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Moisture enhancement of pork: Quality improvement or adulteration?

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By Prof Arno Hugo and Ennet Moholisa, Food Science Division, Department of Microbial, Biochemical and Food Biotechnology, University of the Free State

The addition of brine solutions to pork and other red meat is a widespread, well-established practice in the United States (US) meat industry. The United States Department of Agriculture (USDA) reported that approximately 90% of pork, 30% of poultry and 15% of beef are enhanced with solutions. Application of enhancement solutions can be done by injection, tumbling or surface application of brines. Unfortunately brine injection of meat cause controversy. The practice of injecting chicken meat with amounts of brine as high as 50% was widely reported on in the South African media during 2011 and 2012.
Those in favour of moisture enhancement argue that it benefits eating quality, improve and stabilise colour, improve shelf-life, improve yield, improve safety and increase water-holding capacity of meat. Those against are of the opinion that the practice dilute the nutrients, expose the consumer to high sodium and phosphate levels, mislead the consumer on the quality of the product and can therefore be considered as adulteration. To prevent future controversy, the South African pork industry should act pro-actively by investigating the effect of this practice on meat quality.

There are two forms of moisture enhancement of meat products. The conventional form of moisture enhancement is the treatment of meat products with a nitrate/nitrite containing brine and include cured products such as pork leg (gammon), cured pork belly (streaky bacon), cured shoulder (shoulder bacon) and cured loin (back bacon and Kasseler rib). These products are often also smoked. In these products the brine act as a carrier for functional ingredients such as salt, nitrites, phosphates, ascorbic acid and sugar with the aim of improving safety, water-holding capacity, colour, oxidative stability and shelf-life of products.

The other group of moisture enhanced meat products are not nitrate/nitrite treated but are the so called “deep-marinated”, “self-basted” or “moisture-enhanced/infused” products. These terms are used instead of “brine injected” because they are considered more positive by consumers.

Formula of water

These are fresh uncured pork that is processed with a formula of water, salt, phosphate, lactates, acetates, enzymes, antioxidants, non-meat proteins, starch, hydrocolloids, flavourings and marinades. This type of moisture enhancement improves the sensory characteristics such as juiciness, tenderness and flavour of pork. It is not done to improve low quality pork products, but to add value for the consumer by improving the overall eating experience of fresh pork and reducing the variation in pork quality.

As meat producers increasingly raise leaner animals that contain significantly less fat, moisture enhancement can be considered a method to replace the flavour and moisture loss due to the reduction in fat on the animal. These enhanced meat cuts are well accepted by the US consumers.

Moisture-enhanced meat will usually have lower nutritional value than untreated meat, due to the dilution effect of added water solutions. Lower protein content was reported in moisture-enhanced pork chops compared to conventional chops. Added salt increases the amount of sodium in the treated meat that impacts negatively on the nutritional value of the treated meat. Sodium levels can be up to eight times higher in treated than in non-treated meat.

The shelf-life of infused and conventional pork products were reported similar. Marinated, or enhanced, products may also be vacuum packaged to extend the shelf-life of the refrigerated products. A risk associated with moisture enhancement is that brine injection may introduce bacteria into deep tissue. Re-circulation of brine also carries the risk of introducing spoilage bacteria and pathogens into injected pork. A higher incidence of Listeria monocytogenes and enterohaemorrhagic Escherichia coli were found in brine-injected pork compared to conventional pork. It was, however, found that micro-organism contamination can be avoided by good manufacturing practices (GMP’s).

Controversial aspect

The most controversial aspect of moisture enhancement is injection level or yield. Where does the value-adding end and where does adulteration start? The regulatory aspect of moisture enhancement is a complex issue. For cured enhanced products such as bacon and ham, the maximum permitted levels are usually quite clear. The injection level of cured pork products usually range between 8 – 20% internationally. There are however highly extended reformed “ham-like” products available with extension levels as high as 100%. In South Africa the enhancement level of cured moisture enhanced products such as bacon, ham and reformed hams are regulated by the minimum total meat protein equivalent, actual total meat content, actual lean meat and maximum fat content according to SANS 885.

For the so called “deep-marinated”, “self-basted” or “moisture-enhanced/infused” fresh uncured products the situation is less clear. Internationally the maximum allowed enhancement levels for this kind of products appeared to be around 5 -15 %. If the pump level of fresh pork exceeds 12%, increased package and retail purge may be a concern. No mention is made of enhancement levels of higher than 18% for these kinds of products. Regulations are currently being developed in South Africa to regulate the amount of brine that may be injected in fresh chicken portions as well as fresh red meat.

In South Africa, Regulation 28, of the South African regulations, relating to the labelling and advertising of foodstuffs (No. 146 of 1 March 2010), under the Foodstuffs, Cosmetics and Disinfectants Act, 1972 (Act 54 of 1972), governs the ingredients which may be added to meat products. It stipulates that water, which is added as an ingredient of a foodstuff during the manufacturing process and exceeds 5% of the finished product, should be declared on the list of ingredients. When water forms part of an ingredient, such as brine in a compound foodstuff, it should be declared as such. If a moisture-enhanced product is water-misted or ice-glazed, the net weight of the product may not include the weight of the applied water or the ice. An acknowledgment to this effect must be indicated on the label. A prominent and conspicuous statement must appear on the principal display panel, adjacent to the product name. It should describe that the product is protected with a water-mist or ice-glaze (e.g. “product protected with ice glaze”).

Processing methods, such as moisture-enhancement, can be used to create pork products that will satisfy both the modern consumer’s and the retailer’s quality demands. It must however be executed in a correct and responsible manner. This will protect the consumer and will also discourage factories and retailers from taking advantage of the increased weight to increase their profits to the detriment of the consumer. The pig processing industry must however guard against a situation where its consumers are informed by the media that fresh pork is injected with up to 50% brine as happened recently with South African chicken.

Maybe you can make the photos below a bit smaller or remove one: The golden key is correct labelling. If a product is moisture enhanced, make sure that the consumer understand that it is a processed product and label and name it as such. Do not inject fresh pork with brine and sell it as fresh pork. Give the enhanced product a specific name.

(This research was co-funded by the Red Meat Research and Development SA (RMRD SA). For more information contact Prof Hettie Schönfeldt at (012) 361 2333 or info@rmrdsa.co.za. Alternatively visit the website www.rmrdsa.co.za).