Effect of heat treatment on the secondary metabolites composition of Curcuma longa L. rhizome

Abstract

Abstract Turmeric (Curcuma longa L.) is a widely known plant that is commonly used as a spice. It is also a valuable raw material that is increasingly used in the pharmaceutical industry and, notably, in dietary supplement recipes. For a long time, the healing properties of turmeric have been used in folk medicine in many regions of the world, mainly to treat various types of diseases. When developing recipes and preparing preparations with medicinal properties, the turmeric rhizome is subjected to various types of thermal treatment. These processes cause qualitative and quantitative changes in the composition of the secondary metabolites present in the turmeric rhizome. Due to its great popularity and widespread use as a raw material with health-promoting properties, turmeric undeniably deserves an in-depth analysis in order to optimize the treatment process and minimize its negative impact on active compounds. The presented review summarizes the current state of knowledge on the impact of thermal treatment of the turmeric rhizome on the composition of its biologically active compounds. The data provided in this review indicate that the content of active compounds in turmeric rhizomes is strictly correlated not only with the used type of processing, but it also strongly depends on the selection of key parameters. Therefore, it is difficult to clearly indicate the type of processing that would be the most beneficial for the composition of its active compounds.