The role of pulsed electric field (PEF) with thermocontrol modification as an elicitor to increase bioactive compound in local soybean

Abstract

Soybean is an agricultural commodity, being third in harvest amount after paddy and corn. The processing of soybean using heat causes the bioactive compounds to decrease. There is another way to increase the bioactive compounds in soybeans. Elicitation is a method that functions to increase biosynthesis of secondary metabolite formation in plants by using elicitor. This research used Factorial Randomized Block Design method with 2 factors which were temperature (25 °C, 35 °C and 45 °C) and pulsed field (3 kV, 5 kV and 7 kV). Electrical voltage test result from device obtained input voltage 0.76 V resulted 3 kV, 1.04 V resulted 5 kV, 1.4 V resulted 7 kV. Research results on soybean extract obtained total phenol as much as 2.76 mg GAE/g, total flavonoid 0.31 mg QE/g, tannin content 0.18 mg/g, IC50 as much as 626.95 ppm. Whereas for the results of extraction of soybeans in the best treatment was obtained at the pulsed field of 3 kV and temperature of 25 °C. Total phenol result was 2.92 mg GAE/g, total flavonoid 0.37 mg QE/g, tannin content 0.19 mg/g, antioxidant activitiy IC50 128.84 mg/L. The voltage and temperature treatment is given gave a significant difference in effect (p < 0.05) and interaction on all parameters. The best treatment in this study was obtained at a value of 3 kV and a temperature of 25 °C with characteristics of total phenol of 2.92 mg GAE/g, flavonoids of 0.37 mg QE/g, tannin of 0.19 mg TAE/g and antioxidant activity IC50 of 128.84 ppm. In the results of this study, there was no elicitation process because there were no research steps that showed that the elicitation process could occur.