Rapid Fire Oral Presentation 49th Nutrition Society of Australia Annual Scientific Meeting 2025

Enhancing the functional potential of black sorghum through germination: Polyphenol profile, antioxidant activity, and nutritional implications (129803)

Nidhish Francis 1 2 , Yogita Sharma 1 2 , Chris Blanchard 1 2 , Abishek Santhakumar 1 2
  1. School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
  2. Gulbali Institute, Charles Sturt University, Wagga Wagga, NSW, Australia

Sorghum (Sorghum bicolor L.), a climate-resilient grain, is gaining recognition for its rich polyphenol content, particularly tannins, flavonoids, and phenolic acids and is strongly linked to antioxidant and metabolic health benefits(1). Germination is an accessible, sustainable grain processing technique shown to enhance nutrient density(2), but its effects on the polyphenol profile and functional properties of pigmented sorghum varieties remain underexplored. This study aimed to evaluate the impact of germination on the polyphenolic composition and antioxidant capacity of black sorghum. Grains were soaked for 24 hours and germinated in the dark for 72 hours, followed by heat drying. Polyphenols were extracted using a standard protocol(3). Antioxidant activity was assessed using total phenolic content (TPC), DPPH radical scavenging, and Ferric Reducing Antioxidant Power (FRAP) assays. The TPCs of germinated and non-germinated sorghum samples were 65.013 and 60.012 mg GAE/g dry weight, respectively. At concentrations of 50 and 100 µg/mL, germinated samples exhibited significantly higher (p < 0.05) DPPH radical scavenging activity, with increases of 22.3% and 33.6% compared to controls. Trolox Equivalent Antioxidant Capacity (TEAC), based on DPPH, was significantly enhanced by germination, with values of 777.02 µmol TE/g in germinated samples versus 455.34 µmol TE/g in non-germinated samples (p < 0.05). FRAP values were 738.39 µmol TE/100 g for germinated and 722.38 µmol TE/100 g for non-germinated samples, indicating a modest increase in ferric-reducing capacity. These findings suggest that germination improves the antioxidant potential and nutritional profile of black sorghum, supporting its development as a functional food. This research contributes to the advancement of value-added, climate-smart grains in Australia and aligns with public health nutrition goals.

  1. Francis N, Rao S, Blanchard, C, et al (2019). Molecules, 24(18), 3321.
  2. Ansari F & Pourjafar H (2022). In Retention of Bioactives in Food Processing (pp. 277-308). Springer International Publishing.
  3. Collins A, Francis N, Chinkwo K, et al (2024). Molecules, 29(22), 5229.