A study was undertaken to research the polyphenolic composition of various plant materials by the use of UPLC and HRAM mass spectrometry. This was done in the context of proof-of-principle projects with the intention of attracting new funding.
Polyphenols are natural products present in all plant material. They are of benefit to animals as they play a role in the prevention of disease though the main focus of published research has been that of human health. The analytical challenge here is the characterisation of the polyphenols present within a complex biochemical background matrix. Also this will be applied to plant materials that have not yet been characterised in this manner or detail.
The aim of this study is to address these challenges by using cutting edge instrumentation, namely UPLC to provide efficient chromatographic separation followed by detection using high resolution/accurate mass, mass spectrometry. Furthermore it is hoped that this new information will provide a route for adding value to industrial waste and also provide a way of satisfying consumer needs and demands within the tea industry by gaining a better understanding of the phytochemistry involved. An example of this is the profound effect of tea processing methods on the flavours and odours of the finished product, which is so far poorly understood.
The focus included 3 areas of study: firstly the study of forestry waste, secondly the study of agricultural and aquacultural waste and thirdly the study of various types of tea. The techniques used were discovery metabolomics (untargeted) and external standard analysis for quantification (targeted). Also multivariate statistics were used for data interpretation including supervised and unsupervised models.
The results provide a path for each of the industries involved to gain a commercial advantage or a competitive edge. In terms of the waste from the forestry, agriculture and aquaculture industries, profit could be made from this waste plant material and hence this can add to their financial viability. A wide array of polyphenolic compounds were shown to be present here including Rutin, Epigallocatechin gallate and Matairesinol. In the case of the tea industry, this analytical approach gave detail on the phytochemistry of teas which had undergone a variety of harvesting and processing methods and also provided tentative identifications for many compounds of interest including , Theasinensins, Theaflavins, Cyanidin and Theogallin.
From a wider perspective this approach can be readily applied to other plant materials to reveal metabolites of importance. Although polyphenols were the focus of this study, with minor adjustments, this workflow could be applied to the study of many other groups of compounds.