Comparison of Distillation and Extraction Methods in TBARS Determanation of Cured Meat

Thiobarbituric acid reactive subsrances,TBARS,has been well determined as an index of lipid oxidation in food.Addition of nitrite as a color developnent agent to cured meat results in a low TBRS value.Therfore,we examined whether nitrite suppresses lipid oxidation or if it interferes with color development during determination of TBRS.The relationship between nitrite concentration and TBARS value was compared under both extraction and distillaton methods.TBARS values,whether determined by either extraction or distillation method,were depressed with concentrations of nitrite above 80 ppm.When adding either Orange I reagent,OI,as a coupling reagent with nitrite or suofamic acid,SA,which decomposes nitrite,the decline in the TBARS value was restrained.Nitrite interference could be eliminated completely in the extraction method,which used SA,and this procedure was the most effective.However,these reagents were not effective under strongly acidic conditions.This observation suggests that TBARS reacts with nitrite resulting in a subsrance which does not develop any color with TBA.The extraction method is here recommended because of the high recovery of TBARS value and rapid operation compared with the distillation method.