Study on the toxicity and allergenicity of recombinant soybean hemoglobin

Abstract Recombinant soybean hemoglobin (RSH) can give plant protein based meat a color and bloody taste that mimics animal meat, which is essential for plant protein meat. In this study, the toxicity and allergenicity of RSH were investigated, with bovine hemoglobin (BHb) as a reference. No significant toxic reactions were observed in any group received a single oral dose of 125, 250, or 500 mg/kg RSH within 14 days. Meanwhile, no apparent toxic reactions were noted in terms of organ coefficients, hematological parameters, serum biochemical indices, histopathological examination, and gut microbial diversity in mice orally administered 400 mg/kg RSH daily for 28 days, with BHb showing a comparable safety profile. Minor statistical changes in a few parameters were observed in both RSH and BHb groups, but all values remained within normal ranges. Allergenicity prediction and immune markers study indicated that RSH demonstrated no significant risk of sensitization. These results together proved that RSH exhibited no apparent acute or subacute toxicity and no significant sensitization potential, which could be used as the key ingredients in plant protein meat production.