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The dairy–cereal‐based food, known as Doowina, is one of the traditional fermented foods in Iran. We aimed to improve the health‐promoting properties of Doowina by using turnips, butternut squash, and sourdough as a new functional food with high nutritional value and antioxidant activity. Therefore, the physicochemical, microbial, and sensory properties of samples with nutritional supplements (8% turnip and 8% butternut squash) and different concentrations of sourdough (0, 0.5, and 1%) were studied during 0, 3, 6, and 9 days of fermentation time. The results showed that there was no significant difference (p <.05) in the moisture and ash content between the different formulations of Doowina. There was also no significant difference (p <.05) in the phenolic compound content and antioxidant activity of the Doowina samples during the fermentation period. However, the number of lactic acid bacteria (LAB) increased significantly (p <.05) until the 6th day of fermentation, and the protein content decreased significantly (p <.05) in all samples during the fermentation period. According to the results, the samples with butternut squash and sourdough had the highest total phenolic content, the highest antioxidant activity, the highest linoleic acid content, and the highest sensory rating of all samples. [ABSTRACT FROM AUTHOR]

Background: The widespread consumption of industrial fermented products instead of traditional products leads to the loss of various lactic acid bacteria (LAB), especially the strains producing bioactive compounds. The present study aimed to isolate and molecularly identify LAB and investigate their antifungal impact on Aspergillus niger growth. Materials & Methods: Oat bran was purchased from the Gorgan city market in 2019 and sourdough was prepared. Afterwards, bacteria were isolated and identified in the Microbiology Laboratory of Golestan University of Medical Sciences, Gorgan, Iran. Next, the antifungal activity of LAB and their supernatant against A. niger was investigated. Finally, the identification of the cellfree supernatant of LAB was completed using gas chromatography-mass spectrometry. Results: Findings of the current study demonstrated that Lactobacillus brevis and Lactobacillus sakei had the highest inhibitory effects of 30.25% and 18.47% against A. niger, respectively. Moreover, the minimum inhibitory concentration of L. brevis and L. sakei supernatants against A. niger was found as 3%. We observed that the greater effect of the supernatant of L. brevis could be due to the presence of ester, phenolic, and barbiturate compounds. Conclusion: According to our results, dominant LAB from oat bran sourdough, as well as their cultured pellets have suitable antifungal potential against A. niger. Therefore, these bacteria can be used as a starter culture or co-culture in the fermentation products process, such as sourdough to decrease fungal contamination. [ABSTRACT FROM AUTHOR]

The purpose of this study was to use a mixture of whole wheat-barley flour mixture in the preparation of traditional Iranian bread (Barbari) in the optimum condition of fermentation to benefit from all available nutrients. In this study, bread parameters such as specific volume, porosity, textural characteristics, zinc, iron, phytic acid and organoleptic properties were investigated. In this research, different percentages of sourdough (15-30%) and fermentation time (30 - 120 min) were applied. Results showed that the phytic acid content significantly decreased ( p  < 0.05) (0.23 - 0.14) by increasing sourdough and fermentation time, which result in increasing in zinc (17.49 - 22.89%) and iron (36.44 - 45.32%) content. Both the sourdough content and fermentation time parameters had a significant effect ( p  < 0.05) on the better porosity (9.05 - 13.50%) and overall acceptability of bread (2.15 - 3.85). The hardness, gumminess, chewiness, porosity, phytic acid and overall acceptance parameters were used to optimize the fermentation conditions of Barbari bread by response surface methodology using a central composite design. Optimal conditions for the production of Barbari bread were 29.53% sourdough and 120 min fermentation time. Under optimal conditions, the overall acceptance, hardness, porosity, chewability, gumminess and phytic acid were 3.84, 60.81 N, 14.09%, 302.01 N/mm, 41.37 N and 0.15%, respectively.

Seventeen traditional sourdough samples were collected from the Northern regions in East-Azarbaijan province of Iran. The pH and total titratable acidity (TTA) values of the sourdoughs varied from 3.71-4.07 and 15.2-26.8 ml, respectively. A total of 50 Lactobacillus strains were isolated from the sourdoughs and identified by biochemical methods. Of the isolates, 74% were identified as L. plantarum and L. curvatus or L. casei subsp. rhamnosus, 10% as L. morinus or L. paralimentarius and 4% as L. sake or L. bavaricus and L. casei subsp. Casei. Three isolates from the main groups were selected and identified using 16S rRNA gene sequencing. The results of gene sequencing revealed the isolates as L. plantarum, L. curvatus and L. paralimentarius. All three Lactobacillus strains produced exopolysaccharide from sucrose in MRS broth medium and also showed proteolytic activity. Lactobacillus curvatus had weak proteolytic activity compared to other strains. The strains showed some differences in acidification properties both in MRS broth and sourdough fermentation. All the strains had good acidifying activity in sourdough fermentation and were able to reduce the pH to less than 4 during 9-12 h incubation at 30°C. [ABSTRACT FROM AUTHOR]

The lactic acid bacteria (LAB) and yeast strains with phytate degrading ability were isolated from Iranian traditional sourdough, and based on the acid and bile tolerance, three LAB and three yeast strains were selected and molecularly identified. In this study, baker's yeast (Saccharomyces cerevisiae) was considered as a positive control strain to investigate the nutritional and technological properties of the isolated strains. All of the identified microorganisms were characterized based on additional probiotic properties and were evaluated for nutritional and technological characteristics. The functional features are associated with degradation of phytate, antioxidant capacity, exopolysaccharides, phenolic compound content and in vitro starch digestion. Among all the tested strains the highest amount of phytase production capacity (1.64 Unit/ml) and lowest phytate content (17.49 mg/5 g) belonged to Kluyveromyces marxianus. According to the results, the bread prepared by using Kluyveromyces aestuarii possessed the highest porosity percentage (70.43%), and the lowest hardness (508.71 g)., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The effects of the bread-making process including fermentation with Saccharomyces cerevisiae and lactic acid bacteria (Lactobacillus casei, Lactobacillus rhamnosus, Lactobacillus acidophilus and Lactobacillus fermentum) and baking at 200°C on zearalenone (ZEA) levels were investigated. Standard solutions of ZEA were added to flour and then loaves of bread were prepared. Sourdough and three types of yeast including active dry yeast, instant dry yeast and compressed yeast were used for the fermentation of dough. ZEA levels in flour, dough and bread were determined by HPLC with fluorescence detection after extraction and clean-up on an immunoaffinity column. The highest reduction in levels of ZEA was found in the first fermentation (first proof), while the lowest reduction was observed in the baking stage. In addition, the results showed that compressed yeast had the maximum reduction potential on ZEA levels even at the baking stage.