African Journal of
Food Science

  • Abbreviation: Afr. J. Food Sci.
  • Language: English
  • ISSN: 1996-0794
  • DOI: 10.5897/AJFS
  • Start Year: 2007
  • Published Articles: 975

Full Length Research Paper

Optimization of fermentation and malting process of sorghum beverage and effects on nutritional quality

Kiptanui Elisha Bwamu
  • Kiptanui Elisha Bwamu
  • Department of Food Technology and Nutrition, Faculty of Agriculture, University of Nairobi, Kenya.
  • Google Scholar
Kunyanga Catherine Nkirote
  • Kunyanga Catherine Nkirote
  • Department of Food Technology and Nutrition, Faculty of Agriculture, University of Nairobi, Kenya.
  • Google Scholar
Ngugi Eliud Kahiu
  • Ngugi Eliud Kahiu
  • Department of Food Technology and Nutrition, Faculty of Agriculture, University of Nairobi, Kenya.
  • Google Scholar
Kimani David Edgar
  • Kimani David Edgar
  • Department of Food Technology and Nutrition, Faculty of Agriculture, University of Nairobi, Kenya.
  • Google Scholar


  •  Received: 11 July 2022
  •  Accepted: 07 October 2022
  •  Published: 31 October 2022

Abstract

Sorghum is a nutritious and under-utilized cereal whose potential in development of nutritious ready-to-drink beverages remains unexplored. The objective of the study was to optimize malting and fermentation conditions to obtain a nutritionally superior new sorghum product. Four beverage formulations containing sweetened sorghum malt extracts were developed through fermentation using kombucha culture at different temperatures (between 20 and 35°C). The formulations were also malted for three, four and five days and analyzed for nutritional characteristics. The iron, total phenolics and vitamin C contents in the formulations ranged from 0.125 ± 0.292 to 2.956 ± 13.83 mg/100g, 0.1328 ± 0.00594 to 1.6601 ± 0.0640 mg GAE/100 ml and 4.3505 ± 0.2797 to 6.1304c ± 0.2797 mg/100 ml respectively. Iron was used in the process optimization to select the best beverage which had high nutritional and sensory quality. The mean contents of iron in the beverages ranged from 1.25 ± 0.292 mg/kg (formulation 5D1) to 29.56 ± 13.83 mg/kg (formulation 4D). The best formulation was obtained from an optimum of four days malting and fermentation temperature of 25°C (4D). The findings indicate that nutritious beverages can be developed from sorghum by employing different malting days and fermentation conditions to come up with products having varying levels of iron, vitamin c and phenolics depending on your process or consumer needs.

 

Key words: Sorghum, kombucha, malting, fermentation.