Manufacturing of meat sausage: Grinding and mincing

Of all the various processed meats, sausage is the most appetizing and widely utilized. The word “sausage” is derived from the Latin word salsus, which means salted.

Grinding
Before grinding, it is important to trim the meat of glands and sinew. Although the process of “cleaning” the meat of these items makes more work, it will help produce a better sausage.

The screw is the main working part of the grinder. It steadily pushes meat down the shaft and toward the blades. The blade and plate are what do the actual grinding. The key to doing a good job grinding is to use sharp blades and plates that match. The blade is a small, cross-shaped piece with a sharp edge on each arm that rotates against the plate (also called the die).

The sausage may be ground twice, especially if two meats, such as a fat meat and a lean meat, are being used. The fist-size chunks of lean meats are first ground by running them through a 3-6 mm grinder plate while fat trimmings or fatty tissues are reduced through a 6-9 mm grinder plate. Grinding improves the uniformity of the product by distributing the ingredients and making the particles the same size.

Ideally, meat should always be chilled between 0-2ºC for a clean cut. Since refrigerator temperatures are roughly 3-4º C, meat should be placed in a freezer for about 30 min just before grinding.

Mincing
After grinding, the meat is minced in to a very fine particle size for easy protein extraction. Proteins have the function of binding the water surrounding fat droplets and keeping them dispersed.

Mincing mechanically disrupts these protein structures and enhances the sensory tenderness of the finished product. The disruption of cellular membranes allows a rapid distribution throughout the meat particles of subsequently added salt (usually around 1% of the meat weight in a mince or a hamburger patty) or other spices, flavors, or additives for fresh sausage manufacturing.

The time of mincing, the lean meat should be chopped for a sufficient period, normally not less than 6-8 minutes. Chopping is then continued until the batch is thoroughly chopped.
Manufacturing of meat sausage: Grinding and mincing

Curing: Preservation process of food

Postharvest technology is concerned with handling, preservation, and storage of harvested foods, and maintaining its original integrity, freshness, and quality. The methods of preservation depend on the origin of foods—particularly whether they are of plant or animal origin.

The basic concept in curing of foods like meat, fishes and vegetables is to reduce the moisture contents by osmosis process. When moisture contents in any food are much low, there are much lesser chances of getting microbial infection and subsequently growth.

Curing is also done for flavoring. It is done by adding salt, nitrates, sugar, nitrites in combinations which are capable of dehydrating the food. Higher salt used for curing also dehydrates bacteria resulting in their killing.

For crops, curing is a postharvest healing process of the outer tissues of root crops by the development of a wound periderm by application of heat.

The purposes of curing are
*to heal wounds of tubers and bulbs sustained during harvesting,
*to strengthen the skin,
*to dry superficial leaves, such as onion bulbs to prevent microbial infection during storage and distribution,
*to develop desired skin color (onion),
*to reduce water loss during storage in potatoes, sweet potatoes, cassavas, yams, onions, and garlic.

In term of meat process, curing is the treatment of meat with preservative chemicals that restrict or prevent the growth of spoilage bacteria and food poisoning bacteria. It is used together with processes that use heat, smoke or low temperatures to give the required shelf life of cured meats. Meat can be defined as the edible flesh of a number of species of mammal or bird, both wild and domesticated.

The cure ingredients can be rubbed on to the food surface, mixed into foods dry (dry curing), or dissolved in water (brine, wet, or pickle curing). In the latter processes, the food is submerged in the brine until completely covered. With large cuts of meat, brine may also be injected into the muscle.
Curing: Preservation process of food

Manufacturing of meat sausage: Ingredients and processing

Sausage is a food product resulting from the assemblage of proper ingredient in the right proportion coupled with a structured design and controlled process. The quality of the product is always a reflection of the status of the raw materials and the process. Its taste, texture, tenderness and color are related to the ratio of fat to lean.

Fresh sausage is typically prepared from one or more kinds of meats. It may contain water (not exceeding 3 percent of the total ingredients in the product) and binders and extenders (for example, wheat flour and non-fat dry milk).

Good sausage begins with good meat. Beef, veal, pork, lamb, mutton, and poultry are all suitable for use in sausage. A majority of sausage products are prepared with pork and beef. Meat should be fresh, high quality, have the proper lean-to-fat ratio and have good binding qualities. The meat should be clean and not contaminated with bacteria or other microorganisms.

Other ingredients such as salt (addition to taste, extract some proteins from meat, enhances flavor, reduce microbiological spoilage and increases water holding), water ice (assist the process of mixing and help salt to solubilize meat proteins), curing agents (inhibit microbial growth, provide pink color and enhance flavor), spices (add flavor to the product) and binder (promote fat and moisture retention) and extender (reduce formulation costs).

The basic steps in sausage making are:
• Weighing/measuring the ingredients
• Grinding
• Stuffing/linking
• Smoking/cooking

Sausage making has become a unique blend of old procedures and new scientific, highly-mech-anized processes. Traditionally, sausage was formed into a symmetrical shape, but it now can be found in a variety of shapes and sizes to meet consumers’ needs.
Manufacturing of meat sausage: Ingredients and processing  

Process of tenderizing meat by enzymes

Tenderizing meats may be desirable prior to cooking. The less tender cuts of meat may be artificially tenderized to break down the proteins of muscle or connective tissue.

The amount and distribution of connective tissues and the size of both muscle fibers and bundles of fibers determine the tenderness of meat.

Meat can be tenderized by the use of natural and artificial tenderizers. The tenderizing action results from the hydrolysis of the amide linkages of the protein in the meat. Most powdered tenderizers use the plant enzyme papain as the tenderizing agent. The art of using enzymes for tenderizing meat is an old one. Wrapping of meat in papaya leaf before cooking results in tenderization.

Commercial papain sprinkled on the surface of meat penetrates to a depth of 1 mm per hour. In general tenderizers work on the surface of the meat.

Some enzymes treat the muscle tissue and others treat the connective tissue. For example, the enzymes chymopapain, or papain and ficin exert a greater effect on tenderising muscle fibers than connective tissue, while bromelain degrades connective tissue more than the myofibrils.

Meat tenderizers enzymes extracted from a number of plants, including papaya, pineapple fig, kiwi and ginger.

The enzymes act slowly at refrigerator or room temperature, and some five times faster between 60 and 70°C, so nearly all the tenderizing action takes place during cooking. Exceeding 85 °C denatures the enzyme, thus inhibiting its activity.

Some of the best tenderizers for meats have an alcohol base as beer and hard coder. The fermentation chemical process gives these products the tenderizing quality.
Process of tenderizing meat by enzymes

Meat curing process

Curing refers to modifications of the meat that affect preservation, flavor color, and tenderness due to added curing ingredients.

The curing process is achieved by adding a number of curing agents to the meat, each ingredient having unique characteristics and playing an important role in the process.

Cured meats are attractive in their color, flavor, texture, and are popular because they combine variety with convenience of relatively long shelf –life and storage stability.

The major ingredients include salt, sugar, nitride and /or nitrate sodium ascorbate and often phosphate.

The characteristics cured meat color that develops is attributed to the formation of heat-stable nitrogen monoxide complexes with muscles myoglobine.

Technologies used for curing were greatly refined during the 1950s and 1960s; automation of processes and use of reducing agents, such as ascorbates and erythorbate, was introduced to speed up the curing process. 

Curing is designed to grossly alter the nature of the meat and produce distinct products such as smoked and salted bacon, ham, corned beef and highly flavored sausages including bologna and frankfurters.
Meat curing process