s Recent Approaches in the Extraction of Citrus Metabolites

The review summarizes the recent (2016-2019) practical applications of novel extraction methods for Citrus metabolite extraction, such as microwave-assisted (MAE), ultrasound-assisted (UAE), super-critical carbon dioxide (SC-CO2) and enzyme-assisted extraction (EAE) with the aim to compare efficiencies based on the criteria of enhanced (%) yield, cost-effectiveness, reproducibility, eco-friendliness, time/energy consumed and industrial scale application. It was found that supercritical carbon dioxide extraction (SC-CO2) is the most successful and scaled-up technique when compared to MAE, UAE, Soxhlet and EAE, following the trend: SC-CO2 > EAE > UAE > MAE. However, other novel approaches, including pulse-electric field (PEF), sub-critical water extraction (SWE), solarenergy assisted extraction (SE) and molecularly imprinted polymers (MIPs), that have not been well explored for Citrus bioactives extraction, have the potential to be coupled with conventional as well as contemporary methods leading to an innovative hypothetical scaled-up design.