OSC Activity H.4

The current practices for production of the organic versions of cured meats use an alternative to the direct addition of nitrate from vegetable sources such as celery juice powder and converting into nitrite by bacterial starter cultures that possess nitrate reductase activity. However, these organic meats may present safety problems because they may not contain adequate residual nitrite and they lack other built-in protection against pathogens such as C. botulinum and L. monocytogenes. Conversely, they may present risks associated with nitrosamine formation when they contain high levels of residual nitrite. The use of bacterial cultures can also present a practical problem with respect to uniform distribution of brine containing starter cultures for products that require brine injection, resulting in uneven curing of the product. There is a need to address the issues of safety and stability of the organic cured meats, in addition to achieving nitrite-cured meat characteristics.

Thus the objective of this research activity over a period of 4 years is to develop effective alternatives to direct addition of nitrite for organic cured meats. Specifically, the research will aim at developing a curing mixture composed of natural ingredients or other acceptable agents, where each component of the mixture can effectuate one or more specific functions, and protocols to produce organic cured meats with nitrite-cured meat properties and in-built protection against pathogens, nitrosamine formation and lipid oxidation.

Organic processed meats such as ham, bacon, frankfurters and other cured products have become a significant part of the market growth of natural and organic foods. It is generally understood that cured processed meats contain nitrite or nitrate with salt and other ingredients such as ascorbate, sugar, spices and phosphates, but it is the addition of nitrite/nitrate that imparts distinctive characteristics of cured meats and provides antimicrobial protection. However, the requirements of organic processed meats prohibit direct addition of nitrite or nitrate. However, indirect addition of nitrate, using ingredients from plant sources with high nitrate content, does not appear to violate the requirements of organic processed meats since such products are marketed in the US and Canada but labelled as uncured. Because of lower nitrite/nitrate content in organic cured meats compared with conventional processed meats, their shelf life is greatly reduced. Nitrite is a unique ingredient for which there is no effective substitute currently available; but nitric oxide (NO), derived from nitrite, is the active compound that is involved in several meat curing reactions. The affinity of NO for iron plays a role in several functions of nitrite in cured meats including the characteristic color of the cured meats, inhibition of anaerobic bacteria, particularly Clostridium botulinum, and reduction of lipid oxidation. Nitric oxide is also a signaling molecule in biology and regulates a wide range of physiological functions The effects include: muscle functions such as vasodilatation and blood flow, respiration and glucose homeostasis; neurotransmission, and gastrointestinal immunity. The concern about nitrite as food additive rose with the recognition that carcinogenic nitrosamines could be produced by nitrosation of amines.

The current practices for production of the organic versions of cured meats use an alternative to the direct addition of nitrate from vegetable sources such as celery juice powder and converting into nitrite by bacterial starter cultures that possess nitrate reductase activity. However, these organic meats present safety problems because they do not contain adequate residual nitrite and they lack other built-in protection against pathogens such as C. botulinum and  Listeria monocytogenes. Conversely, they may present risks associated with nitrosamine formation when they contain high level of residual nitrite. The use of bacterial cultures can also present a practical problem with respect to uniform distribution of brine containing starter cultures for products that require brine injection, resulting in uneven curing of the product. There is a need to address the issues of safety and shelf-life of the organic cured meats, in addition to achieving nitrite-cured meat characteristics.

Thus the objective of this research activity over a period of 4 years is to develop effective alternatives to direct addition of nitrite for organic cured meats. Specifically, the research will aim at developing a curing mixture composed of natural ingredients or other acceptable agents, where each component of the mixture can effectuate one or more specific functions, and protocols to produce organic cured meats with nitrite-cured meat properties and in-built protection against pathogens and nitrosamine formation.

Two approaches will be pursued: one involves the addition of nitrate indirectly, and other consists of the addition of nitric oxide, the reduction product of nitrite and the active molecule in the production of cured meat properties. The first approach will build on the current practice for production of organic cured meats that employs nitrate from vegetable sources, and find ways to use natural ingredients to combat potential pathogen contamination. The second approach consists of direct exposure of meats to controlled concentrations of NO mixed with nitrogen.

The objectives for the next two years (2011-2013) are: (1) The identification of a nitrate source from vegetable sources; natural reductant, acidulant and antioxidant ingredients for conversion of nitrate to nitrite and development of cured meat properties, and inhibition of nitrosamine formation and lipid oxidation; and antimicrobial compounds from natural sources exhibiting anticlostridial activity; and (2) Exploration of the feasibility of direct exposure of meats to NO to achieve cured meat color, stability against lipid oxidation, and anticlostridial effect. The results of this research will lead to the development of two alternative methods and ingredients to the direct addition of nitrite for organic cured meats with cured meat properties and protection against pathogens and nitrosamine formation.

• Nitrates and Nitrites In Preserved Meats – An Evolving Process [PDF - 3.2 MB]
  • The Canadian Organic Grower. 2012

• Cured meat products without direct addition of nitrate or nitrite: what are the issues?
  • Meat Science (2007) 77: 136-147

• Agriculture and Agri-Food Canada
• Olymel