Comparison effects of PEF and SC-CO2 treatments on lycopene, β-carotene, lutein, β-cryptoxanthin, total polyphenols values, and antioxidant activity of tomato fruits.

Abstract

Since the recycling of composites from plant tissues is difficult, extraction of bioactive compounds from plant sources requires pre-treatment by new technology such as pulsed electric fields (PEF). Due to the reduced consumption of organic solvents, the extractive techniques such as using supercritical CO2 (SC-CO2) are of interest to researchers. This work aimed to investigating the influences of different parameters of SC-CO2 (pressure, modifier volume, temperature, and dynamic time) and PEF (frequency and field strength) treatments on the amount extraction of β-carotene, lycopene, lutein, β-cryptoxanthin, total phenol content (TPC), and also antioxidant activity percentage of tomato to obtain the optimum circumstances extraction via PEF and SC-CO2 methods. PEF data showed that treatments with moderate intensity (1 Hz and 0. 25 kV/cm) enhanced the extractability of lycopene (88%), β-carotene (69%), and β-cryptoxanthin (24%). The maximum recovery in total polyphenols was achieved at a 1 Hz and 1.75 kV/cm, leading to a 41.68% growth. The SC-CO2 results showed that extraction at 55°C and 35 MPa, and in a short time of 20 min (without any modifier: methanol) resulted in the highest levels of carotenoids (100% recovery), especially lycopene, and antioxidant activity. Largest value of total polyphenols was obtained at 35 MPa, 35°C, during 30 min, and 250 μL methanol as a modifier (58.79% recovery). Results showed that the extraction of polyphenols, unlike carotenoids, required a modifier. Organic solvents, often called modifiers, are sometimes added to the supercritical fluid to increase the polarity range of the extraction process and to help overcome analyte retention in the matrix. In this study, methanol was used as a modifier in different volumes. Therefore, the SC-CO2 gentle processing conditions, compared with PEF, improved the recovery of tomato bioactive compounds and antioxidant activity. Nevertheless, further studies are needed to optimize such treatments.