Effect of Various Starter Cultures on the Viscoelastic Properties of Bovine and Caprine Yogurt Gels

Bovine and caprine yogurt gels made using ‘ropy’ (extracellular polysaccharide‐producing starters) and ‘non‐ropy’ starter cultures were examined using dynamic (oscillatory) testing. The storage (G¸) and loss (G˝) moduli of the ropy gels were found to be lower than those of the equivalent non‐ropy ones. Both moduli of the ropy gels declined on storage (at 4°C). On the other hand, the loss tangents of the gels made using the ropy starters were higher than those of the non‐ropy gel systems. Caprine yogurt gels were some eight times weaker than the equivalent bovine systems, the ropy gels again being weaker that the non‐ropy systems. These data suggest that the secreted polysaccharide may well interfere with the gel structure and development.