Study on the dissolution of heat-induced ovalbumin gel in alkaline solutions relevant to the removal of fouling deposits

Heat-induced whey protein concentrate gels (HIWPCG) have previously been used to simulate milk fouling and cleaning processes. The related research has generated considerable knowledge, which is of practical interest. In the current study, heat-induced ovalbumin gels (HIOVAG) have been employed to investigate the dissolution process (related to chemical cleaning process). Both HIOVAG and HIWPCG are sensitive to NaOH solution, which is a common cleaning fluid in food industry. In contrast to the HIWPCG behavior, HIOVAG dissolution presents no optimal NaOH concentration where the rate of dissolution is highest. The dissolution temperature was found to positively influence the dissolution process of HIOVAG, i.e. the dissolution rate increased with increasing dissolution temperature. In addition, ovalbumin (OVA) concentration in HIOVAG was found to be another important factor influencing the dissolution process. However, the stirring speed (convection) and heating time had no effect in the range tested, indicating that the process was internally limited.