Tag Archives: lactic acid bacteria

2117-2129 L. Nadtochii, A. Orazov, L. Kuznetsova, A. Pinaev, L. Weihong, S. Garbuz and M. Muradova
Identification of yeast species involved in fermentation of the Kazakh camel dairy product–shubat
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Identification of yeast species involved in fermentation of the Kazakh camel dairy product–shubat

L. Nadtochii¹*, A. Orazov¹*, L. Kuznetsova², A. Pinaev³, L. Weihong⁴, S. Garbuz¹ and M. Muradova¹

¹ITMO University, Department of Applied Biotechnology, Lomonosov street 9, RU191002 Saint Petersburg, Russian Federation
²The Russian Academy of Agricultural Sciences, The Saint Petersburg Branch State Research Institute of a Baking Industry, Podbelsky Chaussee 7, RU196608 Saint Petersburg, Pushkin, Russian Federation
³All-Russia Research Institute for Agriculture Microbiology, Laboratory of Genetics of Plant-Microbe Interactions, Podbelsky Chaussee 3, RU196608 Saint Petersburg, Pushkin, Russian Federation
⁴Harbin Institute of Technology, Institute of Food Science and Engineering, School of Chemistry Engineering, Xidazhi street 92, CN150001, Harbin, Heilongjiang, P.R. China
*Correspondence: l_tochka@corp.ifmo.ru, orazov@corp.ifmo.ru

Abstract:

In certain countries of the world, camel’s milk is used for food on a level with cow’s milk. Shubat is a traditional food product based on camel milk in Kazakhstan. It is a fermented milk product obtained as a result of spontaneous fermentation of camel’s milk under the influence of native microflora. Received dairy product from the southern region of Kazakhstan became the object of the investigation of the microflora of the fermented milk product shubat. The aim of the research was to study the microflora of camel milk, which causes its spontaneous fermentation. During the experiment, the dynamics of acid accumulation by the change in active acidity (pH) and titratable acidity (°T) was studied. In addition to lactic fermentation fermented product (shubat), alcoholic fermentation was noted, which has given the finished product an increased acidity and a high degree of gassing. To enumerate and identify microorganisms, shubat was sown to the following nutrient media: MRS, Malt wort-agar medium at 36 °C and 30 °C respectively both for 3 days. We suppose that the dominant component of the shubat’s microflora was yeasts: Brettanomyces anomalus, Naumovozyma castellii. Pathogenic microorganisms, such as Salmonella, Shigella, were not detected during the research, considering that the shubat is formed as a result of spontaneous fermentation and has poor hygienic characteristics in comparison with pasteurized milk. Identification of individual strains of bacteria allows us to simulate a starter microflora for the production of a safe fermented product based on camel milk on an industrial scale in Kazakhstan. The identified microflora, which causes spontaneous fermentation of camel milk and isolated strains of lactic acid bacteria, will make a significant contribution to the improvement of food safety in arid regions.

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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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