Utilization of intestines as animal casings

1. UTILIZATION OF
INTESTINES
Dr. Irshad A, MVSc
Assistant Professor

2. Animal Casings
 India is a major exporter of animal casings like cattle casings,
guts for animal casings, sheep casings and casings of other
animals.
 Indian animal casings - high quality with excellent
calibration and shining colour .
 The major destinations for exports are Vietnam, Italy, South
Africa, Portugal, Germany, Denmark and Spain.

3. Animal Casings
The country has exported 260.15 MT of Animal Casing products
to world for the worth of Rs. 19.32 crores during the year
2014-15.
Major Export Destinations (2014-15) : South Africa, Turkey,
Portugal, Lebanon andTunisia.
The individual products under this sub-head are as below:
Cattle Casings
Sheep Casings
Casings of other animals
Bladders and stomach of animals

4. Animal Casings Exports From India

5. Animal Casings

6. Intestine of domestic animals as slaughterhouse
by products
Non edible use: surgical catguts, sports guts, musical strings and
collagen sheets.
Edible use: When part of the processed intestine used as food
container called casing

7. Casings
Definition:-
Alimentary tract of sheep, goat, cattle and pigs, sometimes
urinary bladder when used as food containers are called Casings.
Or
Casings are soft cylindrical containers used to contain sausage
mixes

8. Types of Casings
• Animal intestines
derived from
slaughtering
Natural
origin
• Cellulose,
• Collagen or
• Synthetic materials
Artificial

9. Natural Casings
Natural casings are mainly derived from small and large
intestines from sheep, goats and pigs, but also from cattle
and horses.They
1. Are strong enough to resist the pressure produced by filling
them with sausage mix
2. Are permeable to water vapour and gases, thus allowing fillings
to dry
3. Absorb smoke for additional flavour and preservation
4. Expand or shrink firmly attached to the sausage mix and
5. Can be closed at the ends by tying or clipping.

10. Characters:
 Variable strength & length
 Low cost
 Best smoke penetration
 Stored in salted condition
 Most tender
 Breakage during processing
 Suspected quality (hole/tear, microbial)

11. Characteristics of casings Natural Collagen Cellulose
Refrigeration storage Yes Yes No
Degree of tenderness Most tender Less tender Peeled
Break during processing Most likely Less likely Least likely
Cost Low High Low
Soaking & flushing before use Yes No Sometimes
soaking
Ease of smoke penetration Most
penetration
Less
penetration
Least
penetration
Best machinability Least Less Best
Best product yield Least Less Best
Printability None Limited Best
Ease of plant storage Least storage Less storage Best storage
Strength Variable High and
Uniform
Good and
Uniform
Length Variable Standardized Standardized
Microbial quality Suspected Good Good

12. FACTORS INFLUENCETHE QUALITY
 Health of the animal,
Species, age, breed,
Fodder consumed,
Conditions under which the animal was raised,
Portion of the intestinal tract utilized,
And how the product is handled and
Processed after the animal is slaughtered etc.

13. INTESTINE AS RAW MATERIAL FOR CASINGS
I. Mucose membrane with finger-like outgrowths for enlarged surface area
II. Submucose membrane, firm-elastic layer mainly of connective tissue
III. Muscular layer, the circular internal one, the outside one longitudinal
IV. Serose membrane thin coating covering the abdominal cavity from inside
and surrounding all organs.
IV
III
II
I

15. Terminology used in Casing Industry
Casings Generally refers to sheep and goat intestine alone
Rounds
Casings from small intestine of cattle mainly, but
also from sheep, goat or pig
Runners Casings form small intestine of cattle
Middles
Casings from large intestine of cattle or sometimes
pig
Weasand Casings from the oesophagus of all species
Bung Casings from the caecum
Maws or
Stomachs
Casings from cleaned pig stomach
Chitterlings Casings from part of large intestines of pigs.

16. CASING FROM SHEEP INTESTINE

17. CASING FROM PIG INTESTINE

18. CASING FROM CATTLE INTESTINE

19. Cleanliness: Clean & sound, stain free, devoid of fat, parasite
nodules, ulcer , defects
Strength: Strong enough to withstand pressure during filling,
stuffing & processing
Length: Standardized (sheep & hog-91.4 m, beef round-180 m)
Caliber (thickness): Sheep-14 mm, hog-35 mm, beef-35 mm
Curing: Two types, salted & cleaned, some time it may be dried
Packaging: Mainly wooden and plastic container
FACTORS INFLUENCING THE QUALITY
OF CASING

20. APPROXIMATE LENGTH OF CASING
FROM ANIMALS
Species Type
Length
In meters In feet
Cattle Runner 25-40 90-135
Middle 5.5-7.5 20-25
Bung 1-1.5 4-4.5
Weasand 5.5 18-20
Bladder
20-35 cm
wide
8-15 inches
wide
Sheep Round 27 90
Goat Round 22 75

21. Storage of casings
 Sheep and Goat casings are generally stored wet and
salted– called salted sheep casings/salted goat
casings
 Cattle casings are generally dried in processing and
sprinkled with insecticide—dried cattle casings
 A. For salted sheep / goat casings, 1 hank= 91.4 m
 B. For dried cattle casings , 1 Hank= 180m in case
of runner and 90 m in case of middles

22. 1. Casings should be manufactured from gut of healthy
animals
2. Intestines for processing should not have ulcers and
heavy parasitic infestation with nodules.
3. Sanitary handling conditions should be maintained
from slaughter till final packaging.
4. The product should be clean with good colour and
without objectionable odour.
5. It should have proper length and be sufficiently cured

23. STEPS IN CASING PREPARATION
Removal
Pulling/running(separation of mesenteric membrane)
Chilling (at 10º C)
Stripping
Flushing
Fatting (removal of fat)
Fermentation (for 1-2 days, at 20ºC)
Turning (turn inside out)
Sliming (removal of mucous lining)
Measuring (in inflated condition)
Inspection & grading (checking of colour, cleanliness, pin hole, cuts
etc.)
Preservation (sheep, goat-in wet salted; cattle-dried)
Packing (tin cans lined with polyethylene)

24. STEPS IN CASING PREPARATION
1. Removing the intestine from the animal- the
intestinal tract should be removed carefully without any
damage or cuts. A ligature is made to check the escape
of contents.
2. Running or Pulling - the intestines are detached from
loose mesentery attachment and fat.
Pulling of sheep intestine

25. STEPS IN CASING PREPARATION
3. Chilling- the green intestines may be chilled at 10oC if the
processing is not possible immediately
4. Stripping - The intestinal contents are stripped from the
intestines either by hand or by machine under a spray of
water, which washes away the contents as they are
expressed.
The water spray also serves to
clean the casing.
Stripping

26. STEPS IN CASING PREPARATION
5. Flushing- tap water can be forced through the gut in
order to flush off the remaining intestinal contents
6. Fatting- all fat adhering to the intestines must be
removed. Scrapping in case of sheep and goat intestines
can do it, whereas in buffalo, it may require tearing,
pulling and even use of knife or Brushes.
Loosening of tissue layers
using a small-scale
manual casing cleaning
machine

27. STEPS IN CASING PREPARATION
7. Fermentation- the intestines are allowed to ferment
for 1-2 days in winter by immersion in water at 20o C.
This facilitates easy removal of mucous membrane and
slime due to bacterial action. However, in summer little
salt can be added to prevent over fermentation.
8. Turning- buffalo and cattle intestines only are
required to be turned inside out for efficient
sliming.

28. STEPS IN CASING PREPARATION
9. Sliming -It is the removal of tissue layers done with
the help of sliming stick or plastic knife or shells.
The process becomes easier if casings are dipped in a
sliming solution containing 0.2% Sodium
pyrophosphate and 1% sodium chloride for 15-20
minutes.

29. a = unprocessed casing
b1 = processed casing
(slimed and cleaned)
b2 = processed casing
(slimed and cleaned and
being flushed with
water)
c = "slime" removed
from inside of casing
d = tissue layers
removed from outside

30. STEPS IN CASING PREPARATION
10. Measuring- the width and length of the casing are
measured.
11.Inspection and grading- the casings are inspected
for cleanliness,colour, pin holes, cuts, blood spots etc.
12. Preservation- Stored overnight in ice and 15 to
20% saturated salt solution. Cured - rubbing with salt;
allow to set for 1 week.

31. STEPS IN CASING PREPARATION
13. Packing:- Containers such as barrels or boxes
preferably of hard wood should be used with
recommended insecticide for dried cattle casings.
For wet salted sheep casings metal tins, which are
completely lined from inside with food grade
polyethylene are used for storage and transport.
14. Resalting

32. SALTED SHEEP
CASINGS

36. Hard wooden box used for
dried cattle casings

37. Required equipments
 Plastic/wooden scrapper
 Gut cleaning table
 Fermentation & chilling tank
 Stripper with rubber roller
 Bronze crusher

38. DEFECTS COMMON IN CASING
Dull colour: grayish or greenish instead of white or
milky
Nodules: it may be due to round worm in intestine
Holes & laceration: formed due to negligence or rough
handling
Salt burn: due to long storage in salt or due to loose
packing,leaving air inside
Defective grading
Twisting of gut (kink)
Black spot (due to bacterial purification)
Cicatrices (scar of healed up wound)

39. ARTIFICIAL CASING
Artificial casings are made of collagen, cellulose, or even plastic and
may not be edible.Artificial casings from animal collagen can be
edible, depending on the origin of the raw material.
Collagen
Cellulose
Plastic casings

40. CELLULOSE CASINGS
Cellulose casings are usually classified into three types:
1. Small cellulose,
2. large cellulose and
3. Fibrous (paper impregnated with cellulose).
Cellulose casings are prepared from a special grade of cotton lintels,
which are solubilized, and regenerated into casings of any desired like.
A clear cellulose casing is commonly used for sausage, which is not
coloured or which is to be coloured by adding dyes to the water in
the cooker.
Plain cellulose casings are available in a variety of sizes with stretch
and shrink characteristics (similar to those of natural casings).

41. CELLULOSE CASINGS

42. COLLAGEN CASING
Collagen casings are mainly produced from the collagen in beef
or pig hides, and the bones and tendons. It can also be derived from
poultry and fish.
The latest generation of collagen casings are usually
more tender than natural casings but do not exhibit the
“snap” or “bite” of natural casing sausages.
The biggest volume of collagen casings are edible, but a
special form of thicker collagen casings usually peeled off
Collagen casings are less expensive to use,
give better weight and size control, and
are easier to run when compared to natural casings.

43. COLLAGEN CASING

44. PLASTIC CASINGS
Plastic casings are extruded like most other plastic products
generally made from polymers such as Polyamide, Polypropylene
or Polyethylene
Polyamide (Nylon) plastic casings are the most commonly used in
production of cooked sausages