Spectrophotometric quantification of nitrite and nitrate in cured processed meat

Abstract

A total of 115 samples of different cured meat products – locally processed and imported ones – were purchased from various groceries and supermarkets in Egypt then analyzed for their contents of both nitrite and nitrate by the aid of spectrophotometer and expressed as mg/kg (ppm). The surveyed samples consisted of 25 corned beef (9 locally processed plus 16 imported ones), 20 locally processed beef sausage, 15 locally processed patirma, 10 locally processed beef luncheon, 5 imported canned beef luncheon, 20 canned chicken sausage (8 locally processed and 12 imported ones), 10 imported canned chicken luncheon, in addition to 10 locally processed chicken luncheon samples. Spectrophotometric analyses quantified the range (minimum – maximum) &mean ± S.E. levels of nitrite in the tissues of locally processed and imported corned beef samples as 4.35 – 43 & 14.59 ± 4.13 mg/kg and 4.07 - 78.37 & 38.94 ± 6.98 mg/kg, respectively, while similar findings for the nitrate were 13.91 - 40.58 & 22.8 ± 2.64 mg/kg and 12.32 - 102.5 & 43.88 ± 6.62 mg/kg in the same samples, consequently, the sum of both nitrite and nitrate residues were calculated as 23.91 - 62.2 & 37.39 ± 4.5 mg/kg in locally processed corned beef besides 30.77 - 141.9 & 82.82 ± 9.2 mg/kg in imported corned beef samples, consecutively. The aforementioned analytical technique exhibited the minima, maxima, and mean ± S.E. values of nitrite 6.65, 82, 28.72 ± 4.34 mg/kg; of nitrate 8.93, 113.01, and 40.6 ± 5.94 mg/kg; of sum nitrite and nitrate 16.49, 138.7, and 69.33 ± 7.92 mg/kg, respectively, in the tissues of locally processed beef sausage. While, those findings were 2.03, 69, and 22.35 ± 4.96 mg/kg for nitrite; 0.76, 114.25, and 54 ± 10.42 mg/kg for nitrate; as well as 18.99, 142.71, and 76.35 ± 10.06 mg/kg for sum nitrite and nitrate, successfully in the samples of locally processed pastirma. The lowest levels of nitrite, nitrate, and sum nitrite and nitrate in the analyzed tissues of both locally processed beef luncheon and imported canned beef luncheon samples were 5.22 & 36.73, 1.99 & 2.99, and 18.99 & 63.29 mg/kg ; whereas the highest amounts of such residues were 75.5 &75.78, 74.7 & 59.56, and 131.7 & 96.29 mg/kg ; meanwhile the mean levels ± S.E. of these findings were 30.63 ± 8.28 & 59.22 ± 8.32, 32.81 ± 6.4 & 21.78 ± 11.16, and 63.43 ± 12.46 & 81 ± 6.81 mg/kg in the same samples, successfully. Tissues of locally processed canned chicken sausage revealed nitrite nitrate, and sum nitrite/nitrate by levels ranged from 7.46 – 47.08, 7.5 - 44.8, and 22.06 - 91.88 mg/kg with mean ± S.E. values 27.54 ± 4.54, 16.22 ± 4.6, and 43.77 ± 7.96 mg/kg, respectively. While, those findings in surveyed samples of imported canned chicken sausage were 18.46 – 64.11, 2.65 – 93.78, 43.51 – 132.08 with mean ± S.E. values 39.21 ± 3.61, 29.07 ± 7.36, and 68.28 ± 7.07 mg/kg, consecutively. The mean ± S.E. levels and ranges (minimum – maximum) of the investigated analytes in the samples of imported canned chicken luncheon were found 45.86 ± 9.37 and 21.69 - 99.52 mg/kg for nitrite, 49.55 ± 14.55 and 12.65 - 149.76 mg/kg for nitrate, in addition to 95.43 ± 16.03 and 46.59 - 198.36 mg/kg for sum nitrite/nitrate, respectively. Meanwhile, similar findings in the tissues of locally processed chicken luncheon were 35.96 ± 5.55 and 11.21 - 58.4 mg/kg for nitrite, 37.92 ± 9.05 and 1.06 - 99.81 for nitrate, as well as 73.88 ± 6.94 and 47.36 - 120.98 mg/kg for sum nitrite/nitrate, successfully. An overviewing the obtained results, none of surveyed samples of cured meat products possessed nitrite or nitrate level more than their limits (150 & 250 mg/kg, respectively). Also, public health significance of nitrite and nitrate in cured meat products – marketed in Egypt – as well as the conclusion and recommendations of the present study were also mentioned.