Betalains from Opuntia stricta peels: UPLC-MS/MS metabolites profiling, computational investigation, and potential applicability as a raw meat colorant

Given consumers', environmental and sustainability apprehensions, the meat industry investigated the natural colorant resources. As proof, betalain, <i>Opuntia stricta</i> peels (OSP) pigment, is premeditated in the meat industry. Here, OSP betalains were qualitatively profiled using UPLC-MS/MS, and 7 metabolites were identified: 6 betacyanins and a betaxanthin (arginine-betaxanthin). Molecular docking simulations of cyclo-Dopa-5-O-β-glucoside, as the core betacyanins structure, and the arginine-betaxanthin, displayed the lowest free energies of binding at -8.1 and -7.6 kcal/mol, respectively. These compounds inhibit the <i>L. monocytogenes</i> replication and transcription processes by targeting dihydrofolate reductase (DHFR). Then, OSP extracts (0.003, 0.006 and 0.012 %) were incorporated in the raw refrigerated beef meat, and compared to Allura red E129 at 0.002 % for 14 days. By the end of storage, OSP at 0.012 % decreased the chemical oxidation, enhanced the sensory traits, and improved the instrumental color. In addition, chemometrics could distinguish between all samples linking oxidative and microbiological variables to sensory/instrumental color attributes.