Sustainable management of rosemary wastewater and essential oil in agri-environmental bioprocessing

anglais. peer reviewed

anglais. In agriculture, fragrant and medicinal plants offer significant untapped potential for generating biomass-derived materials, particularly from wastewater by-products. In this context, the present study investigates the chemical compositions, antioxidant capacities, antimicrobial properties, acute oral toxicity, and diabetes management potential of wastewater by-products and essential oil from R. tournefortii de Noé. Utilizing advanced analytical techniques, including ATR-FTIR, GC/MS, and HPLC-DAD, were employed to conduct the analyses. ATR-FTIR analysis revealed intricate molecular compositions in both the essential oil and wastewater, confirming terpenoids, phenolic acids, and other functional groups. GC/MS and HPLC-DAD identified dominant compounds in the essential oil, notably camphor (25.49%) and 1,8-cineole (18.03%), while the wastewater contained significant levels of hydroxycinnamic acids such as caffeic acid (23.51%) and rosmarinic acid (21.15%). In terms of bioactivity, the essential oil demonstrated robust antimicrobial effects, with inhibition zones up to 17.1 mm, whereas the wastewater exhibited moderate activity, with zones up to 15.15 mm. Additionally, antioxidant assessments revealed exceptional potency of the wastewater, with IC50 values of 0.046 ± 0.007 mg/mL for DPPH, 0.082 ± 0.013 mg/mL for ABTS, and 2.45 ± 0.71 mg/mL for the beta-carotene/linoleate model system, surpassing the essential oil. Furthermore, both the essential oil and wastewater showed significant inhibitory effects on pancreatic α-amylase, crucial for diabetes management, with wastewater demonstrating remarkable inhibition (IC50 = 0.48 ± 0.021 mg/mL). Acute oral toxicity assessment confirmed the safety of these components, alleviating concerns about potential adverse effects. In summary, these findings highlight the untapped potential and environmental significance of wastewater by-products as valuable resources, positioning R. tournefortii de Noé's essential oil and wastewater as promising agents for sustainable healthcare and environmental sustainability.