Fig. 3.

Box plot comparison of bound phenolic acids in maize seeds extracted by the conventional and improved methods. a Determination of p-coumaric acid. b Determination of trans-ferulic acid. c Standard deviation of p-coumaric acid. d Standard deviation ferulic acid. Horizontal line represents the median. Vertical line represents the maximum and minimum value. Box covers the 75th and 25th percentiles. [⁺Results expressed as µg per g dry weight (µg/g dw). Significant differences between the methods were established by ANOVA (α = 0.05), ns: no significance, * p < 0.05; ** p < 0.001; *** p < 0.001]