Intermediate Moisture Meat Products


  • Sundrying of meat was one of the earliest preservative techniques used by man.
  • Such meat had meager dehydration capacity resulting in poor juiciness and texture.
  • Later studies revealed that meat products with 20-50% moisture had moderate juiciness and texture on rehydration.
  • Such products were resistant to bacteriological spoilage and could be held without refrigeration.
  • These products were referred as Intermediate Moisture Meats (IMM).
  • The basic reason for the stability of these products lay in the reduced availability of water to the microorganisms.
  • Since water activity generally remains in the range of 0.6 to 0.85.
  • These semi-moist meats are of special significance to the developing countries where refrigeration facilities are not always available.
  • Such products can be easily carried in defense expeditions and stress situations like floods, famines, for airdrop, etc.


  • Various additives employed for lowering the water activity of foods are known as humectants.
  • Some of the most commonly used humectants are:
    • Glycerol
    • Propylene glycol
    • Sodium chloride
    • Polyhydric alcohols (e.g. sorbitol)
    • Sugars (e.g. sucrose, dextrose, corn syrup etc)
  • The humectants are generally low molecular weight compounds, which are easily soluble in water.
  • These are chemically inert and do not modify the normal sensory qualities of the product.
  • Besides, these compounds are edible in large quantities without any adverse effect.
  • In addition to humectants, use of antimycotic agents like potassium sorbate, sodium benzoate, propylene glycol etc. is a must in the semi-moist meats because 0.6 to 0.85 water activity ranges specifically permits the growth of moulds.

Basic processing techniques

Moist infusion or desorption

  • It involves soaking and / or cooking of meat chunks or cubes to yield a final product having desired water activity level,
  • E.g. sweet and sour pork, Hungarian goulash etc.

Dry infusion or adsorption

  • It involves initial dehydration of meat chunks or cubes followed by soaking in an infusion solution containing desired osmotic agents.
  • E.g. ready-to-eat cubes of roast pork, chicken a la king, etc.

Component blending

  • In this process dry and wet ingredients or components are blended, cooked and extruded or otherwise mixed to give a final product of desired water activity.

Whatever process is adopted, the thumb rules for the preparation of IMM are:

  • Reduction of water activity by addition of humectants,
  • Retardation of microbial growth by addition of antimicrobial especially antimycotic agents and
  • Improvement of sensory properties such as flavour and texture through physical and chemical treatments.
  • Composition of infusion solution developed by Brockmann (1970) for the preparation of sweet and sour pork (aw=0.85) is given below to give an idea about the balancing of various additives:













Starch hydrolysate




Corn starch


Monosodium glutamate


Potassium sorbate


Mustard powder


Onion powder


Garlic powder


Stability of intermediate moisture meats
  • IMF products are fairly stable at ambient temperature for several weeks or even months.
  • However, prolonged storage may result in some quality deterioration due to the following reasons:
  • Limited breakdown of both myofibrillar and sarcoplasmic proteins.
  • Collagen being more susceptible to degeneration results in more hydroxyproline formation.
  • Degradation of haemoprotein (myoglobin and haemoglobin) causing loss of colour
  • Development of rancidity
  • Non-enzymatic browning resulting in loss of colour, consumer appeal, nutritive value and possibly off-flavour
  • Formation of lipid protein crosslinks causing decreased water binding capacity and net protein utilisation of meat products.
Last modified: Saturday, 24 December 2011, 5:48 AM