Intensification of phenolic compounds extraction from purple maize using IVDV (Intensification of Vaporization by Decompression to the Vacuum)

Abstract

Purple maize is a pigmented variety originally cultivated in Latin America; it has the highest phenolic and anthocyanin content. Recently, a new process has been developed, called «Intensification of Vaporization by Decompression to the Vacuum» (IVDV). IVDV is a thermo-mechanical treatment inducing an intense extraction of inside components. Purple maize (Zea mays indurata L.) was rehydrated by soaking in distilled water at 25°C. Samples were then subjected to IVDV consisting in exposing them to a saturated steam (up to 15 bars) for a few second (compression time is less than 1 second) followed by an instant decompression towards vacuum. The resulting extraction rate varies according to the operating conditions. The study was carried out by measuring the antioxidant components of treated kernels. IVDV treatment induces a direct extraction of almost 50% of the phenolic compound content in less than 15 seconds. Phenolic compounds remaining in the product can be extracted in less than 30 minutes by maceration, compared to 24 hours for the raw product. Conclusion: IVDV extract and intensify the extraction of biomolecules from vegetable matrices.