In recent years, sorghum has gained increasing attention not just as a climate-resilient staple crop, but also as a source of high-value bioactive compounds with applications beyond the food and feed sectors. A growing body of research highlights the potential of sorghum storage proteins—particularly kafirins—as a sustainable source of antioxidant peptides and cosmeceutical ingredients. Five recent studies collectively shed light on how these peptides, derived from enzymatically hydrolyzed kafirins, show promise for skin protection, anti-aging applications, and food-grade antioxidant formulations.
From Grain to Skin: Kafirin Peptides in Cosmeceuticals
Two recent studies led by Castro-Jácome et al. (2021, 2025) explored the use of enzymatically derived peptides from white sorghum kafirins as functional ingredients in skin care formulations. The researchers hydrolyzed α-, β-, and γ-kafirins using alcalase, and separated the products by ultrafiltration to yield peptide fractions of <1 kDa (PE-1 or KAF-UF1) and 1–3 kDa (PE-3 or KAF-UF3). Both fractions demonstrated significant protective effects on human skin cell cultures exposed to UVB radiation—reducing oxidative stress, suppressing pro-inflammatory cytokines (IL-1β, TNF-α, IFN-γ), and inhibiting enzymes associated with photoaging such as elastase, collagenase, and tyrosinase.
Using response surface methodology, the team also optimized the enzymatic conditions for maximal yield of these functional peptides. The optimal peptides were rich in hydrophobic amino acids (e.g., proline, leucine, isoleucine), and mimicked the antioxidant and anti-aging effects of glutathione, a benchmark compound in skin care. These findings suggest that white sorghum-derived peptides could become a valuable ingredient in the cosmeceutical industry, particularly for natural or plant-based skin care products.
Simulated Digestion and Functional Food Potential
Jiang et al. (2022) took a comparative approach to evaluate antioxidant peptides generated through simulated gastrointestinal (GI) digestion of sorghum and rice proteins. They identified the sorghum-derived peptide KP9, which showed notable ABTS radical-scavenging activity and was predicted to have favorable ADMET (absorption, distribution, metabolism, excretion, and toxicity) properties. Although some rice peptides performed better in DPPH and hydroxyl radical assays, the study confirms that digested sorghum peptides exhibit functional antioxidant activity and potential as dietary supplements to mitigate oxidative stress and chronic diseases.
Antioxidant Powerhouse: Kafirin Hydrolysates in Food Applications
Complementary studies by Xu et al. (2019) provided a systematic characterization of antioxidant activities of sorghum kafirin hydrolysates. The authors compared several enzymatic treatments and identified alcalase and Neutrase hydrolysis as particularly effective. Through ultrafiltration and gel-filtration chromatography, they found that medium-sized peptide fractions (3–10 kDa) had superior free radical scavenging ability, metal ion chelation, and oxidative stability in both emulsion and ground meat model systems. Inhibitory effects on lipid oxidation were especially promising, with over 80% reduction in oxidative products over a 14-day storage period.
Their peptide profiling via MALDI-TOF/TOF MS revealed several candidate sequences that could serve as functional antioxidants or natural preservatives. These studies not only expand the food applications of sorghum peptides but also present an eco-friendly alternative to synthetic antioxidants in food systems.
A Breakthrough in Biofabrication: Sorghum-Based Bioinks
Expanding sorghum’s utility into yet another cutting-edge domain, Barekat and Ubeyitogullari (2025) recently demonstrated the first use of sorghum proteins as a printable bioink for 3D food printing. By optimizing gel concentrations (20–30% w/w) and printing parameters (25% protein, 0.64 mm nozzle, 20 mm/s speed), the team developed hydrophobic protein-based gels with robust textural and rheological properties that allowed for high-fidelity printing.
Their work showed that gel microstructure and β-sheet content influenced printability, while maintaining an amorphous molecular organization confirmed by X-ray diffraction. These innovations position sorghum as a sustainable, plant-based material for 3D-printed foods and pharmaceuticals, unlocking new markets for sorghum-derived proteins in bioengineering (Barekat & Ubeyitogullari, 2025).
Implications for Sorghum Researchers and Breeders
These findings not only position sorghum as a promising source of natural antioxidants and skin-protective peptides, but also redefine its potential value across multiple sectors. For researchers and breeders, this opens new avenues to develop dual-purpose sorghum varieties optimized not only for agronomic performance but also for bioactive compound yield. By selecting for kafirin composition, enzymatic hydrolysis efficiency, and peptide bioactivity, sorghum improvement programs can align with growing global demand for sustainable, plant-based ingredients in functional foods, natural preservatives, cosmeceuticals and bioengineering applications. As the frontier of sorghum research expands beyond the grain, integrating biochemical insights with breeding strategies will be key to unlocking its full potential as a climate-resilient crop with high-value industrial applications.
References
Barekat S, Ubeyitogullari A. Maximizing sorghum proteins printability: Optimizing gel formulation and 3D-printing parameters to develop a novel bioink. Int J Biol Macromol. 2025 Apr;300:140245. doi: 10.1016/j.ijbiomac.2025.140245. Epub 2025 Jan 24. PMID: 39864687. Read more
Castro-Jácome TP, Alcántara-Quintana LE, Montalvo-González E, Chacón-López A, Kalixto-Sánchez MA, del Pilar Rivera M, López-García UM, Tovar-Pérez EG. Skin-protective properties of peptide extracts produced from white sorghum grain kafirins. Ind Crop Prod. 2021 Sept 1; 167: 113551, doi.org/10.1016/j.indcrop.2021.113551. Read more
Castro-Jácome TP, Tovar-Pérez EG, Alcántara-Quintana LE. Optimization of enzymatic production of anti-skin aging biopeptides from white sorghum [Sorghum bicolor (L) Moench] grain. Prep Biochem Biotechnol. 2025 Jan;55(1):81-92. doi: 10.1080/10826068.2024.2366994. Epub 2024 Jul 1. PMID: 38949113. Read more
Jiang P, Liu N, Xiu Y, Wang W, Wang C, Zhang D, Li Z. Identification and analysis of antioxidant peptides from sorghum (Sorghum bicolor L. Moench) on the basis of in vitro simulated gastrointestinal digestion. Food Funct. 2022 Sep 22;13(18):9635-9644. doi: 10.1039/d2fo01399a. PMID: 36017637. Read more
Xu S, Shen Y, Chen G, Bean S, Li Y. Antioxidant Characteristics and Identification of Peptides from Sorghum Kafirin Hydrolysates. J Food Sci. 2019 Aug;84(8):2065-2076. doi: 10.1111/1750-3841.14704. Epub 2019 Jul 17. PMID: 31313288. Read more
Xu S, Shen Y, Li Y. Antioxidant Activities of Sorghum Kafirin Alcalase Hydrolysates and Membrane/Gel Filtrated Fractions. Antioxidants (Basel). 2019 May 15;8(5):131. doi: 10.3390/antiox8050131. PMID: 31096591; PMCID: PMC6562729. Read more