P 09 - Chemical and microbiological analysis of 25-year-old lemon essential oils: what to expect?
P 09 - Chemical and microbiological analysis of 25-year-old lemon essential oils: what to expect?
Essential oils (EOs) are volatile natural compounds widely used in perfumery, the food industry, pharmaceuticals, and as solvents [1.2]. Although their nominal shelf life after opening is 12 months, their antibacterial and antiviral properties could allow for longer shelf life if properly stored. This study investigated the long-term stability of fortuitously found lemon EO samples stored in hermetically sealed glass bottles for 25 years. Comprehensive analyses were conducted to evaluate their chemical and biological properties. Gas chromatography with flame ionization detection (GC-FID) was used to compare the aged samples with an authentic, organic lemon EO produced in the same geographical area and packaged in 10 mL bottles in 2024 by LaborBio, Collegno (Turin, Italy). Additionally, microbiological tests and nuclear magnetic resonance (NMR) spectroscopy were performed to identify and characterize a white-gray precipitate present in the samples. The findings revealed that essential oils can maintain their composition and functionality well beyond their expected shelf life, suggesting significant opportunities to reduce industrial waste and optimize storage practices.
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