Preservative Levels and Microbiological Quality of Manufactured Meat - October-December 1997

October - December 1997


  • To determine the bacteriological status of fermented meat products available on the ACT market.
  • To determine the compliance of manufactured meats to the requirements for preservatives in the Standard Food Code;
  • To gain a better understanding of the manufactured meats and how standard requirements apply to them.


Manufactured meats are very popular from delicatessens and from chilled food sections of supermarkets. They are generally available as luncheon meats and frankfurters in a host of varieties produced from small and large manufacturers alike.

In the Code, manufactured meat is defined as :

  • ...the food, not elsewhere standardised in this Standard, containing at least 660 g/kg of meat, prepared from a blend of meat and other foods including water, and includes-

  • (a) smallgoods such as frankfurters, saveloys, brawn, devon, strasburg, salami, meat paste, chicken roll and similar foods; and

  • (b) extended muscle products.

The above definition states a minimum 66 % meat content which includes smallgoods such as frankfurters, saveloys, brawn, devon, strasburg, salami, meat paste, chicken roll. Extended muscle products are those smallgoods of intact muscle formed together and include turkey rolls, roasts and beef rolls. You may be wondering what foods not elsewhere standardised in this Standard means. Basically, the Code has standards for other foods that may ordinarily be considered manufactured meat by many consumers but are treated separately. This includes:

  • Cured meat and salted meat. Although cured meats and manufactured meats can both have been prepared by treatment with nitrite salts, manufactured meats (including manufactured ham) are a blend of meat and other foods whereas cured meats are products such as ham where the meat is "whole".
  • Dried Meat. Again, a product where the meat is not blended with any other foods (except what may be used in a marinade).
  • Sausage, sausage meat. Sausage is minced meat and meal which has been formed into discrete units. It is specifically stated in the Code that sausage and sausage meat must not include offal or rendered trimmings (derived by cooking meat trimmings). This is the only category of meat product where offal is excluded by definition. Some types of manufactured meat may contain rendered trimmings.
  • Processed meat products. These are also very similar to manufactured meats, but are differentiated from manufactured meats by their lower meat content.

Confused? The table below indicates some of the fundamental differences of these very similar foods as defined by the Food Standards Code. It should also be noted that the Australian New Zealand Food Authority (ANZFA) is undertaking a review of the Code which will include standards relating to processed meats. For further information concerning the Review, please contact ANZFA on 6271 2222.



  Meat content Rendered




pH Water


Manufactured Meat

Before 1 July 1998

Cooked minimum 660 g/kg meat Max100mg/kg      
Uncooked fermented minimum 660 g/kg meat Not permitted      
Semi-dry heat treated minimum 660 g/kg meat Max100mg/kg


>5.5 0.91-0.95
Other minimum 660 g/kg meat Max100mg/kg      
From 1 July 1998
Fermented, not heat treated minimum 660 g/kg meat Not permitted      
Fermented heat treated minimum 660 g/kg meat Not permitted

55C, 20 mins

Fermented cooked minimum 660 g/kg meat Max100mg/kg

65C, 10 mins

Other cooked minimum 660 g/kg meat Max100mg/kg      
Semi-dry heat treated minimum 660 g/kg meat Max100mg/kg


>5.5 0.91-0.95
Other minimum 660 g/kg meat Max100mg/kg      
Cured meat and salted meat
cooked cured meat, water added min 130g/kg meat protein fat free        
sterile canned cured          
slow dried cured          
other cured meat          
cooked salted meat,water added min 130g/kg meat protein fat free        
other salted meat          
Dried Meat         Max 0.85
Sausage Meat,Sausage minimum 500 g/kg fat free Not permitted      
Processed Meat Products

Before 1 July 1998

cooked 300g/kg to 660g/kg meat Max 100 g/kg      
uncooked fermented 300g/kg to 660g/kg meat Not permitted      
semi-dry heat-treated 300g/kg to 660g/kg meat Max 100 g/kg


>5.5 0.91-0.95
Other 300g/kg to 660g/kg meat Max 100 g/kg      
From 1 July 1998
Fermented, not heat treated 300g/kg to 660g/kg meat Not permitted      
Fermented heat treated 300g/kg to 660g/kg meat Not permitted

55C, 20 mins

Fermented cooked 300g/kg to 660g/kg meat Max100mg/kg

65C, 10 mins

Other cooked 300g/kg to 660g/kg meat Max100mg/kg      
Semi-dry heat-treated 300g/kg to 660g/kg meat Max100mg/kg


>5.5 0.91-0.95
Other 300g/kg to 660g/kg meat Max100mg/kg      


Some manufactured meats, such as salami, are prepared according to traditional methods which only involve fermentation and drying. They dont necessarily undergo any form of heat treatment or cooking in their preparation. Instead, preservation is achieved via lactic acid bacteria fermenting sugars to acid in conjunction with dehydration of the meat (reduction in water activity). These types of products were implicated in the Haemolytic Uraemic Syndrome (HUS) outbreak in South Australia in 1995, being contaminated with a virulent strain of E. coli causing hospitalization of several people and the death of a child. Following on from this food poisoning outbreak, ANZFA introduced specific requirements into the Code concerning their manufacture and sale. This included strict controls on manufacturing processes (to minimize possible contamination) and more stringent labelling requirements. Commencing from 1 July 1998, labelling for fermented comminuted manufactured meat will have to include one of the following terms associated with the label according to the nature of processing used:

  • fermented manufactured meat - not heat treated
  • fermented manufactured meat - heat treated
  • fermented manufactured meat - cooked

There is a slight difference between heat treated and cooked meat. Heat treated products are those who have been heated to 55 C for a minimum of 20 minutes, and cooked refers to products which have been heated to a minimum of 60 C for more than 10 minutes. Labelling requirements also specify that any trade name used for these foods must also have the words "fermented", or "fermented heat treated" or "fermented cooked" associated with it, whichever most accurately describes the processing.


Samples were tested for E. coli (Escherichia coli), Listeria monocytogenes (L. monocytogenes), Clostridium perfringens (C. perfringens), Coagulase positive Staphylococcus (Coag+Staph), and Salmonella spp. Where appropriate, Standard Plate Count (SPC) was performed to assess the overall hygiene quality.

The following standards in the Code are applicable for manufactured meats including pastes, pate and uncooked comminuted meat products:

Standard C1, Part 13, subclause 60, states that Uncooked Fermented Meat products must:

  • (a) have a coagulase-positive Staphylococci count not exceeding 1,000 coagulase-positive Staphylococci per gram as examined by Method 3.2 in the schedule;

  • (b) be free from Salmonella in 25 g of the food when examined by Method 4 in the schedule; and

  • (c) in the case of an uncooked fermented comminuted meat product to which clause 60A applies, after fermentation or any other process, be free from Escherichia coli (E. coli) in 0.1 g of the food when examined by Method 9 in the schedule.

Sub clause 61 states that paste or pate which is, or is described as, a manufactured meat or a processed meat product must:

  • (a) be free from Salmonella in 25 g of the food when examined by Method 4 in the schedule; and

  • (b) have a standard plate count not exceeding 1 000 000 micro-organisms per gram when examined by Method 5 in the schedule; and

  • (c) be free from Listeria monocytogenes in 25 g of the food when examined by method 6 in the schedule.

Table 2 gives the surveys acceptability criteria for foods not covered by the ANZFA standards.

Table 2


Test Organism





<50 - 1000

1000 - 10,000


E. coli


2 - 1000




50 - 1000


C. perfringens


50 - 1000


L. monocytogenes

Not detected*



Salmonella spp

Not detected*




#Units expressed in terms of Colony forming units (cfu) per gram. *Organism not detected in 25 gms


Sulphur dioxide and other sulphite preservatives (additives 220 - 228) are permitted in cooked manufactured meats up to a level of 260 mg/kg (expressed as sulphur dioxide). They perform the following functions:

  • to act as a preservative. In aqueous solutions they form Sulphurous Acid which is thought responsible for the anti-microbial activity of these compounds ( Ref_3).
  • to act as an antioxidant and help maintain meat colour (Ref_3).

Sulphites are known to trigger asthmatic attacks in susceptible individuals (Ref_6) and accordingly, their use in foods is restricted.


Nitrates and nitrites (additives 249,250,251,252) are also permitted in these foods. The Code states that manufactured meat may contain

  • ...potassium nitrite, sodium nitrite or a mixture of these provided that the manufactured meat does not, except as specified in subclause 38(1), contain more than 125 mg/kg in total of nitrites and nitrates, calculated as sodium nitrite.

Subclause 38(1) of the Code states that

  • ...uncooked fermented manufactured meat may contain added potassium nitrate, sodium nitrate or a mixture of these provided that the uncooked fermented manufactured meat contains not more than 500 mg/kg in total of nitrites and nitrates, calculated as sodium nitrite.

So in general, nitrates/nitrites are permitted in manufactured meats to 125 mg/kg and for uncooked fermented meats, they are permitted at higher concentrations up to 500 mg/kg. They are used as curing agents with the following specific functions:

  • as a food preservative, particularly inhibiting the growth and toxin production of Clostridium botulinum, the bacterium responsible for botulism. Nitrite has been shown to inhibit growth of Clostridium perfringens very effectively. (Ref_4)
  • to develop and fix the pink colour of cured meats. Nitrites in meat form nitric oxide, which reacts with haem compounds to form food pigments. (Ref_3)
  • to develop characteristic flavours. (Ref_3)

It has been showed that in high concentrations in the body, nitrites convert the blood oxygen carrying molecule haemoglobin to methemoglobin, which in this form, is unable to carry oxygen (Ref_6). It has been documented that the ingestion of high levels of nitrites may cause nausea and vomiting, dizziness, headaches, de-oxygenation of the blood, low blood pressure and collapse of the circulatory system (Ref_5). However, most of these toxic effects are only observed at concentrations greater than those used in curing (Ref_6).

Nitrites are also known to react with amines, amino acids for example, to form nitrosamines. This group of compounds have been shown to be carcinogenic in animals. Research has shown that the levels of nitrosamines found in foods have been low. It is also known that the formation of nitrosamines may also take place in the strongly acidic conditions of the human stomach (Ref_3, 6). As yet, research has not found an acceptable alternative to nitrite for preventing the growth of toxic micro-organisms in these meat products, but in the meantime their use is regulated.


For this survey, samples were collected over the counter by laboratory staff. Staff undertaking the sampling were given a general definition of manufactured meats, similar to the one described above, and asked to use their judgment to decide whether a meat product was a manufactured meat or not. Many of the samples tested were purchased unpackaged from delicatessens and as such, only scant details of the product were available, usually only the name.

In total, the laboratory collected 47 samples, 2 of which were subsequently judged to be cured meats, and one which was subsequently judged to be a sausage. Results for these three samples have not been included in this survey. The following pie chart divides the samples into various food categories. The fermented samples (salamis) were not categorized as cooked or uncooked because this information was not readily available.


Standard plate count (SPC)

SPC was performed on pastes and pates. A total of 12 paste and pate samples were tested with one samples SPC plates not counted due to overgrowth by spreading organisms. The following table gives the range median and compliance of the results.





45.5% failed to comply

<50 - 170,000,000



Coagulase-positive Staphylococcus

All except for two sample were below the methods detection limit of 50 cfu/g. One sample of Twiggy stick salami had 100 cfu/g while the other sample of chicken loaf had a level of 50 cfu/g. The pastes, pates and uncooked fermented products complied with their respective standards.

Escherichia coli

The presence of E. coli was detected in the following three samples. Green Peppercorn pate, Pastrami and Scottish breakfast sausage. This represents 6.7% of samples. The Green Peppercorn pate also failed the Standard for SPC.


All samples were negative for Salmonella spp.

Listeria monocytogenes

L. monocytogenes was detected in two samples i.e. bacon loaf and brawn purchased on the same day from the same outlet and manufactured by the same company. This represents 4.4% of samples.

C. perfringens

All samples were below the methods detection limit of 50 cfu/g for C. perfringens.


Nitrates and Nitrites

In keeping with the standard, results of nitrates and nitrites were combined and expressed as total sodium nitrite concentration. All samples tested, showed levels of nitrate/nitrite below the respective standard requirement. Appropriately one third (15/47) had no detectable amounts, 23 samples had levels of total sodium nitrite in the range 20-60 mg/kg and the remaining 9 samples had levels in excess of 60 mg/kg with the highest found to be 115 mg/kg in a hot and spicy salami. These results are in keeping with the observation that " approximately 50% of the amount added is undetectable after processing, and the amount detected continues to decline during storage." (Ref_4).

Sulphur Dioxide

All the samples bar two were analysed for sulphur dioxide preservative. For one sample, a salami, it contained sulphur dioxide at a concentration of 2600 mg/kg, 10 times the permitted amount!! This product was manufactured locally and promptly investigated by an Environmental Health Officer who undertook a review of the manufacturers process. As the preparation of this salami included cooking and smoking at 70 C for three to four hours, it was classed a cooked manufactured meat. Testing a new batch of this product gave a result of 120 mg/kg, well inside the standard requirement of 260 mg/kg.

The following chart demonstrates that the majority of samples analysed contained little or no sulphur dioxide. 58% (25/43) of the samples analysed did not have detectable levels of sulphur dioxide, and 41% (18/43) contained sulphur dioxide below the respective standard, with one failing the standard requirement as highlighted above. Of the salamis, eight of the eleven samples did not have detectable amounts of sulphur dioxide.


chart demonstrates that the majority of samples analysed contained little or no sulphur dioxide

Labelling Claims

Ten of the samples received were packaged indicating the product name, manufacturer and ingredients, including any preservatives used. The labelling information appeared to be accurate. One sample was labelled as "preservatives free" and testing demonstrated no detectable amounts of either nitrate/nitrite or sulphur dioxide.


Microbiological Assessment

It is not pleasing to see 45.5% of samples pate and paste samples failing their SPC Standard. The presence of E. coli and Listeria monocytogenes in 2 and 3 samples respectively is regarded as being at the lower end of the isolation rate and encouraging. The fact that the L. monocytogenes were isolated from products purchased from the same outlet on the same days tends to suggest a cross contamination of products is occurring. The reason for 45.5% of paste and pate samples failing are most probably due to poor handling and storage procedures.

Problems with Identification of Manufactured Meats

The Food Standard Code divides meat products into several different categories, but the differences between the categories are often arbitrary distinctions. For us, it was difficult to interpret the standard and categorize the sample correctly. Manufactured meat, processed meat and sausage are all treated differently in the Code with the major criteria distinguishing these products being the meat content. Protein (meat) analysis was not performed for this survey and so could not aid interpretation. Even within the category of manufactured meat, it was hard to divide the products according to their preparation methods, as is required to properly analyse compliance with the Code. For example cooked manufactured meats are permitted to contain sulphur dioxide preservative. Product labelling does not indicate if the product is cooked or not. To find out this information, it is necessary to contact the manufacturer and ask them. This process is time consuming and not always productive.

On the whole, this may not seem to be a problem to the general public who choose a product on the basis of their preferences for taste, consistency and other criteria like cost. However, some consumers may be seeking further information about the product, most importantly whether it has had any heat treatment or cooking as part of its manufacture. This information is not conveyed by trade names. For example, two samples of mortadella were tested during this survey. Mortadella can be fermented, dried, smoked or cooked (Ref_5). The particular recipe used is generally only known to the manufacturer.

As from July 1 1998, labelling standards for comminuted manufactured meats will need to include labelling details about the heat treatment used in manufacture. This should hopefully provide better information for consumers when purchasing such products. As a recommendation, checking the compliance of these labelling conditions should be included in any future survey of these products.

Preservative levels

With only 1 sample failing the requirements of the Code (i.e. a locally produced salami with excessive amounts of sulphur dioxide preservative), there are minimal public and health concerns raised regarding the levels of nitrite and sulphur dioxide preservatives in manufactured meat products.


In regards to the standard, there is good compliance of manufactured meat products to nitrite and sulphur dioxide preservative levels.

Applying standard requirements for these products was found to be difficult as distinctions in their characteristics are difficult to judge. The standard conditions for these foods are not easy to understand and probably very confusing to manufacturers, and consumers alike. It is hoped that new labelling requirements will aid the interpretation of these foods to the consumer and furthermore, the Standard Review currently underway will address other concerns.


Refer to recommendations document.


Australia and New Zealand Food Authority, Food Standards Code, incorporating amendments up to and including Amendment 38, April 1998.

Food Act 1992 (ACT), reprinted as at 31 January 1996.

O. Fennema (ed), Food Chemistry, 2nd edition, Marcel Dekker, 1985.

A. Branen, P. Davidson & S. Salminen (ed), Food additives, Marcel Dekker, 1990.

M. Hanssen, Additive Code Breaker, Lothian Publishing, 1986.

J.A.Maga and A.T.Tu (ed), Food additive toxicology, Marcel Dekker, 1995.

A.M Pearson & T.A.Gillett, Processed Meats, 3rd Edition, Chapman and Hall, 1996.


Sampling Officers: Louisa Bartolome and Chris Wixon

Sample analysis: Fiona Wojtas

Report: Fiona Wojtas and Simon Christen