a b s t r a c t
The microstructure and texture of yoghurts produced by four different exopolysaccharide (EPS)-producing
starter cultures and mechanically treated post-fermentation at four levels of intensity (applied
back-pressure) were studied. Two Lactobacillus delbrueckii ssp. bulgaricus (LB) strains were used in
combination with two Streptococcus thermophilus (ST) strains and yoghurts were formulated by pairwise
combining one LB and one ST strain. The choice of ST strain was the major determinant for the rheological
properties of the yoghurts, since one of the ST strains conferred a ropy texture and resulted in
yoghurts with decreased water holding capacity and an open microstructure. In addition, one of the LB
strains used produced both aggregated and threadlike EPS and improved water holding. When combined
with an ST strain that produced neglible amounts of EPS this LB strain resulted in yoghurt where a
moderate mechanical treatment post-fermentation was able to further improve the water holding
capacity.