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Hungarian Meat Research Institute

Role of nitrite and nitrate in fermented sausages Gabriella Zsarnóczay. Hungarian Meat Research Institute. Leonardo da Vinci. Start of the use of sodium nitrite.

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Hungarian Meat Research Institute

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  1. Role of nitrite and nitrate in fermented sausages Gabriella Zsarnóczay Hungarian Meat Research Institute Leonardo da Vinci

  2. Start of the use of sodium nitrite Sodium nitrite is an indispensable additive in meat industry. Thanks to an incidence salt used for preservation of meat was contaminated with saltpetre (potassium nitrate). Meat prepared with this salt remained nice pink and became palatable. This effect of saltpetre was discovered in 19th century.

  3. Start of use of sodium nitrite POLENSKI detected in 1891 that from nitrate is formed thanks to bacterial reduction, while LEHMAN found that characteristic color of cured meat is caused not by nitrate but by nitrite. HALDENE discovered that this characteristic pink color is formed through the reaction of nitrogen-oxide with meat pigments.

  4. Use of curing agents Curing agents for meat products are as follows: • potassium nitrite – E 249 • sodium nitrite – E 250 • sodium nitrate – E 251 • potassium nitrate – E 252 Since sodium nitrite is poisonous it can be used only in form of curing salt mix (contains 0,5 % sodium nitrite) in order to avoid overdosage.

  5. Its use has to be labeled tra Preservative (E 250) Preservative (sodium nitrite)

  6. Regulations 2006/52/EC

  7. Role of nitrite in meat products Advantages: Food safety • Inhibition of Clostridium botulinum • Preservative effect Food quality • Color formation • Inhibition of rancidity • Formation of flavor

  8. Inhibition of Clostridium botulinum Clostridium botulinum is a soil microbe, capable of neurotoxin production causing botulism. Spores are resistant to heat and some Clostridia can grow at chilling temperature. Nitrite inhibits outgrowth of spores and toxin formation.

  9. Characteristics of Clostridium botulinum

  10. Characteristics of Clostridium botulinum Most effective poison: 0,0024 mg is lethal. Favorable effect (?): BOTOX Small amount of toxin is injected s.c.which paralyses facial muscles thus avoiding formation of wrinkles to a certain period.

  11. Food-born diseases Unknown Mushroom

  12. Preservative effect Inhibition of: • Coliformes • St. aureus • Cl. sporogenes • Listeria monocytogenes • Salmonella No inhibition against (starter cultures): • Dairy microbes • Staphylococcus

  13. Color formation Original color of fresh meat is formed by meat myoglobin and hemoglobinof blood. These pigments are not stable: brownish metmyoglobin by oxidation, greyish color caused by heat treatment. In order to attain stable red color myoglobin and hemoglobin have to be react with nitrogen oxide. Nitrogen-oxi-myoglobin formed in this reaction is a stable cherry-red compound. Nitrogen oxide necessary for this reaction is formed from sodium nitrite.

  14. Nitrogen-oxi-myoglobin

  15. myoglobin + oxygen metmyoglobin myoglobin + nitrite + oxygen nitrogen-oxi-myoglobin

  16. Inhibition of rancidity Nitroso group protects hem-group in hemoglobin during heat treatment by inhibiting release of iron. Released iron catalyses oxidative (rancidity) processes.

  17. Formation of flavor Due to the effect of nitrite characteristic cured flavor is formed by inhibiting oxidative processes causing off-flavors.

  18. Role of nitrite in meat products Disadvantages: • Poison 0,1 g = vasodilator 2,5 g = lethal • Methemoglobinaemia Hemoglobin carries oxygen in human organism. For this purpose iron of hemoglobin has to be in ferro (Fe2+) form. Should iron be oxidated affected e.g. by nitrite, disease occurs.

  19. Role of nitrite in meat products Disadvantage: • Nitrosamine formation Cancerogenic, teratogenic, mutagenic, embryotoxic It is formed if: secondary amine is present pH is < 5.5 temperature is high (> 170 °C) reaction time is long

  20. Nitrosamine Nitrosamine formation is inhibited by: • Antioxidants: ascorbic acid (vitamin C), tocopherol (vitamin E) • Spices: rosemary, paprika • Fruits: grape seed, citrus fruits, tea

  21. Nitrosamine intake, µg/capita/day 0,17 Cured fried meats Smoked cheeses Smoked fish Smoked malt beer N-rich cigarette Whiskey 0,52 17 0,03

  22. Source of nitrite in human organism • From soil and water of natural sources • From artificially fertilized plants • From food additives (meat products and cheeses)

  23. Nitrite intake 18% through food • 4% fresh meat • 6% milk, dairy products • 3% egg • 1% fish • 19% meat products • 15% vegetables • 7% water • 47% cereals, oil, sugar, stone fruits 82% through bioconversion

  24. Circulation of nitrate in human organisms

  25. HEALTHY NUTRITION

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