Nutritional Compositions of Optimally Processed Umqombothi (a South African Indigenous Beer)

Abstract

Umqombothi (a South African indigenous beer) is an important dietary beverage for many undernourished, low-income consumers in rural, semi-urban and urban areas. Umqombothi was brewed using optimal conditions earlier obtained and compared to the customary beer brew (CB) and mixed raw ingredients (RI). The products were evaluated for proximate compositions, minerals, amino acids, B-group vitamins, and sugar compounds. The optimised beer brew (OPB) was relatively higher in energy (165 kcal), crude protein (8.6%), and ash content (1.0%). The CB had the highest concentration of sodium (299.8 mg/kg), magnesium (1170.5 mg/kg), potassium (2993.8 mg/kg), and phosphorus (2100.7 mg/kg). Glutamic acid was the highest detected amino acid, with concentrations of 1.5 g/100 g, 1.5 g/100 g, and 1.6 g/100 g in the RI, CB, and OPB, respectively. The OPB contained a higher concentration of the two forms of vitamin B3, nicotinamide (0.2 µg/g) and nicotinic acid (0.7 µg/g) in comparison to the CB. The concentration of the antioxidant, mannitol, was 0.4 mg/g, 0.2 mg/g, and 2.0 mg/g in the RI, CB, and OPB respectively. Overall, OPB displayed a desirable nutritional profile compared to the CB.

Biochemical properties, nutritional quality, colour profile and techno‐functional properties of whole grain sourdough and malted cowpea and quinoa flours

“…The digestion of the samples was achieved using the modified method by Hlangwani et al . (2021) and employing a MARS 6 microwave digester (CEM, Batch Microwave Acid Digestion system; One Touch TM Technology, Matthews, NC, USA). Briefly, 0.5 g of flour samples in triplicate were measured into MARS Xpress vessels (CEM Corporation, Matthews, NC, USA).…”

“…1.1 (PerkinElmer, Inc., Waltham, MA, USA) was employed for this analysis using the modified method by Hlangwani et al . (2021). Calibration standards and certified reference material for spectroscopy (De Bruyn spectroscopic solutions, Midrand, South Africa) were prepared as pure stock and working standard solutions of Calcium (Ca), Chromium (Cr), Copper (Cu), Magnesium (Mg), Manganese (Mn), Molybdenum (Mo), Phosphorus (P), Potassium (K), Iron (Fe), Sodium (Na) and Zinc (Zn).…”

“…Microwave digestion. The digestion of the samples was achieved using the modified method by Hlangwani et al (2021)…”

Analysis of the bacterial and fungal populations in South African sorghum beer (umqombothi) using full-length 16S rRNA amplicon sequencing

“…The mixture was then fermented at 29.3 °C for 25.9 h to obtain the OPB. In contrast, the customary beer brew (CB) was prepared following the traditional production method highlighted in Hlangwani et al ( 2021b ). The mixed ingredients were cooked for 30 min at 95 °C and the mixture was allowed to cool to 25 °C.…”

Physicochemical and microbiological changes during two-stage fermentation production of umqombothi

“…The effective determination of chemical and microbiological content and nutritional composition by Ref. [ 15 ] encourages the need to investigate the production of Umqombothi (Xhosa version) under different controlled fermentation temperatures. The objective of this study was to determine the optimal fermentation temperatures of Umqombothi and to evaluate the physicochemical, microbiological, and sensory characteristics of the final product.…”