Tag Archives: sourdough

1260–1272 O. Parakhina, M. Lokachuk, L. Kuznetsova, O. Savkina, E. Pavlovskaya and T. Gavrilova
Evaluation of selected lactic acid bacteria as starter cultures for gluten-free sourdough bread production
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Evaluation of selected lactic acid bacteria as starter cultures for gluten-free sourdough bread production

O. Parakhina, M. Lokachuk, L. Kuznetsova, O. Savkina*, E. Pavlovskaya and T. Gavrilova

St. Petersburg branch Scientific Research Institute for the Baking Industry, Podbelskogo highway 7, RU196608 St. Petersburg, Pushkin, Russian Federation
*Correspondence: 1103savkina@mail.ru

Abstract:

Sourdough is one of the most promising technologies for gluten-free bread. The selection of appropriate starter cultures for the production of gluten-free sourdoughs is of a great importance, since not all microorganisms can adapt equally to the same raw material. The aim was to create a new starter microbial composition for gluten-free sourdough preparation, allowing improving the quality and the microbiological safety of gluten-free bread. Screening was conducted on 8 strains of lactic acid bacteria (LAB) and 5 strains of yeast previously isolated from spontaneously fermenting rice and buckwheat sourdoughs. The strain S. cerevisiae Y205 had the highest fermentative activity and alcohols content. The lactic acid bacteria L. brevis E139 and L. plantarum Е138 were also experimentally selected for new gluten-free sourdoughs on the basis of acidity and volatile acids production and antagonistic activity. Two types of microbial composition were created and its influence on sourdough biotechnological indicators was studied. Sourdough with L. plantarum Е138 had in 1.2 times lower titratable acidity, in 3.4 times lower volatile acids content compared to sourdough with L. brevis E139. Alcohol content was the same in both sourdoughs similarly to yeast cells amount. Sourdough dough proofing time increased in 1.2–1.3 times compared to the control. Sourdough did not affect the specific volume, porosity and compressibility of gluten-free bread, but its sensory characteristics were improved. Bread made with sourdoughs had more pronounced taste and flavor, brighter crust color and better texture compared bread without sourdough. The microbiological safety of sourdough gluten-free bread was also increased, especially when L. brevis E139 was used.

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1348–1357 L. Kuznetsova & O. Savkina
A study of factors which influence mould spoilage in flat (sourdough) bread
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A study of factors which influence mould spoilage in flat (sourdough) bread

L. Kuznetsova & O. Savkina*

Institute of Refrigeration and Biotechnologies, ITMO University, Lomonosova Street 9, 191002 St Petersburg, Russia;
*Correspondence: 1103savkina@mail.ru

Abstract:

Bakery products are an excellent substrate for the development of microbial spoilage, especially mould spoilage and lime disease (otherwise known as chalk disease), because they have high levels of water activity aw = 0.94-0.97 and pH 5.5-6.0. Sliced bread in its packaging is highly susceptible to moulds and lime disease during storage. The aim of this study was to investigate the effects shown by the microbial contamination of flour quality, and the type of sourdough and organic acid, especially acetic acid, on mould spoilage in wheat and rye wheat bread. Microbial contaminations were studied in two batches of wheat flour and three batches of rye flour which had been manufactured in Belarus and Russia and in sourdough bread which had been produced using this flour. Investigated here was the impact of the quality and type of sourdough with various starter cultures of micro-organisms and the impact of the content of organic acid, especially acetic acid, on mould spoilage in wheat and rye wheat bread. The content of organic acids, including acetic acid, in different types of sourdough which has been prepared using different starter cultures and in different kinds of sourdough bread which have been studied using liquid chromatography. It was found that, in spite of the presence in flour of spore-forming bacteria, yeasts, and fungi, microbial contamination of the finished product immediately after baking was absent. It was proven that the use of starter cultures and sourdough can slow down or prevent entirely the microbial spoilage of bread. It was found that the content of acetic acid which had been accumulated during the fermentation of various types of sourdough served to effect the presence of mould spoilage on sourdough bread.

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