Sustainable Production of Polyphenols and Antioxidants by Plant In Vitro Cultures

Abstract

Phenolic compounds represent big group of plant secondary metabolites that influence flavor, color, and texture and can be used as food additives, nutraceuticals, and pharmaceuticals. However, there are some limitations in obtaining sufficient amount of these bioactive compounds from plants, because they are rather seldom or occur naturally in plant tissues only at very low concentrations. Alternatively, it is possible to synthesize them chemically, but this way if oft technologically not possible or very sophisticated and economically infeasible. Plant in vitro cultures provide an attractive route to produce high-value plant-derived products and therefore can be an alternative source of valuable phenolics. Moreover, compounds synthesized by plant in vitro cultures are natural products and therefore can be more easily accepted by consumers as artificially synthetized substances. The synthesis of phytochemicals by plant in vitro cultures in contrast to these in plants is not depending on environmental conditions and can be regulated through standard physical and chemical conditions in bioreactor, which helps to avoid qualitative and quantitative fluctuations in product yield. The process of obtaining valuable phytochemicals can be represented as a multistage technology, each link of which can vary individually in dependence of specific requirements of in vitro cultures (e.g., phytohormones, nutrients, light) or properties of end product (e.g., antioxidative potential, stability). For the establishment of high-producing and fast-growing cell lines, the parent plants should be selected (Murthy et al. Strategies for enhanced production of plant secondary metabolites from cell and organ cultures. In: Production of biomass and bioactive compounds using bioreactor technology (pp. 471–509). Springer Plus). The expression of synthetic pathways can be influenced by environmental conditions, the supply of precursors, and the application of elicitors (Schreiner, Eur J Nutr 44(2):85–94, 2005) as well as altered by special treatments like biotransformation and immobilization (Georgiev et al., Appl Microbiol Biotechnol 83:809–823, 2009). The efficiency of bioprocessing can be increased by the simplification of methods for product recovery and afterward its stabilization. This chapter reviews the recent advances in the optimization of environmental factors for production of phenolics by plant in vitro cultures, new developments in bioprocessing of plant cell, hairy root and organ cultures, and emerging technologies on phytochemical recovery.