Stirred yoghurts were produced, using a standard protocol and two different bacterial cultures, over a 2-year period. The fermentation time, syneresis, apparent viscosity and rheological moduli were measured for each, and are analysed using standard statistical methods. It is found that, despite the variability in properties common in bacteriological systems, the standard protocol was robust and allowed production of yoghurts with reasonable consistency. Two mixed cultures of Lactobacillus bulgaricus and Streptococcus thermophilus were used: one a classical yoghurt culture and the other a "ropy" culture producing exopolysaccharides (EPS). It was found that all measured parameters were less reproducible for the EPS producing culture. Fermentation times, as measured by pH and rheology, showed considerable variations for both cultures but were significantly longer for the EPS producing culture. The culture was also found to influence the apparent viscosity of the yoghurt, as measured by a funnel flow technique, with that of the EPS producing culture being significantly higher.
|Number of pages||4|
|Publication status||Published - 2003|
- 61 Yoghurt (production protocols)