Fig. 5

In field-grown samples of Plantago ovata, the extraction pipeline has utility in quality testing when coupled with yield and chromatographic analysis. a Visual inspection of damaged seed provides a baseline quality score. b Yield of total mucilage varied most significantly between times of sowing with a minor intervarietal effect. c Heteroxylan content (the proportion of arabinose and xylose residues in extracted mucilage) inversely related to mucilage yield and seed quality. d The ratio of arabinose to xylose residues in extracted mucilage (an approximation of heteroxylan branching) remains unchanged indicating that seed and mucilage development were unperturbed. e Seed grown at trial sites in 2017 is unevenly coloured, with many blackened seeds while, f seeds grown at the same site in 2018 are more consistent, with the light-coloured husk material consistently visible on seeds. g In the 2017 field trials (analysed are samples from 2017a), significant quantities of mannose were identified by monosaccharide analysis in extracted mucilage of each variety grown indicative of seed damage-related endosperm leakage. Contrastingly, only trace amounts (well below the limit of quantitation) were found in the same varieties grown in the following year, 2018. Dotted line in a–d indicates the value of a quality control sample (QC). Error bars represent one standard deviation (some are small and not easily visible)