The acceleration of yoghurt fermentation using peptides derived from proteolytic pre-treatment of milk

Abstract

In this study, yoghurt fermentation time was accelerated by using the proteolytic enzyme Flavourzyme to produce sufficient peptides. Flavourzyme was added directly to the milk used for fermentation at different concentrations (0.1 g/L, 0.01 g/L, and 0.001g/L), and before heat treatment (90˚C for 15 min) where Flavourzyme was inactivated. The liberation of peptides during Flavourzyme pre-treatment was confirmed by RP-HPLC peptide profiling. It was possible to accelerate the fermentation time by 13.33% with Flavourzyme. The yoghurt made with Flavourzyme pre-treated milk did not demonstrate any significant quality changes. However, consumers were able to detect a difference between yoghurt made with Flavourzyme pre-treated milk and yoghurt made with untreated milk (control). Yoghurt made with Flavourzyme pre-treated milk scored lower in taste, texture, appearance, and overall acceptability, but was generally not rejected. Accelerated fermentation times could lead to economic advantages in the yoghurt manufacturing industry.