Effects of Beetroot Powder and Ascorbic Acid as Nitrite Replacers on Physicochemical Properties, Antioxidant Activity, and Storage Stability of Frankfurters

This study evaluated beetroot powder as a natural colorant and partial nitrite replacer in frankfurters. Five formulations were prepared: control with nitrite curing salt, T1 and T2 with 25% and 50% nitrite replacement, T3 with complete nitrite replacement, and T4 with complete nitrite replacement plus ascorbic acid. The samples were analyzed for physicochemical properties, color, water-holding capacity, cooking yield, sensory quality, antioxidant activity, total phenolic content, and lipid oxidation during 7 days of refrigerated storage at 2–3 °C. Beetroot powder markedly increased redness in uncooked frankfurters, with a* values rising from 13.84 in the control to 37.20 in T3 and 35.31 in T4. T2, T3, and T4 also improved cooking yield, reaching 90.19%, 90.42%, and 89.84%, respectively, compared with 85.85% in the control. T2 showed the highest total sensory score (23.3), while T3 had the lowest acceptability (19.8). During storage, T4 showed the strongest oxidative stability, with TBARS increasing from 0.23 to 1.10 mg MDA/kg, compared with 0.44 to 2.42 mg MDA/kg in T3. T4 also maintained the highest DPPH activity and total phenolic content after 7 days: 2.53 μmol TE/g and 95.68 mg GAE/kg, respectively. Beetroot powder improved color and antioxidant potential, but complete nitrite replacement required ascorbic acid to control oxidation and maintain quality. These findings support the use of beetroot powder–ascorbic acid systems in reduced-nitrite frankfurter formulations.