The document summarizes various physical methods for preserving meat, including controlling temperature through heating, cooling, and drying. It discusses heating methods like pasteurization and canning that kill microorganisms. Cooling methods like refrigeration and freezing halt microbial growth at low temperatures. Drying preserves meat by removing water that microbes need. The document provides details on the mechanisms, effects, and quality impacts of each preservation method.

1. Chapter 4
The storage, preservation & further processing of meat
1 . physical methods of preservation
 Includes the two widely used means to preserve meat namely:
* Control of temperature (heating or cooling)
* Regulation of moisture content =Drying
 Especially important in the circumstances where:
* Chemical preservatives are neither available nor desired
 Physical methods are normally employed to retard microbial
growth
NB: High temperature can be used to kill microorganisms (as in
canning)
Research & development on heating, cooling and drying is
focused on :
* Maintaining preservation properties/objectives

2. 1.1. HEATING
 Meat is subjected to thermal processing under two broad
circumstances
First: is production of a pasteurized or commercially sterile meat
product
Objective: Stabilizing or preserving the product
Second : is cooking before consumption In the latter
Objective: improve palatability and appearance

3.  Severe heating conditions can result in
 Not only destroy microorganisms and enzymes
 But also accelerates chemical reactions leading to
• Changes in ORGANOLEPTICPPROPERTY of meat
• Some destruction of nutrient components
• Decrease in soluble components from fluid loss during
heating
Desirable vs Objectionable changes

4. Heat Transfer
 Heat is transferred by conduction, convection and radiation
* Conduction: Transfer of heat by direct contact of one particle
(of the meat) with another
* Convection: Transfer of heat by the physical movement of the
heating medium itself ( Transfer of heat via the flow of fluid)
* Radiation : Transfer of heat in the form of wave through space
/vacuum
( Electromagnetic radiation emitted by a hot body and absorbed by a
cold body)
NB:
* Since meat is a solid mass, most of heat transfer occurs by
conduction.

5. Methods used to cook Meat
 Cooking of meat is done with dry or moist techniques or a
combination.
* The dry procedures employed for home cookery include roasting,
broiling, frying and grilling.
* Moist methods encompass such procedures as stewing, braising &
boiling

6. PASTEURIZATION:
 Pasteurization is the process of heating meat to kill microorganisms
that can cause disease
 Pasteurized products generally reach an internal T° 70-1000C
 Pasteurization provides only short-term stability
• Requires additional preserving factors (hurdles) such as
refrigeration or low pH for long-term effectiveness
Reason:
– The T° used in pasteurization is not enough to kill spores
– If the T° is not raised much above 60°C, there may still be
residual enzymic activity
 Pasteurizing process can provide safe meat in case of cured product
 From the point of view of minimizing damage to texture it is
preferable to apply HTST

7. CANNING:
 The canning industry is based on the original efforts of the French worker
Appert that appeared in print in 1810
 The procedures he stated are quite simple and consisted of
(1) Enclose the food to be preserved in a bottle or jar,
(2) Cork with great care (success depends on this closing) and
(3) Submit to boiling water
 The aim is to:
• Destroy spoilage and toxigenic microorganisms
• Maintaining acceptable quality and textural properties in the meat
 This is best accomplished by exposing the meat to a high temperature for a
short time ( HTST)
 The commercially sterile products should be stable at ambient temperatures
for several years

8.  An important consideration in achieving sterility is:
– Certain MOS form spores which may be exceedingly heat-resistant
 Thus any attempt to destroy the spores of certain thermophiles
greatly lower the organoleptic attributes of the meat
 The eating quality of canned, cured meats can be retained by
using a low degree of heat treatment Insufficient to kill spores
Reason: in such products the curing ingredients (NO3/NO2)
reinforce the bactericidal and bacteriostatic effects of the heat

9. STERILIZATION:
 Commercially sterile foods are heated at a high temperature, up
to 1210C for varying periods of time
 The majority of canned meats are ‘commercially’ sterilized
i.e. They are processed to the point at which most micro-
organisms and their spores have been killed
 This permits more or less indefinite storage life in the can,
at any ambient temperature, provided it is kept sealed
 But the product is markedly different from fresh meat and
may alter chemically and physically in the course of time

10. LOSSES ON HEATING
i. Temperature and duration of cooking
 The higher the T° and the longer: the higher the Cooking
losses
 Cooking losses are a result of
(a) Loss of juice followed by evaporation
(b) Direct evaporation
 Mode of heating:
• Highest losses in moist heat
• Crust formation with dry heat

11. ii. PH the of meat
– The lower the PH the greater the losses
– Because WBC proteins decreases as PH
lowered
Fig. Effect of PH on WBC OF BEEF

12. iii. Technological treatments
(a) Cooking process
– High pressure: improves tenderness due to damage to the
myofibrillar structure and decreases the losses
(b) Changes in pH
– Decrease in losses as the pH differs from IEP: by immersion
in acid or basic solutions
(C) Additives
– Polyphosphates: pH-increase + salt (lowering IEP): result a
decrease in losses

13. QUANTITATIVE CHANGES ASSOCIATED WITH LOSS OF
JUICE
 Lost materials: lipids, minerals and proteins
Lipids
• lipids in lean tissue↑ and surface fat↓
• Heating increases the unsaturated/saturated fatty acid
ratio
Minerals
• K, Na & Ca: mobile
• P & Mg: remain in the meat
• Fe: Complete immobilisation at T°>70°C
• S: negligible loss
Loss of nitrogenous constituents
• Losses up to 20% can occur
• protein N up to 25% cooking losses

14. COOKING AND MEAT QUALITY
I. Nutritional value:
 Influenced by
– Loss or concentration of nutrients (essential amino acids,
essential fatty acids, vitamins,…)
– Changes in digestibility
 Few changes in amino acid composition
 Vitamin B: thiamine exhibits the poorest heat stability

15. II. Organoleptic quality
A. Colour
• Myoglobin to ferrihaemochrome (= grey)
• Denaturation of proteinaceous parts of myoglobin
• Denaturation of globin
• Cleavage of haem-globin linkage
• Denaturation of haem nucleus
• Nitrite (Cured meat )
• Reduction of nitrite to NO
• NO + myoglobin → nitrosomyoglobin (bright red)
• Nitrosomyoglobin + heat → nitrosohaemochrome (bright
pink)
•> 90°C: Maillard + caramelization→ BROWNING
Visual from 40°C

16. B. Flavor
 Raw meat have weak flavor
 When meat is cooked flavor increases
– Precursors in the lean: meat taste
– Precursors in the fat: taste specific to the animal species
 The following are reactions responsible for cooked meat flavor:
(a) Auto oxidation, hydrolysis, dehydration and decarboxylation of
the lipid constituents → fatty acids, lactones and ketenes
(b) Reactions affecting carbohydrates resulting in degradation
products of importance as flavoring agents
(c) Maillard reaction between sugars and amino acids

17. C. Juiciness:
 Two phenomena
a) Impression of moistness during first mastication due to rapid
release of fluid by the meat
b) Sustained juiciness due to stimulatory action of the fat on salivation
 Juiciness decreases as cooking T° increases
D. Tenderness
 Set of mechanical sensations perceived during mastication
– Matured raw meat: collagen is cause of toughness
– On heating: collagen solubilizes → Tender meat
– Intramuscular fat Vs Tenderness
Collagen :
• Insoluble animal proteins, with high contents of the amino acids
glycine, hydroxyproline and proline
• Collagen is the main fibrous component of skin, tendons and
bones

18. 1.2. COOLING /Low T° preservation
 Low temperature does not destroy MOS or enzymes but
depresses their activity
WHY??????
 Food preservation at low temperature comprises two
distinct processes: Chilling and Freezing
1.2.1 Refrigeration
 is the most widely used and effective means of preserving
meat
 It is employed at the slaughter plant immediately after

19. Mechanism of cooling:
 The desired results are achieved by adjusting and balancing
• Temperature , Air flow & humidity in the chilling rooms
• Size, shape, composition and uniformity of the carcasses
 Carcass chilling rooms are normally operated in the T° range of -
2°C to -4°C with a relative humidity of 88 to 92%
 Air movement promotes more rapid cooling but it results:
• Greater dehydration at the surface
• Greater weight loss of the carcass
 If cooling does not occur rapidly it results
• Greater microbial growth
• Shelf-life may be shortened

20. Remark:
 For refrigerated and properly packaged retail meat:
– The shelf-life is probably 72 hours, after which some
discoloration appear
– Ground meat may display acceptable condition for only one
day ????
– Vacuum packaged and refrigerated meat the quality is
expected to remain stable for at least three weeks
– In the case of cured meat, vacuum packaged and
refrigerated, at least two months is expected before obvious
changes become visible.

21. 1.2.2. Freezing :
 Is a more effective means to preserve meat over an extended
time period ?????????
 Freezing provides an excellent means for storing meat for long
periods of time while maintaining it at a high level of quality
 As far as microbial safety is concerned
* Freezing does not normally kill microorganisms
* Frozen storage is effective in destroying parasites such as
trichinae
 The recommended storage temperature for frozen meat is -
18°C
NB: A lower temperature may be more desirable in maintaining
quality but the advantage gained must be balanced against

22.  Although freezing is so effective and is used extensively for storing
meat, it has not been adopted for retail use with meat
Reasons:
* Consumer probably thinking it has been frozen to hide a defect
* Appearance (color) has also been a factor
 Different products respond differently during freezing:
 Cured meats can be frozen but the freezing is not as often used
• Cured meat is more susceptible to oxidative and textural changes
when held frozen
• The curing agent enforce preservative effect of refrigeration
 Cooked meats may be frozen→ development of off-flavors

23. The Freezing process
 There are four areas or phases of importance in a consideration of
frozen meat: pre-freezing, freezing, frozen storage and thawing
Pre-freezing :Relates to the quality of the meat and to preparing it for
freezing
1. The time postmortem that freezing is undertaken plays a role
NB: If temperature is decreased pre-rigor with sufficient rapidity, then
cold shortening and associated toughening may result
2. Slower freezing will occur with a larger size or a cube shape
compared to thin dimension meat
3. Impermeable packaging is important to protect the surface of the
meat from exposure to oxygen and water loss
4. Packaging should be applied in a manner to minimize dead space
within the package that would also allow migration of water

24. Freezing : The freezing process of meat consists of two steps :
(a) Formation of crystal nuclei or nucleation
- « Super cooling effect » required
- In animal tissues: impurities or water absorbed onto a
substrate act as crystal nuclei
- Extracellular: concentration is lower and nuclei form
preferentially in this environment
- If intensity of cooling is great enough: intracellular nucleation
(b) Growth of crystals
- Tendrites or needles
- The rate of growth and the final size of the crystals depend on
the speed with which heat is extracted
NB: DESTRUCTION OF CELL WALLS & DRIP LOSS

26. Frozen storage
 Is the phase that is potentially the most damaging to the quality of the meat
especially if there is fluctuation of temperature
1. This is the time when growth of ice crystals can occur and result in structural
damage
2. Even though low temperature slows enzymatic and chemical reactions they
may still proceed in frozen meat
* For example, oxidation of lipids occurs during frozen storage of meat
3. There is also a zone during the freezing process where reactions may
proceed rapidly
When & How???
*As freezing progresses and water is being crystallized, the concentration of
solutes actually increases, which may speed up reactions
* This could be especially important if freezing rate is slow and high solute
concentration is present for longer time periods

27. Thawing :
 The final phase to consider and is essentially the reverse of
freezing
 Thawing may be done in cold , warm air or micro oven heating
 Immersion in water gives an improved thawing rate due to the
direct contact
Care: The meat must be in an impermeable bag otherwise
•There will be surface extraction of meat constituents such as protein
•The problem of microbial cross-contamination also exists

28.  It is not possible to use the same degree of temperature differential
for thawing as is used for freezing
The problem is that
• The surface of the meat may be at ambient temperature for a
very long time period while the center of the meat remains frozen
• Since most of the bacterial contamination is on the surface of the
meat, the situation provides an excellent condition for growth of
microorganisms
Effect of freezing rate on quality
A. Nutritional quality:
• No significant changes regarding proteins, fats and carbohydrates
• B-vitamins: 10-20%

29. B. Organoleptic quality
 Flavor is unaffected
 No effect on the Colour after thawing
NB: Appearance of the frozen product is determined by the rate of local
formation of ice crystals at the surface:
Thus : A lot of small crystals intense reflection of light and pale Colour
 Texture and juiciness
- Progressive denaturation of myofibrillar proteins
- Increase in insolubility of collagen
 Freezer burn occurs when moisture evaporates from the surface of
the meat
Freezer burn: Brown discoloration through surface dehydration
Reason: This normally takes place as a result of poor packaging so
there are air pockets in the package
Result:The outcome is a blanched color and a more or less dehydrated
layer on the surface of the meat
Less tender
and dryer
after cooking

30. C. Drip loss:
The phenomenon of drip may be experienced.
Drip : is a watery, red exudate that is not only unsightly but also
contains nutrients such as proteins, vitamins and minerals
• Obviously, drip results in a shrinkage or weight loss
• It is most severe if the pH of the meat is low, giving poor water
holding properties
• Fast freezing = less drip loss
D. Hygienic
– Pathogens: -1°C
– Spoilage flora: -18°C
– Parasites
• Taenia saginata & Taenia solium: 3 weeks at –7°C
10 days at –18°
• Trichinella spiralis: 20 days at –18°C

31. 3. CONTROL OF MOISTURE
 Drying as a means of preservation is a very old technique, and
basically is accomplished by removing water
 If water is removed from meat a point is reached where the available
water is not sufficient to support microbial growth
 With simple air drying, the control of proper hygiene may be a problem
Reason: The meat is exposed to ambient conditions such as dust, insects and
animals
 Extremely lean meat is the most desired for drying
 Fat is subject to oxidation and the production of off-flavors, especially
if heat is used in the drying procedure
 The use of an antioxidant may be nearly prerequisite to production of a good product
 Denaturation of protein and some loss of nutritional value may occur,
and depends largely on the heating process

33. MICROWAVE APPLICATION
 Microwave technology has possible application in numerous
processing procedures, as well as in home preparation.
 The microwave component provides a rapid rate of internal
heating while the conventional heating is used for surface effect
 Microwaves travel in straight lines, are pass through such
substances as glass, paper and plastic
 They are absorbed by food constituents including water and
cause the absorbing substance to become heated

34. Working principle:
* Microwaves contain alternating electric fields and are reversing/ oscillate so
many times per second
* The molecules with dipole nature (water ...) there fore rotate as they try to
align themselves with the alternating electric field of the microwaves
* The oscillation is so rapid that it more or less generates an intermolecular
friction causing the food to heat  Dielectric heating
Thus:
* Conventional heating is a surface inward effect, meaning that the surface is
exposed to a higher heat for a longer time
* In the case of microwave heating, penetration to the interior of the food occurs
and heat is generated quickly and uniformly throughout

35. Pros and Cons associated with the use of micro ovens
Advantages:
 Microwave heating is 10 to 20 times faster than the usual thermal
transfer
 Surface browning does not occur or is minimal
 improve quality , reduce costs and increase yield
Concerns
 Heating of a given product may be uneven
NB: Minimized by the use of ovens with wave stirrers and rotation of the
product
 The possibility of low microbial inactivation because heat is not
concentrated at the surface
 Trichinae could sometimes survive microwave cooking
procedures
Reason: due to the rapid heating rate that meant exposure to a
given temperature for a shorter period of time

36. 2. CHEMICAL METHODS OF PRESERVATION
 Chemical preservatives are used to:
▪ Prevent or slow microbial spoilage or the growth of pathogens
▪ Prevent or slow chemical processes such as oxidation
▪ Maintain desirable color
▪ Impart desirable palatability properties, such as the special
flavor and texture of cured meat

37.  Preserving meat by salting (and then by the process of curing)
is an extremely old and well-accepted procedure.
 Similarly, the use of vinegar (acetic acid) to pickle meat, and
spices has been quite acceptable
 However, consumers really raised questions when attempts
were made
* To preserve meat with such chemicals as formaldehyde,
sodium benzoate and boric acid
* To revive a poor color with sulfurdioxide
 Concern about using chemical preservatives resulted the need
of legislation to protect the consumer

38.  The control and regulation of use of chemical preservatives in
food are complex and intricate.
 This regulation vary from country to country, are different for
different foods and are constantly being reviewed
 In general
▪ The additive had to be shown safe before permitted for use
▪ Some additives were permitted based on the status known as
GRAS (generally recognized as safe)
▪ Compound found carcinogenic to animals or man are
absolutely prohibited
 For meat, the following are the major chemical preservatives

39. 1. SALT/ SODIUM CHLORIDE
 Is the major ingredient used in curing and generally is present in the
finished product at a level of about 2.5 %
 Sodium chloride has only a very low capacity to destroy MOS
 Its preserving power is attributed to the capability to bind water and
to deprive the meat of moisture
 The water holding capacity of meat can be increased with the
addition of salt up to a concentration of about 5%
Mechanism : The water loosely bound to the protein molecules as well
as “free” water will be attracted by the sodium and chloride ions
causing a reduction of the water activity (aw) of the product
Result: Less water will be available and the environment will be less
favorable for the growth of microorganisms

40. 2. SODIUM NITRITE
 Is the vital ingredient for meat curing
 Nitrite can be safely used in tiny concentrations for food preservation
and coloring purposes
 Nitrite afforded specific protection against outgrowth of spores of
Clostridium botulinum
 Potential major problem is the possibility that nitrite reacts with
secondary amines to form nitrosamines ( carcinogenic properties)
 Levels of 150 mg/kg in the meat product, which is 0.015%, are
normally sufficient

41. 3. SUGAR
 Sugar is normally included in curing formulations for
▪ A flavor function an
▪ To moderate the potential harsh flavor associated with high salt
concentrations
▪ In the case of cured fermented products, the sugar is necessary as
an energy source for the organisms performing the fermentation
4. REDUCTANTS
 Ascorbic acid, erythorbic acid and their salts are commonly used in
modern curing practice
 They are used primarily to speed up the curing process and to make
it more uniform
 Ascorbate, for example,
▪ Is active and effective in reducing metmyoglobin to myoglobin
▪ It also promotes the formation of nitric oxide from nitrous acid
▪ Finally, the residual reductant remaining acts as an antioxidant
prolonging shelf-life

42. 5. PHOSPHATES
 The alkaline polyphosphates are used in the meat
processing industry with sodium tripolyphosphate being
the most common
 Sodium acid pyrophosphate is known :
▪ To speed the development of cured color
▪ For its detrimental effects on water binding and emulsion
stability
▪ Retard development of oxidative rancidity and may also
slow microbial growth
 Some problem may be encountered in their use due to
▪ Low solubility
▪ The possibility that they may impart a metallic or soapy
taste to the product.

43. 6. SULFITE: (Sulfur dioxide, sodium/ potassium sulfite )
 They are effective to preserve the freshness and prevent
discoloration
 Also, in foods containing 10 ppm sulfite, despite source, a label
so stating must be used
 The concern is for individuals who are sensitive or allergic to
sulfites
 These compounds are not allowed for use in meat in the United
States
Reasons:
▪ A small amount in meat imparts a very bright red colour and ev
spoiled meat may looks fresh
▪ Sulfites are also known to degrade the thiamine, of which meat
is a good source

44. 7. SORBATES
 Sorbic acid (2,4-hexadienoic) and its salts are effective and rather
widely used preservatives.
 Sorbic acid is an effective inhibitor of mold and yeast growth as well
as an effective antimicrobial agent in meat
 It has also been studied as a nitrite sparing agent in cured meat
because of its antibotulinal activity
 However, concern that it may be harmful to human health has kept it
from being approved for use.

45. 8. Smoking
 Smoke for treatment of meat products is produced from raw wood
 Smoke is generated through the thermal destruction of the wood
components lignin and cellulose
 The thermal destruction sets free more than 1000 desirable or
undesirable components of These useful components provide the
following effect on meat products:
 Anti-microbial effect: Meat preservation through aldehydes,
phenols and acids
 Retarding fat oxidation: Antioxidant impact through phenols and
aldehydes
 Smoking taste: Smoke flavor through phenols, carbonyls and
others
 Attractive colour : Smoke colour formation through carbonyls and
aldehydes
 Surface hardening of sausages/casings through aldehydes
 wood

46.  The most known undesirable effect of smoking is the risk of
residues of benzopyrene in smoked products
NB: Benzopyrene can be carcinogenic if the intake is in high doses over long
periods
 Depending on the product, smoke is applied at different temperatures
 There are two principal smoking techniques:
 Cold smoking
 Hot smoking
 The principle of both methods is that
“The smoke infiltrates the outside layers of the Meat in order to

47. Cold Smoking
 This is the traditional way of smoking primarily used for meat
preservation
 Nowadays it serves more for flavour and colour formation
 The cold smoking has an important preservative effect as it
prevents the growth of moulds on the meat surfaces
 The optimal temperature in “cold” smoking is 15 to 18°C (up to 26°C)
Mechanism of Smoking:
 Sawdust should be burned slowly with light smoke only and
 The meat hung not too close to the source of the smoke.

48. Hot Smoking :
 Hot smoking is carried out at temperatures of 60 to 80°C
 The thermal destruction of the wood is normally not sufficient
to produce these temperatures in the smoking chamber
Solution: Additional heat has to be applied in the smoking
chamber
 The relatively high temperatures in hot smoking assure a rapid
colour and flavor development
 The treatment period is kept relatively short in order to avoid
excessive impact of the smoke (strong smoke colour and flavor)
Antioxidants (a note will provide on Antioxidants )

49. 2.1. Curing
 Is Preservation of foods such as meat, by salting, drying,
pickling or smoking
 Curing have a dual function:
▪ A definite preservative function imparted by curing
agents
▪ Provide entirely new class of meat product with different
appearance and palatability characteristics

50.  It became known that saltpeter (potassium nitrate) was the
critical ingredient for curing
 Under typical circumstances the nitrate is reduced to nitrite
(undoubtedly due to microbial action)
 It is the nitrite which caused the colour change:
▪ The nitric oxide formed from nitrite, reacts with the heme
portion of the myoglobin to form nitrosylmyoglobin ( red )
▪ When the meat is heated, the pigment is converted to
nitrosylhemochrome ( pink colour characteristic of cured meat)
Nitrosomyoglobin

51.  Due to the great uncertainty of conversion of nitrate to nitrite,
many problems experienced with the curing process.
▪ If sufficient conversion to nitrite did not occur
Consequence: The curing process would fail and good color would not develop
▪ If excess nitrate was added and good conversion to nitrite
occurred there could be too much nitrite
Consequence : production of green colour & Higher residual nitrite
 The direct use of nitrite:
▪ Greatly reduced the time for curing, since waiting for reduction
of nitrate to nitrite was no longer required
▪ Make the process became much more reliable and uniform
because the level of nitrite could be much more closely
controlled

52.  The most significant improvement in the curing formulation was
the introduction of use of reductants such as ascorbate or
erythorbate
 The use of reductants have the following benefits:
▪ Speeded up the reduction of metmyoglobin that was formed
from initial contact with nitrite
▪ Provide uniformity because the biological reducing system of
the meat was no longer depended on solely
▪ Residual reductant, by acting as an antioxidant, also
maintained color better in the finished product.
▪ These reductants also participate in the chemical reactions by

53.  The use of vacuum packaging for cured meat products
▪ Greatly extended shelf-life
▪ Permitting a lengthy and complicated distribution chain
 Proper refrigeration is certainly a key component
 Health concerns of cured products
▪ Reduction of salt level used in curing has taken place due to
desire of consumers to have a lower intake of sodium
▪ Cured products are suspecting of being harmful to human health
due to the possible presence of nitrosamines which are carcinogenic

55.  The ingredients commonly used to cure meat are salt, nitrite (nitrate), sugar,
reductants, spices or seasonings and phosphates
Cured meat production
 The first step is applying the curing agent on the meat
 The curing ingredients may be added during grinding or comminution or
injected /pumped to entire piece meat
 Method of curing agent application may be:
1. The blend of ingredients may be rubbed on the surface of the meat as a
dry powder.
NB: This is a specialized and old time procedure that requires extended
periods for penetration of the chemicals
Fig. Blend of curing ingredients rubbed on the surface of the meat as a dry

56. 2. The ingredients may be dissolved in water to form a curing
solution or pickle. The meat pieces may be
▪ Soaked in the pickle (Wet curing)
▪ Injected into the piece of meat
▪ Automatic injection followed with a tumbling exposure
Why tumbling ? To speed final distribution of cure and ensure it is
thorough and uniform
Wet curing by immersion of meat pieces in brine is primarily used for the fabrication
of cured raw fermented products with shorter ripening periods

57. Fig. Manual brine injection using a Curing pump & large syringe
 An alternative and quick way of wet curing is to accelerate the diffusion of
the curing substances by pumping brine into the meat tissue.
 Wet curing by brine injection is used for the fabrication of cured cooked
products

58. Fig. Multi-needle brine injection

59.  The results of curing are characterized by specific and
characteristic color, flavor, texture and preservative properties
▪ The color is a light pink, which is relatively heat stable but
may fade on exposure to light
▪ The specific flavour depends on the seasoning, but nitrite
may contribute by itself to flavor
Mechanism: Nitrite contribute for flavor by slows oxidative
rancidity and therefore the development of "off flavors
▪ The curing ingredients, especially salt, contribute to a general
preservative effect
▪ Nitrite has specific attributes as preservative notably the
inhibition of outgrowth of spores of Clostridium botulinum
NB: After incorporation and distribution of cure, the product is exposed
to some degree of heating, and very often to a smoking process