Studies on Different Concentrations of Alcohol-Alkaline and Acid-Alcohol Methods of Modification on some Functional Properties of Starch from Selected Underutilized Legumes

Vivian A. Arazu¹, Ekene J. Nweze² ⃰, Vincent E. Ozougwu², Benneth C. Nwanguma², Sabinus O. Eze²

¹Department of Science Laboratory Technology, University of Nigeria, Nsukka, Nigeria

²Department of Biochemistry, University of Nigeria, Nsukka, Nigeria

Corresponding Author: ekene.nweze@unn.edu.ng; Tel: +234 7033882003

Recieved Date: October 02, 2020; Accepted Date: January 22, 2021; Published Date: 03 February 2021

Citation: Arazu VA, Nweze JE, Ozougwu VE, Nwanguma BC, Eze SO. Studies on Different Concentrations of Alcohol-Alkaline and Acid-Alcohol Methods of Modification on some Functional Properties of Starch from Selected Underutilized Legumes. Trop J Nat Prod Res. 2021; 5(1):140-144.  https://doi.org/10.26538/tjnpr/v5i1.20

Copyright: © 2021 Arazu et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

ABSTRACT

Starch has been employed in so many industries such as food, medical and pharmaceuticals due to its bioavailability and renewable property. It undergoes modifications to attain its maximum potential regarding its solubility, viscosity and gelatinization.  Starch from Cajanus cajan, Mucuna pruriens, Vigna subterranea and Sphenostylis stenocarpa were modified by varying the concentration of acid (between 20 - 36%), alcohol (between 50 - 70%) and alkaline (between 20 - 50%) following the alcohol-alkaline and acid-alcohol chemical modification methods. The physicochemical properties of both native and modified starches were compared. The cold water solubility (CWS) of starches modified by the acid-alcohol method increased with increasing concentration of the reactants. The solubility ranged from 53 - 81 % while the CWS of starches treated with the alcohol-alkaline methods increased from 54 - 78% with an increase in the concentration of the reactants. pH, water absorption capacity, gelatinization temperature, moisture content and swelling power were analyzed. The yields of the native starch legumes ranged from 41- 49% and that of the modified starches was in the range of 84 - 99%. The pH of modified starches was in the range of 4.3-8.7, the water absorption capacity increased after modification especially for acid-alcohol treated starches with a decrease in the gelatinization temperature. Also, the swelling power increased. The alcohol-alkaline modified starches had higher swelling power than the acid-alcohol treated starches which showed a swelling power of 3.89 – 6.35. Similarly, the moisture content was higher in the modified starches than the native starches.