Improving the Quality of Set Yoghurt Using Milk Fat Globule Membrane Fragments

Abstract

Lacprodan®PL20, a dairy ingredient that is rich in protein and polar lipids, was added into set yoghurts produced from nonhomogenized raw milk. The set yoghurts were prepared using concentrations of 2%, 4%, and 6% Lacprodan®PL20, while the control sample was only supplemented with skim milk powder. The effect of Lacprodan®PL20 concentrations on the physical and chemical properties, rheology, and microstructure of set yoghurt was thoroughly investigated to determine some likely improvement or changes in quality. Consequently, Lacprodan®PL20 showed a gradual improvement in the set yoghurt nutritive values, water holding capacity, and apparent viscosity. The results indicated that the firmness of set yoghurt was altered which steadily improved the gel strength, especially at 4% and 6% concentrations. The fermentation process was slightly delayed at 4% and 6% concentrations and pH values were raised as Lacprodan®PL20 concentration increased. The microstructures of the set yoghurts produced with Lacprodan®PL20, as examined by scanning electron microscopy, revealed compacted structures with fewer and smaller holes in the gel matrices. Also, a slight color change was observed in set yoghurt using a colorimeter. These results vividly showed that Lacprodan®PL20, an enriched milk fat globule membrane fragment, has the potential to improve set yoghurt quality by reducing some defects associated with set yoghurt, such as low gel strength, low dry solids, and the likes.