A green and optimized approach for lactic acid recovery from fermented molasses using n ‐butanol for local industrial applications in Côte d’Ivoire

This study reports the development and optimization of a sustainable, cost-effective process for recovering lactic acid from fermented molasses using n-butanol as the extraction solvent. Successful extraction was confirmed by nuclear magnetic resonance (NMR) spectroscopy, which demonstrated the presence of monomeric and dimeric lactic acid with minimal impurities. Enantiomeric analysis revealed a near-racemic mixture (51.4% d-lactic acid and 48.6% l-lactic acid), highlighting the heterofermentative nature of the strain, and this composition remained stable even after 6 months. Racemic lactic acid can be exploited for the synthesis of amorphous poly(lactic acid), a preferred candidate for the production of biodegradable materials, drug delivery vehicles, and low-strength scaffolding material for tissue regeneration. This would expand the potential applications of the product in the pharmaceutical, biomedical, and cosmetic industries. The extraction process was optimized through response surface methodology (RSM), identifying ammonium sulfate concentration, solvent-to-broth ratio, and pH as significant parameters influencing recovery. The quadratic model exhibited strong predictive performance (R2 = 0.9996) with no significant lack of fit, validating the reliability of the model. Optimal conditions (57.5% ammonium sulfate, solvent-to- broth ratio of 4.12, and pH 1.24) improved lactic acid recovery. These findings contribute to the valorization of local agro-industrial waste, promoting greener biotechnological processes, and providing a scalable approach to high-value products in Côte d’Ivoire, aligning with the nation’s goals of sustainable development and circular economy.