Biotransformation of phenolic acids from by-products using heterogeneous biocatalysts: One more step towards a circular economy

Abstract Biotransformations face the challenge of transforming industrial by-products into high added-value ingredients for the cosmetic, food, and pharma industry. Phenolic acids are interesting molecules contained in several agro-industrial by-products and a nice example of how enzymatic technology can transform them into high-value products. Nonetheless, most of the employed enzymes are labile and need to be immobilized to achieve robust heterogeneous biocatalysts for the intensification of sustainable processes. Through heterogeneous biocatalysts employing these economical and available raw materials, modified hydrophilic-lipophilic balance phenolics acids derivatives or interesting aromas and flavours can be obtained, turning environmental risks into business opportunities. In this review, we give an outlook of the most recent state of the art in this topic, which may allow giving a step towards a circular economy.