Effect of freezing and freeze-drying process on the survival of sourdough lactic acid bacteria

Sourdough plays a key role in improving flavour, texture, nutritional and shelf-life of bakery products. Studies have shown that the microorganisms of sourdough influence the properties of final product. Therefore, selected lactic acid bacteria which are the dominant microflora of sourdoughs were used. In this study L. plantarum, L. reuteri and a mixture of both bacteria were used in the preparation of freeze-dried sourdoughs. Results showed that L. reuteri led to a slight decrease in pH of sourdough. Survival rate of L. reuteri was higher than that of L. plantarum. Thus, L. reuteri resisted in freeze drying process and can be regarded as a suitable candidate for production of type-III sourdough.