Proximate and Mineral Composition of A Sorghum Stem Sheath Beverage (Poporo) Spiced with Aframomum melegueta Extract

Aims: The nutritional quality of a non-alcoholic beverage produced from sorghum stem sheath (Poporo) spiced with alligator pepper (Aframomum melegueta).
Study Design: Multifactorial design was used for this study.
Place and Duration of Study: The study was carried out in the Chemistry, Food Processing, Sensory and Microbiology Laboratories of the Department of Food Science and Technology, Federal University of Technology, Akure, Ondo State, Nigeria, between September, 2011 and July, 2012.
Methodology: Dried sorghum stem sheath was cleaned by removing extraneous materials, milled and sieved. The most appropriate ratio of 1:30 (w/v) stem sheath flour to water based on preliminary test was employed for the beverage formulation. Alligator pepper was added in sequential concentrations of 0.5, 1, 1.5, 2, and 2.5% making a total of 6 samples with the control. The nutritional quality of the beverage (poporo-which is the beverage obtained from aqueous extract of dried stem sheath of Sorghum bicolor) was investigated. The samples were subjected first to pasteurization at 75ºC for 15mins. The formulated beverage samples with alligator pepper extract were analyzed to determine its nutrient profile: proximate and mineral compositions.
Results: Proximate analysis of the spiced stem sheath beverage showed the moisture content to range between 87.7-88.2%, crude protein between 0.005-0.047% and crude fat from 0.009-0.140% while pH and titratable acidity were 7 and 4 for all the beverage samples respectively. The plain beverage sample had the least protein and fat contents thereby indicating the significant effect of the Aframomum melegueta spice on the beverage samples at p<0.05. High mineral contents were also recorded for the spiced beverage samples: magnesium ranged between 145-200 mg/100ml, sodium ranged between 25.00-25.20mg/100ml, potassium 23.03-26.68mg/100ml, calcium 50.00-54.54mg/100ml, iron 4.00-5.91mg/100ml, zinc 2.50-3.51mg/100ml, manganese 0.38-0.89 and copper 0.041-0.079mg/100ml. In all the samples the plain ones (control) had the least mineral contents.
Conclusion: The nutrient profile increased significantly at p<0.05 with the addition of alligator pepper, the degree of enhancement was dependent on the concentration of the spice. The overall sensory evaluation revealed that the sample spiced with 0.5% extract of alligator pepper was most preferred by the panellists.