Polyphenols content of berry leaves and calluses

Abstract

Secondary plant metabolites are synthetized as stress-responding compounds and provide selective advantages to plants. This is a huge group of compounds with heterogeneous structures. One of the biggest classes of these compounds are polyphenols. Most of them also act as antioxidants, providing benefits for human health. Consequently, food scientists explore possibilities for the isolation and application of these bioactive compounds in food industry. In order to obtain polyphenols, which are present in the plant in low quantities, conventional plant cultivation is not efficient enough. In vitro plant tissue culture techniques, in highly controlled conditions and using appropriate medium, allow, in shorter period of time, production of the whole plant or the plant tissue with ability to synthesize desired compounds, overcoming this problem. In order to determine whether in vitro tissues can be a good source of polyphenols, in this paper, in vitro shoot and callus cultures were established. It was done with two berry fruit genotypes – blackberry (Rubus subg. Rubus Watson ‘Čačanska Bestrna’) and blueberry (Vaccinium corumbosum L. ‘Toro’). Extraction and quantification of total phenolics (TPC) and total flavonoid content (TFC) were done both from callus and leaves tissues obtained from in vitro plants, as well as from field-grown plants. TPC and TFC were the highest in leaves of blueberry (13.47–14.06 mg GAE/g DW, for in vitro and field-grown plants, respectively) whereas low TPC and TFC values (0,78–2,39 mgGAE/g DW) for both callus cultures were obtained. Results show that in vitro tissues could be a good source of polyphenols. Considering the cultivation time reduction and the process simplification, tissues are rentable sources of polyphenols.