The Effect of pH on Foaming Properties of Cowpea (Vigna ungiculata L.walp) Flour and Protein Isolates
- *Corresponding Author:
- Ikhlas Ibrahim Khalid
Chemistry Department Faculty of Science
Taif University Saudi Arabia
Tel: +966 948494849
Fax: +966 89484849
E-mail: [email protected], [email protected]
Received date: May 21, 2015 Accepted date: June 02, 2015 Published date: June 08, 2015
Citation:Khalid II, Elhardallou SB (2015) The Effect of pH on Foaming Properties of Cowpea (Vigna ungiculata L.walp) Flour and Protein Isolates. J Nutr Food Sci 5:385. doi: 10.4172/2155-9600.1000385
Copyright: © 2015 Khalid II, 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.
The effect of pH on foaming properties on cowpea (Vigna ungiculata) seeds as whole cowpea flour (WCF), dehulled cowpea flour (DCF), dehulled defatted cowpea flour (DDCF) and cowpea protein isolates (CPI) obtained from DDCF by isoelectric (CPIA) and micellization (CPIB) precipitation was studied. The protein % was found to be 22.3% in (WCF) and 26% in (DDCF) flour, while 75 and 76% for CPIA and CPIB respectively. The foaming capacity (FC) and foam stability (FS) were greatly affected by pH values. FC of DDCF and CPIB showed minimum level at pH 2.0 while CPIA at pH 4.0. However, the FS of DDCF was highest at pH 5.0 while CPIA and CPIB were less stable. CPIB have poor FS compared to CPIA at all pH ranges (2-12). Maximum FS was observed at pH 9.0 for DDCF which remain stable up to standing period of 2 hr. CPIA form foam with highest initial volume and maximum FS was observed at pH 9.0. FC of all products was found to be higher at alkaline region of pH compared to acidic side. Defattening markedly increase the FC in the flours.