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

Abstract

Given consumers', environmental and sustainability apprehensions, the meat industry investigated the natural colorant resources. As proof, betalain, Opuntia stricta 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 L. monocytogenes 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.

Keywords

• Opuntia stricta
• Betalains
• Molecular docking
• Anti-Listeria monocytogenes
• Raw beef meat quality
• Chemometrics