Enhanced Lycopene Extraction from Gac (<i>Momordica cochinchinensis</i> Spreng.) by the <i>Z</i>‐Isomerization Induced with Microwave Irradiation Pre‐Treatment

Abstract

This study aims to improve the efficiency of lycopene extraction from gac ( Momordica cochinchinensis Spreng.) by the Z ‐isomerization induced with microwave irradiation pre‐treatment. Although 93.6% of lycopene exist as all‐ E ‐isomers in dried gac aril, the total Z ‐isomer content reaches 35.6 and 58.5% by microwave irradiation at 900 W for 40 s and at 1050 W for 60 s, respectively. The 35.6 and 58.5% Z ‐isomerization treatment improves lycopene content of extract (by 6.0 or 8.5 times for press extraction, 7.8 or 13.5 times for ethanol extraction, and 4.5 or 6.1 times for supercritical CO 2 (SC‐CO 2 )extraction, respectively) compared with no treatment. In addition, the extracts containes high amounts of lycopene Z ‐isomers, which have higher bioavailability and antioxidant capacity than (all‐ E )‐lycopene. Practical Applications : This study clearly shows that lycopene recovery by press, organic solvent, and SC‐CO 2 extraction from dried gac aril improved by the increase in the Z ‐isomer content. It indicates that the Z ‐isomers are more soluble in oil, organic solvent, and SC‐CO 2 than the all‐ E ‐isomer. Moreover, the thermal Z ‐isomerization pre‐treatment increases the content of lycopene Z ‐isomers in the extract. Therefore, this procedure is important not only for improving the productivity of lycopene, but also for providing a highly functionalized extract. The effect of the Z ‐isomerization, induced by microwave irradiation pre‐treatment of gac ( Momordica cochinchinensis Spreng.) aril, on the lycopene recovery and lycopene content of the extracts obtained using press, ethanol, and SC‐CO 2 extractions is investigated. For all extraction methods, as the content of Z ‐isomers in the raw material increases, the recovery and lycopene content of gac extracts improve.