A non-conventional method to extract D-limonene from waste lemon peels and comparison with traditional Soxhlet extraction

• Published in: Separation and purification technology Vol. 137; pp. 13 - 20
• Main Authors: Lopresto, Catia Giovanna, Petrillo, Francesca, Casazza, Alessandro Alberto, Aliakbarian, Bahar, Perego, Patrizia, Calabrò, Vincenza
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 24.11.2014
• Subjects: D-limonene; High pressure; High temperature; Lemon peels; Response surface methodology; Solvent extraction; D-limonene; High temperature; Response surface methodology; Lemon peels; Solvent extraction; High pressure
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2014.09.015

[Display omitted] •High-pressure high-temperature extraction of D-limonene from lemon peels was tested.•Effect of extraction time, temperature and matrix/solvent ratio on yield was studied.•Influence of particle size distribution and pre-treatment was evaluated too.•Three-way ANOVA, one-way ANOVA and response surface methodology were performed.•Non-conventional HTPE was compared with traditional Soxhlet extraction. Waste citrus peels can be used as source of several bioactive compounds. Among these, D-limonene is the major constituent in lemon essential oil and is of great interest in several fields. With the aim of optimizing D-limonene extraction from lemon peels after citrus processing, a non-conventional solvent extraction was studied. Hexane was used as solvent at high pressure and temperature and influence of extraction time, temperature–pressure and matrix/solvent ratio (M) on yield of D-limonene was analyzed by a statistical approach applied to a three-level full factorial design (33). The highest yield was reached when extraction was performed with M=1:15 at 150°C for 30min (3.56%). Furthermore, a response surface methodology (RSM) was used and experimental results were fitted by a second-order polynomial equation. The effects of drying pre-treatment and particle size were also evaluated in this work. The effectiveness of this innovative method in extraction of citrus essential oils – and, in particular, of D-limonene – has been evaluated and compared to conventional Soxhlet extraction. High pressure – high temperature extraction (HPTE) of D-limonene from lemon peels was better than Soxhlet extraction even with low matrix/solvent extraction (1:4) in terms of energy saving (0.6kWh vs 2.5kWh), extraction time (30min vs 4h) and product yield (2.97% vs 0.95%).