Methods of Processing Meat: Processed Meat and Meat Preservatives
Processed meat product are those in which the properties of fresh meat have been modified by the use of one or more procedures, such as grinding, adding of seasoning, alteration of colour or heat treatment.
It includes curing by smoking and any treatment or process resulting in a substantial change in the natural state of the meat but does not include boning, cutting, cleaning or trimming.
There is a concept of inevitable association between processing and preservation of meat. This is because some processing method result in products which have long shelf life, for example salted and smoke meat is processed for flavour and it is also preserved by the presence of sale, smoke and heat treatment. On the contrary raw, seasoned beef sausage is processed but it is not preserved.
Reasons for Processed Meat:
- Meat is processed to provide a product with desired texture, flavor and aroma.
- It is a means of providing meat variety other than fresh meat.
- Processing transforms raw meat to products with longer shelf life. An example is salted and smoked beef.
- It allows incorporation of non-meat component into processed meat product thereby increasing the volume and improving other desirable qualities as colour and flavour.
- It allows the utilization of fat, other meat offals and water for the production of higher quality products.
- Raw meat is processed into cooked and ready-to-eat product such as “kilishi” or strips of seasoned and dried beef
Principles Involved in Meat Processing:
There are interaction of protein, salt, water, smoke, heat and other chemicals in processing. Salt solution of 2 to 10% insures extraction of protein, inhibits bacterial growth and has a desirable flavor at lower concentration. About 0.5% polyphosphate in the final product ensures retention of water.
Meat protein extracted from gel on heating. This gel encapsulates fat and other non-meat additives or fillers to form a uniform product. Fat in processed product modifies a dry, leathery texture, which can develop in all lean meat products. Cell damage through grinding or blending is necessary to release fat in processed product. Hot smoke provides heat for dehydrating meat in addition to imparting acids such as “aldehydes and phenols as preservative. It also imparts smoke flavor and colour on the products.
Nitrite, if used, is involved in pink colour development. Ascorbates are used to stabilize the colour and to speed up nitrite reaction.
Processed meat are either cooked or uncooked and they could be ground or unground, whole-meat products. Heace we could have products of the following combinations: uncooked grounded products, cooked ground products, uncooked whole meat product, and cooked whole meat products.
- Uncooked Ground Products: These are fresh sausages. Sausages is a food that is prepared from comminuted and seasoned meat and is usually form into a shape. Fresh British sausage contains ground meat, salt, sulphite as preservative, cereal as binder and some fat. The sausage is stuffed into a casing. These are cooked by frying or in water before eating.
- Cooked Ground Product: These are cooked sausage in which meat is ground in presence of salt, fat and other ingredients. The product is stuffed in casing and cooked in water or moist air. Usually the product is smoked to develop a desired flavor and colour. In this case porous casing casing is used. Example of the group are luncheon meat, meat loaf, frankfurters or wieners. These are eaten cold or worm.
- Uncooked Whole Product: This is salted meat product in which nitrite is also in solution at 500 ppm. The meat is immersed in salt solution and the product takes several days to cure. It is treated with mild smoke and sold in slab or in slices. It is fried before eating.
- Cooked Whole Product: This product is usually cure, smoked and cooked. Ham and canned meat are examples of cooked whole product. Fully smoked game meats produced in the tropics fall into this category. Most dry meats sold are not cured prior to smoking. These products develop off-flavour in their interior where some microbial damage had occurred. Treatment with salt protects the product during the period of smoke-drying. Seasoned dried meat consist of beef cut into small, thin (0.5cm) slices, rubbed with mixture of spices and then sun dried. The product is consumed in its raw form or a state slightly cooked. This product is called “kilishi” in Nigeria and “charqui” in South America. The seasoning used for 2kg “kilishi” are salt 52gm, red pepper 8gm, black pepper 1gm, ginger 5gm, clove 1.5g and ground raw groundnut 1.5gm. “Kilishi needs no refrigeration storage. Occasionally it is grounded into powder and it is called “dambu” or and ground dried meat. This can be eaten with soaked gari.
Seasonings Used in Processing Meat:
Seasoning is a term applied to any ingredient, which by itself or in combination adds flavor to processed meat product. Seasoning allows for creation of a new product and provides variety in existing product. Some seasoning such as clove, ginger, black pepper possess antioxidant properties while others like red pepper and ginger have bacteriostatic properties.
The common spices found in Africa are red pepper, ginger, garlic, clove, onion, black pepper and mugeno. They are usually ground for uniform dispersion in meat products. Salt and black pepper form the basis for sausage seasoning formula, all other ingredients are supplementary.
Extenders, Binders, and Fillers:
These are non-meat products incorporated into sausage or ground meat. They are included in sausage formulation for one or more of the following reasons:
- To improve emulsion stability
- To improve cooking yield
- To enhance flavor
- To improve slicing characteristics
- To reduce formulation cost
- To reduce shrinkage during cooking
Binding function to retain water, cause fat emulsification, and cause meat chunks to adhere to one another. Binding have high protein content as in soyabean products,. Soyabean flour is a good binder.
Filler are starchy products, such as cereals, which are capable of binding several times their own weight in water. Binder is different from filler in that it can emulsify fat in addition to binding water.
Extender is non-specific term that refers to any non-meat product, with the exception of water composition. In sausage industry, the word binder and extender are interchangeably used.
The amount of filler or binder allowed individually or collectively is up to 3.5% non-meat ingredients is referred to as imitation product.
Sausage products are moulded in casings, either natural or manufactured. Except for plastic film, most casings are permeable to smoke and moisture. The process of placing into casing is referred to as stuffing.
Two types of casing in general use are natural and manufactured or artificial casing. Natural casings are prepared from intestines of cattle, sheep, goat and swine. Natural casing are salted after they are cleaned in approximately 40% salt.
Manufactured casings could be in form of cellulose, inedible collagen, edible collagen and plastic. Plastic casing is used with products that are not smoked as they are impermeable to smoke and moisture.
Smoking and Heat Processing in The Tropics:
Dried meats are important parts of diet in the tropics. Smoking and drying are often combined. The two processes occur simultaneously or in immediate succession. In some counties, fresh meat is for immediate consumption while processes meat products have been subjected to procedures such as heavy smoking, drying and in some cases with some salt to confer consideration shelf stability.
Sausage production is not native to tropical and it is not popular. Its production requires some refrigeration, which is naturally not present in the tropics. It is produced by foreign culture and consumed by them and come other countries are exposed to that culture.
However, ingredients used in sausage production could be employed in extending shelf-life of smoke meat. This is because some smoked meat on the market have slight rotten smell in the interior near the bones. Smoke would not penetrate deep enough and salt is not always used.
Smoked meat originated from hunting wild animals and game. Drying by smoking was the method employed and it is still in use. With the reduction in off take hunting or wild animals killed during hunting, there is a decline in smoked meat as they are popularly called.