Fermented Radish and Beetroot Powder as Natural Sources of Nitrite in Beef Burger

Growing concern over synthetic nitrite in processed meat has increased interest in natural curing alternatives for clean-label meat products. This research aimed to evaluate the potential of fermented radish and beetroot powders as natural sources of nitrite and bioactive compounds for preserving and improving the quality attributes of beef burgers during refrigerated storage. Burgers were formulated with different levels (3% and 6%) of fermented radish (R3 and R6) and beetroot (B3 and B6) and compared with negative (no additive) and positive (sodium nitrite) controls during 14 days of refrigerated storage, with physicochemical, color, oxidative, microbial, and sensory properties evaluated throughout storage. At day 7, radish and beetroot treatments improved color attributes, reduced lipid oxidation, and controlled microbial growth compared with the negative control. Among the natural treatments, R3 showed the best overall performance, with marked phenolic enrichment, high sensory scores, improved color properties, reduced lipid oxidation, enhanced DPPH radical scavenging activity, and more controlled microbial growth. Radish and beetroot treatments showed performance close to that of the positive control across most evaluated parameters, while showing higher cooking yield, higher phenolic content, greater DPPH radical scavenging activity, better consumer sensory acceptance, and lower diameter shrinkage than the positive control. Overall, the results support the potential of radish and beetroot fermented powders, especially R3, as promising clean-label alternatives for enhancing the quality and storage stability of raw beef burgers.