Meat Science

SAUSAGE INGREDIENTS

Raw materials

• Excellent sausages can be made from various fresh trimmings and cuts that might ordinarily be underutilised.
• Materials such  as cheek, jowl,  head meat, pork fat and trimmings, which are seldom used freshly, make palatable sausages and are as good for this purpose as are any other cuts of meat.
• Other cuts from low quality carcasses may also be used.
• Only clean fresh or cured meats free from bones, tendons, and joints should be used.
• The skin should be removed from the pork.
• Meat by-products such as heart, liver, kidney, tongue and tripe obtained from beef, calves, sheep and hogs are used in many sausages.

Water

• Water is the most important non-meat ingredient and it should be permitted up to 3% for fresh sausages, luncheon meats and meat loaves.
• The final cooked sausage product should not exceed four times the protein content plus 10%.

Protein

• During preparation of sausage batters or emulsion, meat proteins serve two functions:
  • To encapsulate or emulsify fat, and 
  • To bind water.
• If either of these is not accomplished properly, the sausage will be unstable and subject to breakdown during cooking.
• The fraction of muscle that contains salt-soluble myofibrillar (contractile) proteins is more important than the sarcoplasmic fraction, which contains water-soluble proteins.
• Approximately 55% of total muscle protein is myofibrillar, composed largely of myosin and actin.
• During the onset of rigor, myosin and actin are complexed to form actomyosin.
• The dissociated proteins are more extractable and have a greater ability to swell and bind water.
• After the onset of rigor the swelling and extractability are influenced mainly by temperature and ultimate pH.
• The presence of excessive collagen in most sausage is undesirable and it is usually desirable for finished sausages to have no more than 25% of the total protein as collagen.

Fat

• Fat contributes greatly to palatability of sausages, but it is also the source of many processing problems.
• Tenderness and juiciness of cooked sausages are affected by their fat content.
• Fat is added to emulsions or batters primarily through inclusion of beef and pork trimmings in formulations.
• Since the pork fats are softer and melt at lower temperatures, they are easier to comminute than beef fats.
• During comminution, beef fats require higher temperatures than pork fats.
• Cooked sausages such as frankfurters, bologna and similar comminuted sausage products are limited by U.S. government regulation to a maximum of 30% fat.

Non-meat ingredients

Salt

• Salt is the most critical ingredient in sausage manufacturing.
• Without salt sausages cannot be made.
• Salt has 3 primary functions - preservation, flavour enhancement and protein extraction to create the product to bind.
• Most sausages have 2-3 % of added salt.

Sugar

• A variety of sugars are commonly used ranging from sucrose (cane or beet sugar C₁₂H₂₂O₁₁) to dextrose (corn sugar C₆H₁₂O₆), corn syrup, corn syrup solids, sorbitol are also used in later group.
• Sugars are used mostly as flavouring agents to counteract the salt flavour intensity and to provide food for microbial fermentation in fermented sausages.
• Most sugars, except sorbitol increase the browning of meat during cooking.
• Dextrose is usually added at the 0.5 to 1 per cent level (of the meat weight) for fermented sausages.

Spices and flavourings

• Spices are dried aromatic vegetable substances.
• The term may be applied to all dried plant products, which include herbs, aromatic seeds and dehydrated vegetables.
• Spices are liable to certain variations in flavour, strength and quality.
• Allspice, ginger, nutmeg and pepper are products of tropical plants.
• They may represent the root, bark, bud, flower or fruit.
• Spices are used either whole or in one of the following processed forms: (1) ground, (2) essential oils, or (3) oleoresins.
• The latter two must be classified as flavourings.
• Most spices are used in processed form.
• Whole peppercorns used in certain dry sausages are an example of a whole spice.
• Flavourings are spice extractives: essential oils or oleoresins.
• Extractives have the advantages of elimination of colour specks, freedom from bacteria, reduced shipping costs and less storage area.
• Herbs are leaves of plants grown in both temperate and tropical zones and are relatively low in total oil content while true spices are relatively high.
  • Marjoram, sage and thyme are examples of herbs.
• Aromatic seeds are derived from plants cultivated in both temperate and tropical areas.
  • Anise, coriander, dill and mustard are examples of aromatic seeds.
• Vegetables are used in the dehydrated form. Examples are garlic and onions.
• Seasonings and flavourings are included in sausage emulsions or batters to add flavour to the product.
  • Examples of seasonings and flavourings are
  • Monosodium glutamate and nucleotides – enhance flavour.
• Hydrolyzed plant proteins contribute a characteristic meaty flavour.
• Black pepper, cloves, ginger, mace, rosemary, sage and thyme possess antioxidant properties.
• Other flavour additives include smoke flavouring which is usually added as an oil or water solution of natural smoke and vinegar used in products like sulze or some pickled sausages. Both of these have definite bacteriostatic properties.

Extenders and binders

• These are called as nonmeat materials and also are less frequently referred to as fillers, emulsifiers or stabilizers.
• They are added to basic meat formulations for one or more of the following reasons:
  • To improve emulsion stability
  • To improve cooking yields
  • To improve slicing characteristics
  • To improve flavour, and
  • To reduce formulation costs.
• The use level is generally restricted to 3.5% with exception of soy protein isolate, which carries a 2% limit.
• Many extenders have an effect on colour, flavour and texture.
• Milk products are well accepted due to their positive flavour contribution.
• Nonfat dried milk, dried wheys, modified wheys and partially delactosed wheys are also available.
• Cereal extenders are mainly starch, bind water and impart a bland flavour.
• Soy proteins include grits or flour (50% protein), concentrate (79% protein) and isolate (90% protein).
• They may be available in a textured as well as a powder or ground form.
• Soy isolate is a good binder, functioning much like meat protein in an emulsion or batter.
• Among other extenders are mustard flour and deheated ground mustard, which may be used at levels up to 1%.
• Yeast proteins represent another group of extenders as do milk protein hydrolysates.
• Many of these can be classified as flavourings.
• Gelatin, while not specifically an extender, is used as a binder for some loaf type products.
• Gelatin varies in gel strength and clarity according to Bloom number.
• Fillers such as starch, cereals and wheat flour and corn meal are used occasionally to lower the cost and the shrinkage and to bind to the product.

Nitrite and Nitrate

• Sodium nitrite (NaNO₂) or potassium nitrite (KNO₂) is added directly to sausage batter.
• Nitrite has four functions in cured meat and sausage products
  • To develop the characteristic pink colour
  • To provide bacteriostatic properties
  • To improve the flavour
  • To serve as a powerful antioxidant
• The bacteriostatic properties of nitrite are extremely important in the thermally processed, vacuum packaged products.
• Without nitrite the organism Cl.botulinum will jeopardize the safety of these products, the bacteria that causes botulism.
• Nitrite prevents the outgrowth of Cl.botulinum spores and subsequently the production of toxins.
• About 400 ppm of nitrite in the finished product is considered necessary for the formation of the cured colour.

Ascorbates and Erythrobates

• Ascorbates and Erythrobates are strong reducing agents that accelerate the conversion of metmyoglobin to myoglobin and nitric oxide.
• The vitamin ascorbic acid (C₆H₈O₆) derivatives are also known as cure accelerators, since they hasten the curing reaction.
• The use level is 7/8 oz per 100 lb of meat (approximately 550 ppm).

Antioxidants

• Antioxidants are added to the fresh and dry sausages to retard the development of oxidative rancidity.
• Oxidative rancidity develops in the unsaturated (double) carbon-carbon bonds in fatty acids present in meats.
• Salt, light, heating and freezing and traces of certain metals also increase oxidative rancidity.
• Grinding and chopping of meat for sausage production exposes more of the membrane fatty acids to oxidation.
• The most common antioxidant compounds used are BHA (Butylated hydroxy anisole), BHT (Butylated hydroxy toluene) and propyl gallate. They are added at 0.01 to 0.02% of fat content.

Phosphates

• Phosphates are added to improve the water binding capacity of meat and solubilize proteins and act as antioxidants and help protect and stabilize the flavour and colour of finished product.
• Through the use of phosphates, processors can attain a longer product shelf life and improve smokehouse yield.
• Phosphates are approved at a level not to exceed 0.5% in the finished product.
• The following phosphates are approved – Di-sodium phosphate, Sodium metaphosphate, Monosodium phosphate, Sodium poly phosphate, Sodium triphosphste, Sodium pyrophosphate, Dipotassium phosphate and Potassium pyrophosphate.

Anti-microbial agents

• In general these are not permitted in sausage products.
• But they are allowed as a surface application on dry sausage to retard mold growth.
• A 3.5% solution of propyl paraben or a 2.5% solution of potassium sorbate may be used for this purpose.
• Usually these are applied as a drip.

Monosodium glutamate (MSG)

• Monosodium glutamate is the sodium salt of glutamic acid, which is one of the common, naturally occurring, non essential amino acids found in protein.
• MSG brings out food tastes without contributing any noticeable odour or taste.

Sodium lactate

• Sodium lactate is the sodium salt of lactic acid.
• It naturally occurs in animals and humans.
• Sodium lactate improves product stability and improves shelf life because of its bacteriostatic effect.
• It is a colourless syrupy liquid.