Phenethyl isothiocyanate microwave with hydrodiffusion and gravity

The presently described, for the first time, the application of microwave gravity hydrodiffusion (MHG) technique, a solvent-free extraction technique, with the aim of obtaining isothiocyanates (ITC) from cruciferous vegetables. For this, we discovered that freezing is essential for forming ITC and an important step for its extraction by MHG (microwave power: 1.5 – 2.5 W/g; extraction time: 10 – 30 min). The advantages of this method are obtaining two liquid fractions (PLF + WLF) that can be used in different applications and a solid fraction (plant biomass) that can be reused, contributing to the preservation of biodiversity. In conclusion, this green extraction method facilitates scaling-up, greater purity of the extract (no traces of polluting solvents), and reduced extraction time from hours to minutes, a low environmental impact process. In our prototype, the amount of phenylethyl isothiocyanate (PEITC, 1557 ± 487 μg PEITC/g watercress dry basis) are comparable to the conventional and non-conventional extract techniques reported in the literature.