Upcycling Whole Tomato Pomace into Functional Cosmetic Oils through Comparative Extraction and Bioactive Evaluation

Tomato pomace is a major byproduct of tomato processing and is often discarded, even though it contains many bioactive compounds with potential cosmetic benefits. Unlike most studies that focus only on tomato seed oil, this work uses whole tomato pomace—both pulp and seeds—to provide a more complete profile of its lipids and bioactive compounds. Turning this byproduct into functional oils can support the development of sustainable cosmetic ingredients. This study aimed to extract and characterize oils from tomato pomace using different extraction methods and to evaluate their physicochemical and antioxidant properties. Oils were obtained by solvent extraction (hexane and ethanol) and hydraulic pressing. The chemical properties of the oils were analyzed using high-performance size-exclusion chromatography (HPSEC) for acylglycerol profiling and gas chromatography – flame ionization detector (GC-FID) for fatty acid composition. Antioxidant activity was assessed through total phenolic content, ABTS^•+, and DPPH^• assays. Ethanol extraction produced the highest and statistically significant oil yield, giving 1.22 times more oil than hexane extraction and 2.70 times more than hydraulic pressing (p<0.05). Linoleic acid and oleic acid were the predominant fatty acids, and HPSEC results showed that triacylglycerol was the major lipid group. The ethanol-extracted oil exhibited the strongest antioxidant activity, with the highest phenolic content (486.41 µg GAE/g oil) and the lowest IC₅₀ values for ABTS (2.74 mg/mL) and DPPH (8.42 mg/mL). Its high linoleic acid content suggests potential benefits for skin barrier improvement and anti-aging effects, making it a promising base oil for cosmetic formulations.