Etiket Arşivleri: Meat

Slaughtering Process

FE 446

Technology of Meat and Meat Products

“Slaughtering Process”

Supervisor by: Doç. Dr. Hüseyin BOZKURT

Submitted by: Mutlu DEMİREL

Smoked Meat

PURPOSE:

        Smoking of meat is a technique in which meat is exposed directly to wood smoke which may be generated by a variety of methods. In smoke produced from wood there are various substances which contribute to the flavour and the appearance of the smoked meat product and which have a certain preserving effect on the product.

TYPES OF SMOKE:

A)   Natural smoke:

         Smoke has been applied for around 80,000 years in the production of meat products and is produced by incomplete combustion(pyrolysis) of wood material such as sawdust or woodchips. Friction or steam condensation are two other methods of generating smoke. In the friction method, a piece of wood of a certain size is pressed against a fast runningrotor with a ripped surface and high frictional forces are the result.Friction smoke is obtained, which exhibits a high level of phenols, carbonyls and other acids whilts showing a low level of tar and polycylic aromatic hydrocarbons (PAHs).

          Pyrolysis takes place through the heat obtained during friction between the piece of wood and the rapidly rotating rotor with the ripped surface.Steam smoke is obtained by the use of overheated low-pressure steam and the temperature within this process is between 300 and 450 0C. A spirally shaped element transports  sawdust into an area where such overheated steam is applied on to sawdust or wood-chips, causing pyrolysis. The generated smoke is cooled to around 85 0C until it reaches the smoking chamber  which causes an increase in moisture(RH) within the smoke and this gives the basis for the name ‘steam smoke’. Steam smoke is basically free of tar as well as PAHs.

        Wood consists of around 50% cellulose, 25% hemicellulose and 25% lignin.From those materials, around 50-70% turn via pyrolysis into smoke and pyrolysis results in burnable coal rather than ash by burning wood slowly at a certain temperature. The term hemicellulose describes polysaccharides which are made from different  pentoses and hexose.Hexoses are monosaccharides containing six carbon atoms whilst pentoses contain five carbon atoms within their molecule. Pyrolysis takes place in four steps.

  1.  Drying of the wood up to around 160 0C.

  2.  Pyrolysis of the hemicellulose between 180 and 2500C.

  3.  Pyrolysis of the cellulose between 250 and 3000C.

  4.  Pyrolysis of the lignin between 300 and 5500C.

      The optimal temperature for combustion is between 350 and 5000C and temperatures below or above this range cause a considerably higher amount of unwanted substances within smoke afterwards.The most well-known and dangerous of those unwanted substances is 3,4-benzopyrene, which is carcinogenic and belongs to the group of PAHs. If smoke is generated at temperatures between 350 and 5000C, PAH contamination is greatly reduced and concentrations of less than 1 ppb per kilogram of smoked meat product are obtained.

       Smoke is a higly complex mixture of gas-like substances, solid particles (particulate phase) and water, and around 600 components within smoke are known today.The particulete phase accounts for around 80% whilst the gaseous phase for around 20%; the gas fraction is not visible to the human eye and is yet very complex.The composition of smoke depends primarily on the type and moisture content of wood utilized as well as on the method used to generate smoke.The main components of smoke, having the largest impact on meat products, are phenols, organic acids and carbonyls.Most of those substances are in the gaseouse phase and not in the particulete phase.

        Phenols are not, as one might think, alcohols but acids (carbolic acid) and are obtained through the pyrolysis of lignin by a temperature between 300 and 4500C.Phenols can release a proton from a hydroxyl group and that makes them a weak acid.The visible particle fraction consists of small liquid colloidal smoke particles.Those particles are very small in size, around 1µm, and are distributed within the gas fraction.Much larger particles such as ash and tar are also part of the visible particle fraction. Two phenolic substances coming from lignin, namely syringol or guaiacol(2-methoxyphenol), are of importance towards the smoke colour and flavour in meat products.Guaiacol results from the lignin present in soft wood and is not favoured as it gives a dark dull smoke colour as well as a rough and unpleseant smoke taste.The desired golden-brown smoke colour, as well as pleseant smoke flavour, originates from syringol, which is obtained from lignin present in hardwood such as oak and hickory.

       Wood chips or sawdust should be stored in a dry area and no animals should have access to this area.It happens quite often that woodchips are contaminated with animal faeces and/or urine. Sawdust or woodchips have to be moistaned first with water; otherwise the wood material becomes too hot very quickly (above 4500C)  and little smoke is obtained. The amount of water added to the wood material is around 20-30% of the weight of the wood material. Also, the smoking chambers must not be overloaded during the application of smoke in order to avoid hot spots. Air still has to move freely within the smoking chamber in order to achieve an even drying, smoking and cooking impact.

Table 1 shows the three different methos of smoking.

The main functions of smoke are described in the following sections.

METHOD

  TEMPERATURE ( 0C )

                RH%

Cold smoke

            15 – 25

              50 – 85

Warm smoke

            25 – 50

              50 – 80

Hot smoke

            50 – 90

              30 – 85

Humidity during smoking :

v  The humidity during smoking in the smokehouse is important as it effects
the smoke deposition on the product.

v  High humidity favors smoke deposition but also tend to limit color development.

v  With high humidity there is higher amount of smoke penetration.

v  When it is too low the smoke is deposited on the surface only and desirable color is not achieved. Its
likely to acquire a dull brown tan.

v  High humidity do not necessarily reduce shrinkage of the products rather it may encourage fat rendering.

v  In case of animal or collagen casings somewhat higher humidity give good results.

v  With collagen casings smoking with low humidity hardens the surface and produce a low quality product.

v  where as too high humidity soften the surface therefore a balanced humidity application has to made.

v  In a gravity house humidity is controlled by opening the dampers.

v  In air- conditioned house the humidity is controlled by adding steam or water vapor and using the dampers.

Development of the smoke color:

          Smoking of meat  and meat products results in a nice and appealing golden- brown color, which is very attractive to the human eye. Carbonyls are the main color – forming agents and carbonyls is absorbed into the slightly  moist surface of the product.Ssubsequently, carbonyls react with amine to from the desired smoke colour.To a small degree, phenols also contribute to smoke colour.It is important to have the correct level of moisture on the surface of the meat and meat products in order to obtain a nice smoking colour. Evenly dried products result in a very appealing smoke colour and a dry surface absorbs significantly less smoke (as well as ash and tar) than a wet surface.If the surface is too wet(underdried), a brownish colour and even streaking (tiger stripes) can be the result of smoke absorbed unevenly on products such as frankfurters.Streaking occurs when there is some free moisture on the surface of the product.When the surface is overdried, a lighter than wanted colour is obtained. Hence, moderate levels of moisture must be present within the smoking chamber during the smoking process as such to obtain an evensmoke colour. Uneven smoke colour is also commonly the result of not having achieved the same conditions regarding surface moisture and temperature of the product to be smoked inside the smoking chamber prior to smoking. In this case it might be necessary to ‘condition’ products such as frankfurters by showering all for a short while in order to obtain the same level of moisture and surface temperature.

         Filling of large smoking chambers with trollies of frankfurters can take a while and the product going into the smoking chamber first can exhibit a dry surface, compared with a wet surface from the last products until the chamber is finally full.Basically, the surface of the product to be smoked should be slightly tacky before smoke is applied. For sausages such as hot dogs which are filled into naturel casings, the casing should feel like human skin after drying prior to the application of smoke.

         If a dark, or black, smoke colour is wanted on the meat product, a high level of humidity is required within the smoking chamber and the drying phase must be short or not part of the smoking process at all. Prolonged periods of smoking commencing on a wet product surface without prior drying produce such a dark and almost black colour because a wet surface demonstrates high smoke absorbtion. S ome of those dark-coloured meat products are called pit smoked. High levels of moisture, around 80-85%, are also maintained during the smoking process to obtain such a dark colour.To fixate the dark colour, some of those wet-smoked products are finished off with hot air (baked) and such treatment enhances the darkness of the product in comparison with being finally steam cooked.Generally, the smoking chamber must not be overloaded with products,in order to secure an even airflow and thus an even distribution of smoke and humidity within the chamber.In order to even out  the smoke colour, short drying steps of 3-5 min are commonly introduced between smoking cycles for products such as hot dogs or frankfurters.

Development of the smoke flavour:

 It is a well-known fact that smoked meat products taste differently from nonsmoked products.Substances such as formaldehydes, lactones and up to 20 different phenols(guaiacol and syringol) are primarily responsible for the smoke flavour.Hardwood such as maple, oak, beech, hickory and mahogany is preferred because these types of wood give a clean and non-tar flavour.

Smoke as preservative:   

 Smoked meats and meat products last longer, a well-known fact for thousand of years.Formaldehyde, phenols and acetic acid are the main agents for extending shelf life of smoked products as these are very effective antimicrobial substances.Phenols are acids which denature proteins and disrupt cell membranes.Disrupted cell membranes eventually kill the cell or make it very hard for the cell to survive or even to grow.

Smoke adding to bite:

 Smoked sausages such as farnkfurters obtain a much better bite, or snap, through smoking. Components of smoke, mainly formaldehyde and other organic acids, combine with the activated protein on the surface of the noncooked sausage and subsequent thermal treatment creates a firm layer around the sausage, which is largely responsible for the snap.Smoke contains around 0.6-1.0% formaldehyde.

Mistakes during smoking:

The most common mistakes during smoking are as follows:

1.    Overloading of the smoking chamber leads to uneven airflow and also can cause uneven smoke color.

2.    A negative impact on the flavour can be seen by using mouldy sawdust or chips. Hence, sawdust or chips must be free of wood impregnation substances and urine from animals.

3.    If smoked is too long, the product can aquire a slightly bitter taste and a wrinkly product is often the result as well.

4.    Overdrying of the product leads to toughening of the casing and natural casing lose their ability to strecth and shrink. As a result, wrinkles are obtained and the product also loses its shine. 

LIQUID SMOKE:

        Liqid smoke is produced by burning selected woods under controlled conditions. The smoke obtained is condensed on water and recycled until the desired concentration is given. Liquid smoke can be applied on to meat product via atomization a dipping or shower system, brine addition to meat products and in the form of smoke- impregnated casings. Atomization is the spraying of the liquid smoke under a predetermined pressure through a nozzle into smoking chamber and creating a cloud of smoke made by from very tiny particles.

        Before liquid smoke is introduced into the smoking chamber, the meat product first has to be dried properly. After atomization, the cloud of smoke is allowed to dwell for around 10 -15 min. Within the chamber before a drying steps of 5-10 min is introduced. The spraying process can be repeated several times until the desired smoke colour is obtained and two or three applications of spraying results in a nice golden-brown colour.

        Within a shower or dipping system, products such as frankfurters are showered with or dipped into a liquid smoke solution for a short time. The dipped or showered products are dried afterwards to fixate the smoke on to the surface before being thermally heat treated afterwards, primarily by the application of steam. Processes such as dipping or showering, colour  fixation and thermal heat treatment of products such as frunkfurters run continuously in large-scale operations.

Liquid smoke shows a several advantages compared with natural smoke:

1)  Liquid smoke is standardized , an even smoke colour on the finished products can be obtained all the time.

2)  There is no emission of smoke into the air and therefore smoking with liquid smoke is environmentally friendly.

3)  Smoke chamber are easy to clean as liquid smoke does not contain tar and other tacky substances.

4)  Most of time, the smoking chamber can be cleaned with water only and no chemical cleaning detergent is required.

5)  Liquid smoke is almost free of PAHs.

Laboratory‎ > ‎Analysis of Meat

Purpose :

Our purpose is analysing the meat and meat products and their quality parameters which are determination of total fat content as percent value, the moisture content, pH values, and off-odour of the products from şahin( sucuk), pınar(sausage), maret(sausage), pınar(salami), and banet(sucuk). 

Theory :

THE COMPOSITION OF MEAT:

Water

Water content can be decreased (e.g. dried or dehydrated meat), and it varies in many processed meats such as sausages, salamis, bacon and ham. During these processes, care must be taken to protect the nutritional and organoleptic (taste, smell, texture and appearance) properties of the meat.

Protein: Protein is the source of the essential amino acids necessary for life. It is the building block of the muscular tissue.

Fat: Fat itself consists of triglycerides (see below), and is the main energy reserve for the animal. Other important substances (e.g. some vitamins) are dissolved in this fat.

Soluble non-protein organic substances: These substances fall into two categories: nitrogen-based substances such as free amino acids and vitamins, and carbohydrates such as lactic acid and glucose.

Inorganic substances: The major minerals consist of phosphorous and potassium together with small amounts of sodium, magnesium, calcium, zinc, and other trace metals.

•         Addition of reducing sugars (e.g. glucose solids, dextrose) to the brine also helps in browning reactions during thermal processing to produce a desirable colour and a caramel flavour in some products such as bacon.

•         1–2%, are added to the brine during various commercial operations in order to lower the water activity of meat during curing.

Enhancing the texture and sensory quality of high pressure treatment meat products

        Although many in the food industry perceive high pressure treatment as a relatively new technology, early investigations examined the ability of high pressures to increase the shelf-life of milk treated at ambient temperatures. Since then, the effect of high pressure on micro-organisms, proteins and, more recently, in food processing has been studied. Work at The National Food Centre investigated the use of high pressure (150 MegaPascals – MPa) to enhance the functionality and acceptability of frankfurters with reduced salt and phosphate concentrations, and breakfast sausages with reduced phosphate, in an effort to address consumer demands for high quality products with fewer added ingredients.

        Sodium chloride (salt) and phosphate are essential ingredients in meat processing, where they act by solubilising the myofibrillar proteins that contribute to water-holding capacity, thus reducing cook loss. These ingredients also enhance fat binding in meat products, entrapping other ingredients to form a uniform and cohesive mass. Salt also decreases water activity, which significantly extends the shelf-life of the product. However, consumption of excess sodium chloride has become a major issue in the food industry because of the relationship between sodium and hyper-tension in humans. According to the US Department of Agriculture, phosphates are safe when added within the permitted concentration of 0.5%, but such additives generate adverse reactions from the consumer.

        Our research has examined high pressure to compensate for reduction in salt and/or phosphate in frankfurters and sausages. High pressure is obtained using a hydraulic pump and is applied to the products via a pressure-transferring medium. This results in uniform pressure transmission throughout the product, independent of product shape and size. Being a non-thermal process, product flavour and nutritional qualities are maintained.

        Our results indicated that frankfurters treated with high pressure (150MPa) had lower cooking losses than non-pressure treated products. Emulsion stability and texture of pressurised products were as acceptable as control frankfurters. Cook yield was also enhanced when phosphate concentration was reduced to 0.1%, and texture was improved in reduced-salt frankfurters after 300MPa pressure. Pressure treated (150MPa) sausages had similar stability and overall acceptability as non-treated products and texture profile analysis was enhanced when the phosphate was reduced to 0.25% after the pressure treatment. Overall flavour intensity of breakfast sausages with 0.25% phosphate was not affected by the pressure treatment.

        Although high pressure treatment is a batch process, these results are positive for the processed meat industry as a novel route to the production of additive-reduced meat products. Further investigations into minimal processing in the Meat Technology Department are concentrating on the use of high intensity ultrasound as a rapid, energy efficient technique to cook pressurised meat products.

RESULT & CALCILATIONS OF THE EXPERIMENT:

Group name

Fat

content%

Off-odor

Moisture content%

pH

A1-Şahin

Sucuk

32,46

+

45.7

6.5

A2-no mark

Sucuk

 

+

30.08

5.04

A4-pınar

Sausage

11.02

66.33

5.6

A5- maret

Sausage

 

38

6.20

A6-no mark

Sucuk

 

66.1

6.4

A7- pınar

Salami

 

68

5.65

A9- banet

Sucuk

 

54.7

6.03

 Calculation

Fat content:  

Weight of empty flask= 117.88 gr

Weight of the sample  =20.14 gr

Weight of the fat=2.22 gr

Weight of the fat and sample= 120.1gr

 Moisture content:

Weight of the sample= 5.02 gr

Weight of the petri   = 50.18 gr

Weight of samle and plate after drying= 51.87 gr

Weight of the sample and plate= 50.18+5.02= 55.2 gr

Ph value:

Ph of the sausages:5.6

Off odor test:                                                    

There is no off odor smelt.

TSE VALUES FOR SAUSAGE:

Components

Limits

Moisture (mass)

Salt (mass)

Total animal fats

Potassium or sodium nitrate

Potassium or sodium nitrite

Starch

Color and flavor 

Bad flavot test

pH

Coloring matter

Max. 65%

Max. 3%

Min. 15%

Max. 500 mg/kg

Max. 200 mg/kg

Max. 5%

Appropriate

Negative

Max. 6.3

No

TSE VALUES FOR SOUDJUCK:

Components

Limits

Moisture(mass)

Salt(mass)

Coloring matter

pH

fat(mass)

       for first quality

       for secand quality

       for third quality

protein(mass) N*6.25

       for first quality

       for secand quality

       for third quality

 Max. 40%

Max. 5%

None

Max. 5.8 Min. 5.4

 

Max. 30%

Max. 40%

Max. 50%

 

Max. 22%

Max. 20%

Max. 20%

DISCUSSION OF THE EXPERIMENT:

        In this experiment, some quality parameters were examined which are fat content, moisture content, ph values and off-odor test. They are very important parameters to understand quality of the meat products also we can understand any adulteration taken place in processing.

    Fat content of the meat products are important. Fat content is characterized textural quality of meat products. Also fat content is very important for sensory quality flavor and mouth feel.

        And this sensory parameters change human to human so for this reason fat content acceptability range is very large. Al so standards of the type of meat products changing. , We can say that the amount of fat content in the sucuk is higher than the sausage. If we look at the TSE value for the fat content for sausage must be 15% of the mass at min. value and also fat content for soudjuck must be between 30 and 50% of the total mass depending on the quality of the soudjuck. If we look at our table the fat content for the  was recorded as a 11.02 which is no trade, comparing this result with TSE, our value is lower than the TSE. we can decide that this sausages is not a higher quality can be made on home for their mouth feel al so low fat content increase the shelf life of the soudjuck with decreasing the oxidation capability of the soudjuck. On the other hand, the fat content for soudjuck is recorded as 32.46%, if we compare this value for TSE, we can classified this soudjuck as first quality according to the TSE and then we can decide that this soudjuck is a first quality soudjuck.al so  we can decide that this sausages is not a higher quality can be made on home for their mouth feel al so low fat content increase the shelf life of the soudjuck with decreasing the oxidation capability of Therefore, we can say that the textural property of this soudjuck is good.

        The  other quality parameter is odor detection which is named as off-odor test. If we have a positive result means that odor of the sample is bad. If we look at our result, the şahin and no mark sucuk was given the positive result. This means that these products contain the ammonia gas, resulting from the reaction of the potassium hydroxide and also we can observe the some color changes from the products as a dark orange-brown color when they were given the bad odor. Ammonia gas production occur during microbial activity of microorganisms so this indicates spoilage of the food product.

           In addition to the another quality parameter of the meat product is the moisture content. The moisture content of meat product is very important due to the microbiological aspect, such as microbial spoilage, textural properties, and also important terms of yield. And moisture is added for adulteration by adding starch and enhancing trhe capability of moisture. As we discussed price of the water and meat water adulteration decreasing the production cost so usually factories which produce meat products use their moisture to reach their acceptable limits.  According to the TSE standards the moisture content for sausage must be 65% at max. value and for the sucuk must be 40% at a max. value.  If we compare these values with our results, moisture content for sucuk was recorded as 45%(şahin), 66%(no mark) and 54%(banet). This means that these products are susceptible to the spoilage easily, because the moisture content is higher than the TSE values. However, if we compare the sausage values for moisture content, our result is suitable for theTSE value.

          On the other hand, the pH of the meat products is very important due to the microbial aspect again. If pH increase too much, this causes purification in meat. If the ph of the meat increase at 6.7, causing  decomposition of meat proteins by the microorganisms. According to the TSE value, the ph for sausage must be 6.3 at max. value and also for the sucuk must be 5.4 and 5.8.If we compare our results, the ph value for sucuks are higher than the TSE value. This is dangerous for consumption. However, the ph values for the sausage is suitable for TSE value, there is no any risk for consumption.  

Meat Fermentation

MEAT FERMENTATION (CURING)

• Traditional, empirical methods of improving the shelf life of meat have relied on salting or drying (with or without chopping), or smoking.

• Some methods involve microorganisms, which in addition to increasing the shelf life affect the texture and flavour of the final meat product, called fermented meat products, are represented mainly by fermented sausages.  

• The shelf-life, safety, the specific flavour, texture and colour = acidulation, the lowering of water activity (aw) by the addition of salt (curing) and by drying.

• The role of microorganisms in fresh sausages, cooked sausages and dry-cured ham is limited

• Different varieties of sausage are defined according to their formulation, their area of production and their physical and chemical characteristics.

      Sausages grouped under four major category

•  Fermented sausages or sausages dried in air ( can be consumed without cooking, normal   sausages) Ham ( from pork )—- equivalently pastırma ……prepared from uncooked materials

• Boiled sausages …..prepared from uncooked materials but during processing either boiled in water or treated with steam …frankfurter, salami ( in Turkish sosis, salam..)

• cooked sausages

• fried sausages

                Fermented Sausages

• classified as semidry or dry sausages.

• mincing and mixing lean and fat meat with additives (e.g. nitrate, nitrite, NaCl, ascorbate) and seasonings (e.g. sugar, garlic, pepper).

• The meat mixture is always stuffed into casings, which can be natural (i.e. gut) or artificial (e.g. collagen) and which are available in a range of diameters.

• the products are fermented and air-dried.

• the desired characteristics are obtained by:  temperature, humidity and air velocity, to the intrinsic parameters, such as fat content, sodium content, degree of comminution and the nature and diameter of the casings.

Semidry sausages (in USA) : by rapid fermentation at an elevated temperature, either without drying or with a short period of drying followed by cooking (at 60–68°C) at the end of fermentation. Traditional Mediterranean products have a slow ripening process, which allows the development of moulds and yeasts on the surface. In northern and central Europe, fermentation is generally combined with smoking, preventing the
development of yeasts and moulds, and the drying period is shorter.

Microbiology of Fermentation

•  naturally contaminated with Lactobacillus, Carnobacterium, Micrococcus, Staphylococcus, Pseudomonas, Acinetobacter, Enterococcus, Arthrobacter, Corynebacterium, Brochothrix and Listeria, and also Enterobacteriaceae, yeasts and moulds.

Spoilage Bacteria

• Gram-negative aerobic microorganisms (e.g. Pseudomonas, Acinetobacter) may be involved in the spoilage of the products, due to their proteolytic activity and/or the catabolism of sulphur-containing amino acids, which cause defects in texture and flavour.

• these disappear through the fermentation period.,

Pathogenic Bacteria

• many pathogenic bacteria, including Clostridium, Staphylococcus aureus, Listeria and Enterobacteriaceae (including Salmonella) is easily controlled if good practice is applied during the processing of the sausages .

Desirable Flora

• lactic acid bacteria are generally the dominant bacterial flora .

• NATURAL ONES:  Lactobacillus curvatus, L. sakei, L. plantarum, L. viridescens, Carnobacterium divergens, C. piscicola and Leuconostoc

• Pediococcus is only found when inoculated as a starter culture.

•  Carnobacterium is present during the fermentation period, but disappears afterwards.

      In dry sausages with a pH above 5, Staphylococcus  warneri, S. saprophyticus, S. sciuri, S. cohnii, S. epidermis, S. xylosus and S. carnosus.

• During drying, yeasts (Debaryomyces hansenii, Candida, Kluyveromyces, Hansenula) and moulds (Penicillium, Aspergillus, Mucor, Cladosporium) are commonly found growing on the casings of sausages, mainly those made in southern Europe, which are ripened over a long time.

• Some  Mediterranean type sausages have moulds on the surface, usually strains of Penicillium nalgiovense, P. chrysogenum and P. camenberti, used as starters mainly to prevent growth of other mycotoxin-producing moulds and give a typical white colour on the surface.

• They may also contribute to flavour development through proteolytic, lipolytic and deaminase activity, and, more likely, through β-oxidation of free fatty acids and may delay rancidity by consuming oxygen.

Starter Cultures for Fermented Sausages

• The LAB used in starter cultures belong to the species Lactobacillus sakei, L.curvatus, (18-25C) L. plantarum, Pediococcus acidilactici and P. pentosaceus. ( 35-40 C)

• Yeasts (Debaryomyces hansenii, Candida famata) and moulds (Penicillium nalviogense, P.chrysogenum or P. camemberti) are added to the surface of the casing.

• microbial activity is also used for the ripening and improving dry-cured hams and bacons.

                 The Processing of Fermented Sausages

• The industrial production ( ‘ripening’) : fermentation followed by drying.

• differ mainly in the length of the total ripening period in relation to that of the fermentation period.

• High initial rates of LA production due to  use of LAB starter  and/or high temperatures during fermentation are associated with short drying periods.

• summer sausage’,  fermented at 38 °C and no drying.

Northern type sausages (NS) : ripened for short periods (up to 3 weeks) and are usually subjected to smoking.

Mediterranean sausages (MS): ripened for longer periods (several weeks or even months) and smoke is not so typically applied. Shelf-life is mostly due to drying and reduced water activity.

                                                      Raw Materials and Additives

• Chilled meats (frozen meat tempered to  −4 °C) and frozen (≤18 °C) porcine fats are most often mixed in a ratio of 2:1.

• ( pH should be 5.8 or lower because higher pH values favor the growth of undesired or hazardous acid-sensitive bacteria)

• salt (2–4%) containing sodium nitrite (NaNO2) (added as curing salt containing 0.4–0.6% NaNO2),

• Sodium chloride is the salt most commonly used in brine solution, and its usage level varies with the type of product being 1–2% in sausages, 2–3% in hams, 1.2–1.8% in bacon and 2–4% in jerkies.

• About 0.4–0.7% of potassium chloride on a finished-weight basis is used in low-sodium meat products, but it may impart a bitter and metallic flavour if used at >0.75%.

• As the use of salt from the sea, desert and rocks in preservation of meat spread, it was found that only certain types of salt helped in developing a desirable pink colour and a special flavour in cured meat.

• Investigations in the nineteenth century revealed that sodium nitrate, present as an impurity in these salts, was the precursor responsible for developing the characteristic colour and flavour in cured meat.

• Further, it was reported that nitrite, which was produced by microbial reduction of nitrate, was responsible for the curing effect.

• the reaction of haemoproteins with nitric oxide derived from nitrite was the chemical basis for the colour of cured meats.

• glucose (0.5–1%) table sugar (sucrose), brown sugar, dextrose, glucose solids, corn syrup solids and lactose can be added at different levels mainly to impart flavour and moderate the harshness of salt in certain products.

• Addition of reducing sugars (e.g. glucose solids, dextrose) to the brine also helps in browning reactions during thermal processing to produce a desirable colour and a caramel flavour in some products such as bacon.

• 1–2%, are added to the brine during various commercial operations in order to lower the water activity of meat during curing

Ascorbates/Erythorbates(isoascorbic acid)

• sodium ascorbate or ascorbic acid (0.5–1%) ( to prevent oxidation, improve color stability)

• The primary function of ascorbic acid may be in reducing metmyoglobin to myoglobin, thus accelerating the overall curing reaction.

• ascorbic acid also helps in the production of nitric oxide (NO) from nitrite .

• Besides their role in colour development, ascorbates and erythorbates have been shown to block the formation of carcinogenic N-nitrosamines in cooked cured meats (particularly in bacon).

• The USDA FSIS regulations permit the addition of 550 ppm /100 lbs of chopped meat , ascorbic or erythorbic acid

Seasonings (spices)

• Different types and levels of seasonings are used.

• The most common flavourings used in brine preparation are extracts from pepper, cloves (karanfil), allspice (yenibahar)and cinnamon.

• Garlic and onion flavourings may also be added.

• An aqueous smoke solution is sometimes introduced into the curing pickle to provide a smoked flavour.

• certain spices and herbs used as seasonings act as antioxidants by reducing the rate of oxidative rancidity development in cured meats.

Sodium Nitrite/ Sodium Nitrate

• sodium nitrite (or nitrate) is the most important cure additive responsible for the typical colour and flavour associated with cooked, cured meats.

• provides oxidative stability to meat by preventing lipid oxidation and helps in controlling the development of warmed-over flavour in cooked, stored meats.

• Nitrite also serves as a vital bacteriostatic agent for control of the outgrowth of Clostridium botulinum, particularly under conditions of product mishandling.

• addition of sodium nitrite to meat and meat products is highly regulated owing to the possible risk of formation of N-nitrosamines.

• In Canada,the maximum allowable limit for the use of sodium nitrite, potassium nitrite or their combinations in preserved meat and meat products: 200 ppm (20 g per 100 kg;

• In the United States, in all products except bacon: 200 ppm;

• Residual nitrite levels in the finished pumped bacon may not exceed 40 ppm.

• For Mediterranean type sausage part or all of the nitrite is substituted for by potassium nitrate (KNO3which needs to be reduced by Micrococcaceae to form the nitrosylating
NO
bacteria inhibited by pH values below 5.2. This hampers their use in Northern processing technology.

• Ground pepper (0.2–0.3%) ( Mediterranean :1–3%, and paprika and garlic …. effective antioxidants). 

Additional additives for Northern type sausages

                Phosphates (0.5%)

• Phosphates and polyphosphates are used primarily to increase the water-holding capacity of cured meat products.

• Alkaline phosphates increase the pH of the meat and also help in solubilizing muscle proteins in order to impart the water-retention action.

• In addition to increased water binding (i.e., increase in product yield), phosphates improve the cured meat flavour by retention of natural juices and by reduction of oxidative rancidity.

•  They also help improve retention of the cured meat colour.

• Phosphates: sodium pyrophosphate, monosodium phosphate, sodium hexametaphosphate, disodium phosphate, sodium tripolyphosphate and sodium pyrophosphate, as well as mono- and dipotassium phosphate, potassium tripolyphosphate and potassium pyrophosphate.

• Tripolyphosphates and their combinations with hexametaphosphates are the most widely used phosphates for cured meat cuts, as they provide the proper pH, good solubility, calcium compatibility and a high degree of the protein modifying effect.

• glucono-δ-lactone (GdL, 0.5%) to ascertain fast chemical acidulation with negative effects on flavour development;  (GdL) is only used for products with a short shelf-life ( because many strains of lactic acid bacteria ferment this compound to lactic and acetic acid acetic acid interferes with reactions leading to and stabilizing desired sensory properties.)

• manganese sulfate (˜50 ppm) as cofactor for lactic acid bacteria;

• vegetable proteins (mainly soya isolate), which may also accelerate fermentation.

             Comminution or Chopping

• Raw materials and additives, including microbial starters, are added for mixing and chopping, often under vacuum, in a mincer or ‘cutter’.

• The cutter consists of a set of knives that rotate rapidly (1–3 × 103 r.p.m.), producing a batter in a bowl that rotates slowly (10–20 r.p.m.)

• The relative speeds of the knives and bowl and the sequence of addition of raw materials and additives determine the fat particle size and are optimized to produce a batter within less than 5 minutes at temperatures ≤2 °C, ensuring minimal damage to the fat tissue.

Stuffing

• the batter is immediately stuffed under vacuum into natural, semisynthetic (collagen) or synthetic casings that are permeable to water and air, and both ends are clipped.

• The sausage diameter (e.g. 2–15 cm) is related positively to the relative importance of fermentation (pH) versus drying (aw) for stability.

                   SAUSAGE CASINGS      

Animal Casings

• the oldest of our packaging materials for sausage: the animal casing.

• As in the case of all collagen materials, the collagen is hardened and rendered less soluble by the application of salt.

• Initially, as the collagen is exposed to heat and drying, it becomes less permeable to moisture.

• the initial step in the processing of a sausage in animal casings requires drying to develop the appropriate smoke permeability.

• The sheep casings are the smallest in diameter and are also the tenderest.

• These are the most adaptable to fresh sausages, where there is no further processing to tenderize the casing, as well as to small-diameter cooked and smoked sausages.

                               Manufactured Collagen Casings

• Manufactured casing made from the same material chemically as the animal casing that is collagen.

• The manufactured collagen casing: any source of collagen could be used

• The collagen is solubilized and later extruded and hardened

Alginate Casing

Cellulose Casings

• Cellulose casings are made from regenerated cellulose derived from high-grade wood pulp.

Plastic casings

• In some cases, a moisture-impermeable material such as PVDC, Mylar, polyethylene or a polyamide (Nylon) is used as a casing.

• cost-effective but they may have drawbacks such as dimensional instability.

Ripening

• The sausages are hung in racks and placed in natural or, mostly, air-conditioned fermentation chambers at high relative humidity (RH).

• ripening in two consecutive stages:

A) Fermentation for bacterial growth

– Northern (20–26 °C/50–90%/62 h)

Mediterranean (5–24 °C/10–90%/100 h)

B) Transfer to another chamber, drying for development of sensory characteristics.

• air RH values not more than 0.10 points below the associated aw values of the sausage, to prevent case hardening, and recommended air speeds are approximately 0.1 m s-1.

Smoking

• After fermentation ,

• Northern type: subjected to smoke( controlled combustion of oak wood (300–600 °C) to minimize the production of polycyclic hydrocarbons.

• Smoke: antimicrobial,antioxidant effects, generates specific flavour and colour components

Sausage Metabolism and Safety (by the introduction of  ‘hurdles’ for undesirable mo.)

• The lowering of the redox potential ( omission of oxygen by chopping under vacuum,  addition of ascorbic acid or ascorbate). This inhibits aerobic bacteria and improves the bactericidal effectiveness of nitrite, a major hurdle.

• production of lactic acid ( pH drop), acetic acid, hydrogen peroxide, bacteriocins.

• Drying, addition of salt ( reduction in the water activity, aw <0.92 or <0.94 at pH <5.0).

• smoke in Northern type production, ensures stability and safety.

• The use of starters that are amino acid decarboxylase-deficient and contain antioxidant enzymes ( to ensure the absence of amine formation and undesirable lipid oxidation, respectively. )

•  undesirable moulds on the sausage exterior is prevented by pretreatment of the casing with potassium sorbate or pimaricine solutions.

Typical Defects and Their Causes

• Surface is blurred, fat particles cannot be seen distinctly: temperature of the fat was not low enough during comminution, blending and stuffing.

• Sausage is deformed: too rapid drying, case-hardening, smeared fat under the casing.

• Discoloration of the surface: too high smoking when the surface is wet; smoking with high RH; ripening with RH.

• Discoloration inside: insufficient curing salt; insufficient oxygen removal during comminution and stuffing; too old (rancid) fat.

• White spots (yeasts) or moulds on the surface: inefficient drying; ripening room is contaminated with yeasts and moulds.

• Too acidic taste: too high carbohydrate concentration; higher than necessary temperature (starter culture-dependent), starter culture-specific (production of acetic acid in addition to lactic acid).

• Poor sliceability: unsatisfactory pH-drop and/or aw drop; fat smearing inhibits binding; chemical acidulants react too early (before stuffing).

• Spoilage on the surface: under high humidity conditions micrococci, yeasts and moulds can grow causing characteristic off-odours (microorganism-dependent).

• Spoilage inside: too slow drying at elevated temperature; too low initial salt concentration; highly contaminated ingredients; failure of the starter culture; too high initial pH of the meat; too low carbohydrate concentration; insufficient oxygen removal.

MEAT  CURING  ( salamura, pastırma ——-ham( from pork))

Dry curing:

• Meat rubbed with cure mixture (50 kg salt+ 0.5 kg nitrate + 1 kg sucrose )àtheb rubbed with sat àput in to cask and press for 1-2 days.

Wet curing:

• Mixture of (100 kg water+24 kg salt+1 kg nitrate salt + 2 kg sugar ) àboiledàcooled   ( 5 C )àpoured in to cask which is containing meatàlater wash the meat with hot wateràthen put in to cold water (10-30 m)

• ( NO3( nitrate ) —-NO2 (nitrite)

• 3NO2 + GDL ————- 2NO + HNO3 + H2O

• NO + Myoglobin —- nitrosomyoglobin ( color stability)

Pastırma

The Turkish horsemen of Central Asia used to preserve meat by placing slabs of it in pockets on the sides of their saddles, where it would be pressed by their legs as they rode.

This pressed meat was the forerunner of today’s pastırma, a term which literally means being pressed in Turkish, and is the origin of the Italian pastrami.

Pastırma is a kind of cured beef, the most famous being that made in the town of Kayseri.

• series of processes  about a month.

• Fresh meat rests at room temp. for 4-8 hours before being divided.

• salted on one side, stacked, and left for around 24 hours.

• salted on the other side, stacked and left for a further 24 hours.

• rinsed in plenty of water to remove the excess salt

• dried in the open air for a period varying between 3 and 10 days.

• further processing, the meat is hung up to dry again( in the shade and spaced out so that the joints do not a touch one another.)

• After 3-6 days, they are covered with a paste of ground spices known as çemen(Trigonella foenum groecum  ( buy otu tohumu ) seeds, garlic and chilli pepper mixed to a paste with a little water. ) , and left to cure for 10-24 hours in hot weather, and 1-2 days in cold weather.

• Then the excess çemen is removed, leaving a thin layer, and the joints dried again. Finally the pastırma is ready for the table

• Gourmets do not approve of pastırma sliced by machine but insist on the thin slices being cut by hand with a sharp meat knife. They also reject ready cut slices of pastırma as sold packaged in some delicatessens and supermarkets

Making Salami

• Ground meat+spices(garlic,redpepper,black pepper, fennel seed)+salt+starter culture(Pediococcus cerevisiae and Lactobacillus plantarum. )Curing, IncubatingDrying  (totaly around 3 weeks)

Curing : refrigerate for 2 days and

incubate at 28-30 C, 90% RH

Drying: The temp. during this phase is generally 10-15 C and RH 70-80%.  The maintenance of this high  humidity is necessary to prevent case hardening. During this time, the casing of the salami will mold. This is natural and some say it imparts complexity to the flavor of the salami

Frankfurters

• This product is believed to originate from Frankfurt, Germany in 1487.

• The frankfurter name is often used interchangeably with frank, wiener and hot dog.

• Frankfurters are typically 20–25 mm in diameter and are linked in  12.5 cm lengths.

• a natural casing or a cellulose casing.

• Hot dogs (Hot dogs were first seen in the late 1800s, at baseball games in the Unites States ) are typically smoked.

• The cellulose casing is removed before packaging of this product, which results in what is called a skinless product( over 95% of total)

• 80-90 % lean meat + 10-20 % fat + 5 % potato starch + 0.2-0.4 % red pepper + 0.2-0.4 % black pepper + 0.5 % sugar + 0.05 % nitrate + 0.02 % nitrite + 0.03 % ascorbic acid + 2.5 % salt + 20-30 % water as ice

• Process: 

–meat + salt + nitrate + nitrite

–mix and grind

–rest (-3 C, 12 hours to increase water holding capacity)

–add remaining spices and ice

–grind

–add fat

–add ascorbic acid

–fill to casings

–dry at 40 C, 15-20 minutes

–smoking (75-78 C, 35-45 minutes, horn beech wood or oak wood is used

–phenol and phenol aldehyde is produced to have antimicrobial and antioxidative effect) 

–dip into water , 80 C, 15-20 minutes

–treat with cold waters

–ready to sell

Meat Fermentation Presentation

•Geography dictates the types of fermented meet products.
•In warmer areas, the Middle East and around the Mediterranean, spices were often added, and a drying step was common.
•In colder, Northern areas, where sausage technology is more recent, spices were rarely added, and instead products were usually smoked or sometimes cooked following fermentation.
•the preservation of fermented meats serves as a perfect example of what food scientists now refer to as the hurdle or barrier concept of food preservation.
•Today the variety of fermented meat products ~ cheese in the world.
•In Spain : 50 different types of fermented sausages
•in Germany: more than 350.
•this variation is due to
-the meat source (i.e., beef, pork, goat, sheep, etc.)
-the cut of meat
-the amount and coarseness of the fat
-the casing material used
•The level of dryness, smoking or mold growth are important factors and form the basis of fermented meats classification
• Meat Composition
•Fresh meat is a nutrient-rich medium and is, in fact, one of the best for supporting growth of microorganisms.
•Skeletal bovine muscle contains:
•- 20% of high quality protein
•- 2% to 3% lipid
•-small amount of carbohydrate
•-non-protein nitrogen and inorganic material.
•-about 75% is water( aw is nearly 0.99)
•-pH of the fresh tissue, before rigor, is 6.8 to 7.0, but decreases to about 5.6 to 5.8 following rigor, due to post-mortem glycolysis by endogenous enzymes present within muscle cells.
• Fermentation Principles
•the meat fermentation has been, until recently, considerably less well studied and understood.
•the use of pure, defined starter cultures begun in the 1950s and ‘60s. Before backslopping were common.
•Backslopping works for several reasons:
•-selects bacteria that are well suited for growth in the sausage environment.
•-the bacterial population is heterogenous consisting of multiple species and strains. (If one strain were to suddenly die remaining strains could complete the fermentation.)
•-effective due to large size of the inoculum (usually around 5%, can be as high as 20% of the total mass to overwhelm the background flora)
•drawbacks of backslopping:
•-inconsistent quality
•-fermentations can be unreliable and difficult to control.
•-can’t meet tight production schedules
•-microbiologically risky, may permit growth of Staphylococcus aureus, Listeria monocytogenes, C. botulinum, or other pathogens of public health significance
•If a cooking step is not included, fermentation is the main barrier against pathogens.
•a slow or failed fermentation may not be discovered right away permitting growth of pathogenic bacteria.
•subsequent acid production (or even a heating step) may not be sufficient to inactivate these high level of pathogens.
Sausages grouped under four major category
• -Fermented sausages or sausages dried in air
•( can be consumed without cooking, normal sausages) Ham ( from pork )—- equivalently pastırma ……prepared from uncooked materials
•-Boiled sausages …..prepared from uncooked materials but during processing either boiled in water or treated with steam …frankfurter, salami ( in Turkish sosis, salam..)
•-cooked sausages
•-fried sausages
•Semidry sausages (in USA) : rapid fermentation at an elevated temp, without or with a short period of drying followed by cooking (at 60–68°C).

Traditional Mediterranean:slow ripening process, development of moulds and yeasts on the surface. No smoking. Shelf-life: due to drying and reduced aw .
In northern and central Europe, fermentation+smoking, of yeasts and moulds are prevented, and the drying is shorter.
summer sausage, fermented at 38 °C and no drying.
Microbiology of Fermentation
• meat is naturally contaminated with Lactobacillus, Carnobacterium, Micrococcus, Staphylococcus, Pseudomonas, Acinetobacter, Enterococcus, Arthrobacter, Corynebacterium, Brochothrix and Listeria, and also Enterobacteriaceae, yeasts and moulds.
•Spoilage Bacteria
•Gram-negative aerobic spoilage mos, disappear through the fermentation period.
•Pathogenic Bacteria
Clostridium, Staphylococcus aureus, Listeria and Enterobacteriaceae (including Salmonella):easily controlled if good practice is applied.
Starter Cultures for Fermented Sausages
•The LAB : Lactobacillus sakei, L.curvatus, (18-25C)(slow fermentation to provide sufficient time for nitrate-reduction and color and flavor development )L. plantarum,
Pediococcus acidilactici and P. pentosaceus. ( 35-40 C)
( for fast, consistent large scale productions)
•Yeasts (Debaryomyces hansenii, Candida famata) and moulds (Penicillium nalviogense, P. chrysogenum or P. camemberti) are added to the surface of the casing.
• acetic acid:undesirable in fermented sausage because it imparts a sour, vinegar-like flavor
•the inclusion of Micrococcaceae (mesophilic : 18°C to 25°C) in meat starter cultures is optional.( don’t produce acid to convert nitrate to nitrite by enzyme nitrate reductase in turn ( they form flavor and enhance color )
•If ferment at higher temp (e.g., 32°C to 40°C), the rapid acid development would inhibit growth of the micrococci
functions of meat starter cultures
(1) produce L acid and lower the pH;
(2) produce desirable flavors;
(3) out-compete spoilage and pathogenic mos;
(4) lower the Eh, ( inhibits Salmonella, S. Aureus);
(5) Micrococcaceae :flavor and color via reduction of nitrate.
•Bacteriocins: proteinaceous substances with bactericidal activity.Produced by: P. acidilactici, L. plantarum, and L. sakei.
•Bacteriocins provides one more barrier and an extra margin of safety.
•- nisin: only bacteriocin recognized GRAS
How to include bacteriocin?
•- adding bacteriocin-producing strains in a starter culture
•-a pure bacteriocin : added directly to the sausage batter or applied to the surface in the form of a dip or spray.
•- incorporate bacteriocins into packaging films.
Raw Materials and Additives
•only five ingredients are essential:
•meat, sugar, salt, culture, and a curing agent.
•Meat the main ingredient. Beef fat ( more unsaturated lipids) than pork fat ( susceptible to oxidation rxns, rancid flavors) pH should be 5.8 or lower to prevent undesired bacteria)
•Salt ( essential ingredient in all types)
•Functions: -extracting and solubilizing the muscle proteins
•-provides flavor, -controlling the microflora.
(2–4%) containing 0.4–0.6% sodium nitrite (NaNO2)
Sugar
•fresh meat contains little fermentable sugar, and addition of sugar is necessary.
•glucose (0.5–1%) can be added to impart flavour and moderate the harshness of salt
•Addition of reducing sugars (e.g. glucose solids, dextrose) to the brine: helps in browning reactions (bacon.)
•Ascorbates/Erythorbates(isoascorbic acid)
•sodium ascorbate or ascorbic acid (0.5–1%) ( to prevent oxidation, improve color stability)
•helps in the prod. of nitric oxide (NO) from nitrite
•Seasonings (spices) act as antioxidants
•pepper, cloves (karanfil), allspice (yenibahar)and cinnamon ,Garlic and onion .
•aqueous smoke solution:to provide a smoked flavour.
•Sodium Nitrite/ Sodium Nitrate
• sodium nitrite (or nitrate): colour and flavour
• oxidative stability: by preventing lipid oxidation
•addition is highly regulated due to the possible risk of formation of N-nitrosamines.
•In Canada, 200 ppm (20 g per 100 kg;
United States, in all products except bacon: 200 ppm
•addition is highly regulated due to the possible risk of formation of N-nitrosamines.
•In Canada, 200 ppm (20 g per 100 kg;
United States, in all products except bacon: 200 ppm;
•additional additives for Northern type sausages
-phosphates (0.5%) Tripolyphosphates, hexametaphosphates, most widely used, to increase the water-holding capacity of cured meat products.
-Alkaline phosphates: increase the pH, solubilizing muscle proteins to impart the water-retention action.
– increase in product yield),
– phosphates improve the cured meat flavour by retention of natural juices and by reduction of oxidative rancidity.
-glucono-δ-lactone (GdL, 0.5%): fast chemical acidulation for products with a short shelf-life
Culture
•Most common commercial cultures
•Frozen cultures: (US), Cell densities, 108 to 109 cells per ml.
-70 ml can: 150 kg of sausage batter.
-dry ice and to store the cans at _40°C or below.
-The cans should be thawed in cold water prior to use.
•Lyophilized cultures:
•- less common
•Sausage Making
Comminution( grinding) or Chopping
•Raw materials and additives, including microbial starters: under vacuum, in a mincer or ‘cutter’.
•knives that rotate rapidly (1–3 × 103 r.p.m.), producing a batter in a bowl that rotates slowly (10–20 r.p.m.)
•relative speeds, knives and bowl, determine the fat particle size and are optimized to produce a batter within less than 5 minutes at temperatures ≤2 °C,
• meat grinder Bowl chopper
Stuffing
•the batter is immediately stuffed under vacuum into natural, semisynthetic (collagen) or synthetic casings that are permeable to water and air, and both ends are clipped.
•The sausage diameter (e.g. 2–15 cm)
SAUSAGE CASINGS
Animal Casings
•the oldest of packaging matls for sausage
•the collagen is hardened and rendered less soluble by the application of salt.
•Initially, as the collagen is exposed to heat and drying, it becomes less permeable to moisture.
•The sheep casings are the smallest in diameter and are also the most tender.
Manufactured Collagen Casings
•manufactured casing: collagen.
•collagen casing: Alginate Casing, Cellulose Casings from high-grade wood pulp, Plastic casings, polyethylene or a polyamide (Nylon).
•The collagen is solubilized and later extruded and hardened
Ripening ( Fermentation + others )
•hung in racks, put into natural or, mostly, air-conditioned fermentation chambers at high RH.
•Thermocouples and pH probes inserted directly into product samples… a computer….constant monitoring…recording…. feed-back control: no need full time operator.
•ripening in two consecutive stages:
•fermentation
• -Northern (20–24 °C/50–90%/2-3 days)
•- Mediterranean (5–24 °C/10–90%/100 h)
•- in USA( 37-40 C, 12-18 h)
•the pH at the end of fermentation should be less than 5.1, …. provide a reasonable protective barrier against most foodborne pathogens.
•Cooking, drying, and smoking
•In the USA: any pork containing sausage must be cooked to destroy Trichinae cause the disease Trichinella in humans.)(usually 60°C to 62°C)
•in Europe : raw sausages are the norm, and post-fermentation heating steps are rarely applied.
•Cooking inactivates the culture and stops the fermentation, but it also kills pathogenic microorganisms
•B) transfer to another chamber, drying for development of sensory characteristics.
•If the RH is too low, temp too high, drying will initially be rapid. …….. the surface will become dehydrated and form a hard, water-impermeable skin. This phenomenon, called case hardening,
•air RH: not more than 0.10 points below the associated aw values of the sausage, to prevent case hardening, and recommended air speeds are approximately 0.1 m s-1.
Smoking
•Northern type: oak wood (300–600 °C) to minimize the production of polycyclic hydrocarbons.
•Smoke: antimicrobial,antioxidant effects, generates specific flavour and colour components.
•Sausage Metabolism and Safety
the starting material,meat,is raw and cannot be heat-processed to inactivate spoilage or other undesirable microorganisms
•To lower redox potential ( omission of oxygen by chopping under vacuum, addition of ascorbic acid or ascorbate). This inhibits aerobic bacteria and improves the bactericidal effectiveness of nitrite, a major hurdle.
•Drying, addition of salt ( reduction in the water activity, aw •undesirable moulds on the sausage exterior is prevented by pretreatment of the casing with potassium sorbate or pimaricine solutions.
Typical Defects and Their Causes
•surface is blurred: temp of the fat was not low enough during comminution, blending and stuffing.
•sausage is deformed: too rapid drying, case-hardening, smeared fat under the casing.
•• Discoloration of the surface: too high smoking when the surface is wet; smoking with high RH; ripening with RH.
•• Discoloration inside: insufficient curing salt; insufficient oxygen removal during comminution and stuffing; too old (rancid) fat.
•• White spots (yeasts) or moulds on the surface: inefficient drying; ripening room is contaminated with yeasts and moulds.
• Too acidic taste: too high carbohydrate ,higher temp (starter culture-dependent), starter culture-specific (production of acetic acid in addition to lactic acid).
• Poor sliceability: unsatisfactory pH-drop and/or aw drop; fat smearing inhibits binding; chemical acidulants react too early (before stuffing).
• Spoilage on the surface: if high RH; micrococci, yeasts and moulds: off-odours
•Spoilage inside: too slow drying; too low initial salt concentration; highly contaminated ingredients; failure of the starter culture; too high initial pH of the meat; too low carbohydrate concentration; insufficient oxygen removal.
•MEAT CURING ( salamura, pastırma ——-ham( from pork))
• Dry curing:
•Meat rubbed with cure mixture ( 50 kg salt+ 0.5 kg nitrate + 1 kg sucrose )—— theb rubbed with sat ———- put in to cask and press for 1-2 days.
•Wet curing:
•Mixture of ( 100 kg water + 24 kg salt + 1 kg nitrate salt + 2 kg sugar ) —–boiled—-cooled ( 5 C )—poured in to cask which is containing meat—– later wash the meat with hot water—– then put in to cold water ( 10-30 minutes)
•( NO3( nitrate ) —-NO2 (nitrite)
•3NO2 + GDL ————- 2NO + HNO3 + H2O
•NO + Myoglobin —- nitrosomyoglobin ( color stability)
Pastırma
– The Turkish horsemen: by placing slabs of it in pockets on the sides of their saddles, where it would be pressed by their legs as they rode.
– This pressed meat was the forerunner of today’s pastırma, a term which literally means being pressed in Turkish, and is the origin of the Italian pastrami
• series of processes about a month.
•Fresh meat : rest at room temp. for 4-8 hours before being divided.
•salted on one side, stacked, and left for around 24 hours.
•salted on the other side, stacked and left for a further 24 hours.
•rinsed in plenty of water to remove the excess salt
•dried in the open air for a period varying between three and ten days.
•further processing, the meat is hung up to
• dry again( in the shade and spaced out
•so that the joints do not a touch one another.)
•After 3-6 days, covered with a paste of ground spices known as çemen(Trigonella foenum groecum ( buy otu tohumu ) seeds, garlic and chilli pepper mixed to a paste with a little water. ) , and left to cure for 10-24 hours in hot weather, and 1-2 days in cold weather.
•Then the excess çemen is removed,
• leaving a thin layer, and the joints
• dried again.
• Making Salami
•Ground meat+spices(garlic,redpepper,black pepper, fennel seed)+salt+starter culture(Pediococcus cerevisiae and Lactobacillus plantarum. ) …….. Curing, Incubating, Drying
•(totaly around 3 weeks)
rezene
•Curing : refrigerate for 2 days
and incubate at 28-30 C, 90% RH
Frankfurters
• originate from Frankfurt, Germany in 1487.
used interchangeably with frank, wiener and hot dog.
• 20–25 mm in D, linked in 12.5 cm lengths.
•a natural casing or a cellulose casing.
• Hot dogs; typically smoked.
•cellulose casing is removed before packaging results in skinless product( over 95% of total)
•80-90 % lean meat + 10-20 % fat + 5 % potato starch + 0.2-0.4 % red pepper + 0.2-0.4 % black pepper + 0.5 % sugar + 0.05 % nitrate + 0.02 % nitrite + 0.03 % ascorbic acid + 2.5 % salt + 20-30 % water as ice
•Process: meat + salt + nitrate + nitrite —-mix and grind —– rest ( -3 C, 12 hours to increase water holding capacity) — add remaining spices and ice —grind— add fat—- add ascorbic acid——- fill to casings—- dry at 40 C , 15-20 minutes —smoking ( 75-78 C , 35-45 minutes, horn beech wood or oak wood is used—–phenol and phenol aldehyde is produced to have antimicrobial and antioxidative effect) ——- dip into water , 80 C, 15-20 minutes —–treat with cold waters—ready to sell