Fig. 4

Left: Raman spectra of nine different potato varieties separated into three groups (a–c) for clarity of visualization. Asterisk (*) denotes 1460 cm⁻¹ peak was used to normalize spectra. Right: Means (circles) and confidence intervals for the intensities of the potato spectra at 1126 cm⁻¹ (starch), 1527 cm⁻¹ (carotenoids), 1600 cm⁻¹ (phenylpropanoids) and 1660 cm⁻¹ (proteins). ANOVA of starch revealed 3 groups of potato varieties (blue, red and black) with significantly different starch contents. ANOVA of carotenoids revealed 2 groups of potato varieties (blue and red) with significantly different carotenoid contents. ANOVA of phenylpropanoids revealed 3 groups of potato varieties (blue, red, and black) with significantly different phenylpropanoid contents. ANOVA of proteins revealed 2 groups of potato varieties (blue and red) with significantly different protein contents. Multiple colors indicate a member of a group that has overlap between two separate groups. The caption and figure reproduced with permission from Morey et al. [34]