Regulating the composition of anthocyanins and phenolic acids in a sweetpotato cell culture towards production of polyphenolic complex with enhanced physiological activity

Abstract

Recent confirmation in the scientific literature of the health-promoting qualities of natural food colorants prompted their increased application in food products. Anthocyanins, a large group of natural pigments, include compounds with diverse molecular structures and different physiological activities. Therefore, selection of specific anthocyanins with enhanced bioactivity for application in functional foods needs to be addressed. Biotechnology offers an opportunity for ongoing production of selected phytochemicals for application in pharmaceutical, cosmetic or food industries. However, application of plant cell culture for commercial production of natural food colorants is still not an achieved goal due to lack of economical viability. One of the ways of improving the efficiency of the system is the production of high-value compounds superior to those accumulated in field-grown plant. This paper presents a review of our earlier works aiming to establish a plant cell culture-based system for the production of anthocyanin–phenolic acid complex with enhanced stability and physiological activity from a high-anthocyanin accumulating cell line generated from the storage root of sweetpotato ( Ipomoea batatas L.), cv. Ayamurasaki. Modifications of the physical and chemical environment of culture growth have been employed to direct the in vitro production of anthocyanins towards the generation of components with enhanced stability and radical scavenging ability. Under the same conditions we have enhanced the accumulation of caffeic acid and chlorogenic (caffeoylquinic) acid and induced accumulation of derivatives: 4,5-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 3,4-dicaffeoylquinic acid and 3,4,5-tricaffeoylquinic acid. In vitro generation of polyphenolic complex consisting of selected anthocyanins and phenolic acids with enhanced nutraceutical value has been achieved.