title: Effect of curing agents on the oxidative and nitrosative damage to meat proteins during processing of fermented sausages.
abstract: The effect of increasing concentrations of curing agents, ascorbate (0, 250, and 500 ppm), and nitrite (0, 75, and 150 ppm), on the oxidative and nitrosative damage to proteins during processing of fermented sausages was studied. The potential influence of these reactions on color and texture of the fermented sausages was also addressed. Nitrite had a pro-oxidant effect on tryptophan depletion and promoted the formation of protein carbonyls and Schiff bases. The nitration degree in the fermented sausages was also dependent on nitrite concentration. On the other hand, ascorbate acted as an efficient inhibitor of the oxidative and nitrosative damage to meat proteins. As expected, nitrite clearly favored the formation of the cured red color and ascorbate acted as an enhancer of color formation. Nitrite content was positively correlated with hardness. The chemistry behind the action of nitrite and ascorbate on muscle proteins during meat fermentation is thoroughly discussed. The results suggest that ascorbate (500 ppm) may be required to compensate the pro-oxidant impact of nitrite on meat proteins.
  
  
  CONCLUSIONS
  This study provides insight on the action of curing agents on meat proteins during processing of fermented sausages. This chemistry background provides understanding of the potential influence of the oxidative and nitrosative damage to proteins on the quality of processed muscle foods. The study provides novel information on the impact of the combination of nitrite and ascorbate on the chemical deterioration of proteins and the influence on particular quality traits of fermented sausages. These data may be of interest for the design of cured muscle foods of enhanced quality.
authors.affiliation: Authors are with TECAL research group, Animal Production and Food Science, Univ. of Extremadura, 10003, Cáceres, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Villaverde
authors.forename: D
authors.initials: D
authors.lastname: Morcuende
authors.forename: M
authors.initials: M
authors.lastname: Estévez
mesh_terms: D000818:Animals; D005285:Fermentation; D005511:Food Handling; D005520:Food Preservatives; D008461:Meat Products / Q000032:analysis*; D009573:Nitrites / Q000737:chemistry*; D010084:Oxidation-Reduction; D011506:Proteins / Q000737:chemistry*; D017382:Reactive Oxygen Species; D013552:Swine
chemical_list: D005520:Food Preservatives; D009573:Nitrites; D011506:Proteins; D017382:Reactive Oxygen Species
keywords: ascorbic acid; meat quality; nitrite; protein nitration; protein oxidation