Water Mobility in Accelerated Ripening of UF Feta Cheese

The aim of this study was to investigate the effect of the addition of commercial lipase in various forms on the acceleration of the ripening of UF-Feta cheese. Commercial lipase from Aspergillus niger was encapsulated by using silica composition based on Sol-Gel method. Lipase was then added to cheeses in three forms, namely, free lipase, encapsulated lipase, and encapsulated lipase with Arabic gum. Lipase was added to the retentate in the ratio of 4 g:100 kg. The effects of free lipase, encapsulated lipase, and encapsulated lipase with Arabic gum on lipolysis, quantity of free water, bounded water, and chemical compounds were studied during the 60 days of ripening. Based on FTIR analysis, encapsulated lipases were completely released from the capsules during the first 15 days of ripening period. The greatest amount of lipolysis was detected in free lipase samples, compared to encapsulated and encapsulated with Arabic gum treatments. Thermal analysis of all treatments indicated that lipolysis could affect the free and bounded water content by decreasing both of them from the 15 th to 60 th days of ripening. The amount of salt, moisture, and fat changed during the first 15 days of ripening significantly (P < 0.05). In comparison with free or encapsulated lipase, the encapsulated lipase with Arabic gum caused more changes in types of water and chemical compositions because the produced emulsions were uniform.