How Can Near‑Boiling Water Turn White Rose into a Super Supplement?

White rose (Rosa alba L.) is more than a fragrant flower: it holds oils, polyphenols, sugars and proteins. Scientists applied subcritical water extraction—water heated to 150 °C but kept below boiling pressure—for 30 minutes. This eco‑friendly method maximized the yield of all bioactive components. The essential oil is rich in phenylethyl alcohol, citronellol, geraniol and hydrocarbons, typical scents in many cosmetics. Polyphenols include gallic acid (30‑113 µg/mL) and ferulic acid (44‑100 µg/mL), plus flavonoids like quercetin and kaempferol. Simple sugars such as glucose, galacturonic acid, galactose, rhamnose and xylose are also present. Antioxidant tests (DPPH, ABTS, FRAP, CUPRAC) showed strong radical‑scavenging activity. This mix of aroma, antioxidants and nutrients makes Rosa alba extract suitable as a food supplement or in creams and lotions, offering a natural, sustainable alternative to conventional chemicals.

Subcritical extraction exploits water's properties near its critical point (374 °C, 22 MPa). At 150 °C, water's dielectric constant drops, making it a better solvent for both polar and non‑polar compounds. This enables simultaneous extraction of volatile oils and hydrophilic molecules without organic solvents. Identified polyphenols (gallic, ferulic, rosmarinic, protocatechuic acids) are known for anti‑inflammatory and anticancer activities in vitro, modulating cellular signaling pathways (NF‑κB, MAPK). Flavonoids quercetin and kaempferol, present in free and glycosylated forms, enhance essential oil stability against oxidation. Simple sugars, especially glucose, act as natural co‑solvents, improving solubility of hydrophobic compounds. Antioxidant activity measured by DPPH, ABTS, FRAP and CUPRAC reflects electron and hydrogen donation capacity, crucial for combating oxidative stress. Industrially, subcritical technology lowers solvent disposal costs and allows more sustainable production, with scalability potential for food and cosmetic sectors.