**Background:** Halophytes such as Salicornia ramosissima J. Woods are salt-tolerant plants that produce high concentrations of bioactive secondary metabolites (phenolic acids, flavonoids) as a defense against extreme environmental conditions. While fresh shoots are used as a commercial vegetable, the lignified residual fraction after food production is often considered agricultural waste. This study aimed to evaluate the potential of these residual fractions—partly lignified fiber residue and completely lignified biomass—as feedstock for biorefinery to produce high-value botanical extracts for nutraceutical, cosmetic, and biopharmaceutical industries.
**Methods:** Partly lignified S. ramosissima biomass was obtained from two producers: Les Douceurs du Marais in France (open-field, seawater-exposed) and Riasearch in Portugal (greenhouse, brackish water irrigation). Completely lignified, woody biomass was also obtained from Riasearch after seed production (~8 months after germination). Fresh biomass was fractionated into green juice and fiber residue using a screw press. Green juice was centrifuged, filtered, and freeze-dried; fiber residue was dried and milled. Completely lignified biomass was rinsed, dried, shredded, and sifted. Botanical extracts were prepared using water, 70% aqueous ethanol, and n-hexane via Soxhlet extraction (8 h for water, 6 h for organic solvents). Extracts were characterized for fatty acid profile (GC-MS), total phenolic content (Folin-Ciocalteau), total flavonoid content (aluminum chloride method), condensed tannins (DMACA-HCl), anthocyanidins, and photosynthetic pigments (spectrophotometry). In vitro antioxidant activity was assessed using DPPH, ABTS, and nitric oxide radical scavenging assays, as well as iron chelating, copper chelating, and ferric reducing antioxidant power (FRAP) assays. Enzyme inhibition was tested against α-amylase, α-glucosidase, tyrosinase, acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and pancreatic lipase. Positive controls included acarbose (anti-diabetic), arbutin (tyrosinase inhibitor), galantamine (dementia treatment), and orlistat (weight-loss drug).
**Key Results:** The green juice fraction constituted >80% of fresh weight from French biomass and 66.7% from Portuguese biomass, with ash content of 81.8% in French juice. The fatty acid profile of fiber residue showed 58.2% polyunsaturated fatty acids (PUFA), 41.0% saturated fatty acids (SFA), and 1.3% monounsaturated fatty acids (MUFA), with linoleic acid (34.5%) and palmitic acid (30.9%) as the predominant FAs; the ω-6/ω-3 ratio was 1.5. The ethanol extract from fiber residue had the highest total phenolic content (41.06 mg GAE/g DM), followed by the water extract from completely lignified biomass (30.10 mg GAE/g DM). Total flavonoid content was detected only in the ethanol extract (2.97 mg QE/g DM) and water extract from lignified biomass (2.91 mg QE/g DM). Condensed tannins were not detected in any extract. Anthocyanidins were not detected despite the red color of French juice. The ethanol extract contained 2,847.3 μg/g DM total chlorophyll (CHL a/CHL b ratio 2.3) and 1,003.9 μg/g DM total carotenoids. In antioxidant assays, the water extract from fiber residue showed the highest activity across most assays, with EC50 values of 0.63 mg/mL (ABTS), 0.30 mg/mL (FRAP), 0.18 mg/mL (ICA), and 4.91 mg/mL (CCA). For enzyme inhibition at 10 mg/mL, the ethanol extract from fiber residue showed 68.63% α-glucosidase inhibition (vs. 85.61% for acarbose), 71.85% tyrosinase inhibition (vs. 93.28% for arbutin at 1 mg/mL), 68.42% AChE inhibition (vs. 88.70% for galantamine at 1 mg/mL), and 41.74% lipase inhibition (vs. 87.74% for orlistat at 1 mg/mL). Water extracts showed moderate α-glucosidase inhibition (34.12% from fiber residue, 8.93% from lignified biomass) but no cholinesterase inhibition. Green juice fractions showed low to moderate enzyme inhibition.
**Clinical Implications:** The study demonstrates that residual fractions of S. ramosissima—particularly the ethanol extract from fiber residue and water extract from completely lignified plants—contain bioactive compounds with antioxidant and enzyme-inhibitory properties relevant to diabetes (α-glucosidase inhibition), hyperpigmentation (tyrosinase inhibition), obesity (lipase inhibition), and neurodegenerative diseases (AChE inhibition). The high antioxidant activity of aqueous extracts, comparable to organic solvent extracts, is advantageous for industrial scale-up by reducing reliance on toxic solvents. The favorable ω-6/ω-3 fatty acid ratio (1.5) supports potential cardiovascular benefits. However, the study notes significant variability in phytochemical content depending on cultivation conditions (open-field vs. greenhouse, salinity levels, UV exposure), which poses challenges for consistent product quality in biorefinery applications. The authors conclude that while raw extracts show promising bioactivity, further purification could enhance potency, and full metabolomic profiling is needed to identify specific active compounds and potential synergistic effects.