Nisin-loaded pectin and nisin-loaded pectin-inulin particles: Comparison of their proteolytic stability with free nisin

Proteolytic stability of nisin-loaded pectin and nisin-loaded pectin-inulin particles, previously developed for food preservation, was investigated and compared with free nisin. The acid protease from Aspergillus saitoi and trypsin were used. The hydrolysis of free nisin by the mentioned proteases resulted in four and three peaks of degradation products, respectively, in the analysis by capillary zone electrophoresis method. The complexation of nisin with biopolymers increased its proteolytic stability. The areas of detected peaks significantly decreased. The stability of particles was dependent on the degree of pectin esterification. The particles prepared using pectic acid or the pectin with low degree of esterification exhibited the highest proteolytic stability. Overall, nisin-loaded pectin-inulin particles were more stable than nisin-loaded pectin particles.