Smoked precooked sausages comprise a heterogeneous class of sausages. They are smoked and/or air heated, often cured, but not fermented. Due to their formulation and the necessity, in general, of additional cooking before serving, smoked air-cooked sausages are usually classified together with fresh sausages but differ from the latter by considerably longer shelf life.
Smoking is normally performed immediately after stuffing. The sausages are generally precooked in a smokehouse in two phases: (a) steaming for 3–5 or more minutes to an internal temperature slightly above 50°C and (b) dry heating to an internal temperature of 64–65°C. Following this procedure quick chilling is advisable. The chilling operation contributes to the texture, appearance and overall consumer acceptability of the final product.
The shelf life of sausages depends to a large extent on the methods of processing that are employed. A long and slow process and any delay in operations lead to the development of extensive microflora. On the contrary, if the bacterial count of raw materials is low and kept to a moderate number during processing subsequent smoking and precooking may inhibit or kill most of the bacteria. When such a product is held at lower temperatures and lower relative humidity, a progressively smaller proportion of the bacterial contaminants is able to grow and their growth occurs at a lower rate. This is the reason why fresh sausages, produced in strict accordance with hygienic and technological requirements and then slightly smoked and only partly cooked, may be stored for a prolonged period even in tropical conditions.
The contents of salt and fat and the addition of rusk and soy protein reduce to a certain extent water activity of the product, contributing to its shelf life. The microbial numbers decrease as the level of fat increases and increase with reduced meat particle size.
The precooked sausages are usually recooked by consumers from the chilled or thawed state by grilling for 3–5 minutes. If in a frozen state, they should be cooked for 8–10 minutes.
In the class of smoked precooked sausages a particularly special position belongs to the group of Chinese sausages.
These sausages should not be too fat. An excessive amount of fat results in considerable shrinkage during smoking. Typical smoked pork sausages are somewhat underspiced in order not to interfere with the smoke flavour. Smoked pork sausages are mostly a cured product.
FORMULATION
Basic ingredients for 100 kg
75 kg lean pork
25 kg fat trimmings (pork) or pork jowls
Characteristic seasoning formula per 1 kg
20.0 g nitrite salt for curing
1.5 g pepper
1.0 g mace
1.5 g sage
1.0 g sugar
0.2 g monosodium glutamate
Casings
Pig rounds: medium (35–38 mm), regular medium (32–35 mm) and rarely narrow medium (28–32 mm)
Processing and handling
Lean meat and fat trimmings are coarsely ground. After grinding, the batch is mixed for approximately 2 minutes in a mixer to distribute the added fat and seasoning and then stuffed into casings.
Smoking can be performed either immediately after stuffing or the links can be kept overnight in a chiller at 0–4°C. A variety of smoking procedures exists: hot smoking at 65°C for 25 minutes, cold smoking for about 10–12 hours with dense smoke at temperatures not exceeding 20°C etc.
Smoked pork sausages are kept at temperatures close to freezing point but it is not recommended to freeze them. Refrigeration shelf life of smoked pork sausages is not more than 3–4 days.
Precooked pork sausages are known in many varieties.
FORMULATION
Basic ingredients for 100 kg
100 kg pork trimmings
or
80 kg pork trimmings
10 kg beef trimmings
10 kg pork cheeks
Characteristic seasoning formula per 1 kg
18.0 g nitrite salt for curing
2.5 g white pepper
2.5 g fenugreek
2.5 g red pepper
1.2 g coriander
0.3 g chilli
Casings
21–22 mm animal or artificial edible casings
Processing and handling
The chilled trimmings are ground through a plate, having holes of 5–8 mm in diameter. The salt and spices are sprinkled into the ground meat while mixing. The sausages are stuffed into 22 mm sheep or collagen casings or into 21–22 mm cellulose casings. Linking is performed at 10 cm intervals. The smoking schedule is as follows: 2 hours at 38°C with dampers closed, then 1 hour at 50°C with dampers partially open and finally at 78°C or until a 65°C internal temperature is reached.
If skinless precooked sausages are wanted, steam cooking at 75°C for 3–4 minutes should be applied and after cold showering for 3 minutes, the sausages are peeled.
The formulation of these sausages differs from fresh grill beef sausages by having a considerably higher fat content and a fairly small diameter.
FORMULATION
Basic ingredients for 100 kg
40 kg lean beef
20 kg mutton
20 kg beef trimmings
20 kg zebu boss or beef brisket fat or mutton tail fat
Characteristic seasoning formula per 1 kg
22.0 g nitrite salt for curing
0.5 g chili
5.0 g red pepper
0.3 g garlic
0.2 g cinnamon
1.0 g ground pepper
0.5 g sugar
Casings
Goat or sheep casings: narrow (under 18 mm), and exceptionally narrow medium (18–20 mm)
Processing and handling
Beef meats are run through the grinder with a fine plate (2–4 mm), mutton through a 6 mm plate and fat through a coarse plate. The ground meats are thoroughly mixed with the other ingredients, adding a small quantity of water or milk, if necessary, and then filled into narrow sheep or goat casings. Air pockets within the sausages produce unsatisfactory results, causing uneven cooling, nonuniform weight and possible curving of the product.
The sausages are further processed by smoking and air heating, normally for 3–5 days or longer as may be required at suitable temperatures, preferably at 16–19°C with sufficient circulation. Higher temperatures can be applied, provided narrow casings are used. If they are sufficiently smoked and dried, the sausages have a good keeping quality.
Fresh beef sausages which have been precooked have been introduced in some countries. These sausages enjoy the advantage of a longer refrigerated life.
FORMULATION
Basic ingredients for 100 kg
80 kg beef trimmings
10 kg beef brisket or flank
10 kg beef fat
Characteristic seasoning formula per 1 kg
18.0 g nitrite salt for curing
2.5 g black pepper
3.5 g red pepper
0.3 g chilli
0.5 g garlic
0.6 g corn syrup
Casings
22 mm sheep or goat casings; 21–22 mm collagen casings
Processing and handling
Processing operations are performed as described in the instructions for precooked pork sausages.
Smoked air-cooked beef sausages are characterized by a longer shelf life. Apart from smoking and slight cooking, the shelf life of these sausages is increased by a higher level of salt and by an elevated fat content.
To delay or prevent oxidative reactions of fat and improve the product storage life, a combination of spices, including rosemary, sage and whole mustard seed is incorporated in the formulation. The ground mustard seed may be added directly into the cutter. It should be pointed out that only by carefully controlling the degree of rehydration is it possible to avoid the development of an excessive mustard flavour in the final sausage product.
FORMULATION
Basic ingredients for 100 kg
55 kg beef (if possible prerigor beef)
25 kg mutton fat
20 kg beef flank
Characteristic seasoning formula per 1 kg
22.0 g nitrite salt for curing
2.0 g red pepper
0.3 g garlic
0.3 g cardamom
5.0 g sage
1.5 g celery
0.5 g rosemary
12.0 g ground dehydrated mustard seed
4.0 g corn syrup
10.0 g soy protein concentrate (textured)
Casings
Goat and sheep narrow casings: 16 mm in diameter
Processing and handling
After grinding, the pork is sprinkled with seasoning and mixed thoroughly to distribute all components evenly. Other operations are as described in the instructions for smoked beef sausages. The only exception is the use of a higher smoking temperature or, if excessive smoking is undesirable, higher drying temperatures. The whole process may take from 4 to 5 days.
Chinese sausages, the most popular meat products in China, are basically made from pork. The Chinese name for sausages is “Lap Chong” of which the nearest translation would be “winter stuffed intestine” or “waxed intestine”, because “chong” not only means “intestine” but also “sausage”.
Chinese sausages differ according to their formulations, size and methods of processing. Chinese sausages differ essentially from other sausages. Their formulations and manufacture are unique, based on long tradition and their kitchen preparation is also rather particular. Sausages are used primarily in China as a flavouring agent and as protein fortification for a number of rice, noodle or other dishes in which they are added in quite small amounts.
An important part of Chinese sausages flavour consists of monosodium glutamate, soy sauce and sugar that are added to the sausages in exceptionally high levels. The addition of selected Chinese wines is common for certain quality products. The most popular spice is cinnamon (Cassia) since Chinese sausage producers believe that it acts as a preservative.
Sausages are eaten all the year round in China but consumption is greater during festive seasons, especially during the Chinese New Year.
According to the formulation, Chinese sausages may be divided into meat sausages (Yuen Chong) and liver sausages (Goin Chong). A special class of sausages are chicken liver sausages containing chicken livers or chicken livers combined with selected young pork livers. Processing methods and seasoning formulae are similar in both main groups of Chinese sausages.
FORMULATIONS
Basic ingredients for 100 kg
meat sausages
60–74 kg lean pork or lean pork trimmings
25–40 kg pork backfat
Liver sausages
25–50 kg lean pork
30–40 kg pork backfat
20–40 kg pork livers
Additional ingredients per 100 kg
10–18 kg water
1.5 kg Chinese wine (“Mei Kwei Lo” etc.)
Characteristic seasoning formula per 1 kg
20.0 g nitrite salt for curing
10–50 g sugar
1–3 g monosodium glutamate
15–20 g soy sauce
0.6–1.2 g cinnamon
(ginger and other spices may be blended in limited quantities)
Casings
Pig rounds narrow medium (28–32 mm) and narrow (diameter less than 28 mm)
Processing and handing
Operations involved in the production of Chinese sausages usually include running of deboned meat and fat through a grinder or reducing the meat by knife in small pieces or dices, adding seasoning, and mixing, stuffing into casings, linking, heating or hot smoking, chilling, “sweating” and packaging. Throughout this chain of operations, the meat mixture is gradually transformed into the final product or sausages
Grinding and mixing. The normal Chinese way, still commonly applied, is a time-consuming operation of cutting lean pork and fat by hand into small cubes. Using semi-industrial methods, pork is broken down through a 16–18 mm grinder plate and the fat diced by means of a semi-automatic fat cube cutter in approximately 0.7 cm particles. The fat cubes are then scalded with hot water, drained and coated with an “antioxidant-vegetable fat” mixture; the fat should be allowed to stand for 3 hours for the antioxidant to penetrate into the cubes. Such a procedure enhances the shelf life of the product against fat rancidity and off-flavour. With the industrial method, meat and fat can be placed in a cutter along with the other ingredients and the work is completed in 2 or 3 minutes.
If nitrite salt for curing is added, the mix should be allowed to stand for 3 hours at 5–8°C in a pan in the chillroom. At the end of the reaction period, the diced fat is added and mixed with the seasoning and water. An important amount of water is deliberately added to the meat mixture to facilitate mixing and stuffing operations. The mixing operation is performed either by hand or in a mixer.
Stuffing. Typical Chinese-style sausages are usually stuffed into dried pig or sheep narrow casings, 18–24 mm in diameter. Stuffing is usually done manually and by means of very simple fillers, resembling ordinary funnels. Filling should not be too compact or too loose as this would ultimately affect the size of the finished product. The sausages are linked with pieces of straw (traditional Chinese method) or both ends are tied into 10 or 15 cm links with light twine. The filled sausages are further washed in water to remove small pieces of adhering meat and left to dry in a smoke chamber.
Immediately after stuffing the sausages are densely perforated on all sides for the escape of entrapped air and also water vapour during the next stage of smoking.
Fig. 31CHINESE SAUSAGES LINKED WITH PIECES OF STRAW PRIOR TO SMOKING
Drying and smoking. This is the most important operation in Chinese sauage manufacture. The most suitable type of drying room or smokehouse for Chinese-style sausages is usually an especially designed brick-built unit with very simple installations. In its more sophisticated form the unit can be equipped with two or three doors, one or more dampers and be very different in size and shape. Small manufacturers successfully use a small gas oven for drying their sausages.
In drying Chinese sausages, the main aim is a constant and uniform supply of heat (and smoke, if desired) to produce a uniformly dry product. Maintenance of good air circulation is essential and the sausages must be hung in a well-spaced manner on racks in the smokehouse. At the beginning of drying and smoking, the relative air humidity is quite high, but it is gradually lowered and the degree of sausage dehydration is accelerated. Drying is done at 48–50°C for 72 hours.
Some manufacturers prefer a combination of smoking and drying, and this is done in two phases: at 50°C for 48 hours with or without added smoke (dehydration through added water) and at 60–65°C for an additional 15–24 hours, usually without added smoke (dehydration of the original meat water). As hardening of casings and surface microbial growth must be avoided, the successful execution of the drying and smoking process requires special skill and long experience.
Generally, weight losses may be estimated at about 40 percent for meat sausages and 45 to 48 percent for liver sausages. Irrespective of the initial moisture content in the formulation. Chinese sausages are normally dried to reach a low moisture percentage.
Fig. 32 CHINESE SAUSAGES, KUALA LUMPUR MARKET.
The differences in grades, reflecting qualities are marked by the colour of the sausage hanging strings.
Chilling and “sweating” process. The sausages are removed from the smokehouse and placed in a well-ventilated room for chilling. They are then either stored in bins or in cardboard cartons to undergo the “sweating” process, i.e. for one or two days, the moisture in the sausages becomes evenly distributed causing softening of the outer parts from the sausage interior. The product is then ready for packaging.
EATING AND KEEPING QUALITY CHARACTERISTICS OF CHINESE SAUSAGES
Chinese sausages are dry, smoked, strongly flavoured products. Their flavour is a combination of heavy seasoning, in which soy sauce has a dominant role, smoke components and products of thermal degradation of the meat itself. There is no doubt that the simultaneous effects of both smoke and heat have a marked impact on all organoleptic and structural properties of the meat. High temperature treatment also initiates oxidative changes of fat and other constituents which are continued throughout storage.
The surface colour is dark reddish-brown in Chinese meat sausages and dark brown or brown-black in liver sausages. Fat colour is yellowish-grey, rarely yellowish-white. The sausage surface is normally shrivelled due to quick drying. The casings adhere well to the sausage content.
Moisture content is lowest at 7–8 percent and highest at over 20 percent. At the same time, the minimum fat content is about 40 percent and the maximum about 70 percent. Sugar content ranges from 9–20 percent, while the amounts of protein and salt vary from about 9 to 24 percent and 3 to 5 percent, respectively.
The excellent keeping quality of Chinese-style products is influenced both by appropriate formulation and by processing methods. High fat, salt, sugar and protein contents and an amount of water reduced by drying to a very low level cause an important decrease in water activity value. A sausage product containing 40 percent of fat, 3 percent of salt and less than 20 percent of water has a final water activity value under 0.85 and the multiplication of bacteria and yeasts is basically blocked. Preserving compounds, resulting from smoking and heat degradation of the meat itself, together with the soy sauce components and the effect of cinnamon which is known for its antimicrobial activity, are further factors contributing to the keeping life of Chinese sausages.
Most producers of Chinese sausages have their own quality grades. The differences in grades, reflecting quality and proportion of ingredients used, are mostly distinguished by the colour of the sausage hanging string.
