Limited proteolysis of bambara groundnut proteins and evaluation of their surface functional and sensory properties in cake products

Loading...
Thumbnail Image
Date
2011-06-02
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Limited proteolysis approach was used to modify Bambara groundnut protein isolates (BPIs) to find how the modified protein isolates compare to egg white by studying their surface functional properties and sensory characteristics. Proteolytic treatments were carried out for 10, 35, 60 and 120 minutes to give products labeled as BAM-10, BAM-35, BAM-60 and BAM-120 respectively. The untreated protein isolate was also labeled as Native. The surface functional properties were compared to egg white which served as the control at pHs 4, 7 and 9. The results showed that limited proteolysis increased the foaming properties with BAM-35 at pH 9 giving most of the desired results: foam activity and foam stability were 376 % and 78.4 % respectively; emulsion capacity also increased with the highest value of 70 % at pH 4. Emulsion activity and emulsion stability however decreased with proteolysis. Water binding capacity (WBC) and Oil absorption capacity (OAC) also increased with the highest values being 424 % and 386 % respectively for BAM-120. The optimum results obtained for the protein isolates were all comparable to those obtained for the egg white. Improved foaming properties, WBC and OAC suggest that the modified BPIs could find applications in foods that require high foaming and flavour retention. The BPIs however, showed poorer sensory characteristics compared to the egg white when applied in model cakes.
Description
This thesis is submitted to the Department of Food Science and Technology in partial fulfilment of the requirement for the Master of Science (MSc.) Degree of Food Science and Technology, 2011
Keywords
Citation