Effect of the espina corona gum on caseinate acid-induced gels

Abstract

Espina corona gum (ECG) is a galactomannan extracted from the seeds of a leguminous tree native to America. In spite of its potential application in the food industry, casein protein aggregation and gelation in systems containing this gum have not yet been characterized. Here, the effect of ECG on the aggregation and gelation of sodium caseinate (NaCAS) and on the microstructure, the mechanical properties and color of acid-induced gels were studied. The aggregation process of NaCAS was studied in the presence of calcium, sucrose and ECG. ECG caused an increase in the aggregation time, without modification of the aggregation pH. The presence of calcium produced an increase in the aggregation pH due to the neutralization of the negative charges of the protein surface, resulting in a decrease in the aggregation time. However, the time required for NaCAS gelification was not affected by the presence of ECG. NaCAS/ECG mixed gels presented different color, water holding capacity and mechanical properties compared to NaCAS gels in the absence of ECG. Moreover, the presence of ECG produced differences in the microstructure of the acid-induced NaCAS gels.