Research on extraction and formulation intensification processes for natural actives of wine

Figure 1. Temperature profiles for the different extraction processes

Polyphenols are considered as high value products by cosmetic and food industry due to, mainly, their great antioxidant power. Therefore, new extraction techniques have been investigated in recent years in order to find how to preserve the extract quality during the process. Microwave assisted extraction has been found to provide good results. It allows to reduce extraction time and the amount of solvent required. However, during this work, microwave radiation has been used as a pretreatment for a conventional process: instead of irradiating the sample up to a mild temperature (difficult industry implementation), an intensive pretreatment has been employed. In it, temperature is raised up to close to the solvent’s boiling point by a short microwave pulse; then, the sample is rapidly cooled down and undergoes a brief solid-liquid conventional extracion. An innovative aspect of this research is that the combination of microwaves and pressure has also been studied. As pressure increases, solvent boiling point rises too. This enables extraction to be carried out at a higher temperature, and in consequence, extraction kinetices are accelerated. Continue Reading →