Fig. 4
From: Metabolic Evidence on Vintage Effect in Tea (Camellia sinensis L.) Plants
OPLS-DA score (A – G) and loading (B – H) plots derived from 1H NMR spectra of tea leaf extracts, providing a pairwise plot for metabolic comparison between leaves of Jangwon 2 tea cultivar harvested from vintage years 2015 and 2016 (A and B), 2016 and 2017 (C and D), 2017 and 2018 (E and F) and 2018 and 2019 (G and H). In the loading plot (B), the upper section represents metabolites higher in tea leaves from 2016 vintage compared to tea leaves in 2015 vintage, whereas the bottom section denotes metabolites lower in tea leaves in 2016 vintage tea plants. The color code in the loading plot corresponds to the correlation of the variables. All OPLS-DA modes were generated with one predictive component and one orthogonal component and validated by a permutation test (Additional file 1: Fig. S8). Ala, alanine; Ara 2-O-(β-L-Arabinopyranosyl)-myo-inositol, EC epicatechin, ECG epicatechin gallate, EGC epigallocatechin, EGCG epigallocatechin gallate, EGCG3''Me, epicatechin 3-O-(3-O-methyl)-gallate, GABA γ-aminobutyrate, GC gallocatechin, Glu glutamate, Gln glutamine, Ile isoleucine, Leu leucine, ThG theogallin, Thr threonine, Val valine