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Presentation2 effects of preservation on quality attributes 2

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Felix Vigilio

This document discusses the effects of nitrite addition on various quality attributes of cured meat products. It describes how nitrite contributes to desirable color formation and flavor development. Nitrite also plays an important safety role by inhibiting pathogenic bacterial growth. Additionally, nitrite acts as an antioxidant, significantly delaying lipid oxidation and development of rancidity even in the presence of pro-oxidants like salt. The specific compounds and reactions involved in these nitrite-mediated effects are still not fully understood.

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Effects of preservation method on quality attributes of product (nutritional & sensory attributes) BY: Tombe Felix Vigilio
Introduction Color. The fixation of a desirable red color, shaded pink, is the most obvious effect from nitrite addition and is often considered an extremely important attribute for consumer acceptance (Cornforth and Jayasingh, 2004). Interestingly, very little nitrite is needed to induce a cured color. It has been reported that as little as 2 to
Cont. 14 parts per million (ppm), depending on species, is necessary to induce a cured color. However, significantly higher levels are required to prevent rapid fading and non-uniform curing while also maintaining cured color throughout an extended shelf life (Sebranek and Bacus, 2007).
Flavor Cured meat associated with nitrite was first described by brooks et al. 1940, comparing pork cured in brines containing different levels of nitrate and nitrite. The role nitrite has on meat flavor is complex stimulus involving properties such as , aroma, odor, texture, and temperature Gray et al 1981. Nitrite chemistry and associated reactions likely play a role in imparting a unique flavor resulting from addition of nitrite,
However, the specific compounds involved eluded scientists and are not yet known.
Investigating the consumer acceptance of hams manufactured with varying levels of nitrite (0, 25, 75, and 125 ppm), DuBose et al. (1981) reported that no significant (P > 0.05) differences existed for color among the 25, 75, and 125 ppm nitrite containing samples while all were found different (P < 0.05) than the sample containing 0 ppm nitrite.
When nitrite is added to meat systems, it reacts with or binds to a number of chemical components such as protein (Cassens, 1997b). Much of the nitrite added during the product manufacturing is either depleted through a series of reactions or physically lost during certain manufacturing steps. Typically, between 10 and 20 percent of the originally added nitrite normally remains after the manufacturing process and those levels.
Safety Impact from Curing Another important function of nitrite is the role it plays as a bacteriostatic and bacteriocidal agent. Although not well understand, nitrite has been shown to have varying degrees of effectiveness on either preventing or controlling the growth of certain bacteria. A recent risk-benefit review of nitrite included a discussion of the antibacterial benefits of nitrite in cured meat products (Milkowski et al., 2010 ).
Generally considered to be more effective against gram positive bacteria, nitrite has been shown to contribute in controlling growth of pathogenic bacteria. Bauermann (1979) concluded in a study comparing the coliform levels in poultry products with and without nitrite that sodium nitrite does provide improved bacterial shelf-life. Bang et al. (2007) also reported a nitrite-coliform control phenomenon when nitrite was present.
The inhibitory mechanism which results in the effects nitrite has on some bacteria likely differs among bacterial species (Tompkin, 2005). For example, nitrite is not generally considered to be effective for controlling gram-negative enteric pathogens such as Salmonella and Escherichia coli (Tompkin, 2005).
Sensory research suggests that cured flavor is not solely a result of retarding lipid oxidation but a combination of a complex cured aroma and flavor in cooperation with a lack of rancid flavors. It is thus possible that a combined effect from the suppression of lipid oxidation by nitrite and the development of
Cont. nitrite-related flavor, through yet unknown reactions, is responsible for the development of cured meat flavor. If nitrite does form volatile flavor compounds, this premise would suggest an unknown mechanism of nitrite or nitric oxide reactions may exist.
Cont. Lipid Oxidation. One of the most note worthy properties of nitrite is its ability to effectively delay the development of oxidative rancidity. This prevention occurs even in the presence of salt, which is a strong oxidant. Lipid oxidation is considered to be a major reason for the deterioration of quality in meat
cont. and poultry products which often results in the development of rancidity and subsequent warmed over flavors (Yun et al., 1987; Vasavada and Cornforth, 2005). The rate and degree of lipid oxidation is related to the levels of unsaturated fats present as well as temperature, time, oxygen exposure, the removal of oxygen, and the addition of antioxidants and/or reducing agents (Shahidi, 1998).
Cont. The antioxidant effect of nitrite is likely due to the same mechanisms responsible for cured color development involving reactions with heme proteins and metal ions, chelating of free radicals by nitric oxide, and the formation of nitriso- and nitrosyl compounds having antioxidant properties (Sebranek, 2009).
Cont. The antioxidant effect of nitrite has been well documented (Townsend and Olson,1987; Pearson and Gillett, 1996; Pegg and Shahidi, 2000; Honikel, 2004). Nitrite has been shown to inhibit warmed over flavor development at relatively low levels. Sato and Hegarty (1971) reported significant inhibition of warmed over flavor development at a 50 ppm nitrite level with complete inhibition at a 220 ppm level.
Cont. Investigating the effect of nitrite on lipid oxidation in various muscle systems, Morrissey and Tichivangana (1985) reported as little as 20 ppm nitrite was sufficient to significantly (P< 0.01) inhibit oxidation of lipid in fish, chicken, pork, and beef systems.
Presentation2 effects of preservation on quality attributes 2

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Presentation2 effects of preservation on quality attributes 2

  • 1. Effects of preservation method on quality attributes of product (nutritional & sensory attributes) BY: Tombe Felix Vigilio
  • 2. Introduction Color. The fixation of a desirable red color, shaded pink, is the most obvious effect from nitrite addition and is often considered an extremely important attribute for consumer acceptance (Cornforth and Jayasingh, 2004). Interestingly, very little nitrite is needed to induce a cured color. It has been reported that as little as 2 to
  • 3. Cont. 14 parts per million (ppm), depending on species, is necessary to induce a cured color. However, significantly higher levels are required to prevent rapid fading and non-uniform curing while also maintaining cured color throughout an extended shelf life (Sebranek and Bacus, 2007).
  • 4. Flavor Cured meat associated with nitrite was first described by brooks et al. 1940, comparing pork cured in brines containing different levels of nitrate and nitrite. The role nitrite has on meat flavor is complex stimulus involving properties such as , aroma, odor, texture, and temperature Gray et al 1981. Nitrite chemistry and associated reactions likely play a role in imparting a unique flavor resulting from addition of nitrite,
  • 5. However, the specific compounds involved eluded scientists and are not yet known.
  • 6. Investigating the consumer acceptance of hams manufactured with varying levels of nitrite (0, 25, 75, and 125 ppm), DuBose et al. (1981) reported that no significant (P > 0.05) differences existed for color among the 25, 75, and 125 ppm nitrite containing samples while all were found different (P < 0.05) than the sample containing 0 ppm nitrite.
  • 7. When nitrite is added to meat systems, it reacts with or binds to a number of chemical components such as protein (Cassens, 1997b). Much of the nitrite added during the product manufacturing is either depleted through a series of reactions or physically lost during certain manufacturing steps. Typically, between 10 and 20 percent of the originally added nitrite normally remains after the manufacturing process and those levels.
  • 8. Safety Impact from Curing Another important function of nitrite is the role it plays as a bacteriostatic and bacteriocidal agent. Although not well understand, nitrite has been shown to have varying degrees of effectiveness on either preventing or controlling the growth of certain bacteria. A recent risk-benefit review of nitrite included a discussion of the antibacterial benefits of nitrite in cured meat products (Milkowski et al., 2010 ).
  • 9. Generally considered to be more effective against gram positive bacteria, nitrite has been shown to contribute in controlling growth of pathogenic bacteria. Bauermann (1979) concluded in a study comparing the coliform levels in poultry products with and without nitrite that sodium nitrite does provide improved bacterial shelf-life. Bang et al. (2007) also reported a nitrite-coliform control phenomenon when nitrite was present.
  • 10. The inhibitory mechanism which results in the effects nitrite has on some bacteria likely differs among bacterial species (Tompkin, 2005). For example, nitrite is not generally considered to be effective for controlling gram-negative enteric pathogens such as Salmonella and Escherichia coli (Tompkin, 2005).
  • 11. Sensory research suggests that cured flavor is not solely a result of retarding lipid oxidation but a combination of a complex cured aroma and flavor in cooperation with a lack of rancid flavors. It is thus possible that a combined effect from the suppression of lipid oxidation by nitrite and the development of
  • 12. Cont. nitrite-related flavor, through yet unknown reactions, is responsible for the development of cured meat flavor. If nitrite does form volatile flavor compounds, this premise would suggest an unknown mechanism of nitrite or nitric oxide reactions may exist.
  • 13. Cont. Lipid Oxidation. One of the most note worthy properties of nitrite is its ability to effectively delay the development of oxidative rancidity. This prevention occurs even in the presence of salt, which is a strong oxidant. Lipid oxidation is considered to be a major reason for the deterioration of quality in meat
  • 14. cont. and poultry products which often results in the development of rancidity and subsequent warmed over flavors (Yun et al., 1987; Vasavada and Cornforth, 2005). The rate and degree of lipid oxidation is related to the levels of unsaturated fats present as well as temperature, time, oxygen exposure, the removal of oxygen, and the addition of antioxidants and/or reducing agents (Shahidi, 1998).
  • 15. Cont. The antioxidant effect of nitrite is likely due to the same mechanisms responsible for cured color development involving reactions with heme proteins and metal ions, chelating of free radicals by nitric oxide, and the formation of nitriso- and nitrosyl compounds having antioxidant properties (Sebranek, 2009).
  • 16. Cont. The antioxidant effect of nitrite has been well documented (Townsend and Olson,1987; Pearson and Gillett, 1996; Pegg and Shahidi, 2000; Honikel, 2004). Nitrite has been shown to inhibit warmed over flavor development at relatively low levels. Sato and Hegarty (1971) reported significant inhibition of warmed over flavor development at a 50 ppm nitrite level with complete inhibition at a 220 ppm level.
  • 17. Cont. Investigating the effect of nitrite on lipid oxidation in various muscle systems, Morrissey and Tichivangana (1985) reported as little as 20 ppm nitrite was sufficient to significantly (P< 0.01) inhibit oxidation of lipid in fish, chicken, pork, and beef systems.