A Z I N A T E COATINGS FOR CARCASSES*
*
R . L. WEST, C . R . LAZARUS, J . L . OBLINGER
AND A. Z . PALMER
University of Florida
INTRODUCTION
The l o s s of moisture, shrinkage, associated with carcasses during
t h e post-slaughter c h i l l i n g , s t o r i n g and d i s t r i b u t i n g periods i s of
paramount importance t o t h e meats industry. The major concern i s w i t h
weight l o s s and t h e r e s u l t i n g reduction i n t o t a l carcass value. However,
q u a l i t y reduction, as well as increased t r i m l o s s e s , occur as shrink
i n c r e a s e s . Surface d e s s i c a t i o n and color d e t e r i o r a t i o n a r e detrimental
t o s h e l f - l i f e a.nd consumer a c c e p t a b i l i t y .
During t h e i n i t i a l c h i l l i n g period post-slaughter, shrink l o s s i s
controlled by r e g u l a t i o n of t h e r e f r i g e r a t i o n .
Fleming and Earle (1968) and Smith and Carpenter (1973) indicated t h a t
carcass shrinkage can be reduced by t h e maintenance of low temperature
conditions accompanied by high r e l a t i v e humidity and minimal a i r
c i r c u l a t i o n . However, the maintenance of m o i s t carcass surfaces
r e s u l t i n g from reduced a i r c i r c u l a t i o n would be expected t o be conducive
t o microbial growth, e s p e c i a l l y i f temperature f l u c t u a t i o n s a r e
encountered.
Application of a l g i n a t e coatings t o meat products i s not a new
concept f o r shrinkage c o n t r o l . Algin, a component of seaweed, forms an
e d i b l e g e l or f i l m upon t h e addition of a polyvalent ion, p a r t i c u l a r l y
calcium ions (Anonymous, 1973). The a p p l i c a t i o n of a Ca-alginate film
onto t h e surface of a carcass o r a cut would be expected t o lower t h e
l o s s of moisture f r o m t h e meat t i s s u e s s i n c e moisture would be removed
p r e f e r e n t i a l l y from t h e f i l m . Following t h e d e s s i c a t i o n of t h e film,
meat t i s s u e s would lose moisture.
Previous r e p o r t s have d e a l t with t h e a p p l i c a t i o n of a Ca-alginate
f i l m t o beef c u t s t o be frozen (Berlin, 1957), chicken pieces (Mountney
e t al . , 1963).
and W i n t e r , 1961) and beef s t e a k s and pork chops (Allen The previous s t u d i e s showed t h e a l g i n a t e coating t o be e f f e c t i v e i n
reducing t h e shrinkage loss. Allen e t a l . (1963) reported an improvement
i n t e x t u r e and j u i c i n e s s f o r coated steaks and chops. However, Allen
et a
-l . (1963) a l s o observed a b i t t e r , o f f - f l a v o r i n coated samples which
t h e y a t t r i b u t e d t o t h e high concentration of t h e CaC12 s o l u t i o n ( 5 M )
used, and t h e length of immersion time required i n t h i s s o l u t i o n f o r
formation of a f i r m g e l .
--
* Presented
a t t h e 28th Annual Reciprocal Meat Conference of t h e American
M e a t Science Association, 1975.
* Appreciation
is expressed t o D. H . McKee Inc., Tampa, f o r allowing
t h e authors t o test the Flavor-Tex concept on f r e s h meats and f o r
providing f i n a n c i a l support.
The procedure f o r f i l m formation followed by e a r l y i n v e s t i g a t o r s
was t h e coating of t h e product by submersion i n a s o l u t i o n of sodium
a l g i n a t e followed by immersisn of t h e coated sample i n a s o l u t i o n of
CaC12. The r e t e n t i o n time i n t h e CaC12 ranged from two t o s i x t y seconds.
T h i s long r e t e n t i o n time i n t h e saturated CaC12 s o l u t i o n could lead t o
b i t t e r , o f f - f l a v o r noted by A l l e n e t a l . (1963).
--
Earle (1968) reported the develqment of a process f o r t h e Caa l g i n a t e coating of products wherein t h e r e t e n t i o n time i n t h e CaC12
s o l u t i o n w a s d r a s t i c a l l y reduced. He observed t h a t g e l l i n g time could
be g r e a t l y reduced and t h e required concentration of CaC5 lowered by
a d d i t i o n of an e d i b l e gum t o t h e calcium g e l l i n g b a t h . The addition o f
t h i s thickening agent increased t h e v i s c o s i t y of t h e s o l u t i o n and
allowed f o r t h e instantaneous formation of a strong f i l m without
imparting a b i t t e r f l a v o r . I n addition, Earle (1968) noted t h a t t h e
film can be broken down and removed w i t h water soluble calcium
sequestering agents such a s polyphosphates.
The process developed by Earle (1968)i s patented and marketed
under t h e tradename Flavor-TexR. McCormick (1975) reviewed t h i s
process and indicated t h a t it i s p r e s e n t l y being used f o r coating f i s h
f i l l e t s , shrimp, onion r i n g s , mushrooms and various cold extruded
products.
The present r e p o r t concerns t h e application of t h e Flavor-Tex
process t o f r e s h meat carcasses f o r t h e c o n t r o l of shrinkage. An
extensive study of i t s a p p l i c a t i o n t o lamb carcasses, which has been
reported elsewhere (Lazarus e t a l . , 1975), w i l l be reviewed and
preliminary s t u d i e s of t h e coating of beef and pork carcasses w i l l be
discussed.
EXPERIMENTAL FINDINGS
Ninety lamb carcasses were subjected t o t h r e e shrinkage treatments
immediately post -slaughter ( Lazarus e t a l . , 1975 )
T h i r t y (30)
carcasses were coated with Flavor-Tex, 30 carcasses were enshrouded
with a polyvinyl chloride (WC) f i l m f o r t h e i n i t i a l 24 h r postmortem
and t h e remaining 30 carcasses were l e f t a s c o n t r o l s . The WC film
used had very low moisture-vapor transmission r a t e s .
.
The Flavor-Tex was applied by spraying w i t h a compressed a i r
system. An aqueous s o l u t i o n sf sodium a l g i n a t e and maltodextran w a s
applied first t o t h e carcass, followed by spraying w i t h an aqueous
s o l u t i o n of CaC12 and carboxymethyl c e l l u l o s e . The Ca-alginate f i l m
was formed instantaneously and became stronger a s t h e moisture was
removed. The added f i l m weight was approximately 1.5% of t h e hot
carcass weight. Since go'$ of t h e added weight i s water and a l l the
added material i s edible, t h e o r i g i n a l hot carcass weight vas used t o
c a l c u l a t e shrinkage loss.
293
A comparison of shrinkage values between t h e various treatments i s
shown i n t a b l e 1. A t 1, 2, 3, 5 and 7 days postmortem, t h e carcasses
coated with Ca-alginate and those wrapped f o r t h e f i r s t 24 h r postmortem
with t h e WC f i l m had s i g n i f i c a n t l y ( P < .O5) lower shrinkage values
than d i d t h e c o n t r o l carcasses. Those carcasses wrapped i n WC f i l m
had t h e lowest shrinkage l o s s a t a l l time periods. Upon removal of
t h i s f i l m on day 1, t h e carcass surfaces were extremely m o i s t h t d r i e d
somewhat during t h e d u r a t i o n of t h e observation period.
Table 1. Postmortem shrinkage ( 3 ) of lamb carcasses
a s r e l a t e d t o shrinkage treatment
Day
postmortem
Control
Shrinkage treatment
C a -Alginate
1 .55bb
2.25
2 -96
4 .Olb
4.81b
WC wrap
1.20c
1.88C
2.49c
3 .43c
4.19C
abc Means 3n t h e same h o r i z o n t a l l i n e bearing d i f f e r e n t s u p e r s c r i p t s
d i f f e r significantly (P < .OS).
the
the
had
Few
Visual a p p r a i s a l of t h e carcasses indicated t h a t those wrapped i n
WC f i l m had b r i g h t e r , more appealing surface f a t color than did
c o n t r o l of a l g i n a t e coated carcasses. The a l g i n a t e coated carcasses
a glossy appearance which diminished a s t h e f i l m was dehydrated.
differences in lean color were noted.
The e f f e c t s of shrinkage treatments on c h i l l r a t e were monitored by
determining i n t e r n a l l e g temperatures f o r t h e i n i t i a l 24 h r periods.
These d a t a a r e presented i n t a b l e 2 . As expected, t h e WC wrapped
carcasses had a s l i g h t l y slower c h i l l r a t e s i n c e moisture evaporation
from carcass surfaces was r e t a r d e d . A t 6 hr postmortem, t h e WC wrapped
carcasses had s i g n i f i c a n t l y higher ( P < .05) i n t e r n a l l e g temperatures
than did t h e other groups. However, no ilifferences were observed a t 24
h r postmortem.
Shrinkage treatment e f f e c t s on t o t a l aerobic microbial counts of
carcasses are shown In t a b l e 3 . The mean loglo v a l e s presented i n t a b l e
3 r e f l e c t t h e t o t a l counts obtained by swabbing a 6.45 cm2 a r e a .
Incubation of t h e p l a t e s (Standard P l a t e Count Agar) was f o r 5 days a t
2OC. The fat-covered s i r l o i n a r e a and t h e lean covered b e l l y area
(flank-breast Juncture) were swabbed i n i t i a l l y and again a t 2, 5 and 7
days postmortem.
294
I n t e r n a l leg temperature ( C ) during
c h i l l i n g cycle of lamb carcasses
Table 2 .
Time (hr)
Control
0
38 .7a
10 .3a
4 .la
6
24
Shrinkage treatment
Ca-Alginate
38.2"
10
.oa
4 .4a
WC wrap
38 .ka
14.3b
5 .oa
ab Means on t h e same h o r i z o n t a l l i n e bearing d i f f e r e n t s u p e r s c r i p t s
d i f f e r s i g n i f i c a n t l y ( P < .O5).
3. T o t a l aerobic microbial counts
f o r s i r l o i n and b e l l y areas 3f lamb
carcasses a t 0, 2, 5 and 7 days postmortema
Table
Day
postmortem
0
2
5
7
0
2
5
7
C ont rol
*aD
-33.64D
3.04b
3 .47b
3.45b"
3 .gou
3.84b
4 .24b
4.4p
Shrinkage treatment
C a -Alginate
Sirloin area
33.75"
*75:
,ap
2
2.87
2.80C
3 .1iC
B e l l y prea
3.90"
3 *99b
4.34b
4 .46b
PVC wrap
3
3.64c
3 .82d
4 ~4~
4.03O
4 .Ogb
4.31p
4.01b
a Mean loglo values per 6.45 cm2.
bc Means on t h e same h o r i z o n t a l line bearing d i f f e r e n t s u p e r s c r i p t s
d i f f e r s i g n i f i c a n t l y (P < .O5).
Values f o r the s i r l o i n area ( t a b l e 3 ) i n d i c a t e t h a t by 2 days
postmortem, t h e carcasses wrapped i n PVC f i l m had s i g n i f i c a n t l y higher
microbial c m n t s (3.64 bacteria/6.45 cm2) t h a n d i d the control (3.04)
o r a l g i n a t e coated carcasses (3.87). A t 5 and 7 days postmortem, t h e
a l g i n a t e coated carcasses continued t o have s i g n i f i c a n t l y lower counts
than t h e PVC wrapped carcasses. These d i f f e r e n c e s possibly r e f l e c t t h e
r e l a t i o n s h i p of increased surface moisture t o increased microbial growth.
295
The lower microbial counts found f o r t h e Ca-alginate coated carcasses
could also be r e l a t e d t o t h e i o n i c e f f e c t s of t h e chloride ions i n t h e
film.
I n t h e b e l l y area ( t a b l e 3 ) , no d i f f e r e n c e s i n microbial counts
were observed between t h e t h r e e treatments. A l l counts were higher i n
t h i s area than i n s i r l o i n area and were attribuked t o increased crosscontamination i n t h i s area during t h e d a i l y handling f o r obtaining
shrinkage d a t a .
- -.
Since A l l e t a 1 (1963) had reported adverse off -f lavors f o r
a l g i n a t e coated steaks and chops, a n evaluation of t h e e f f e c t s of
coating lamb carcass l e g s with calcium a l g i n a t e on sensory panel scores
w a s conducted. Legs from six c o n t r o l and six calcium a l g i n a t e coated
carcasses were removed following t h e conclusion of the shrinkage t r i a l
( 7 days postmortem) and paired l e g s were coated o r recoated with
calcium a l g i n a t e o r l e f t f o r evaluation of t h e o r i g i n a l treatment. The
coating of c o n t r o l l e g s and t h e recoating of a l g i n a t e coated l e g s was
performed, s i n c e t h e f i l m had almost completely dehydrated by t h e end
of 7 days. I n addition, t h e recoating doubled t h e film concentration
f o r d e t e c t i o n of o f f - f l a v o r s and odors. P r i o r t o cooking, t h e coated
l e g s could be distinguished from t h e c o n t r o l l e g s by t h e presence of
t h e f i l m . This d i f f e r e n c e w a s e s p e c i a l l y evident f o r t h e l e g s coated
3r recoated following t h e shrinkage t r i a l . After cooking, no d i f f e r e n c e s
i n appearances were evident because the calcium a l g i n a t e g e l d i s s i p a t e s
upon h e a t i n g
.
Cooking l o s s percent and sensory panel scores a r e summarized i n
t a b l e 4. Treatment groups were found not t o d i f f e r s i g n i f i c a n t l y f o r
cooking l o s s o r f o r any of t h e sensory panel evaluations. A l l samples
were r a t e d acceptable ( 5 o r above) i n flavor, j u i c i n e s s and o v e r a l l
s a t i s f a c t i o n . No off-odors were recorded.
Results similar t o those reported f o r lamb carcasses, have been
obsekved in preliminary s t u d i e s with pork and beef carcasses. Although
very small numbers ( 7 per treatment) a r e involved, d a t a presented i n
t a b l e 5 f o r pork carcasses i n d i c a t e s t h a t alginate coated carcasses
shrank less than uncoated c o n t r o l carcasses. Additionally, t h e skin
of coated pork carcasses remains very p l i a b l e , even during extended
storage times. This p l i a b i l i t y should a i d ease i n machine skinning
and, therefore, increase y i e l d s . The alginate coating a l s o appears
t o r e t a r d d i s c o l o r a t i o n of t h e s p l i t v e r t e b r a l column normally observed
a f t e r s e v e r a l days postmortem.
A preliminary comparison of percent shrink l o s s f o r c o n t r o l and
Ca-alginate coated beef carcasses i s shown i n t a b l e 6. Up through 96
hours postmortem, t h e coated carcasses had approximately 0.6% l e s s
shrinkage than the shrouded c o n t r o l carcasses. Microbial counts were
similar f o r both treatment groups ( t a b l e 7 ) .
Table 4. Cooking l o s s and t a s t e panel scores f o r
c o n t r o l , coated and recoated lamb legs
Factor
Control
Cooking loss (%)
Flavor"
Juici n e s s a
Overall
satisfactiona
O f f -odorb
25.20
6.25
5 956
6.03
1.04
Control
Ca -alginate
Ca -Alginate
Control
Ca-alginat e
26 -77
5 -68
5 045
25 -52
6.13
5.46
5 -72
5.55
1.a3
1.15
25 -71
5098
5.33
5 *67
1.10
a Based on a n 8-point s c a l e i n which 8 = l i k e extremely and 1 = d i s l i k e
extremely.
Based on a 3-point s c a l e i n which 3 = d e f i n i t e off-odor detected and
l=no d e t e c t a b l e off-odor.
Table 5. Comparison of s h r i n k l o s s ($ ) of
c o n t r o l and Ca-alginate coatedapork carcasses
Preliminary d a t a
b
Factor
Control
shrinkage treatmentC
Ca-alginate
1.49
2.24
a N = 7 carcasses per treatment.
A t 24 h r postmortem.
C Average amount of Ca-alginate added was l.&$
1.03
1.56
of carcass weight.
297
Table 6 . Comparison of shrink loss ( d ) o f
c o n t r o l and Ca-alginate coated beef carcasses
Time postmortem
C ont r ol
24
2 .o
2.2
48
96
Shrinkage treatmentb
Ca -alginate
1.3
1.5
2 -3
2 *9
a N = 22 carcasses per treatment.
Average amount of Ca-alginate added was
Table
2.9 kg
per c a r c a s s ,
7.
Comparison o f microbial loads on c o n t r o l
and Ca-alginate coated beef carcassesa
-
Day postmortem
Control
Shrinkage treatment
Ca -alginate
3 -19
3 *@
3.41
3.48
4.29
3 065
2 .go
2.85
3 *27
4.30
4.54
a Mean loglo values per 6.45 cm2 from neck a r e a .
I n addition t o t h e shrinkage advantage, coated carcasses do not
have t o be shrouded. The removal of moisture f r o m t h e f i l m causes a
t i g h t e n i n g of t h e f i l m which smooths t h e surface f a t . This t i g h t e n i n g
i s not s u f f i c i e n t t o produce t h e same e f f e c t a s a shroud i n such a r e a s
a s t h e cod and b r i s k e t , b u t does adequately smooth other a r e a s .
One s e r i o u s problem associated with t h e a l g i n a t e coating f o r beef
carcasses was t h a t t h e surface was not as white a s it was following
shrouding. I n f a c t , a slight yellow f a t color was accentuated by
coating. I n v e s t i g a t i o n s i n t o methods of circumventing t h i s problem a r e
c u r r e n t l y underway.
ADDITIONAL CONSIDERATIONS
The a p p l i c a t i o n of Flavor-Tex t o carcasses would be economically
f e a s i b l e only i f t h e carcass weight saved ( o r added) i s s u f f i c i e n t t o
overcome t h e c o s t s of ingredients and t h e i r a p p l i c a t i o n . Based on t h e
average shrinkage d i f f e r e n c e between c o n t r o l and coated lamb carcasses
(0.86%) shown i n t a b l e 1, t h e t o t a l weight saved f o r a 22.6 kg carcass
would be 0.196 kg (0.867% x 22.6 kg) A t a n average p r i c e of $2.18/kg,
this weight savings would be $0.43 per carcass. Film ingredients a t
t h e present time c o s t $0.35/kg a s applied t o t h e carcass. Using 1.546
of carcass weight a s t h e average amount of f i l m added, t h e c o s t of
ingredients f o r a 22.6 kg carcass would be $0.12. Therefore, a
preliminary savings of $0.31 per carcass could be r e a l i z e d , excluding
cost of labor, equipment and maintenance.
.
The labor, equipment and maintenance cost f o r applying Fhvor-Tex
t o carcasses would depend on t h e degree of automation b u i l t i n t o the
system. The spraying process could be fully automated using USDA
approved s a n i t a r y spraying systems. Labor would be required only f o r
mixing t h e s o l u t i o n s and monitoring t h e equipment. For a beef k i l l
operation, t h e process would lower l a b o r requirements by eliminating
t h e labor used f o r shrouding.
P r i o r t o t h e commercial use of t h e Flavor-Tex process, USDA
approval f o r i t s a p p l i c a t i o n t o f r e s h meat and l a b e l l i n g requirements
a r e needed. Alginates a r e approved f o r use i n many food products and
Flavor-Tex is approved f o r use on seafoods, onion r i n g s , mushrooms and
various extruded products.
The e f f e c t i v e n e s s of an immediate post-slaughter a p p l i c a t i o n o f a
Ca-alginate coating t o lamb, pork and beef carcasses f o r t h e c o n t r o l
of shrinkage has been t e s t e d under laboratory conditions. Coated lamb
carcasses were shown t o have lower shrinkage values than uncoated
carcasses through 7 days postmortem. Surface microbial growth on
coated and c o n t r o l carcasses w a s similar, except in some instances
where t h e coated carcasses had s i g n i f i c a n t l y lower (P < .05) counts.
The a p p l i c a t i o n of t h e Ca-alginate f i l m did not a f f e c t carcass c h i l l
r a t e o r p a l a t a b i l i t y of lamb l e g s . Preliminary d a t a f o r beef and pork
carcasses i n d i c a t e s similar r e s u l t s .
I n a d d i t i o n t o reduced s h r i n k loss, o t h e r advantages f o r t h e a p p l i cation of Ca-alginate films t o carcasses have been observed. Such
f a c t o r s a s elimination of beef shrouding, l e s s bone d i s c o l o r a t i o n and
increased p l i a b i l i t y of pork s k i n should be considered. The a p p l i c a t i o n
of t h e film a l s o appears t o be econonically f e a s i b l e , based only on the
reduction i n shrinkage.
299
Studies conducted under commercial conditions w i l l d i c t a t e t h e
usefulness of t h i s concept. Information i s needed concerning t h e q u a l i t y
a t t r i b u t e s of Ca-alginate coated products a f t e r vacuum packaging and
a f t e r processing. Ultimately, consumer acceptance of t h e coated products
w i l l be needed.
LITERATLTRF: C I T E D
Allen, L., A. I . Nelson, M . P. Steinberg and J . N . McGill.
corn-carbohydrate food coatings. Food Technol. l7:lOk.
1963. Edible
Anonymous. 1973. Kelco Algin/hydrophilic d e r i v a t i v e s of a l g i n i c a c i d
f o r s c i e n t i f i c water c o n t r o l . Kelco. Clark, New J e r s e y . 07066.
B e r l i n , A . 1957. Calcium a l g i n a t e f i l m s and t h e i r a p p l i c a t i o n f o r
meats used f o r f r e e z i n g . Mayasnaya Ind. S.S.S.R. 28, 44. Chem.
Abstr 5 l , l 7 O O p .
.
Earle, R . D . 1968. Methods of preserving foods by coating same.
Patent 3,395,024.
U.S.
.
Fleming, A. K. and R . L. Earle
1968. Cooling and f r e e z i n g of lamb
carcasses. 2. Weight l o s s during cooling. Food Technol. 22:lOO.
Lazarus, C . R., R. L. West, J. L. Oblinger and A. Z . Palmer. 1975.
Techniques f o r c o n t r o l of lamb czrcass shrinkage. J . Anim. S c i .
40:176. (Abstr.).
McCormick, R . D . 1975. Edible coating i s o l a t e s oxygen and moisture,
c o n t r o l s s t r u c t u r e - s e a l s i n f l a v o r . Food Prod. Dev. 9:14.
Mountney, G . J. and A . R . Winter. 1961. The use of a calcium a l g i n a t e
f i l m f o r coating cut-up p o u l t r y . P o u l t r y S c i . 40:28.
Smith, G . C . and Z . L. Carpenter. 1973.
carcasses. J . Anim. S c i . 36:862.
Postmortem shrinkage of lamb
Don Kropf, Kansas S t a t e : Was t h e r e any unusual d r i p appearance
a f t e r cooking? Was t h e r e any j e l l y - l i k e m t e r i a l i n t h e d r i p ?
heat.
R. L. \!est:
No, it completely breaks down when you s u b j e c t it t:,
Ide d i d not n o t i c e any d i f f e r e n c e i n t h e ammnt of d r i p e i t h e r .
.
D H Kropf : F u r t h e r m r e , when t h i s d r i e s off somewhat i s t h e r e
a rehydration p o s s i b l e under humid conditions?
R. L. West:
possible.
I t ' s an i n t e r e s t i n g idea. I t h i n k it ti0ul.d be
kJe have not r e a l l y looked a t t h a t but it probably w m l d b e .
D . H . Kropf: One f u r t h e r question, l e t us say a f t e r 24 hours, i s
t h e r e any appearance that would be v i s i b l e f o r a r e t a i l cut?
E . L . West: A f t e r 24 hours it r e a l l y depends on how much or what
t h i c k n e s s of film you have added b u t in a r e t a i l c u t a f t e r 24 hours it
?*70Uldp o s s i b l y be n o t i c e a b l e but I t h i n k a f t e r something l i k e 4 t o 5
days, o r 3 t o 5 days t h e f i l m has dehydrated s o much that you v m l d not
even know it jias on t h e r e . It does bond very i n t i m a t e l y t o t h e s u r f a c e
except for a very f a t or o i l y s u r f a c e .
Don Kinsman, Connecticut: Eioger, have you compared t h e a l g i n a t e
coating with propylene g l y c o l which has been approved and used on pork
carcasses and pork l o i n s ?
R . L. West:
No, w e have not.
J . D . Kemp: The t h i r d and f i n a l paper of t h i s s e s s i o n i s t o be
given by D r . Tom Bidner. Tom i s a n a t i v e of I l l i m i s and received h i s
B .S. t h e r e . He received h i s M.S and Ph.D. degrees from Michigan S t a t e
H i s t o p i c i s "Forage-Finished Beef . ' I
U n i v e r s i t y and i s now a t L.S.U.
.