Sorghum phenolic compounds: Revisiting the therapeutic aspects and processing opportunities

Authors: SANTANA, ADINA - Kansas State University; Peterson, Jaymi; SILIVERU, KALIRAMESH - Kansas State University; Smolensky, Dmitriy

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 12/1/2023
Publication Date: 4/18/2024
Citation: Santana, A.L., Peterson, J.M., Siliveru, K., Smolensky, D. 2024. Sorghum phenolic compounds: Revisiting the therapeutic aspects and processing opportunities. In: Mérillon, JM., Ramawat, K.G. (eds) Plant Specialized Metabolites. Reference Series in Phytochemistry. Springer, Cham. https://doi.org/10.1007/978-3-031-30037-0_14-1.
DOI: https://doi.org/10.1007/978-3-031-30037-0_14-1

Interpretive Summary: Sorghum (Sorghum bicolor (L.) Moench) has been commonly processed to produce gluten-free flour. Besides the absence of gluten, sorghum is valued for its bioactive properties attributed to the high concentration of phenolic compounds present in grain and leaf tissues. The goal of this chapter is to revisit the phenolic compounds recently found in sorghum tissues and the processes studied to enhance their recovery, to report on the chemical makeup of flavonoids, phenolic acids, and tannins, and to review the health benefits of the consumption of sorghum products. Many works published recently demonstrated the potential of sorghum phenolics against cancer in vitro and against obesity in vivo. However, there is no consensus on which class of phenolics is more active to promote the health benefits in sorghum. Studies to optimize the extraction of unique 3-deoxyanthocyanidins in sorghum bran and leaves have emerged in the last decade. Also, fractionation of sorghum grain extracts using Sephadex® LH-20 resin has been used to enhance the separation of condensed tannins from other classes of phenolics, since condensed tannins have been studied on their effects to improve animal health. Emerging technologies like supercritical technology, ultrasound- and microwave-assisted extraction coupled with green solvents have been studied to replace time consuming processes that use strong acids. Recent patented processes for the extraction of phenolic compounds for pharmaceuticals and cosmetics are also discussed.

Technical Abstract: Sorghum (Sorghum bicolor (L.) Moench) has been commonly processed to produce gluten-free flour. Besides the absence of gluten, sorghum is valued for its bioactive properties attributed to the high concentration of phenolic compounds present in grain and leaf tissues. The goal of this chapter is to revisit the phenolic compounds recently found in sorghum tissues and the processes studied to enhance their recovery, to report on the chemical makeup of flavonoids, phenolic acids, and tannins, and to review the health benefits of the consumption of sorghum products. Many works published recently demonstrated the potential of sorghum phenolics against cancer in vitro and against obesity in vivo. However, there is no consensus on which class of phenolics is more active to promote the health benefits in sorghum. Studies to optimize the extraction of unique 3-deoxyanthocyanidins in sorghum bran and leaves have emerged in the last decade. Also, fractionation of sorghum grain extracts using Sephadex® LH-20 resin has been used to enhance the separation of condensed tannins from other classes of phenolics, since condensed tannins have been studied on their effects to improve animal health. Emerging technologies like supercritical technology, ultrasound- and microwave-assisted extraction coupled with green solvents have been studied to replace time consuming processes that use strong acids. Recent patented processes for the extraction of phenolic compounds for pharmaceuticals and cosmetics are also discussed.