| Popis: |
Sorghum is among the predominant food plants in sub-Saharan Africa with established dietary and health benefits. The purpose of this study was to evaluate the physical and nutritional characteristics and phenolic compounds of some of the sorghum genotypes grown in South Africa. The varieties investigated were white (Macia-SA), red (M48) and brown sorghum (M153). The Association of Official Analytical Chemists (AOAC) method was used for physical, nutritional and mineral examination and the Waters Synapt G2 quadruple time-of-flight (QTOF) mass spectrometer (MS) for the evaluation of the phenolic compound. The highest mineral content for the genotypes was potassium, in the range of 3599.24, 4248.04, and 4763.45 mg/kg; the highest value recorded was in the brown sorghum (SBrown) variety. The white sorghum (SWhite) variety had higher dry matter (DM), gross energy (GE) and starch contents compared to the red and brown types. Furthermore, higher ash, crude protein (CP) and ether extract (EE) values were observed in respect of the red sorghum variety. The most abundant phenolic compound in this study was caffeic acid, and this was more in the red sorghum. Naringenin-7-O-glucoside was the only quantified flavonoid, the highest content was reported in the red sorghum genotype. The Principal Component Analysis (PCA) showed that p-coumaric acid, chlorogenic acid, caffeic acid and naringenin-7-O-glucoside contributed largely to the clustering of the genotypes in component 1 (PC1), while feruloylquinic acid and ferulic acid contributed to the clustering of component 2 (PC2). High component loadings for PC1 were contributed by the red sorghum (SRed) variety. These results suggest that sorghum varieties grown under South African climatic conditions are rich sources of valuable nutrients and diverse phenolic compounds, with brown and red sorghum types being the outstanding varieties. Sorghum’s unique phenolic profile qualifies it to be used to lessen oxidative stress and prevent diseases such as cancer. It has the potential to be utilized in the development of functional food additives. |
