HPLC-DAD Polyphenolic Profiling and Antioxidant Activities of Sorghum bicolor during Germination

Abstract

The purpose of this study was to assess the suitability of the Romanian Albanus hybrid of Sorghum bicolor as a potential functional food ingredient. Ultrasound-assisted extraction in different solvents, together with spectrophotometric and chromatographic methods, was used to monitor the variation in total phenolic and flavonoid content and the antioxidant activity of raw sorghum grains before and during short germination periods (24, 36 and 48 h). The High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) investigation of the extracts revealed that the ungerminated sorghum grains extracted with methanol had the highest diversity of phenolic compounds, while the total phenolic content (TPC) was the highest after 36 h of germination in both extract types: 1853 mg GAE/100 g for the methanolic extract and 1726 mg GAE/100 g for the ethanolic extract. The findings of this study showed that the TPC of sorghum extracts is strongly correlated with their antioxidant activity and, overall, that the studied extracts presented a good radical scavenger activity, which supports the benefits of alimentary uses of Sorghum bicolor grains.

Reversed-Phase HPLC Characterization and Quantification and Antioxidant Capacity of the Phenolic Acids and Flavonoids Extracted From Eight Varieties of Sorghum Grown in Austria

“…It presented a UV λ max at 325 nm and had a comparable spectrum to the one from chlorogenic acid reported in literature ( Robbins, 2003 ). This compound was also found in sorghum in previous studies, with a similar retention behavior ( Ghinea et al, 2021 ). Moreover, a study on millet reported its presence only in a free form ( Chandrasekara and Shahidi, 2011 ).…”

Sono-Biosynthesis and Characterization of AuNPs from Danube Delta Nymphaea alba Root Extracts and Their Biological Properties

“…For the calibration curves, concentrations between 10 and 400 µg/mL were used. The total polyphenols were analyzed at 300 nm detection [97][98][99].…”

“…After 30 min of standing at room temperature, the samples were placed in a Tecan Pro 200 multiwell plate reader (Tecan, Männedorf, Switzerland) and their absorbance was recorded at 760 nm. As the standard references, gallic acid (0.97-500 µg/mL) and tannic acid (0.97-500 µg/mL) were used, and the results were expressed as equivalents of gallic acid (mg GAEq/g) and tannic acid (mg TAEq/g) per 1 g of sample [97][98][99].…”

“…AlCl 3 and ultrapure water were used to prepare the blank samples. As the standard references, quercetin (0.45-250 µg/mL) and rutin (0.45-250 µg/mL) were used, and the results were expressed as equivalents of quercetin (mg QEq/g) and rutin (mg REq/g) per 1 g of the sample [97][98][99].…”

Protective Effects of Fruit Wines against Hydrogen Peroxide—Induced Oxidative Stress in Rat Synaptosomes

“…In addition, non-enzymatic antioxidants, such as flavonoids and phenolic acids, are significantly involved, too. Flavonoids are known as good antioxidants that are able, due to the fact of their polyphenolic structure, to scavenge free radicals and chelate divalent cations [8,9]. Rich sources of these compounds are fruit, vegetables, nuts, seeds, and beverages (fruit wine, grape wine, as well as tea) [10][11][12].…”