Ohmic heating assisted extraction improves the concentrations of phytochemicals in rice bran oil and unsaponifiable matter

Ohmic heating assisted extraction improves the concentrations of phytochemicals in rice bran oil and unsaponifiable matter


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English :

Abstract: The impact of ohmic heating-assisted solvent extraction (OHM-AE) of oil and unsaponifiable matter (USM) from rice bran was investigated for different concentrations of tocols and γ-oryzanol. Rice bran samples with moisture contents (MC) of 30% and 40% were ohmicallytreated with three levels of electric field strength (E) at 100, 150 and 200 V/cm prior to extraction of rice bran oil and USM. Oil and USM prepared by conventional methods (CM) were included as controls. OHM-AE increased the concentration of phytochemicals and antioxidant activity of both rice bran oil and USM. The highest concentrations of γ-tocopherol, γ-tocotrienol, γ-oryzanol and total phenolic content in the oil and USM were observed in the bran with 30% MC (extracted by OHM-AE at 150 and 200 V/cm), and the bran with 40% MC (extracted at 100, 150, and 200 V/cm). Similarly, OHM-AE under these conditions yielded higher oil recovery with stronger antioxidant activity than the CM method. This suggested that OHM-AE could be an effective method to extract rice bran, offering both increased oil yield and high concentration of phytochemicals.