Bioactives, Aromatics and Sensory Properties of Cold-Pressed and Hexane-Extracted Lemon (Citrus Limon L.) Seed Oils

The objective of this study was to provide more essential data about the bioactive, aromatic volatile composition and sensory properties of lemon seed oils to possibly establish new application areas of this unexplored new oil. Furthermore, cold pressing and hexane extraction were compared. Catechin, eriocitrin, rutin, naringin, naringenin, hesperidin, neohesperidin and kaempherol as flavonoids, and gallic, syringic, tr-ferulic, rosmaniric and tr-2-hydrocinnamic acids as phenolic acids were quantified in the oils. Naringin, gallic and syringic acids were significantly higher in the cold-pressed sample. Around 30 different aromatic volatiles were identified in both samples, and, for the majority, the concentrations were higher in the cold-pressed sample. It was observed that lemon seed oil is very aromatic, mostly characterized by citrus, herbal, terpenic, woody, and floral aroma descriptors. A panel evaluated the oils for sensory properties with 13 different definition terms (clarity, lemon peel, roasted, raw vegetable, grassy, bitter, astringent, waxy, nutty, fatty, spicy and throat-catching). The oil was defined as very bitter, astringent, spicy and throat-catching. In conclusion, lemon seed oil was found unsuitable for direct edible use, but might be preferable for its unique aroma and bioactive components for functional food, pharmaceutical and cosmetic applications.