Tag Archives: lactic acid bacteria

1360-1372 N. Dubrovskaya, O. Savkina, L. Kuznetsova and O. Parakhina
The development of gluten-free sourdough bread technology with rowan powder
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The development of gluten-free sourdough bread technology with rowan powder

N. Dubrovskaya¹, O. Savkina²*, L. Kuznetsova² and O. Parakhina³

¹Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya street 29, RU195251 St. Petersburg, Russia
²St. Petersburg Branch, State Research Institute of the Baking Industry, Podbelskogo Highway 7, RU196608 St. Petersburg, Pushkin, Russia
³Institute of Refrigeration and Biotechnologies, ITMO University, Lomonosova street 9, RU191002 St. Petersburg, Russia
*Correspondence: 1103savkina@mail.ru

Abstract:

A new form of technology was developed which focused on gluten-free bread with gluten-free sourdough and rowan powder (from the botanical species Sorbus aucuparia). This new form of technology allows organoleptic characteristics to be improved, along with structure, texture, microbial spoilage resistance, and the shelf life of gluten-free bread. The gluten-free dry microbial composition with lactic acid bacteria was developed as a starter for sourdough. The lactic acid bacteria, L. brevis E38, was experimentally selected for dry microbial composition on the basis of its antagonistic activity against ropy bread disease pathogens (B. subtilis and B. licheniformis). The dependence was revealed of the accumulation of acetic acid and lactic acid in the sourdough on the microbial composition during fermentation. A gluten-free sourdough technology was developed which involved a new starter, rice, and soy flour at a ratio of 0.2:2:1. It was shown that the use of soy protein slows down the fermentation process in the sourdough. An increase – in acidity levels of between 7.5–9.5 times higher in the dough with sourdough and rowan powder when compared to dough without sourdough. Sourdough usage allowed compressibility of the crumb to be increased by between 1.8–2 times, with a specific volume of 19.0% and a porosity of 9.8% and 11.5%, and for the sensory characteristics to be improved as perceived by consumers. It was proved that microbial composition with a lactic acid bacteria, L. brevis E38, inhibits ropy disease and mould development in bread. The results of the present study showed that the addition of sourdough and rowan powder can be used to improve the quality of gluten-free bread.

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907-918 H. Daba, and S. Saidi
Detection of bacteriocin-producing lactic acid bacteria from milk in various farms in north-east Algeria by a new procedure
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Detection of bacteriocin-producing lactic acid bacteria from milk in various farms in north-east Algeria by a new procedure

H. Daba¹,* and S. Saidi¹

¹University of Setif 1, Nature and Live Sciences Faculty, Department of Microbiology, 19000, Setif, Algeria; *Correspondence: dabhoc@yahoo.fr

Abstract:

Twelve samples of bacteriocin-producing lactic acid bacteria were isolated from raw milk. The screening procedure has the advantage of differentiating directly on agar plates active colonies among thenatural microbial population without subsequent culture. Five of milk isolates had effective inhibitory activity against Staphylococcus, Bacillus and all Listeria monocytogenes strains tested. In addition, two bacteriocinogenic isolates were effective against Gram-negative bacteria including Pseudomonas aeruginosa and Escherichia coli. The action of the bacteriocins was eliminated by a proteolytic enzyme. Simulation tests in liquid medium showed a 3 log reduction of Listeria growth in presence of bacteriocin during a period stockage of 14 days at 4°C.

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