n v e s t i g a t e d q u a l i t y changes o f f r u i t j u i c e s i n c a r t o n packs as compared w i t h g l a s s packages. Both found, s e p a r a t e l y , t h a t j u i c e s and n e c t a r s


FOOD AND PACKAGING INTERACTIONS

70

d e t e r i o r a t e d f a s t e r i n the c a r t o n packs than i n g l a s s b o t t l e s . In p r o d u c t s w i t h low f r u i t c o n t e n t , such as f r u i t d r i n k s , the d i f f e r e n c e between packages was s m a l l . G h e r a r d i (J!_0 ) , found h i g h oxygen and low c a r b o n d i o x i d e c o n t e n t s i n the head space o f c a r t o n packs v e r s u s low oxygen and h i g h c a r b o n d i o x i d e i n g l a s s b o t t l e s . The C 0 c o n t e n t was a t t r i b u t e d t o a s c o r b i c a c i d d e g r a d a t i o n . T h e r e f o r e , G h e r a r d i (10) c o n c l u d e d t h a t the main cause f o r the d i f f e r e n c e i n k e e p i n g q u a l i t y between p r o d u c t s i n c a r t o n packs and g l a s s was due t o h i g h e r oxygen t r a n s f e r r a t e s i n t o the former package. G r a n z e r (JJ_) a l s o c l a i m e d t h a t the oxygen p e r m e a b i l i t y of c a r t o n packs caused the f a s t e r d e t e r i o r a t i o n of j u i c e s packed i n them. G r a n z e r ( V U s t a t e d , w i t h o u t showing p r o o f , t h a t the s o u r c e o f the oxygen p e r m e a t i o n i n t o the c a r t o n pack was the 22cm l o n g s i d e seam. I t i s known t h a t s i n c e then T e t r a Pack improved the s i d e seam by a d d i n g a s t r i p of PET a t t h i s p l a c e .


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K o s z i n o w s k i and P i r i n g e r (j_2) i n v e s t i g a t e d the o r i g i n of o f f - f l a v o r s i n v a r i o u s packages. They e s t a b l i s h e d gas c h r o m a t o g r a p h i c and mass s p e c t r a p r o c e d u r e s c o u p l e d w i t h s e n s o r y t h r e s h o l d odor a n a l y s i s f o r the d e t e r m i n a t i o n of o f f - f l a v o r emanation from p a c k a g i n g m a t e r i a l s . They found r e a c t i o n p r o d u c t s of raw m a t e r i a l s as w e l l as a c o m b i n a t i o n of o x i d a t i o n and p y r o l y t i c e l i m i n a t i o n r e a c t i o n s i n polyethylene or paperboard to be r e s p o n s i b l e f o r o f f - o d o r s . P r o d u c t s packed i n " b a g - i n - t h e - b o x " packages., e s p e c i a l l y i n the l a r g e r s i z e s , a p p a r e n t l y a l s o have a r e d u c e d s h e l f l i f e as compared t o t h o s e packed i n c o n v e n t i o n a l m e t a l l i c packages, due m a i n l y t o damage caused t o the f i l m s d u r i n g t r a n s p o r t a t i o n (13). The r e d u c e d s h e l f l i f e i n t h e s e p a c k a g i n g systems i s p r o b a b l y due t o f l e x c r a c k i n g which causes p i n h o l e s and even "windows" i n the m e t a l l i z e d l a m i n a t e thus r e d u c i n g the b a r r i e r properties. In our l a b o r a t o r y the i n t e r a c t i o n between p o l y e t h y l e n e contact s u r f a c e s o f c a r t o n l a m i n a t e s and " b a g - i n - the box" s t r u c t u r e s and c i t r u s products are being i n v e s t i g a t e d . Some r e s u l t s of t h e s e s t u d i e s are presented here.

E v a l u a t i o n of A s e p t i c Experimental Results

Packages and

C i t r u s Products

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C a r t o n Packages. Orange and g r a p e f r u i t j u i c e s were packed a s e p t i c a l l y on a commercial l i n e i n t o c a r t o n s and g l a s s j a r s (14). The c a r t o n s t r u c t u r e was a l a m i n a t e of polyethylene/carton/ aluminum/ p o l e t h y l e n e made by PKL- Combibloc, Germany. The c a r t o n d i m e n s i o n s were 10x6x17 cm. Browning and a s c o r b i c a c i d d e g r a d a t i o n of orange j u i c e s a r e p r e s e n t e d i n F i g u r e s 1 and 2. In a l l c a s e s the r a t e s of the d e t e r i o r a t i v e r e a c t i o n s were h i g h e r i n c a r t o n s as compared t o g l a s s . D i f f e r e n c e s i n browning and a s c o r b i c a c i d d e g r a d a t i o n between j u i c e s i n g l a s s and c a r t o n s were i n i t i a l l y s m a l l and i n c r e a s e d w i t h s t o r a g e time. I n i t i a l l y , j u i c e s i n g l a s s and c a r t o n s had s i m i l a r d i s s o l v e d and headspace oxygen v a l u e s which a f f e c t e d the above r e a c t i o n s i n the same f a s h i o n . L a t e r on,



MANNHEIM ET AL. Aseptically Filled Products & Laminated Structures

F i g u r e 1. A s c o r b i c a c i d r e t e n t i o n i n orange j u i c e a s e p t i c a l l y packed i n t o g l a s s j a r s and c a r t o n p a c k s , s t o r e d a t 25 C. (Reproduced w i t h p e r m i s s i o n from Ref. 14. C o p y r i g h t 1987 I n s t , o f Food T e c h n o l o g i s t s . )

0.241

1

1

1

ι

ι

ι

ι

TIME ( d a y s )

F i g u r e 2. Browning o f a s e p t i c a l l y f i l l e d orange j u i c e i n g l a s j a r s and c a r t o n packs, s t o r e d a t 25 C. (Reproduced w i t h p e r m i s s i o n from Ref. 14. C o p y r i g h t 1987 I n s t , o f Food Technologists.)


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FOOD AND PACKAGING INTERACTIONS

the e f f e c t o f the l a m i n a t e d package became more pronounced due i t s oxygen t r a n s m i s s i b i l i t y as w e l l as due t o p r o d u c t - p a c k a g e i n t e r a c t i o n . S i m i l a r r e s u l t s (not shown) were o b t a i n e d w i t h grapefruit juice.

to


A r a p i d l o s s of d-limonene, from 70 t o 50mg/l f o r orange j u i c e was o b s e r v e d i n c a r t o n packs w i t h j u i c e s d u r i n g the f i r s t days o f ambient (25 C) s t o r a g e ( F i g u r e 3 ) . S i m i l a r r e s u l t s were o b t a i n e d by o t h e r s (7,8) who c l a i m e d a b s o r p t i o n by the f i l m as the cause f o r t h i s phenomenon. I t can be compensated f o r , i f r e q u i r e d , by i n c r e a s i n g the i n i t i a l d-limonene c o n c e n t r a t i o n . However, d-limonene o x i d a t i o n may a l s o o c c u r and i s a s u b j e c t f o r f u r t h e r studies. T r i a n g l e t a s t e comparisons showed t h a t , f o r orange j u i c e a f t e r about 2.5 months s t o r a g e a t 25 C. t h e r e was a s i g n i f i c a n t (p< 0.05) d i f f e r e n c e between j u i c e s i n c a r t o n s and g l a s s c o n t a i n e r s ( F i g . 4 ) . In g r a p e f r u i t j u i c e s a s i g n i f i c a n t t a s t e d i f f e r e n c e (p< 0.05) was found a f t e r about 3 months ( F i g . 4 ) . The l o n g e r p e r i o d to o b t a i n a t a s t e d i f f e r e n c e i n g r a p e f r u i t j u i c e i s due t o the s t r o n g e r f l a v o r of t h i s j u i c e which tends t o mask s m a l l f l a v o r changes. C o l o r d i f f e r e n c e s were noted e a s i e r i n g r a p e f r u i t j u i c e s than i n orange j u i c e s . In orange j u i c e , some c a r o t e n o i d s may be o x i d i z e d and have a b l e a c h i n g e f f e c t which compensates f o r the change i n appearance due t o browning, thus e x p l a i n i n g the c o l o r d i f f e r e n c e between the two j u i c e s (15). C a r t o n S t r i p s . The i n t e r a c t i o n between c a r t o n packs and j u i c e s was e v a l u a t e d by immersing s t r i p s o f c a r t o n l a m i n a t e s i n j u i c e s s t o r e d i n h e r m e t i c a l l y s e a l e d g l a s s j a r s . S u r f a c e t o volume r a t i o s of 4:1 and 6:1, as compared w i t h the actual r a t i o in 1 liter packs, were used. The c o n t a c t o f orange and g r a p e f r u i t j u i c e s w i t h the c a r t o n s t r i p s a c c e l e r a t e d a s c o r b i c a c i d l o s s and browning as compared t o s i m i l a r j u i c e s s t o r e d i n g l a s s w i t h o u t the l a m i n a t e , a t the same temperatures ( F i g u r e s 5 and 6 ) . A f t e r 14 days t h e r e was a l s o a s i g n i f i c a n t t a s t e d i f f e r e n c e (p

Interaction Between Aseptically Filled Citrus Products and Laminated

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