Antioxidant Compounds in Helichrysum italicum Distillation Waste: Preliminary Findings

Background: Steam distillation of Helichrysum italicum for essential oil production generates considerable amounts of by-products, including solid plant residues and hydrosols. Although usually treated as waste, these materials may serve as valuable sources of bioactive compounds. This study aimed to determine the content of antioxidant compounds – total phenolic, total flavonoids, fat-soluble vitamins (E and K1), and β-carotene – in the biomass remaining after steam distillation of H. italicum. Methods: Residual biomass was collected from two essential oil producers in north-eastern Bulgaria. Total phenolic content (TPC) was determined using the Folin–Ciocalteu method, while total flavonoid content (TFC) was quantified spectrophotometrically. Fat-soluble vitamins and β-carotene were analysed by HPLC/UV. Results: TPC ranged from 67.95 to 170.01 mg GAE/g lipid, and TFC from 5.31 to 9.82 mg QE/g lipid. The distillation biomass also contained notable amounts of fat-soluble antioxidants: vitamin K1 (27–54 μg/g lipid), vitamin E (19–35 μg/g lipid), and β-carotene (8–23 μg/g lipid). Conclusion: The findings demonstrate that distillation waste of H. italicum retains significant levels of bioactive compounds with antioxidant potential. These results highlight the possibility of utilizing this by-product as a sustainable source of functional ingredients for cosmetic, pharmaceutical, and nutraceutical applications.