Volatile compounds and some physico-chemical properties of pastirma produced with different nitrate levels

Abstract

Objective: The aim of the study was to evaluate the effects of different nitrate levels (150, 300, 450, and 600 ppm KNO3) on the volatile compounds and some other properties of pastirma. Methods: Pastirma samples were produced under the controlled condition and analyses of volatile compounds, and thiobarbituric acid reactive substances (TBARS) as an indicator of lipid oxidation, non-protein nitrogenous matter content as an indicator of proteolysis, color and residual nitrite were carried out on the final product. The profile of volatile compounds of pastirma samples was analyzed by gas chromatography/mass spectrometry using a solid phase microextraction. Results: Nitrate level had a significant effect on pH value (p<0.05) and a very significant effect on TBARS value (p<0.01). No significant differences were determined in terms of aw value, non-protein nitrogenous substance content, color and residual nitrite between pastirma groups produced by using different nitrate levels. Nitrate level had a significant (p<0.05) or a very significant (p<0.01) effect on some volatile compounds. It was determined that the amounts and counts of volatile compounds were lower in the 450 and especially 600 ppm nitrate levels than 150 and 300 ppm nitrate levels (p<0.05). While the use of 600 ppm nitrate did not cause an increase in residual nitrite levels, the use of 150 ppm nitrate did not negatively affect the color of pastirma. However, the levels of volatile compounds decreased with an increasing level of nitrate. Conclusion: The use of 600 ppm nitrate is not a risk in terms of residual nitrite in pastirma produced under controlled condition, however, this level is not suitable due to decrease in the amount of volatile compounds.