Improving the foaming properties and heat stability of whey protein concentrates by phospholipase treatment

Whey protein concentrate solutions (5% w/w) were subjected to treatment using four different phospholipases (Lecitase 10L from porcine pancreas, Lecitase Ultra from Thermomyces lanuginosus/Fusarium oxysporum, an experimental phospholipase A1 from Fusarium venenatum (FPA1) and a lyso-phospholipase A2 from Aspergillus niger). The obtained degrees of hydrolysis ranged from 70 to 90 %. The foaming properties and heat stability of the whey protein concentrates were investigated and in general the foaming properties were improved by treatment with phospholipases. Samples resulting in voluminous foam exhibited a low stability and vice versa, with the highest foam volume obtained using the Fusarium venenatum phospholipase Al. The best foam stability, on the other hand, was achieved using Lecitase 10L All the investigated phospholipase treatments resulted in improved heat stability of the P-lactoglobulin present in the whey protein concentrate with an increase in the measured denaturation temperature of 3-4 degrees C.