AbstractBACKGROUND: Sorghum possesses phenolic compounds that are health‐promoting constituents of the grain. There are approximately 40 000 sorghum accessions, many of which have not been evaluated for the grain's health‐promoting potential. Conventional methods for measuring total phenolic content, flavonoid content and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH)‐scavenging capacity are time‐consuming and labour‐intensive, resulting in low overall throughput. The objective of this study was to develop a high‐throughput screening assay for large sorghum sample sets to determine flavonoid and phenolic content and to modify existing DPPH and total phenolic assays.
RESULTS: The 96‐well assays exhibited a correlation of > 0.9 with the conventional assays. The 96‐well assays allowed for up to 64 samples to be run per day compared with 20–24 samples (depending on the test) for the conventional methods. The 96‐well assays had excellent accuracy (97.65–106.16% recovery), precision (1.06–8.28% coefficient of variation (CV)) and reproducibility (1.32–2.13% CV inter‐day and 1.36–2.09% CV intra‐day).
CONCLUSION: The high‐throughput 96‐well plate method proved to be as robust and reproducible as the conventional method for determining total phenolic content, flavonoid content and DPPH‐scavenging capacity in either sorghum bran or flour. Published 2012 by John Wiley & Sons, Ltd.
