Total phenolic, isothiocyanate and radicle elongation determination of mung bean sprout during germination affected by different variables of pulsed electric field treatment

Abstract

Mung bean germination started with moisture uptake, biochemical modification, interconversion and biosynthesis of metabolites. Mung bean sprout was commonly used a fresh salad vegetable with available amino acids, dietary fiber, minerals, vitamins and phytonutrients. Pulsed electric field (PEF) was a prominent technology as a green approach for improvement of seed germination. This research evaluated some technical parameters of PEF such as pulse electric field strength (300-1500 kV/cm), pulse number (50-250) and pulse width (1.0-3.0 µs) at a stable frequency 1 Hz in ambient temperature on the total phenolic, isothiocyanate and radicle elongation of mung bean sprout. Results showed that pulse electric field strength and pulse number significantly increased isothiocyanate and total phenolic content while retardation of root length extension. Meanwhile pulse width showed a negative impact on total phenolic, isothiocyanate while extending root length extension. PEF should be conducted at pulse electric field strength (1200 kV/cm), pulse number (150), pulse width (1.5 µs) to retain the highest isothiocyanate (33.96±0.35 nmol/sprout) and total phenolic (221.30±1.46 mg GAE/100 g) while keeping a fair radicle elongation (8.39±0.17 mm). PEF treatment would be a promising non-lethal technology feasible for mung bean seed sprouting improvement.