ISSN 2756-3448
Global Journal of Food and Agricultural Sciences Vol. 7 (1), pp. 001-006, January, 2020. © International Scholars Journals
Full Length Research Paper
Nutritional composition of sorghum bicolor starch hydrolyzed with amylase from Rhizopus sp.
Adebiyi A. O1*, Adebiyi, A. P2, and Olaniyi, E.O.1
1Pure and Applied Biology Department, Ladoke Akintola University of Technology, P.M.B 4000, Ogbomoso, Nigeria.
2Food Science and Engineering Department, Ladoke Akintola University of Technology, Ogbomoso, Nigeria.
Accepted 11 November, 2019
Abstract
The partially purified amylase extracted from a local isolate of Rhizopus sp. was used for hydrolysis of Sorghum bicolor starch. The amylolytic activity of the enzyme was 45.33 U/g and the protein content was 0.345 mg/ml. The maximum temperature for the enzyme was obtained at 55°C while it acts best at pH 5.0. The percentage increase of 1.62, 21.00 and 1.42% for the fat, protein and carbohydrate respectively for the hydrolysed sorghum starch compared with the unhydrolysed sorghum starch was recorded. The increase in the vitamin B1 and B2 of the hydrolysed sorghum starch over the unhydrolysed starch was 2.93 and 2.39%, respectively. A percentage increase of 9.10, 0.89 and 2.83% for Ca, Mg and Na, respectively, for the hydrolysed sorghum starch over the unhydrolysed starch sample was recorded. The Thin Layer Chromatogram of the hydrolysed sorghum starch revealed the presence of the following essential amino acids; histidine, methionine, threonine, isoleucine, phenylalanine, tryptophan and valine. The chromatographic and quantitative analysis of the hydrolysed sorghum starch shows that it contains three oligosaccharides; sucrose (7.38%), lactose (1.75%) and maltose (48.0%), and two monosaccharides which are glucose (1.75%) and galactose (1.16%).
Key words: Sorghum, amylase, pH, temperature, hydrolysis, essential amino acids.