MICROENCAPSULATION OF LACTOCOCCUS-LACTIS WITHIN CROSS-LINKED GELATIN MEMBRANES

Lactococci were encapsulated within gelatin membranes cross-linked with toluene-2,4-diisocyanate at an oil/water interface. Reagent toxicity was avoided by use of vegetable or silicone oil as a dispersant, and by minimizing cell exposure to the water insoluble cross-linking agent during membrane formulation. Growth of cells within the gelatin microcapsules was observed during fermentation and acidification activity of the encapsulated cells increased with subsequent reuse. A microencapsulated cell density of 10(9) cfu cm-3 resulted in acidification of milk to pH 5-5 within 2-8 h, similar to that achieved in free cell fermentations.