The role of phenolic acids on sorghum and maize hardness was evaluated among eight cultivars of each of the cereals representing hard and soft classes. Bran and flour fractions were evaluated for monomeric and diferulic phenolic acids using high performance liquid chromatographic and mass spectrometric (LC-MS/MS) techniques. Bran samples of harder grains had more phenolic acids than those of soft types. Intra-class testing showed slight differences in cultivars within the hard and soft classes. The content of phenolic acids was a useful indicator of hardness distinguishing between hard and soft maize and sorghum cultivars. Correlation coefficients between monomeric acids of maize bran, mostly ferulic acid, and grain hardness were higher than those of sorghum. Maize bran ferulic acid content was strongly correlated with Tangential Abrasive Dehulling Device (TADD) hardness (r = -0.776, p < 0.001). This study is the first to show that there is a relationship between bran phenolic acid content and sorghum and maize hardness.
ABSTRACT:To release bound phenolic acids, a microwave-assisted extraction procedure was applied to bran and flour fractions obtained from eight sorghum and eight maize cultivars varying in hardness. The procedure was followed by HPLC analysis and the identities of phenolic acids were confirmed by MS/MS spectra. The extraction of sorghum and maize bound phenolic acids was done for 90 sec in 2 M NaOH to release ferulic acid and pcoumaric acid from bran and flour. Two diferulic acids 8-O-4' and 8-5'-benzofuran form were identified and quantitated in sorghum bran and only the former in maize bran. The contents of ferulic acid and diferulic acids in sorghum bran were 416 to 827 µg/g and 25 to 179 µg/g, respectively compared to 2193 to 4779 µg/g and 271 to 819 µg/g in maize. Phenolic acid levels of sorghum were similar between hard and soft cultivars while those of maize differed significantly (p < 0.05) except for ferulic acid in flour. Sorghum phenolic acids were not correlated with grain hardness as measured using a tangential abrasive decortication device.Maize ferulic acid (r = -0.601, p < 0.01), p-coumaric acid (r = -0.668, p < 0.01) and 8-O-4'diferulic acid (r = -0.629, p < 0.01) were significantly correlated with hardness.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.