Microbiological dynamics involved in cereal-porridge production using maize and sorghum

Cereal-porridge(‘ogi’) was produced by spontaneous fermentation using maize and sorghum substrates. The microbiological dynamics involved were monitored over a period of 48h fermentation. Bacteria, yeasts and moulds were isolated. Based on the morphological, cultural and biochemical test results, the aerobic bacterial isolates were identified as Proteus vulgaris, Proteus mirabilis, Klebsiella sp, Staphylococcus aureus, Lactobacillus sp, Pseudomonas sp, Citrobacter sp, Bacillus sp, Proteus sp, Shigella sp, and Escherichia coli. The Lactic acid bacteria were Lactococcus sp, Enterococcus sp, Lactobacillus fermentum, Lactobacillus sp. The yeast isolates were 2 strains of Saccharomyces cerevisiae, one other Saccharomyces sp and a Candida sp. The moulds were Aspergillus niger, Aspergillus flavus, Rhizopus sp and Penicillium sp. The lactic acid bacteria (LAB) isolated were 2 strains of Lactococcus lactis, 2 Enterobacter spp, 5 strains of Lactobacillus fermentum and 1 other Lactobacillus sp. The initial total viable aerobic bacterial count at 0h in maize, sorghum and maize-sorghum blend were 4.6 × 104, 7.3 × 104 and 2.4 × 105cfu/ml respectively. The growths rose to peaks of 6.5 × 107 and 3.9 × 107cfu/ml at 24h in maize and maize-sorghum blend, respectively. A Peak of 4.7 x 107cfu/ml was attained at 36h in sorghum. Coliform bacteria and moulds growths in the three samples attained peaks of growth at 12h and reduced till there was no growth by 48h. Lactic acid bacteria and yeasts increased in numbers till the end of fermentation. The initial pH value at 0h was lowest in maize-sorghum blend sample (5.43) and highest in maize (5.75). Final values at 48h were 3.76, 3.78 and 3.75 in maize, sorghum and maize-sorghum blend samples respectively. There were no significant differences between the microbial growth patterns, changes in pH, total titratable acidity (TTA) and amylase enzymatic activities in maize, sorghum and maize-sorghum blend samples during fermentation.

Isolation of a Leuconostoc mesenteroides ssp. jonggajibkimchii strain from Parona leatherjacket (Parona signata): behavior in vegetal matrices fermentation

A Gram-positive, facultatively anaerobic, gas-forming, catalase-negative, nonmotile, non-sporeforming, vancomycin-resistant, and ovoid-shaped bacterium, designated strain Tw234, was isolated from the intestinal tract of Parona leatherjacket (Parona signata). The strain grew in the presence of 0–6% (w/v) NaCl, at pH 3.5–8.5 and 8–40 °C; optimum growth was achieved at 1% (w/v) NaCl, at pH 6.0 and 30–32 °C. Exopolysacharides production was detected by the solidification test of skim milk supplemented with sucrose in the temperature range of 8 to 30 °C. Results of phylogenetic analysis based on the 16S rRNA gene sequence similarity indicated that strain Tw234 was closed related to the genus Leuconostoc and 100% homology with the type strain Ln. mesenteroides ssp. jonggajibkimchii DRC1506 (KCCM 43249, JCM 31787). The evaluation of growth and acidification rates were carried out in white cabbage and Chinese cabbage and compared with the strain Ln. mesenteroides ssp. jonggajibkimchii RCTw1.1, isolated from the spontaneous fermentation of red cabbage. No significant differences were observed between the behaviors of the two strains. The strain Tw234 displayed higher growth and acidification rates in controlled fermentation of white cabbage compared with those obtained in Chinese cabbage. New trends are targeted on the isolation and selection of strains to achieve controlled fermentation of vegetables that may ensure uniform quality. The results obtained in this work suggest that strain Tw234 harbored technological useful properties for its potential use as a starter in controlled vegetable fermentations.

Antibacterial Potency of Black Garlic Extract from Allium sativum on Escherichia coli

Background: Diarrhea is still one of the global issues especially in developing countries. Diarrhea can be caused by either an infectious agent or a non-infectious agent. Escherichia coli is one of the infectious agents that is responsible for causing diarrhea. Garlic (Allium sativum) is a plant that has a good antibacterial activity potential because of its organosulfur and phenolic compound. Black garlic is the product of spontaneous fermentation of garlic that has improved its bioactive compounds. Content: Antibacterial potency of black garlic extract on Escherichia coli is shown on the resistance zone that formed where the lowest zone diameter is 9,67 mm while the highest zone is 24 mm. The fermentation of black garlic happened at the temperature of 70-80°C with 75-80% for 28-40 days. Conclusion: Black garlic is shown to exhibit antibacterial activity against bacteria such as Escherichia coli. This fermented product has the potential to be a therapeutic agent for diseases caused by Escherichia coli.

The Influence of Time and Storage Conditions on the Antioxidant Potential and Total Phenolic Content in Homemade Grape Vinegars

Fermented foods have been an integral part of the cuisines of almost all cultures in the world. In recent years, they have gained ground again, mainly due to their potential health benefits. One such product is grape vinegar, which apart from characteristic taste, is also a source of compounds with antioxidant activity. The aim of the study was to determine the changes in the antioxidant potential and the content of polyphenols that occur during the storage of grape vinegar obtained by spontaneous fermentation. The research material consisted of vinegar made from different white grape varieties grown in Poland. For each variety, two variants were prepared: with and without the addition of sugar in the fermentation process. The antioxidant potential, polyphenol content, soluble solids content and pH were monitored both during the two-month fermentation process and the subsequent 6-months storage under various conditions. Storage conditions and time of the storage affected the antioxidant activity and polyphenol content. The content of these compounds was also influenced by the variety of grapes used as well as the method of vinegar preparation.

The Intensification of the Wine Fermentation Process Received from the Variety of Grapes «Bashkortostan»

Разработан способ интенсификации процесса брожения вина, полученного из винограда селекции Башкортостан. Для сбраживания взяты сорта винограда Башкирский, Находка Стреляева и Карагай 2020 г. урожая, выращенные в Кушнаренковском селекционном центре по плодово-ягодным культурам и винограду. Изучена технологическая характеристика выбранных сортов, которая показала, что по органолептическим и физико-химическим показателям все сорта соответствуют требованиям ГОСТ 31782-2012 «Виноград свежий машинной и ручной уборки для промышленной переработки. Технические условия», кроме массовой концентрации сахаров, которая ниже нормируемых показателей на 2,2 и 1,9 г/100 см3 у сорта Башкирский и Карагай, соответственно. Массовая концентрация сахаров у сорта Находка Стреляева составляет 17,1 г/100 см3 при норме 17,0 г/100 см3. Выбранные сорта винограда подвергали спонтанному сбраживанию и из полученных виноматериалов выводили чистые культуры дрожжей, которые дополнительно перед сбраживанием обрабатывали на ультразвуковой установке марки VGT-800 при следующих характеристиках: частота 42 кГц, мощность УЗ излучателя - 120 Вт, интенсивность излучения - 35 Вт/см2. Дрожжи, обработанные ультразвуком в течение 1-10 мин, служили в качестве засевных на этапе сбраживания виноградного сусла. Брожение проводили при температуре 22 °С. В результате проведенных исследований установлено, что ультразвуковая обработка чистых культур дрожжей в течение 2 мин способствует максимальному приросту биомассы дрожжей, почкующихся клеток и клеток с гликогеном, улучшает органолептические и физико-химические показатели готового вина и позволяет сократить процесс получения вина на 12 ч. There is a method of the intensification of the wine fermentation process received from the variety of grapes selected in «Bashkortostan». The following varieties of grapes were selected for the fermentation: Bashkortostan, Nakhodka Strelyaeva, Karagay - the harvest of 2020. They were grown in the selection center of the fruit and berry and grape cultivation in Kushnarenkovskiy region. The technological characteristics of the selected varieties were investigated. According to the organoleptic and physico-chemical parameters all the varieties maintain indicators of the State standard 31782-2012 «Fresh grapes of machine and manual harvesting for industrial processing. Technical conditions» except for the mass concentration of sugars which is 2.2 and 1.9 g/100 cm3 lower than normalized indicators of the varieties of grapes Bashkortostan and Karagay. The mass concentration of sugars of the variety of grapes Nakhodka Strelyaeva is 17.1 g/100 cm3 while the norm is 17.0 g/100 cm3. The selected varieties of grapes were subjected to the spontaneous fermentation. The pure yeas crops were derived from the obtained wine materials which had been treated by ultrasound on the ultrasound engine of VGT-800 model according to the following characteristics: frequency 42 kHz, the power of the ultrasonic emitter is 120 W, radiation intensity - 35 W/cm2. The yeast which was treated by ultrasound during 1-10 minutes serves as seedings during the fermentation of the wine wort. The fermentation was carried out at a temperature of 22 °C. As a result of the conducted studies, it was established that the ultrasound treatment of the pure yeast crops during 2 minutes promotes the maximum growth of the biomass, the budding cells and the cells with the glycogen. It improves the organoleptic and physico-chemical parameters of the ready-made wine and allows to reduce the process of obtaining wine by 12 hours.

Evolution of Food Fermentation Processes and the Use of Multi-Omics in Deciphering the Roles of the Microbiota

Food fermentation has been practised since ancient times to improve sensory properties and food preservation. This review discusses the process of fermentation, which has undergone remarkable improvement over the years, from relying on natural microbes and spontaneous fermentation to back-slopping and the use of starter cultures. Modern biotechnological approaches, including genome editing using CRISPR/Cas9, have been investigated and hold promise for improving the fermentation process. The invention of next-generation sequencing techniques and the rise of meta-omics tools have advanced our knowledge on the characterisation of microbiomes involved in food fermentation and their functional roles. The contribution and potential advantages of meta-omics technologies in understanding the process of fermentation and examples of recent studies utilising multi-omics approaches for studying food-fermentation microbiomes are reviewed. Recent technological advances in studying food fermentation have provided insights into the ancient wisdom in the practice of food fermentation, such as the choice of substrates and fermentation conditions leading to desirable properties. This review aims to stimulate research on the process of fermentation and the associated microbiomes to produce fermented food efficiently and sustainably. Prospects and the usefulness of recent advances in molecular tools and integrated multi-omics approaches are highlighted.

Accumulation and Transformation of Biogenic Amines and Gamma-Aminobutyric Acid (GABA) in Chickpea Sourdough

In general, sourdough fermentation leads to an improvement in the technological, nutritional, and sensory properties of bakery products. The use of non-conventional flours with a specific autochthonous microbiota may lead to the formation of secondary metabolites, which may even have undesirable physiological and toxicological effects. Chickpea flours from different suppliers have been used to produce sourdoughs by spontaneous and inoculated fermentations. The content of nutritionally undesirable biogenic amines (BA) and beneficial gamma-aminobutyric acid (GABA) was determined by chromatography. Fenugreek sprouts, which are a rich source of amine oxidases, were used to reduce the BA content in the sourdoughs. Spontaneous fermentation resulted in a high accumulation of cadaverine, putrescine, and tyramine for certain flours. The use of commercial starter cultures was not effective in reducing the accumulation of BA in all sourdoughs. The addition of fenugreek sprouts to the suspension of sourdough with pH raised to 6.5 resulted in a significant reduction in BA contents. Enzymatic oxidation was less efficient during kneading. Baking resulted in only a partial degradation of BA and GABA in the crust and not in the crumb. Therefore, it could be suggested to give more importance to the control of sourdough fermentation with regard to the formation of nutritionally undesirable BA and to exploit the possibilities of their degradation.